Retinal Vein
Retinal Artery
Venules
Photography
Retinal Neovascularization
Fluorescein Angiography
Arterioles
Blood Vessels
Retinopathy of Prematurity
Fundus Oculi
Retina
Diabetic Retinopathy
Optic Disk
Retinal Artery Occlusion
Blood-Retinal Barrier
Choroid
Retinal Vein Occlusion
Laser-Doppler Flowmetry
Leukostasis
Diagnostic Techniques, Ophthalmological
Ophthalmodynamometry
Image Processing, Computer-Assisted
Retinoscopy
Blood Flow Velocity
Retinal Telangiectasis
Ophthalmoscopes
Axial Length, Eye
Oximetry
Oxygen
Optic Atrophy
Macula Lutea
Capillary Permeability
Retinal Vasculitis
Vitreous Body
Retinal Degeneration
Fluorescein
Endothelium, Vascular
Vasodilation
Fractals
Intravitreal Injections
Disease Models, Animal
Vascular Endothelial Growth Factor A
Glaucoma, Open-Angle
Pericytes
Vasoconstriction
Tomography, Optical Coherence
Laser Coagulation
Lasers
Retinal Detachment
Apyrase
Fluorescent Antibody Technique, Indirect
Visual Acuity
Fluoresceins
Neovascularization, Pathologic
Optic Nerve Diseases
Glaucoma
Fluorescein-5-isothiocyanate
Ischemia
Epiretinal Membrane
Microvessels
Eye
Macular Edema
Endothelial Cells
Ciliary Body
Retinal Ganglion Cells
Leukocytes
Indocyanine Green
Reproducibility of Results
Uveitis
Pigment Epithelium of Eye
Angiogenesis Inhibitors
Diabetes Mellitus, Type 1
Optic Nerve
Immunohistochemistry
Microscopy, Confocal
Photoreceptor Cells, Vertebrate
Expression of thrombospondin-1 in ischemia-induced retinal neovascularization. (1/2152)
Thrombospondin-1 is an extracellular matrix protein that inhibits endothelial cell proliferation, migration, and angiogenesis. This study was performed to investigate the role of thrombospondin-1 in ischemic retinal neovascularization. In a murine model of retinal neovascularization, thrombospondin-1 mRNA was increased from postnatal day 13 (P13), with a threefold peak response observed on P15, corresponding to the time of development of retinal neovascularization. Prominent expression of thrombospondin-1 was observed in neovascular cells, specifically, cells adjacent to the area of nonperfusion. It has been suggested that vascular endothelial growth factor (VEGF) plays a major role in ischemia-induced retinal neovascularization of this model, so we studied the effects of VEGF on thrombospondin-1 expression. In bovine retinal microcapillary endothelial cells, VEGF induced a biphasic response of thrombospondin-1 expression; VEGF decreased thrombospondin-1 mRNA 0.41-fold after 4 hours, whereas it increased, with a threefold peak response, after 24 hours. VEGF-induced endothelial cell proliferation was completely inhibited by exogenous thrombospondin-1 and increased by 37.5% with anti-thrombospondin-1 antibody. The present findings suggest that, in the ischemic retina, retinal neovascular cells increase thrombospondin-1 expression, and VEGF may stimulate endogenous thrombospondin-1 induction, which inhibits endothelial cell growth. VEGF-mediated thrombospondin-1 induction in ischemia-induced angiogenesis may be a negative feedback mechanism. (+info)Polyol formation and NADPH-dependent reductases in dog retinal capillary pericytes and endothelial cells. (2/2152)
PURPOSE: Dogs fed a diet containing 30% galactose experience retinal vascular changes similar to those in human diabetic retinopathy, with selective pericyte loss as an initial lesion. In the present study the relationship among reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reductases, polyol formation, and flux through the polyol pathway in cultured dog retinal capillary cells were investigated. METHODS: Pericytes and endothelial cells were cultured from retina of beagle dogs. NADPH-dependent reductases were characterized by chromatofocusing after gel filtration. Sugars in cultured cells were analyzed by gas chromatography, and flux through the polyol pathway was investigated by 19F nuclear magnetic resonance (NMR) with 3-fluoro-3-deoxy-D-glucose (3FG) as a substrate. The presence of aldose reductase and sorbitol dehydrogenase in these cells was examined by northern blot analysis. RESULTS: Two distinct peaks corresponding to aldose reductase and aldehyde reductase, the latter being dominant, were observed in pericytes by chromatofocusing. Culture in medium containing either 10 mM D-galactose or 30 mM D-glucose resulted in the accumulation of sugar alcohol in pericytes that was markedly reduced by aldose reductase inhibitors. 19F NMR spectra obtained from pericytes cultured for 5 days in medium containing 2 mM 3FG displayed the marked accumulation of 3-fluoro-deoxysorbitol but not 3-fluoro-deoxyfructose. No 3FG metabolism was observed in similarly cultured endothelial cells. With northern blot analysis, aldose reductase was detected in pericytes but not in endothelial cells. Sorbitol dehydrogenase was below the detectable limit in pericytes and endothelial cells. CONCLUSIONS: Aldose, aldehyde, and glyceraldehyde reductases are present in dog retinal capillary pericytes, with aldehyde reductase being the major reductase present. Polyol accumulation easily occurs in pericytes but not in endothelial cells. (+info)Necrosis and apoptosis after retinal ischemia: involvement of NMDA-mediated excitotoxicity and p53. (3/2152)
PURPOSE: Accumulated evidence has shown that apoptosis and necrosis contribute to neuronal death after ischemia. The present study was performed to study the temporal and spatial patterns of neuronal necrosis and apoptosis after ischemia in retina and to outline mechanisms underlying necrosis and apoptosis. METHODS: Retinal ischemia was induced by increasing intraocular pressure to a range of 160 mm Hg to 180 mm Hg for 90 minutes in adult rats. The patterns of neuronal cell death were determined using light and electron microscopy and were visualized by TdT-dUTP nick-end labeling (TUNEL). The mRNA expression profile of p53 was examined using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization histochemistry. Immunohistochemistry was performed using anti-p53, anti-microtubule associated protein-2, and anti-glial fibrillary acidic protein antibodies. RESULTS: Within 4 hours after ischemia, neurons in the inner nuclear cell layer (INL) and ganglion cell layer (GCL) underwent marked necrosis, made apparent by swelling of the cell body and mitochondria, early fenestration of the plasma membrane, and irregularly scattered condensation of nuclear chromatin. After 3 days, the INL and GCL neurons showed further degeneration through apoptosis marked by cell body shrinkage, aggregation, and condensation of nuclear chromatin. Apoptotic neurons were also observed sparsely in the outer nuclear cell layer. Intravitreal injections of MK-801 prevented early neuronal degeneration after ischemia. Of note, mRNA and protein levels of p53, the tumor suppressor gene known to induce apoptosis, were increased in the retinal areas undergoing apoptosis 1 to 3 days after ischemic injury. CONCLUSIONS: Ischemia produces the N-methyl-D-aspartate-mediated necrosis and slowly evolving apoptosis of neurons in the retina. The latter may depend on the expression of the p53 proapoptosis gene. (+info)Angiotensin II-induced constrictions are masked by bovine retinal vessels. (4/2152)
PURPOSE: To unmask the vasoconstricting effect of angiotensin II (Ang II) on retinal smooth muscle by studying its interaction with endothelium-derived paracrine substances. This study focused specifically on determining the changes in vascular diameter and the release of endothelial-derived vasodilators, nitric oxide (NO) and prostaglandin (PG) I2, from isolated retinal microvessels. METHODS: Bovine retinal central artery and vein were cannulated, and arterioles and venules were perfused with oxygenated/heparinized physiological salt solution at 37 degrees C. This ex vivo perfused retinal microcirculation model was used to observe the contractile effects of Ang II on arterioles and venules of different diameters. The NO and PGI2 synthase inhibitors, 1-NOARG and flurbiprofen, respectively, were used to unmask Ang II vasoconstriction; the changes in vascular diameters were then measured. Enzyme immunoassays were used to measure the release of cGMP (an index of NO release) and 6-keto-PG-F1alpha (a stable metabolite of PGI2) from isolated bovine retinal vessels. RESULTS: Topically applied Ang II (10(-10) M to 10(-4) M) caused significant (P < 0.05) arteriolar and venular constrictions in a dose-dependent manner, with the smallest retinal arterioles (7+/-0.2 microm luminal diameter) and venules (12+/-2 microm luminal diameter) significantly more sensitive than larger vessels. After the inhibition of endogenous NO and PGI2 synthesis by 1-NOARG and flurbiprofen, respectively, the vasoconstriction effects of Ang II became more pronounced. Again, the smallest vessels tested were significantly more sensitive, and synthesis of endothelial-derived relaxing factor (EDRF), therefore, may be most important in these vessels. Vasoactive doses of Ang II (10(-10) M to 10(-4) M) caused a dose-dependent increase in the release of NO and PGI2 from isolated bovine retinal vessels, indicating that the increase in EDRF may nullify direct Ang II-induced vasoconstriction. Interestingly, intraluminal administration of Ang II caused only vasodilation. CONCLUSIONS: This study demonstrates that the retinal vascular endothelium acts as a buffer against the vasoconstricting agent Ang II via release of vasodilators NO and PGI2, and the vasoconstriction effects due to Ang II are most prominent in the smallest diameter vessels. (+info)Riluzole improves functional recovery after ischemia in the rat retina. (5/2152)
PURPOSE: Retinal ischemia leads to neuronal death. The effects of riluzole, a drug that protects against the deleterious effect of cerebral ischemia by acting on several types of ion channels and blocking glutamatergic neurotransmission, were investigated in a rat model of retinal ischemic injury. METHODS: Retinal ischemia was induced by increasing intraocular pressure above systolic blood pressure for 30 minutes. Electroretinograms were recorded before ischemia and at different periods of reperfusion. Riluzole was injected or topically applied to the eye before or after ischemia and twice daily during the reperfusion period. Retinas were harvested for histopathology (toluidine blue and silver-impregnation stainings, Tdt-dUTP terminal nick-end labeling [TUNEL] method) and immunohistochemistry for cytoskeletal glial fibrillary acid protein and c-jun NH2-terminal kinase (p-JNK). RESULTS: Ischemia for 30 minutes caused a reduction of a- and b-waves of the electroretinogram. Systemic and topical treatments with riluzole significantly enhanced the recovery of the reduced a- and b-waves after defined reperfusion times. Riluzole also prevented or attenuated ischemia-induced retinal cell death (necrosis and apoptosis) and reduced the activation of p-JNK, c-jun phosphorylation, and the increase of cytoskeletal proteins induced by ischemic injury. CONCLUSIONS: Riluzole acted in vivo as a potent neuroprotective agent against pressure-induced ischemia. Therefore, riluzole may be a major drug for use in protection against retinal injury. (+info)Brightness alters Heidelberg retinal flowmeter measurements in an in vitro model. (6/2152)
PURPOSE: The Heidelberg Retinal Flowmeter (HRF), a laser Doppler flowmetry device, has captured interest as a research and clinical tool for measurement of ocular blood flow. Concerns remain about the range and accuracy of the values that it reports. METHODS: An in vitro blood-flow model was constructed to provide well-controlled laminar flow through a glass capillary for assessment by HRF. A change in material behind the glass capillary was used to simulate changing brightness conditions between eyes. RESULTS: Velocities reported by the HRF correlated linearly to true velocities below 8.8 mm/sec. Beyond 8.8 mm/sec, HRF readings fluctuated randomly. True velocity and HRF reported velocities were highly correlated, with r = 0.967 (P < 0.001) from 0.0 mm/sec to 2.7 mm/sec mean velocity using a light background, and r = 0.900 (P < 0.001) from 2.7 mm/sec to 8.8 mm/sec using a darker background. However, a large change in the y-intercept occurred in the calibration curve with the background change. CONCLUSIONS: The HRF may report velocities inaccurately because of varying brightness in the fundus. In the present experiment, a darker background produced an overreporting of velocities. An offset, possibly introduced by a noise correction routine, apparently contributed to the inaccuracies of the HRF measurements. Such offsets vary with local and global brightness. Therefore, HRF measurements may be error prone when comparing eyes. When used to track perfusion in a single eye over time, meaningful comparison may be possible if meticulous care is taken to align vessels and intensity controls to achieve a similar level of noise correction between measurements. (+info)Metabolic acidosis-induced retinopathy in the neonatal rat. (7/2152)
PURPOSE: Carbon dioxide (CO2)-induced retinopathy (CDIR) in the neonatal rat, analogous to human retinopathy of prematurity (ROP), was previously described by our group. In this model, it is possible that CO2-associated acidosis provides a biochemical mechanism for CDIR. Therefore, the effect of pure metabolic acidosis on the developing retinal vasculature of the neonatal rat was investigated. METHODS: A preliminary study of arterial blood pH was performed to confirm acidosis in our model. In neonatal rats with preplaced left carotid artery catheters, acute blood gas samples were taken 1 to 24 hours after gavage with either NH4Cl 1 millimole/100 g body weight or saline. In the subsequent formal retinopathy study, 150 newborn Sprague-Dawley rats were raised in litters of 25 and randomly assigned to be gavaged twice daily with either NH4Cl 1 millimole/100 g body weight (n = 75) or saline (n = 75) from day 2 to day 7. After 5 days of recovery, rats were killed, and retinal vasculature was assessed using fluorescein perfusion and ADPase staining techniques. RESULTS: In the preliminary pH study, the minimum pH after NH4Cl gavage was 7.10+/-0.10 at 3 hours (versus 7.37+/-0.03 in controls, mean +/- SD, P < 0.01). In the formal retinopathy study, preretinal neovascularization occurred in 36% of acidotic rats versus 5% of controls (P < 0.001). Acidotic rats showed growth retardation (final weight 16.5+/-3.0 g versus 20.2+/-2.6 g, P < 0.001). The ratio of vascularized to total retinal area was smaller in acidotic rats (94%+/-4% versus 96%+/-2%, P < 0.001). CONCLUSIONS: Metabolic acidosis alone induces neovascularization similar to ROP in the neonatal rat. This suggests a possible biochemical mechanism by which high levels of CO2 induce neovascularization and supports the suggestion that acidosis may be an independent risk factor for ROP. (+info)De novo lesions in presumed ocular histoplasmosis-like syndrome. (8/2152)
Two patients with multifocal choroiditis similar or identical to POHS are presented. Colour photographs and fluorescein angiography document the occurrence of de novo lesions in the originally involved eye. The cases also demonstrate the development of new choroidal lesions within the originally involved eye, the early evolution of the "basic choroidal lesion", and the need for fluorescein angiography for visualizing the underlying choroidal lesion. (+info)Examples of retinal diseases include:
1. Age-related macular degeneration (AMD): a leading cause of vision loss in people over the age of 50, AMD affects the macula, the part of the retina responsible for central vision.
2. Diabetic retinopathy (DR): a complication of diabetes that damages blood vessels in the retina and can cause blindness.
3. Retinal detachment: a condition where the retina becomes separated from the underlying tissue, causing vision loss.
4. Macular edema: swelling of the macula that can cause vision loss.
5. Retinal vein occlusion (RVO): a blockage of the small veins in the retina that can cause vision loss.
6. Retinitis pigmentosa (RP): a group of inherited disorders that affect the retina and can cause progressive vision loss.
7. Leber congenital amaurosis (LCA): an inherited disorder that causes blindness or severe visual impairment at birth or in early childhood.
8. Stargardt disease: a rare inherited disorder that affects the retina and can cause progressive vision loss, usually starting in childhood.
9. Juvenile macular degeneration: a rare inherited disorder that causes vision loss in young adults.
10. Retinal dystrophy: a group of inherited disorders that affect the retina and can cause progressive vision loss.
Retinal diseases can be diagnosed with a comprehensive eye exam, which includes a visual acuity test, dilated eye exam, and imaging tests such as optical coherence tomography (OCT) or fluorescein angiography. Treatment options vary depending on the specific disease and can include medication, laser surgery, or vitrectomy.
It's important to note that many retinal diseases can be inherited, so if you have a family history of eye problems, it's important to discuss your risk factors with your eye doctor. Early detection and treatment can help preserve vision and improve quality of life for those affected by these diseases.
The growth of new blood vessels in the retina is a natural response to hypoxia (lack of oxygen) and inflammation caused by these diseases. However, these new blood vessels are fragile and can cause damage to the retina, leading to vision loss. In some cases, RNV can also lead to vitreous hemorrhage, retinal detachment, or glaucoma, which can further exacerbate vision loss.
The diagnosis of RNV is typically made through a comprehensive eye exam, including a visual acuity test, dilated eye exam, and imaging tests such as fluorescein angiography or optical coherence tomography (OCT). Treatment options for RNV depend on the underlying cause of the condition and may include medications, laser therapy, or vitrectomy.
In summary, retinal neovascularization is a common complication of various retinal diseases that can lead to vision loss if left untreated. Early detection and prompt treatment are essential to prevent further damage and preserve visual function.
The exact cause of ROP is not known, but it is thought to be related to the immaturity of the retina and the high levels of oxygen in incubators used to care for premature babies. The risk of developing ROP increases with the degree of prematurity, with infants born before 28 weeks gestation being at highest risk.
ROP typically develops in two stages:
1. Stage 1: Early ROP - This stage is characterized by the formation of small blood vessels and immature retinal tissue.
2. Stage 2: Advanced ROP - This stage is characterized by the proliferation of abnormal blood vessels, bleeding, and scarring in the retina.
There are several subtypes of ROP, including:
1. Type 1 ROP: Mildest form of the disease, with few or no complications.
2. Type 2 ROP: More severe form of the disease, with abnormal blood vessel growth and scarring in the retina.
3. Type 3 ROP: Most severe form of the disease, with widespread scarring and bleeding in the retina.
Treatment for ROP typically involves monitoring the infant's eye development closely and applying laser therapy to the affected areas if necessary. In severe cases, surgery may be required to remove abnormal blood vessels or scar tissue.
Prevention of ROP is primarily focused on reducing the risk factors, such as prematurity and oxygen exposure. This includes:
1. Proper management of gestational diabetes to prevent preterm birth.
2. Close monitoring of fetal development and early delivery if necessary.
3. Careful regulation of oxygen levels in incubators to avoid over-oxygenation.
4. Early detection and treatment of infections that can lead to preterm birth.
5. Avoiding excessive use of ophthalmic drugs that can be harmful to the developing retina.
Early detection and timely intervention are crucial for effective management and prevention of ROP. Regular eye exams and screening are necessary to identify the disease in its early stages, when treatment is most effective.
There are two main types of DR:
1. Non-proliferative diabetic retinopathy (NPDR): This is the early stage of DR, where the blood vessels in the retina become damaged and start to leak fluid or bleed. The symptoms can be mild or severe and may include blurred vision, floaters, and flashes of light.
2. Proliferative diabetic retinopathy (PDR): This is the advanced stage of DR, where new blood vessels start to grow in the retina. These vessels are weak and can cause severe bleeding, leading to vision loss.
DR is a common complication of diabetes, and it is estimated that up to 80% of people with diabetes will develop some form of DR over their lifetime. The risk of developing DR increases with the duration of diabetes and the level of blood sugar control.
Early detection and treatment of DR can help to prevent vision loss, so it is important for people with diabetes to have regular eye exams to monitor their retinal health. Treatment options for DR include laser surgery, injections of anti-vascular endothelial growth factor (VEGF) medications, and vitrectomy, a surgical procedure to remove the vitreous gel and blood from the eye.
Preventing Diabetic Retinopathy
While there is no surefire way to prevent diabetic retinopathy (DR), there are several steps that people with diabetes can take to reduce their risk of developing this complication:
1. Control blood sugar levels: Keeping blood sugar levels within a healthy range can help to slow the progression of DR. This can be achieved through a combination of diet, exercise, and medication.
2. Monitor blood pressure: High blood pressure can damage the blood vessels in the retina, so it is important to monitor and control blood pressure to reduce the risk of DR.
3. Maintain healthy blood lipids: Elevated levels of low-density lipoprotein (LDL) cholesterol and lower levels of high-density lipoprotein (HDL) cholesterol can increase the risk of DR.
4. Quit smoking: Smoking can damage the blood vessels in the retina and increase the risk of DR.
5. Maintain a healthy weight: Obesity is a risk factor for DR, so maintaining a healthy weight can help to reduce the risk of this complication.
6. Get regular eye exams: Regular eye exams can help to detect DR in its early stages, when it is easier to treat and prevent vision loss.
Preventing Diabetic Retinopathy
While there is no cure for diabetic retinopathy (DR), there are several treatment options available to help manage the condition and prevent vision loss. These include:
1. Laser surgery: This is a common treatment for early-stage DR, where a laser is used to shrink abnormal blood vessels in the retina and reduce the risk of further damage.
2. Injection therapy: Medications such as anti-vascular endothelial growth factor (VEGF) injections can be used to shrink abnormal blood vessels and reduce swelling in the retina.
3. Vitrectomy: In severe cases of DR, a vitrectomy may be performed to remove scar tissue and blood from the center of the eye.
4. Blood pressure control: Maintaining healthy blood pressure can help to slow the progression of DR.
5. Blood glucose control: Keeping blood sugar levels under control can also slow the progression of DR.
6. Follow-up care: Regular follow-up appointments with an eye doctor are important to monitor the progress of DR and adjust treatment as needed.
Early detection and treatment of diabetic retinopathy can help to prevent vision loss and improve outcomes for individuals with this complication of diabetes. By managing blood sugar levels, blood pressure, and cholesterol, and by getting regular eye exams, individuals with diabetes can reduce their risk of developing DR and other diabetic complications.
There are two main types of retinal artery occlusion: central retinal artery occlusion (CRAO) and branch retinal artery occlusion (BRAO). Central retinal artery occlusion occurs when the central retinal artery, which supplies blood to the macula, becomes blocked. This can cause sudden vision loss in one eye, often with a painless, blinding effect. Branch retinal artery occlusion, on the other hand, occurs when one of the smaller retinal arteries that branch off from the central retinal artery becomes blocked. This can cause vision loss in a specific part of the visual field, often with some preserved peripheral vision.
Retinal artery occlusion is often caused by a blood clot or other debris that blocks the flow of blood through the retinal arteries. It can also be caused by other conditions such as diabetes, high blood pressure, and atherosclerosis (the buildup of plaque in the arteries).
Retinal artery occlusion is a medical emergency that requires prompt treatment. Treatment options may include intravenous injection of medications to dissolve the clot or other debris, laser surgery to repair damaged retinal tissue, and/or vitrectomy (surgical removal of the vitreous gel) to remove any blood or debris that has accumulated in the eye.
In summary, retinal artery occlusion is a serious condition that can cause sudden vision loss and potentially lead to permanent blindness. It is important to seek medical attention immediately if you experience any symptoms of retinal artery occlusion, such as sudden vision loss or blurred vision in one eye, flashes of light, floaters, or pain in the eye.
The symptoms of RVO can vary depending on the severity of the blockage, but may include:
* Blurred vision
* Double vision
* Flashes of light
* Eye pain
* Reduced peripheral vision
RVO is typically diagnosed through a comprehensive eye exam, which may include imaging tests such as fluorescein angiography or optical coherence tomography (OCT).
Treatment for RVO depends on the severity of the condition and may include:
* Medications to reduce inflammation and improve blood flow
* Injections of medication into the eye
* Laser surgery to clear blockages or reduce inflammation
* Vitrectomy, a surgical procedure to remove the vitreous gel and blood from the eye
Early diagnosis and treatment of RVO can help prevent or reduce vision loss. However, in some cases, permanent vision loss may occur despite treatment.
Preventing RVO is not always possible, but controlling risk factors such as high blood pressure, diabetes, and hypertension can help reduce the likelihood of developing the condition. Maintaining a healthy lifestyle, including regular exercise, a balanced diet, and not smoking, can also help reduce the risk of RVO.
Leukostasis can cause a range of symptoms depending on the location of the affected tissue or organ, including fever, pain, swelling, and difficulty with breathing or blood flow. Treatment options for leukostasis depend on the underlying cause and may include antibiotics, anti-inflammatory medications, or surgery to remove the accumulated white blood cells.
Retinal telangiectasis is a relatively rare condition, but it can be associated with other health conditions such as high blood pressure, diabetes, and sickle cell disease. It can also be caused by certain medications or injuries to the eye.
Symptoms of retinal telangiectasis can include blurred vision, floaters, flashes of light, and distorted vision. In some cases, the condition can lead to retinal detachment, which is a more serious complication that can cause blindness if left untreated.
Diagnosis of retinal telangiectasis typically involves a comprehensive eye exam, including a visual acuity test, dilated eye exam, and imaging tests such as fluorescein angiography or optical coherence tomography (OCT).
Treatment for retinal telangiectasis depends on the severity of the condition and can include close monitoring, medications to control underlying conditions such as high blood pressure, and in some cases, laser surgery or vitrectomy to repair damaged blood vessels. Early detection and treatment can help to slow the progression of the condition and preserve vision.
Optic atrophy is a condition where there is a degeneration or loss of the optic nerve fibers, leading to vision loss. It can be caused by various factors such as trauma, inflammation, tumors, and certain medical conditions like multiple sclerosis.
The symptoms of optic atrophy may include:
1. Blind spots in the visual field
2. Difficulty perceiving colors
3. Difficulty adjusting to bright light
4. Double vision or other abnormalities in binocular vision
5. Eye pain or discomfort
6. Loss of peripheral vision
7. Nausea and vomiting
8. Sensitivity to light
9. Tunnel vision
10. Weakness or numbness in the face or extremities.
The diagnosis of optic atrophy is based on a comprehensive eye exam, which includes a visual acuity test, dilated eye exam, and other specialized tests such as an OCT (optical coherence tomography) scan.
Treatment for optic atrophy depends on the underlying cause and may include medications to manage inflammation or infection, surgery to remove a tumor or repair damaged tissue, or management of associated conditions such as diabetes or multiple sclerosis. In some cases, vision loss due to optic atrophy may be permanent and cannot be reversed, but there are strategies to help improve remaining vision and adapt to any visual impairment.
The exact cause of retinal vasculitis is not known, but it is believed to be an autoimmune disorder, meaning that the body's immune system mistakenly attacks its own tissues. It can occur at any age but is more common in adults between 30 and 60 years old.
Symptoms of retinal vasculitis include:
1. Blurred vision or blind spots
2. Floaters (specks or cobwebs in vision)
3. Flashes of light
4. Redness and pain in the eye
5. Sensitivity to light
6. Blindness in one or both eyes
Retinal vasculitis is diagnosed through a comprehensive eye exam, including a visual acuity test, dilated eye exam, and imaging tests such as fluorescein angiography and optical coherence tomography (OCT).
Treatment options for retinal vasculitis include:
1. Corticosteroids to reduce inflammation
2. Immunosuppressive drugs to suppress the immune system
3. Anti-vascular endothelial growth factor (VEGF) injections to prevent the growth of new blood vessels
4. Photodynamic therapy to damage and shrink the abnormal blood vessels
5. Vitrectomy, a surgical removal of the vitreous gel and any blood or scar tissue in the eye
The prognosis for retinal vasculitis varies depending on the severity and location of the disease, but it can lead to significant vision loss if left untreated. It is important to seek medical attention if symptoms persist or worsen over time.
There are many different types of retinal degeneration, each with its own set of symptoms and causes. Some common forms of retinal degeneration include:
1. Age-related macular degeneration (AMD): This is the most common form of retinal degeneration and affects the macula, the part of the retina responsible for central vision. AMD can cause blind spots or distorted vision.
2. Retinitis pigmentosa (RP): This is a group of inherited conditions that affect the retina and can lead to night blindness, loss of peripheral vision, and eventually complete vision loss.
3. Leber congenital amaurosis (LCA): This is a rare inherited condition that causes severe vision loss or blindness at birth or within the first few years of life.
4. Stargardt disease: This is a rare inherited condition that causes progressive vision loss and can lead to blindness.
5. Retinal detachment: This occurs when the retina becomes separated from the underlying tissue, causing vision loss.
6. Diabetic retinopathy (DR): This is a complication of diabetes that can cause damage to the blood vessels in the retina and lead to vision loss.
7. Retinal vein occlusion (RVO): This occurs when a blockage forms in the small veins that carry blood away from the retina, causing vision loss.
There are several risk factors for retinal degeneration, including:
1. Age: Many forms of retinal degeneration are age-related and become more common as people get older.
2. Family history: Inherited conditions such as RP and LCA can increase the risk of retinal degeneration.
3. Genetics: Some forms of retinal degeneration are caused by genetic mutations.
4. Diabetes: Diabetes is a major risk factor for diabetic retinopathy, which can cause vision loss.
5. Hypertension: High blood pressure can increase the risk of retinal vein occlusion and other forms of retinal degeneration.
6. Smoking: Smoking has been linked to an increased risk of several forms of retinal degeneration.
7. UV exposure: Prolonged exposure to UV radiation from sunlight can increase the risk of retinal degeneration.
There are several treatment options for retinal degeneration, including:
1. Vitamin and mineral supplements: Vitamins A, C, and E, as well as zinc and selenium, have been shown to slow the progression of certain forms of retinal degeneration.
2. Anti-vascular endothelial growth factor (VEGF) injections: These medications can help reduce swelling and slow the progression of diabetic retinopathy and other forms of retinal degeneration.
3. Photodynamic therapy: This involves the use of a light-sensitive medication and low-intensity laser light to damage and shrink abnormal blood vessels in the retina.
4. Retinal implants: These devices can be used to restore some vision in people with advanced forms of retinal degeneration.
5. Stem cell therapy: Research is ongoing into the use of stem cells to repair damaged retinal cells and restore vision.
It's important to note that early detection and treatment of retinal degeneration can help to slow or stop the progression of the disease, preserving vision for as long as possible. Regular eye exams are crucial for detecting retinal degeneration in its early stages, when treatment is most effective.
Hyperoxia can cause damage to the body's tissues and organs, particularly the lungs and brain. In severe cases, hyperoxia can lead to respiratory failure, seizures, and even death.
There are several ways to diagnose hyperoxia, including:
1. Blood tests: These can measure the levels of oxygen in the blood.
2. Arterial blood gas (ABG) analysis: This is a test that measures the amounts of oxygen and carbon dioxide in the blood.
3. Pulse oximetry: This is a non-invasive test that measures the amount of oxygen in the blood by shining a light through the skin.
Treatment for hyperoxia depends on the underlying cause, but may include:
1. Oxygen therapy: This involves administering oxygen to the patient through a mask or nasal tubes.
2. Medications: These may be used to treat any underlying conditions that are causing hyperoxia.
3. Mechanical ventilation: In severe cases, this may be necessary to support the patient's breathing.
In summary, hyperoxia is a condition where there is too much oxygen in the body, and it can cause damage to the body's tissues and organs. Diagnosis is typically made through blood tests or other tests, and treatment may involve oxygen therapy, medications, or mechanical ventilation.
1) They share similarities with humans: Many animal species share similar biological and physiological characteristics with humans, making them useful for studying human diseases. For example, mice and rats are often used to study diseases such as diabetes, heart disease, and cancer because they have similar metabolic and cardiovascular systems to humans.
2) They can be genetically manipulated: Animal disease models can be genetically engineered to develop specific diseases or to model human genetic disorders. This allows researchers to study the progression of the disease and test potential treatments in a controlled environment.
3) They can be used to test drugs and therapies: Before new drugs or therapies are tested in humans, they are often first tested in animal models of disease. This allows researchers to assess the safety and efficacy of the treatment before moving on to human clinical trials.
4) They can provide insights into disease mechanisms: Studying disease models in animals can provide valuable insights into the underlying mechanisms of a particular disease. This information can then be used to develop new treatments or improve existing ones.
5) Reduces the need for human testing: Using animal disease models reduces the need for human testing, which can be time-consuming, expensive, and ethically challenging. However, it is important to note that animal models are not perfect substitutes for human subjects, and results obtained from animal studies may not always translate to humans.
6) They can be used to study infectious diseases: Animal disease models can be used to study infectious diseases such as HIV, TB, and malaria. These models allow researchers to understand how the disease is transmitted, how it progresses, and how it responds to treatment.
7) They can be used to study complex diseases: Animal disease models can be used to study complex diseases such as cancer, diabetes, and heart disease. These models allow researchers to understand the underlying mechanisms of the disease and test potential treatments.
8) They are cost-effective: Animal disease models are often less expensive than human clinical trials, making them a cost-effective way to conduct research.
9) They can be used to study drug delivery: Animal disease models can be used to study drug delivery and pharmacokinetics, which is important for developing new drugs and drug delivery systems.
10) They can be used to study aging: Animal disease models can be used to study the aging process and age-related diseases such as Alzheimer's and Parkinson's. This allows researchers to understand how aging contributes to disease and develop potential treatments.
Open-angle glaucoma can lead to damage to the optic nerve, which can cause vision loss and even blindness if left untreated. It is important for individuals at risk for open-angle glaucoma to receive regular eye exams to monitor their eye pressure and prevent any potential vision loss.
Risk factors for developing open-angle glaucoma include:
* Increasing age
* Family history of glaucoma
* African or Hispanic ancestry
* Previous eye injuries or surgeries
* Long-term use of corticosteroid medications
* Diabetes or other health conditions that can damage blood vessels.
There are several treatment options available for open-angle glaucoma, including:
* Eye drops to reduce eye pressure
* Oral medications to reduce eye pressure
* Laser surgery to improve drainage of fluid from the eye
* Incisional surgery to improve drainage of fluid from the eye.
It is important for individuals with open-angle glaucoma to work closely with their eye care professional to determine the best course of treatment and monitor their condition regularly.
Retinal hemorrhage can cause vision loss or blindness if not treated promptly. The bleeding can lead to scarring, which can cause permanent damage to the retina and affect vision. In some cases, retinal hemorrhage can be a sign of a more serious underlying condition that requires immediate medical attention.
Retinal hemorrhage is diagnosed through a comprehensive eye exam, which includes a visual acuity test, dilated eye exam, and imaging tests such as fluorescein angiography or optical coherence tomography. Treatment options for retinal hemorrhage depend on the underlying cause and can include laser surgery, medication, or vitrectomy.
In summary, retinal hemorrhage is a serious condition that can cause vision loss or blindness if not treated promptly. It is essential to seek medical attention if symptoms such as blurred vision, flashes of light, or floaters are noticed. Early detection and treatment can help prevent or reduce vision loss in cases of retinal hemorrhage.
There are many different types of eye diseases, including:
1. Cataracts: A clouding of the lens in the eye that can cause blurry vision and blindness.
2. Glaucoma: A group of diseases that damage the optic nerve and can lead to vision loss and blindness.
3. Age-related macular degeneration (AMD): A condition that causes vision loss in older adults due to damage to the macula, the part of the retina responsible for central vision.
4. Diabetic retinopathy: A complication of diabetes that can cause damage to the blood vessels in the retina and lead to vision loss.
5. Detached retina: A condition where the retina becomes separated from the underlying tissue, leading to vision loss.
6. Macular hole: A small hole in the macula that can cause vision loss.
7. Amblyopia (lazy eye): A condition where one eye is weaker than the other and has reduced vision.
8. Strabismus (crossed eyes): A condition where the eyes are not aligned properly and point in different directions.
9. Conjunctivitis: An inflammation of the conjunctiva, the thin membrane that covers the white part of the eye and the inside of the eyelids.
10. Dry eye syndrome: A condition where the eyes do not produce enough tears, leading to dryness, itchiness, and irritation.
Eye diseases can be caused by a variety of factors, including genetics, age, environmental factors, and certain medical conditions. Some eye diseases are inherited, while others are acquired through lifestyle choices or medical conditions.
Symptoms of eye diseases can include blurry vision, double vision, eye pain, sensitivity to light, and redness or inflammation in the eye. Treatment options for eye diseases depend on the specific condition and can range from medication, surgery, or lifestyle changes.
Regular eye exams are important for detecting and managing eye diseases, as many conditions can be treated more effectively if caught early. If you experience any symptoms of eye disease or have concerns about your vision, it is important to see an eye doctor as soon as possible.
The retina is a layer of cells that lines the inside of the eye and senses light to send visual signals to the brain. When the retina becomes detached, it can no longer function properly, leading to vision loss or distortion.
Retinal detachment can be caused by a variety of factors, including:
1. Age-related changes: As we age, the vitreous gel that fills the eye can become more liquid and pull away from the retina, causing a retinal detachment.
2. Injury or trauma: A blow to the head or a penetrating injury can cause a retinal detachment.
3. Medical conditions: Certain conditions, such as diabetes, high blood pressure, and sickle cell disease, can increase the risk of developing a retinal detachment.
4. Genetic factors: Some people may be more prone to developing a retinal detachment due to inherited genetic factors.
Symptoms of retinal detachment may include:
1. Flashes of light: People may see flashes of light in the peripheral vision.
2. Floaters: Specks or cobwebs may appear in the vision, particularly in the periphery.
3. Blurred vision: Blurred vision or distorted vision may occur as the retina becomes detached.
4. Loss of vision: In severe cases, a retinal detachment can cause a complete loss of vision in one eye.
If you experience any of these symptoms, it is important to seek medical attention immediately. A comprehensive eye exam can diagnose a retinal detachment and determine the appropriate treatment.
Treatment for retinal detachment typically involves surgery to reattach the retina to the underlying tissue. In some cases, laser surgery may be used to seal off any tears or holes in the retina that caused the detachment. In more severe cases, a scleral buckle or other device may be implanted to support the retina and prevent further detachment.
In addition to surgical treatment, there are some lifestyle changes you can make to help reduce your risk of developing a retinal detachment:
1. Quit smoking: Smoking has been linked to an increased risk of retinal detachment. Quitting smoking can help reduce this risk.
2. Maintain a healthy blood pressure: High blood pressure can increase the risk of retinal detachment. Monitoring and controlling your blood pressure can help reduce this risk.
3. Wear protective eyewear: If you participate in activities that could potentially cause eye injury, such as sports or working with hazardous materials, wearing protective eyewear can help reduce the risk of retinal detachment.
4. Get regular eye exams: Regular comprehensive eye exams can help detect any potential issues with the retina before they become serious problems.
Overall, a retinal detachment is a serious condition that requires prompt medical attention to prevent long-term vision loss. By understanding the causes and symptoms of retinal detachment, as well as making lifestyle changes to reduce your risk, you can help protect your vision and maintain good eye health.
Pathologic neovascularization can be seen in a variety of conditions, including cancer, diabetic retinopathy, and age-related macular degeneration. In cancer, for example, the formation of new blood vessels can help the tumor grow and spread to other parts of the body. In diabetic retinopathy, the growth of new blood vessels in the retina can cause vision loss and other complications.
There are several different types of pathologic neovascularization, including:
* Angiosarcoma: a type of cancer that arises from the cells lining blood vessels
* Hemangiomas: benign tumors that are composed of blood vessels
* Cavernous malformations: abnormal collections of blood vessels in the brain or other parts of the body
* Pyogenic granulomas: inflammatory lesions that can form in response to trauma or infection.
The diagnosis of pathologic neovascularization is typically made through a combination of physical examination, imaging studies (such as ultrasound, CT scans, or MRI), and biopsy. Treatment options vary depending on the underlying cause of the condition, but may include medications, surgery, or radiation therapy.
In summary, pathologic neovascularization is a process that occurs in response to injury or disease, and it can lead to serious complications. It is important for healthcare professionals to be aware of this condition and its various forms in order to provide appropriate diagnosis and treatment.
There are several different types of glaucoma, including:
* Open-angle glaucoma: This is the most common form of glaucoma, and is caused by slowed drainage of fluid from the eye.
* Closed-angle glaucoma: This type of glaucoma is caused by a blockage in the drainage channels of the eye, leading to a sudden increase in pressure.
* Normal-tension glaucoma: This type of glaucoma is caused by damage to the optic nerve even though the pressure in the eye is within the normal range.
* Congenital glaucoma: This is a rare type of glaucoma that is present at birth, and is caused by a developmental defect in the eye's drainage system.
Symptoms of glaucoma can include:
* Blurred vision
* Loss of peripheral vision
* Eye pain or pressure
* Redness of the eye
* Seeing halos around lights
Glaucoma is typically diagnosed with a combination of visual acuity tests, dilated eye exams, and imaging tests such as ultrasound or MRI. Treatment for glaucoma usually involves medication to reduce pressure in the eye, but may also include surgery to improve drainage or laser therapy to prevent further damage to the optic nerve.
Early detection and treatment of glaucoma is important to prevent vision loss, so it is important to have regular eye exams, especially if you are at risk for the condition. Risk factors for glaucoma include:
* Age (over 60)
* Family history of glaucoma
* Diabetes
* High blood pressure
* African or Hispanic ancestry
Overall, glaucoma is a serious eye condition that can cause vision loss if left untreated. Early detection and treatment are key to preventing vision loss and maintaining good eye health.
There are several types of ischemia, including:
1. Myocardial ischemia: Reduced blood flow to the heart muscle, which can lead to chest pain or a heart attack.
2. Cerebral ischemia: Reduced blood flow to the brain, which can lead to stroke or cognitive impairment.
3. Peripheral arterial ischemia: Reduced blood flow to the legs and arms.
4. Renal ischemia: Reduced blood flow to the kidneys.
5. Hepatic ischemia: Reduced blood flow to the liver.
Ischemia can be diagnosed through a variety of tests, including electrocardiograms (ECGs), stress tests, and imaging studies such as CT or MRI scans. Treatment for ischemia depends on the underlying cause and may include medications, lifestyle changes, or surgical interventions.
Epiretinal Membrane Treatment:
Surgical removal of the membrane is the most common treatment for epiretinal membrane. The procedure, called vitrectomy, involves removing the vitreous gel and the membrane from the eye. Laser photocoagulation can also be used to shrink the membrane and relieve symptoms.
It's important to note that not all epiretinal membranes require treatment. Some people may experience no vision problems and may not need any treatment at all. In other cases, the condition may resolve on its own over time. Your eye doctor will be able to determine the best course of action for your specific case.
Epiretinal Membrane Causes:
The exact cause of epiretinal membranes is not fully understood, but they are thought to arise from scar tissue that forms on the retina in response to injury or inflammation. They can also be associated with other eye conditions such as age-related macular degeneration, diabetic retinopathy, and retinal detachment.
Epiretinal Membrane Symptoms:
Symptoms of epiretinal membrane may include:
* Blurred vision
* Distorted vision (e.g., wavy lines or shapes)
* Difficulty reading or performing other daily tasks
* Metamorphopsia (visual distortion)
Epiretinal Membrane Diagnosis:
Your eye doctor will perform a comprehensive eye exam to diagnose epiretinal membrane. This may include a visual acuity test, dilated eye exam, and imaging tests such as optical coherence tomography (OCT) or ultrasonography.
Epiretinal Membrane Prognosis:
In some cases, epiretinal membranes can resolve on their own over time without treatment. However, if the membrane is causing significant vision loss or distortion, your eye doctor may recommend surgical removal. The prognosis for surgical treatment of epiretinal membrane is generally good, with many patients experiencing improved vision following the procedure.
Epiretinal Membrane Treatment:
Treatment for epiretinal membrane depends on the severity of symptoms and may include:
* Watchful waiting: In some cases, your eye doctor may recommend monitoring the membrane over time to see if it resolves on its own.
* Vitrectomy: This is a surgical procedure in which the vitreous gel is removed from the eye and the epiretinal membrane is removed or peeled off the retina.
* Laser photocoagulation: This is a non-surgical procedure that uses lasers to create small burns around the edges of the membrane, causing it to shrink and pull away from the retina.
Epiretinal Membrane Prevention:
There is no known way to prevent epiretinal membranes from forming, but there are some risk factors that may increase your likelihood of developing one. These include:
* Age: Epiretinal membranes are more common in older adults.
* Family history: If you have a family history of epiretinal membranes, you may be at higher risk.
* Previous eye surgery or trauma: People who have had eye surgery or suffered an eye injury may be at higher risk for developing an epiretinal membrane.
Epiretinal Membrane Prognosis:
The prognosis for epiretinal membranes is generally good, especially if the membrane is removed surgically. In some cases, vision may improve spontaneously over time without treatment. However, if left untreated, an epiretinal membrane can cause permanent vision loss. It is important to follow your eye doctor's recommendations for monitoring and treatment to ensure the best possible outcome.
Epiretinal Membrane Complications:
Complications of epiretinal membranes are rare but can include:
* Retinal detachment: This is a serious complication that occurs when the retina pulls away from the underlying tissue.
* Glaucoma: This is a condition that can cause vision loss and is often associated with increased pressure in the eye.
* Macular hole: This is a small hole in the macula, the part of the retina responsible for central vision.
Epiretinal Membrane Surgery:
If an epiretinal membrane is causing vision problems or is not improving with monitoring alone, surgery may be recommended. The goal of surgery is to remove the membrane and prevent it from recurring. There are several types of surgery that can be used to treat epiretinal membranes, including:
* Scleral buckle surgery: This involves sewing a flexible band around the eye to push the retina back into place.
* Vitrectomy: This is a procedure that removes the vitreous gel and any blood or scar tissue that may be causing problems.
* Photocoagulation: This is a procedure that uses laser light to shrink the membrane and seal off any leaky blood vessels.
It's important to note that not all epiretinal membranes require surgery, and in some cases, monitoring alone may be sufficient. Your eye doctor will be able to recommend the best course of treatment based on your specific condition and symptoms.
Symptoms of macular edema may include blurred vision, distorted vision, blind spots, and sensitivity to light. Diagnosis is typically made through a comprehensive eye exam, including a visual acuity test and imaging tests such as optical coherence tomography (OCT).
Treatment for macular edema depends on the underlying cause of the condition. In some cases, medications such as anti-vascular endothelial growth factor (VEGF) injections or corticosteroids may be prescribed to reduce fluid buildup and swelling in the retina. In more severe cases, surgical intervention may be necessary, such as a vitrectomy to remove the vitreous gel and relieve pressure on the retina.
Prevention of macular edema includes managing underlying conditions such as diabetes and age-related macular degeneration, as well as maintaining regular eye exams to detect and treat any changes in the retina early on. Early detection and treatment can help prevent vision loss from macular edema.
There are several different types of uveitis, including:
1. Anterior uveitis: This type affects the front part of the eye and is the most common form of uveitis. It is often caused by an infection or injury.
2. Posterior uveitis: This type affects the back part of the eye and can be caused by a systemic disease such as sarcoidosis or juvenile idiopathic arthritis.
3. Intermediate uveitis: This type affects the middle layer of the eye and is often caused by an autoimmune disorder.
4. Panuveitis: This type affects the entire uvea and can be caused by a systemic disease such as vasculitis or Behçet's disease.
Symptoms of uveitis may include:
* Eye pain
* Redness and swelling in the eye
* Blurred vision
* Sensitivity to light
* Floaters (specks or cobwebs in your vision)
* Flashes of light
If you experience any of these symptoms, it is important to see an eye doctor as soon as possible. Uveitis can be diagnosed with a comprehensive eye exam, which may include imaging tests such as ultrasound or MRI. Treatment for uveitis depends on the cause and severity of the condition, but may include medication to reduce inflammation, antibiotics for infections, or surgery to remove any diseased tissue.
Early diagnosis and treatment are important to prevent complications such as cataracts, glaucoma, and blindness. If you have uveitis, it is important to follow your doctor's recommendations for treatment and monitoring to protect your vision.
Symptoms of type 1 diabetes can include increased thirst and urination, blurred vision, fatigue, weight loss, and skin infections. If left untreated, type 1 diabetes can lead to serious complications such as kidney damage, nerve damage, and blindness.
Type 1 diabetes is diagnosed through a combination of physical examination, medical history, and laboratory tests such as blood glucose measurements and autoantibody tests. Treatment typically involves insulin therapy, which can be administered via injections or an insulin pump, as well as regular monitoring of blood glucose levels and appropriate lifestyle modifications such as a healthy diet and regular exercise.
Retinal vessel analysis
Central retinal artery
Central retinal vein
Branch retinal vein occlusion
Arteriole
Cerebroretinal microangiopathy with calcifications and cysts
Tunable laser
Arnall Patz
Photon etc.
Hyperspectral imaging
Thrombotic storm
Tortuosity
Vitreous hemorrhage
Emixustat
Takayasu's arteritis
White dot syndromes
Fat embolism syndrome
Sunil Pradhan
Canid alphaherpesvirus 1
Blood-ocular barrier
Blood-retinal barrier
Retinal detachment
List of genetic algorithm applications
Computer-aided diagnosis
Coloboma
List of datasets for machine-learning research
Retinal scan
Michael Abramoff
Retinopathy
Entoptic phenomenon
Iprazochrome
Strømme syndrome
Susac's syndrome
PDCD10
Blood-air barrier
Valsalva retinopathy
Diabetic papillopathy
Brain
Eye disease
Pheochromocytoma
Glaucoma
Brain-computer interface
High-altitude cerebral edema
Epigenetic therapy
Lipid signaling
Intraparenchymal hemorrhage
Endophthalmitis
Uveitis
Fyodorov Eye Microsurgery Complex
Sensory neuron
Influenza
Pegaptanib
Conorenal syndrome
Cholesterol embolism
Eales disease
Outline of the human brain
Geordi La Forge
Giraffe
Cardiology diagnostic tests and procedures
AKR1B1
Doppler ultrasonography of the ophthalmic and central retinal vessels
Functional and morphological changes of the retinal vessels in Alzheimer's disease and mild cognitive impairment | Scientific...
Contextual Information Enhanced Convolutional Neural Networks for Retinal Vessel Segmentation in Color Fundus Images - NASA/ADS
Retinal vessel diameters and microvascular abnormalities in patients with carotid stenosis before and 6 months after carotid...
Effects of Color Constancy Algorithm on Retinal Blood Vessel Segmentation - MMU Institutional Repository
BibSLEIGH - Detecting the optic cup excavation in retinal fundus images by automatic detection of vessel kinking
Sturge-Weber Syndrome: Practice Essentials, Background, Pathophysiology
Diabetic Retinopathy | Examination-Based Studies | Information on Data Sources | Vision and Eye Health Surveillance System |...
Complications of Diabetes Mellitus
Advanced Search Results - Public Health Image Library(PHIL)
Collie eye anomaly - Wikipedia
Juvenile macular degeneration: Causes and symptoms
Quinine (PIM 464)
Global and Regional Damages in Retinal Ganglion Cell Axon Bundles Monitored Non-Invasively by Visible-Light Optical Coherence...
Diabetes and eye disease: MedlinePlus Medical Encyclopedia
Surgical and drug treatment options lead to similar outcomes for diabetic eye disease | National Eye Institute
Diabetes and eye disease Information | Mount Sinai - New York
Computer Science authors/titles Mar 2018
Track 7 Tech Vectors to Take Advantage of Technological Acceleration « Kurzweil
Psychiatric Aspects of Marihuana Intoxication
Don't Be Blindsided by Diabetic Retinopathy | Kelsey-Seybold Clinic
Buy Duavee Online - Duavee Price & Side Effects Info
VITO | VITO
Ismail Ben Ayed | ÉTS Montréal
British Journal Of Midwifery - Retinopathy of prematurity: Causes, prevention and treatment
Aging Gracefully - Macular Degeneration - Dr. Weil
Detachment9
- Scar tissue forms which may lead to retinal detachment and blindness). (cdc.gov)
- In 1968, a group of experts developed a grading system for DR called the Arlie House Classification of DR.(Wu L, 2013) The system grades stereo photographs and classifies DR in 13 levels: level 10 indicates no retinopathy and level 85 signifies retinal detachment or severe vitreous hemorrhage. (cdc.gov)
- CEA can also cause retinal or scleral coloboma, coloboma of the optic disc, retinal detachment , or intraocular hemorrhage. (wikipedia.org)
- Retinal detachment -- Scarring that may cause part of the retina to pull away from the back of your eyeball. (medlineplus.gov)
- It may also be used to repair retinal detachment. (medlineplus.gov)
- 4] New vessels develop on the posterior hyaloid face, the iris and in the angle causing vitreous haemorrhage, retinal detachment and neovascular glaucoma. (who.int)
- This stage is characterized by all the above signs plus new because of haemorrhage, tractional retinal detachment or vessels growing at the disc or elsewhere (Figure 2a). (who.int)
- Inflammatory swelling of the choroid may cause fluid to accumulate behind the retina, resulting in partial or total retinal detachment. (vin.com)
- Ophthalmologic findings include macular edema and blot hemorrhages (10), cotton wool spots (1), retinal vasculitis (4), exudative retinal detachment (2), and anterior uveitis (1). (cdc.gov)
Retina20
- Diabetic retinopathy (DR) occurs when high blood sugar damages the blood vessels below the retina. (cdc.gov)
- AOA, 2015) With NPDR, the blood vessels of the retina leak, causing the macula to swell. (cdc.gov)
- NPDR is considered severe when the retina becomes oxygen deprived and signals growth factors to form new blood vessels. (cdc.gov)
- The choroid is a collection of blood vessels supplying the retina. (wikipedia.org)
- It can damage the small blood vessels in the retina, the back part of your eye. (medlineplus.gov)
- Diabetic retinopathy is caused by damage from diabetes to blood vessels of the retina. (medlineplus.gov)
- If your eye doctor notices new blood vessels growing in your retina (neovascularization) or you develop macular edema, treatment is usually needed. (medlineplus.gov)
- Laser eye surgery creates small burns in the retina where there are abnormal blood vessels. (medlineplus.gov)
- A consequence of diabetes, PDR involves the growth of new, abnormal blood vessels in the light-sensing retina. (nih.gov)
- This latest DRCR Retina Network study lets us understand how outcomes in the modern era of retinal surgery compare to treatment with intraocular anti-VEGF injections for vitreous hemorrhage from PDR. (nih.gov)
- There is a rich supply of blood vessels that carry oxygen and important nutrients to the retina that are required for healthy vision, and disruption of this vasculature can be a contributing factor in MD. The retina has no pain nerve fibers, therefore most diseases that affect the retina do not cause pain. (drweil.com)
- The second, exudative or wet MD, is caused by leaks in the blood vessels of the retina. (drweil.com)
- One of these is diabetic retinopathy, a complication that's caused by damage to the blood vessels in the light-sensitive tissue in the back of the eye called the retina. (kelsey-seybold.com)
- This blood vessel damage can cause fluid and blood to leak into the retina. (kelsey-seybold.com)
- Advanced diabetic retinopathy (proliferative diabetic retinopathy) is the more severe form of the condition, during which poor blood flow to the retina can lead to the growth of new, abnormal blood vessels. (kelsey-seybold.com)
- The growth of the new blood vessels can cause bleeding inside the eye and stimulate scar tissue, which over time can cause the retina to detach from the back of the eye. (kelsey-seybold.com)
- The primary cause of diabetic retinopathy is too much sugar in the bloodstream leading to damage of the tiny blood vessels that deliver nourishment to the retina. (kelsey-seybold.com)
- If a branch of the retinal artery is blocked, part of the retina will not receive enough blood and oxygen. (stlukes-stl.com)
- The blood vessels which supply and drain the RETINA. (bvsalud.org)
- Infection of the retina by cytomegalovirus characterized by retinal necrosis, hemorrhage, vessel sheathing, and retinal edema. (bvsalud.org)
Artery6
- therefore, we investigated the prevalence among 33 patients with retinal vein and artery occlu- sions and 80 controls. (who.int)
- The retinal artery occlusion may last for only a few seconds or minutes, or it may be permanent. (stlukes-stl.com)
- The most likely diagnosis is a central retinal artery occlusion (CRAO) due to dermal fillers. (medscape.com)
- Research demonstrates that delivery of larger amounts of filler material, rapid injections, infiltration of material with too much pressure, and placement into vessels that may lead to retrograde flow to the central retinal artery present the greatest risk for blindness. (medscape.com)
- Retinal artery occlusion causes catastroph- embolysis, and there are only 2 reports on ic, sudden visual loss. (who.int)
- More than 90% of eyes with successful use of Reynard and Hanscom's central retinal artery occlusion (CRAO) method [ 4 ], with some modifications, for have a sudden, painless decrease in visual the treatment of retinal artery occlusion. (who.int)
Intraocular1
- Doppler shifts in the central retinal vessels were absent at intraocular pressures above 80 mm Hg. (nih.gov)
Diameters2
Vitreous2
Macular3
- Medicines that are injected into the eyeball may help prevent abnormal blood vessels from growing and improve macular edema. (medlineplus.gov)
- 3] Intra-retinal fluid can accumulate in the macular and is known as macular oedema. (who.int)
- High saturated-fat diets can cause plaque buildup along blood vessel walls, including the macular vessels, which impedes blood flow. (drweil.com)
Diseases3
- The role of OCT in the assessment and management of retinal diseases has become significant in understanding the vitreoretinal relationships and the internal architecture of the retinal structure. (biomedcentral.com)
- OCT has also improved diagnosis and management of retinal diseases by reducing reliance on insensitive tests such as perimetry and subjective disc grading. (biomedcentral.com)
- Methods of Studying Retinal Vessels in Health and Diseases. (bvsalud.org)
Vein1
- Antinuclear antithrombin, protein C, protein S or pres- antibodies were investigated with standard- ence of antiphospholipid antibodies, are ized enzyme-linked immunosorbent assay common in patients with retinal vein occlu- sions and may contribute to the etiology of (ELISA). (who.int)
Uveitis1
- Ocular changes linked to FeLV are related to the ability of the virus to induce immunosuppression, hematologic changes and tumor formation, and include nodular uveal tumors, often with secondary uveitis, retinal dysplasia, retinal hemorrhages and pupillary changes. (vin.com)
Thickness6
- Technically, this problem suffers from various degrees of vessel thickness, perception of details, and contextual feature fusion. (harvard.edu)
- BAX knock-out mice (BAX −/− ) showed increased retinal and RGC axon bundle thickness. (jneurosci.org)
- The green arrows exemplify retinal thickness measurements, the blue arrows exemplify the GCIPL measurements, and the orange arrows exemplify RGC axon bundle measurements. (jneurosci.org)
- C , Distribution of retinal thickness measurements for CTRL (black) and BAX −/− (red) mice. (jneurosci.org)
- At 12 d after ONC injury, mice exhibited reduced retinal and RGC axon bundle thickness. (jneurosci.org)
- Though thickness differences may characterize regions with early pathological signs from normal regions, differences in optical properties and texture descriptors of normal and abnormal retinal tissue may also provide additional information of disease development in pathological eyes. (biomedcentral.com)
Fundus1
- Accurate retinal vessel segmentation is a challenging problem in color fundus image analysis. (harvard.edu)
Diagnosis3
- An automatic retinal vessel segmentation system can effectively facilitate clinical diagnosis and ophthalmological research. (harvard.edu)
- One of the important steps towards a fully automated retinal image diagnosis system is automatic segmentation of blood vessels from the retinal image. (mmu.edu.my)
- The complete vision loss, as opposed to focal paracentral scotoma that is characteristic of retinal ischemia secondary to antiphospholipid antibodies , essentially rules out this diagnosis. (medscape.com)
Diabetic retinopathy4
- These small vessels are one of the key indicators for early detection of diabetic retinopathy. (mmu.edu.my)
- Diabetic retinopathy is a microangiopathy affecting retinal capillaries and venules that occurs in a response to persistent hyperglycaemia. (who.int)
- Early diabetic retinopathy (non-proliferative diabetic retinopathy - NPDR) is the more common form of the condition, which causes the walls of the retina's blood vessels to weaken. (kelsey-seybold.com)
- The most important retinal pathology caused by diabetes is diabetic retinopathy (DR), which is characterized by blood vessels damage. (biomedcentral.com)
Arteries1
- Retinal arteries may become blocked when a blood clot or fat deposits get stuck in the arteries. (stlukes-stl.com)
Optical coherence2
- The aim of this study was to quantitatively investigate the retinal vessels in these disorders, using dynamic vessel analyzer (DVA) and optical coherence tomography angiography (OCTA) analysis. (nature.com)
- The sensitivity of Optical Coherence Tomography (OCT) images to identify retinal tissue morphology characterized by early neural loss from normal healthy eyes is tested by calculating structural information and fractal dimension. (biomedcentral.com)
Ischemia1
- This causes retinal ischemia and results in release of vascular endothelial growth factors that stimulate growth of new vessels. (who.int)
Vasculitis2
- [ 1 ] Its hallmark features include necrotizing granulomatous inflammation and pauci-immune vasculitis in small- and medium-sized blood vessels. (medscape.com)
- CNS manifestations include vasculitis of small to medium-sized vessels of the brain or spinal cord and granulomatous masses that involve the orbit, optic nerve, meninges, or brain. (medscape.com)
Blood clot1
- Estrogens can cause a blood clot in the retinal vessels of the eye. (canadapharmacy.com)
Abnormal2
- It is used to keep vessels from leaking, or to shrink abnormal vessels. (medlineplus.gov)
- Differences in optical properties and roughness measures of normal and abnormal retinal tissue may provide additional information of disease development in pathological eyes. (biomedcentral.com)
Nerve1
- Ophthalmoscopic examination reveals nothing unusual in the nerve head, vessels or retinal background. (druglibrary.org)
Fluid2
- Within the eye the damaged vessels may leak blood and fluid into the surrounding tissues and cause vision problems. (mountsinai.org)
- Structural weakness of the wall of the capillaries results in development of aneurysms, exudation of plasma fluid and bleeding on the retinal surface. (who.int)
Inflammation1
- Temporal arteritisis inflammation and damage to the blood vessels that supply blood to the head, neck, upper body and arms. (stlukes-stl.com)
Vitrectomy2
- To prevent more blood vessels from forming, vitrectomy is usually paired with a laser treatment (laser photocoagulation). (nih.gov)
- There have also been 2 postmarketing reports of electroretinogram changes, 1 case of lens subluxation after vitrectomy that took place 12 days after ocriplasmin injection, a 0.3% incidence of an impaired pupillary response, a 0.18% incidence of ellipsoid zone or inner/outer segment junction changes, and 2 cases of retinal vessel attenuation. (medscape.com)
Angiography1
- tion and retinal flourescein angiography. (who.int)
Leak1
- Mild NPDR refers to the early stages where blood vessels begin to swell and leak. (cdc.gov)
Algorithm2
- In this paper, we investigate the effects of performing color constancy algorithm on retinal image prior to segmentation step. (mmu.edu.my)
- We compared two different algorithms for color constancy, namely Gray World and White Patch that are applied to retinal image before it is used as an input to the segmentation algorithm. (mmu.edu.my)
Microaneurysms1
- As a result, tiny bulges or microaneurysms can develop and protrude from the smaller vessel walls. (kelsey-seybold.com)
Vascular1
- In particular, retinal vascular occlusions says for anticardiolipin antibodies and lupus in patients with primary APS, i.e. with an- anticoagulant. (who.int)
Segmentation1
- Experimentally, sufficient comparative experiments have been enforced on three retinal vessel segmentation datasets, DRIVE, CHASEDB1, and the unhealthy dataset STARE. (harvard.edu)
Ocular1
- It is characterized by endothelial dysfunction and vasospasm of vessels which can be observed by an ocular fundal examination. (bvsalud.org)
Tissue1
- A lack of antioxidants , such as vitamin C, vitamin E and lutein may increase the ability of plaque to stick to the blood vessel walls and promote the damage of the tissue. (drweil.com)
Vision1
- While it can slow or stop the progression of the condition, future retinal damage and vision loss are still possible. (kelsey-seybold.com)
Prone1
- NEI, 2015) In PDR, new blood vessels form, but are weak and prone to leakage. (cdc.gov)
Damage1
- If you already have damage to the blood vessels in your eye, some types of exercise can make the problem worse. (medlineplus.gov)
Occur1
- So-called "retinal migraines" do occur, but they are associated with migraine headaches , which this patient does not report. (medscape.com)
Small2
- Qualitatively, the outputs with color constancy applied have more small vessels, which were mostly left undetected in outputs with no color constancy. (mmu.edu.my)
- It also affects the small vessels of the heart, kidney and brain as well as those supplying peripheral nerves. (who.int)
Oxygen1
- The gas used to pressurize the vessel is usually 100% oxygen. (medscape.com)
Decrease1
- Smoking can decrease blood supply by causing a narrowing of the blood vessels and a thickening of the blood, much the same as in a heart attack or stroke. (drweil.com)
Iris1
- Especially in cats, neovascularisation on the iris surface rapidly develops, with visible blood vessels ("rubeosis iridis") and change in the iris color. (vin.com)
Risk1
- Duavee can increase the risk of serious cardiovascular problems, including stroke and blood clots in the legs, lungs, or retinal vessels of the eye. (canadapharmacy.com)