Results of small incision extracapsular cataract surgery using the anterior chamber maintainer without viscoelastic. (1/436)

AIMS: To assess the efficacy of extracapsular cataract surgery using the anterior chamber maintainer (ACM) without the use of viscoelastic. To compare the effects of this surgical technique on non-diabetic and diabetic patients. METHODS: A prospective single armed clinical trial of 46 eyes in 46 patients undergoing cataract surgery using the ACM without viscoelastic. Patients were assessed preoperatively and at 3 weeks, 3 months, and 12 months postoperatively. The main outcome variables included visual acuity, surgically induced astigmatic change (SIAC), changes in endothelial cell density (ECD), and morphology affecting the central and superior regions of the cornea. RESULTS: Postoperatively, 56% and 70% of patients had unaided visual acuities of 6/12 or better at 3 weeks and 3 months respectively. Even after excluding those patients with pre-existing maculopathy (including diabetic maculopathy), there remains a significant difference between the non-diabetic and diabetic groups in terms of the proportion of patients attaining an unaided visual acuity of 6/12 or better at both 3 weeks (p = 0.003) and 3 months (p = 0.001). Three months postoperatively, the SIAC based upon the keratometric and refractive data was 1.1 dioptres (D) and 1.3 D respectively. There was no statistically significant difference in the SIAC when the non-diabetic and diabetic groups were compared. The mean central and superior endothelial cell losses at 3 months postoperatively were 16% and 22% respectively and at 12 months postoperatively were 20% and 25% respectively. The diabetic group demonstrated greater endothelial cell losses and a more marked and protracted deviation of endothelial cell morphology from normality when compared with the non-diabetic group; however, the differences did not reach statistical significance. CONCLUSIONS: The efficacy of small incision cataract surgery using the ACM in terms of visual outcome and induced astigmatism is comparable with the results obtained using other techniques that utilise a similar size of incision. However, in view of the magnitude and range of the endothelial cell losses associated with this technique the concurrent use of viscoelastic is suggested. There does not appear to be a statistically or clinically significant difference between non-diabetic and diabetic patients in terms of the magnitude of the endothelial cell losses or in the wound healing response in the 12 months after cataract surgery using the ACM.  (+info)

Image quality in polypseudophakia for extremely short eyes. (2/436)

AIM: To evaluate the image quality produced by polypseudophakia used for strongly hypermetropic and nanophthalmic eyes. METHODS: Primary aberration theory and ray tracing analysis were used to calculate the optimum lens shapes and power distribution between the two intraocular lenses for two example eyes: one a strongly hypermetropic eye, the other a nanophthalmic eye. Spherical aberration and oblique astigmatism were considered. Modulation transfer function (MTF) curves were computed using commercial optical design software (Sigma 2100, Kidger Optics Ltd) to assess axial image quality, and the sagittal and tangential image surfaces were computed to study image quality across the field. RESULTS: A significant improvement in the axial MTF was found for the eyes with double implants. However, results indicate that this may be realised as a better contrast sensitivity in the low to mid spatial frequency range rather than as a better Snellen acuity. The optimum lens shapes for minimum spherical aberration (best axial image quality) were approximately convex-plano for both lenses with the convex surface facing the cornea. Conversely, the optimum lens shapes for zero oblique astigmatism were strongly meniscus with the anterior surface concave. Correction of oblique astigmatism was only achieved with a loss in axial performance. CONCLUSIONS: Optimum estimated visual acuity exceeds 6/5 in both the hypermetropic and the nanophthalmic eyes studied (pupil size of 4 mm) with polypseudophakic correction. These results can be attained using convex-plano or biconvex lenses with the most convex surface facing the cornea. If the posterior surface of the posterior intraocular lens is convex, as is commonly used to help prevent migration of lens epithelial cells causing posterior capsular opacification (PCO), then it is still possible to achieve 6/4.5 in the hypermetropic eye and 6/5.3 in the nanophthalmic eye provided the anterior intraocular lens has an approximately convex-plano shape with the convex surface anterior. It was therefore concluded that consideration of optical image quality does not demand that additional intraocular lens shapes need to be manufactured for polypseudophakic correction of extremely short eyes and that implanting the posterior intraocular lens in the conventional orientation to help prevent PCO does not necessarily limit estimated visual acuity.  (+info)

Intraocular lenses in children: changes in axial length, corneal curvature, and refraction. (3/436)

AIM: To assess changes in axial length, corneal curvature, and refraction in paediatric pseudophakia. METHODS: 35 eyes of 24 patients with congenital or developmental lens opacities underwent extracapsular cataract extraction and posterior chamber intraocular lens implantation. Serial measurements were made of axial length, corneal curvature, objective refraction, and visual acuity. RESULTS: For patients with congenital cataracts (onset < 1 year age) the mean age at surgery was 24 weeks. Over the mean follow up period of 2.7 years, the mean increase in axial length of 3.41 mm was not significantly different from the value of an expected mean growth of 3.44 mm (paired t test, p = 0.97) after correction for gestational age. In the developmental cataract group (onset > 1 year of age) the mean age at surgery was 6.4 years with a mean follow up of 2.86 years. This group showed a mean growth in axial length of 0.36 mm that was not significantly different from an expected value of 0.47 mm (paired t test, p = 0.63). The mean preoperative keratometry was 47.78 D in the congenital group and 44.35 D in the developmental group. At final follow up the mean keratometry in the congenital group was 46.15 D and in the developmental group it was 43.63 D. In eyes followed for at least 2 years, there was an observed myopic shift by 24 months postoperatively of 3.26 D in the congenital cases (n = 10) and 0.96 D in the developmental cases (n = 18). CONCLUSION: The pattern of axial elongation and corneal flattening was similar in the congenital and developmental groups to that observed in normal eyes. No significant retardation or acceleration of axial growth was found in the eyes implanted with IOLs compared with normal eyes. A myopic shift was seen particularly in eyes operated on at 4-8 weeks of age and it is recommended that these eyes are made 6 D hypermetropic initially with the residual refractive error being corrected with spectacles.  (+info)

Evaluation of visual outcome of cataract surgery in an Indian eye camp. (4/436)

AIM: To evaluate the results of cataract surgery performed in a rural Indian eye camp. METHOD: The pre- and postoperative visual acuities and surgical complications were recorded prospectively in 6383 eyes undergoing cataract extraction for age related cataract in rural eye camps held in northern India in 1993-4. The best visual acuity and cause of poor outcome were recorded on 3908 eyes seen at 6 weeks' follow up. RESULTS: Of 6383 operated eyes 94.8% had a visual acuity of less than 3/60 preoperatively, and 41% of the procedures were performed on patients who were bilaterally blind (less than 3/60 better eye). At discharge with standard aphakic spherical spectacles, 11.3% of eyes had an acuity of less than 6/60 (poor outcome), and 25.9% had an acuity of 6/18 or better. At 6 weeks' follow up 3908 eyes were examined (61.2%), of which, with best correction, 4.3% had poor outcome (acuity of less than 6/60) and 79.9% obtained 6/18 or better. Pre-existing eye pathology was responsible for poor outcome in 3.0% of eyes and surgical complications in 1.3% of eyes, of which corneal decompensation was the major cause (0.5%). In 237 eyes which received an intraocular lens implantation (IOL) in the camp, the visual acuity at discharge was 6/18 or better in 44.5% of eyes improving to 87.9% in the 157 eyes which were seen at 6 weeks' follow up. Poor outcome (less than 6/60) was seen in 5.7% of the eyes with an IOL at discharge improving to 1.9% at follow up. CONCLUSION: This evaluation suggests that it is possible to obtain acceptable results from cataract extraction with experienced ophthalmologists in well conducted Indian eye camps. Better correction of aphakia at discharge from the camp would improve the immediate visual results, which is important as a significant number of patients do not return for follow up. The use of posterior chamber IOLs in the eye camp by experienced ophthalmologists, appeared to give satisfactory results, although further evaluation with a larger series of cases and more surgeons is required before it can be recommended.  (+info)

Audit of extracapsular cataract extraction and posterior chamber lens implantation as a routine treatment for age related cataract in east Africa. (5/436)

AIMS: To evaluate the outcome of extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens implantation (PC-IOL) in an African eye clinic during the transition from intracapsular cataract extraction to ECCE and PC-IOL. METHODS: A retrospective survey of 461 consecutive operations for age related cataract with a mean follow up of 52.9 weeks (range 0-275) and a minimum follow up of 4 weeks in 87.9% of eyes. RESULTS: A best corrected vision of 6/18 or better was obtained in 94.3% of eyes, and an uncorrected vision of 6/18 or better in 78.2% of eyes. Six eyes (1.5%) had a best corrected vision of less than 6/60. The visual acuity at 2 months was strongly predictive of the vision at 1 year or more after surgery. Preoperative biometry and IOL power calculation increased the proportion of eyes obtaining an uncorrected vision of 6/18 or better from 73.8% to 81.3%. Four eyes developed visually significant posterior capsule opacity. CONCLUSION: ECCE and PC-IOL can give very good results in an African setting. A better visual outcome should lead to increased demand for cataract surgery, which will eventually reduce the number of cataract blind people in Africa.  (+info)

The triple procedure: in the bag placement versus ciliary sulcus placement of the intraocular lens. (6/436)

AIMS: To evaluate the influence of intraocular lens (IOL) placement on triple procedure clinical results and to investigate whether it is appropriate to use phacoemulsification in patients with large lens nucleus. METHODS: 40 consecutive penetrating keratoplasties combined with cataract extraction performed in a single institution were studied. Whenever possible a capsulorhexis was performed and the IOL was placed into the capsular bag. Phacoemulsification was used when the nucleus was too large to pass through the capsulorhexis. RESULTS: Out of 25 patients with an intact capsulorhexis phacoemulsification was used in 13 (52.0%) whereas the entire nucleus passed through the capsulorhexis in the remaining 12 patients (48%). The average 12 month visual acuity was 0.46 (SD 0.21) in patients with in the bag IOL (n = 23) and 0.29 (0.08) in patients with ciliary sulcus IOL (n = 13) (p = 0.04). Elevated intraocular pressure occurred in 26.1% (6/23) of patients with in the bag IOL and 61.5% (8/13) of patients with ciliary sulcus IOL (p = 0.08). The average postoperative graft thickness at 18 months was 552 (27) microns in the former group and 650 (29) microns in the latter group (p = 0.04). No significant difference in graft survival, postoperative endothelial cell density, astigmatism, and videokeratoscopic measurements was found between both groups. CONCLUSION: In the bag placement of the intraocular lens during the triple procedure results in better outcome of transplantation than ciliary sulcus placement of the IOL. Phacoemulsification allows removal of large nuclei through a 5 mm capsulorhexis without performing relaxing incisions out towards the periphery of the capsule.  (+info)

Visual outcome after phacoemulsification and IOL implantation in diabetic patients. (7/436)

AIMS: To follow visual acuity (VA) and progression of diabetic retinopathy (DR) after phacoemulsification in diabetic patients with different stages of DR and controls. METHODS: This prospective study included 27 diabetic patients with no or mild to moderate non-proliferative DR; 25 patients with moderate to severe non-proliferative, or proliferative DR; and 22 non-diabetic controls. All patients underwent uncomplicated, phacoemulsification surgery, with implantation of a heparin-surface modified (HSM) poly(methylmethacrylate) (PMMA) intraocular lens (IOL) into the capsular bag. Colour fundus photographs and fluorescein angiograms (FA) were taken at 1 week (baseline), 3 months, and 1 year postoperatively to determine stability or progression of DR. RESULTS: The VA of 46 diabetic eyes (88%), was improved 1 year after surgery and only six eyes (12%) were unchanged or worse. 41 diabetic eyes (79%) achieved a VA of 0.5 or better and 11 eyes (21%) had a final VA lower than 0.5. Significantly lower final corrected VA was found 1 year after surgery in eyes with advanced DR (median 0.5; range 0.1-1.0) compared with controls (1.0; 0.1-1.0) and eyes with no or mild to moderate DR (1.0; 0.1-1.0). Eyes with mild to moderate DR and clinically significant macular oedema (CSMO) 1 week postoperatively had a lower final VA than those without CSMO. Angiographic cystoid macular oedema (CMO) was detected with FA in 15% of all diabetic eyes 1 week postoperatively. 41 eyes (79%) showed no change or improvement of the retinal status 1 year after cataract surgery. Progression was found in 11 eyes (21%), mainly in eyes with mild to moderate DR and moderate to severe DR. Eyes with an indication for laser photocoagulation at baseline showed a significantly higher rate of progression of DR after surgery than those without indication for laser treatment. CONCLUSION: The final visual outcome was improved in the majority of diabetic eyes. Eyes with CSMO at the time of surgery had the worst prognosis regarding postoperative VA.  (+info)

Two clinical trials of an intraocular steroid delivery system for cataract surgery. (8/436)

PURPOSE: To determine the safety and efficacy of an intraocular dexamethasone drug delivery system (Surodex) in the treatment of inflammation following cataract surgery. METHODS: Surodex is a biodegradable polymer that releases dexamethasone for 7 to 10 days after placement in the anterior segment. Study 1 was a prospective, randomized, double-masked Phase II clinical trial of 90 cataract surgical patients that compared treatment with Surodex to treatment with a placebo drug delivery system and to no anti-inflammatory drug treatment at all. Study 2 was a separate prospective, randomized, double-masked study of 60 cataract surgical patients that compared treatment with Surodex to topical dexamethasone (eye drop) therapy. RESULTS: In the first study, Surodex was superior to placebo in suppressing postsurgical inflammation throughout the 60-day postoperative period, as judged by masked-evaluator, slit-lamp grading of cell and flare. The differences were statistically significant from postoperative day 3 through postoperative week 3. The majority of Surodex patients did not require topical steroid by 2 weeks after surgery (93%) or by 2 months after surgery (88%). In the second study, Kowa laser flare meter readings were lower in Surodex patients throughout the 90-day postoperative period. The results were statistically significant at 4, 8, and 15 days following surgery. There were no significant adverse complications of Surodex in either study. CONCLUSION: Surodex was safe and effective in suppressing postcataract surgery inflammation and appears to be a promising alternative to topical steroids.  (+info)