Polypoidal choroidal vasculopathy treated with macular translocation: clinical pathological correlation. (49/755)

AIMS: To report the histopathology of two specimens of polypoidal choroidal vasculopathy (PCV) obtained from two eyes of Japanese patients. METHODS: Specimens were obtained under direct visualisation during macular translocation surgery with 360 degree retinotomy. The clinical findings were correlated with the light microscopic findings of the two specimens. RESULTS: One specimen from a 77 year old man was the central portion of the lesion that lay under the sensory retina on the retinal pigment epithelium (RPE). The specimen was made up mainly of fibrous tissue with small, thin walled vessels. Indocyanine green angiography after surgery revealed that active leaking polypoidal element remained under the RPE. Another specimen obtained from a 62 year old man was made up of a fibrovascular membrane situated within Bruch's membrane. The part of this specimen inferior to the foveal region included a collection of dilated, thin walled blood vessels without pericytes, surrounded by macrophages that stained positive for CD68. The dilated vessels appeared to be correlated with the orange coloured polyps observed by ophthalmoscopy, the polypoidal structure seen in indocyanine green angiograms, and the pyramidal elevation with intermediate reflectivity by optical coherence tomography. CONCLUSION: Polypoidal structures are located within Bruch's space. They are composed of clusters of dilated, thin walled blood vessels surrounded by macrophages and fibrin material. The positive immunohistochemical staining for vascular endothelial growth factor in the RPE and the vascular endothelial cells suggests that this fibrovascular complex is a subretinal choroidal neovascularisation.  (+info)

In vivo assessment of retinal carotenoids: macular pigment detection techniques and their impact on monitoring pigment status. (50/755)

Of the many carotenoids found within human tissue, only the carotenoids within the human retina can be assessed noninvasively at present. Such assessment should eventually provide a more complete understanding of the functional role of retinal lutein (L) and zeaxanthin (Z) (termed macular pigment, MP) in human vision. The emerging data allow for some initial observations. For example, there appears to be wide variation (>factor of 10) in the concentration of MP. Although MP levels have been recorded from nondetectable to 1.20 OD (optical density), the "average" levels, relative to what is possible, appear low. This may be due in part to the low average dietary intake of L and Z in the typical U.S. diet. Nonetheless, individual differences in MP may also be influenced by nondietary factors such as genetics, demographics and lifestyle characteristics. Some evidence indicates that the MP carotenoids may protect the retina and lens, and could improve vision through some optical mechanisms. Consequently, efforts to determine typical MP levels and the factors that influence individual differences in MP density should be continued.  (+info)

Possible biologic mechanisms for a protective role of xanthophylls. (51/755)

This contribution surveys the evidence linking the presence of the two xanthophylls, lutein and zeaxanthin, to a protective role in the macular region of the retina. Although the evidence is still associative in nature, it is biologically plausible, and may be resolved with additional intervention trials.  (+info)

Visual results in children treated for macular retinoblastoma. (52/755)

PURPOSE: To evaluate the results of patching treatment in children with macular retinoblastoma in one eye. METHODS: Fifteen children affected by macular retinoblastoma received instructions for patching treatment for amblyopia. Data were collected on age at diagnosis of the tumor, presence of unilateral or bilateral disease, area of posterior pole involvement by the scar of the regressed tumor and its relationship to the fovea; and the onset, duration, and compliance of patching. The visual acuities recorded were expressed in logMAR (logarithm minimum angle of resolution) equivalents. RESULTS: Twelve children (80%) had bilateral retinoblastoma with the macular involved in one eye and three children had unilateral macular tumors. The median age at which patching was initiated was 15 months (range 4-36). Compliance to patching was good in 80% of children, with a median duration of 4 h (range 0.5-8) per day, 7 days per week, with total occlusion of the better eye. The median percentage of posterior pole involvement was 34% (range 11-100%). Eighty percent of children had some improvement in their visual acuity, and of the children in whom final logMAR acuity was recorded, 73% had an acuity of 1.0 logMAR or better and 53% an acuity of 0.5 logMAR or better after patching. There was no evidence of association between age of patient, sex, duration of patching, or percentage of posterior pole involvement and the improvement in visual acuity. CONCLUSIONS: In spite of the macular involvement of eyes with retinoblastoma, some visual recovery was achieved in 80% of children. Hence a trial of patching therapy is recommended for all children with involvement of the macula by retinoblastoma.  (+info)

Limited macular translocation with scleral retraction suture. (53/755)

BACKGROUND/AIMS: Macular translocation with scleral imbrication is a new technique for treating subfoveal choroidal neovascular membranes (CNV). This procedure shortens the sclera but may result in a minimal decrease in the internal circumference of the globe and limits the amount of foveal displacement. The authors propose a new scleral retraction suture aimed at decreasing the internal circumference of the globe in an effort to increase foveal displacement. METHODS: Using a cadaver model, they compared the amount of scleral shortening using a standard scleral imbrication technique and a modified three suture scleral retraction technique. Sections of the globes were digitised and specialised software was used to estimate the amount of scleral shortening. Three patients with subfoveal choroidal neovascularisation underwent limited macular translocation using pars plana vitrectomy and macular detachment with the modified scleral suture technique. The main outcome measures were visual acuity, foveal displacement, and complications. RESULTS: In the cadaver model, the scleral retraction suture resulted in a flatter internal scleral fold compared to the standard suture technique and created approximately 890 microm of effective scleral shortening. In the patients who underwent macular translocation and laser photocoagulation of the CNV, visual acuity improved in two patients and worsened in one patient. The range of foveal displacement was 1400-2400 microm. CONCLUSION: The foveal displacements achieved in this limited study compared to median displacement previously published using standard suture techniques demonstrates that the scleral retraction suture technique may be a useful adjunct to limited macular translocation. The advantage of this type of suture in conjunction with translocation may depend on the effective scleral shortening offered by this retraction suture.  (+info)

Morphometric changes of the choriocapillaris and the choroidal vasculature in eyes with advanced glaucomatous changes. (54/755)

PURPOSE: In addition to an elevated intraocular pressure a compromise of the ocular blood supply have been implicated in the pathogenesis of primary open-angle glaucoma. The purpose of this study was to quantify morphologic changes in the choroid including choriocapillaris thickness and density and diameter of large choroidal vessels in post mortem eyes with advanced primary open-angle glaucoma. METHODS: We analyzed 20 eye bank eyes (provided from the Georgia Eye Bank in Atlanta) with end stage primary open-angle glaucoma and compared them with 20 age-matched control eye bank eyes. The eyes were processed for light microscopy and following variables were measured with a digital filar micrometer: density and diameter of large choroidal vessels in the macular and equatorial choroid; thickness of the choroid in the macular and equatorial region; density and thickness of choriocapillaris in the macular, peripapillary, and equatorial choroid; and peripapillary capillary-free area nasal and temporal to the optic disk. RESULTS: Eyes with glaucoma displayed a lower density of the capillaries of the choriocapillaris as compared to control eyes in the macular, temporal peripapillary, and equatorial choroid with 0.50-0.55 (p=0.018), 0.46-0.51 (p=0.016), and 0.50-0.55 (p=0.038), respectively. There was no significant difference for the choriocapillaris density in the nasal peripapillary choroid, the thickness of the capillaries of the choriocapillaris in all assessed locations, and the nasal and temporal peripapillary capillary-free zone of the choriocapillaris between eyes with glaucomatous damage and controls. Assessment of large choroidal vessels in the macular choroid showed that eyes with glaucoma had a decreased density of veins (11.7-38.9 mm(-2); p<0.001) and arteries (7.7-12.4 mm(-2); p=0.005) and arteries with a higher diameter (45.6-28.2 microm; p<0.001) as compared to control eyes. The large vessels in the equatorial choroid displayed no significant difference in diameter but a lower density (21.2-44.1 mm(-2); p=0.017) in eyes with glaucomatous damage as compared to controls. CONCLUSION: Eyes with advanced glaucomatous damage after long standing primary open-angle glaucoma exhibit several changes including decreased density of capillaries of the choriocapillaris and decreased density of large choroidal vessels. We cannot conclude from our study whether the observed vascular changes in the choroid are primary pathogenic factors or secondary phenomena.  (+info)

Fundus photography for measurement of macular pigment density distribution in children. (55/755)

PURPOSE: To evaluate a photographic procedure for reflectometry of the topographic distribution of macular pigment density in normal pediatric subjects. METHODS: Digitized blue (480 nm) and green (540 nm) photographic images were aligned and subtracted to generate optical density difference maps. An 8 degrees x 8 degrees area concentric with the fovea was analyzed. Gaussian curves were fitted through the foveola along the vertical and horizontal meridians. The peak density and full widths at half maximum (FWHMs) were calculated. The subjects (n = 23; median age 10.5 years) had normal eyes and good acuity. RESULTS: The peak macular pigment (MP) density was 0.13 +/- 0.04 density units (DU) which is at the lower end of the range previously obtained by other reflectometry procedures. Density distributions were circularly symmetrical. The FWHM ranged was 2.4 degrees +/- 0.5 degrees. Neither MP nor FWHM varied significantly with age. CONCLUSIONS: The photographic method is feasible and provides quantitative assessment of topographic properties of macular pigment in young subjects. Future application to clinical studies of pediatric patients is envisioned.  (+info)

Effects of granulocyte colony stimulating factor on retinal leukocyte and erythrocyte flux in the human retina. (56/755)

PURPOSE: The blue-field entoptic technique was introduced more than 20 years ago to quantify perimacular white blood cell flux. However, a final confirmation that the perceived corpuscles represent leukocytes is still unavailable. METHODS: The study design was randomized, placebo-controlled, and double masked with two parallel groups. Fifteen healthy male subjects received a single dose of granulocyte colony stimulating factor (G-CSF, 300 microg) and 15 other subjects received placebo. The following parameters were assessed at baseline and at 12 minutes and 8 hours after administration: retinal white blood cell flux, with the blue-field entoptic technique; retinal blood velocities, with bidirectional laser Doppler velocimetry; retinal venous diameter determined with a retinal vessel analyzer; and blood pressure and pulse rate determined by automated oscillometry and pulse oxymetry, respectively. RESULTS: After 12 minutes, G-CSF reduced total leukocyte count from 5.5 +/- 1.4 10(9)/L at baseline to 1.9 +/- 0.4 10(9)/L. This was paralleled by a 35% +/- 11% decrease in retinal white blood cell density. After 8 hours G-CSF increased total leukocyte counts to 20.0 +/- 4.4 10(9)/L. Again, this increase in circulating leukocytes was reflected by an increase in retinal white blood cell density (110% +/- 48%). All effects were significant at P < 0.001. By contrast, none of the other hemodynamic parameters was changed by administration of G-CSF. CONCLUSIONS: The results clearly indicate that the blue-field entoptic technique assesses leukocyte movement in the perimacular capillaries of the retina. Moreover, white blood cell density appears to adequately reflect the number of circulating leukocytes within the retinal microvasculature. Hence, an increase in retinal white blood cell density does not necessarily reflect retinal vasodilatation.  (+info)