Cataract and phthisis bulbi after laser photoablation for threshold retinopathy of prematurity.

PURPOSE: To describe the visual and structural outcome of eyes that developed a dense cataract after laser photoablation for threshold retinopathy of prematurity. METHODS: A retrospective review of eight consecutive infants who developed dense cataract(s) after bilateral laser photoablation for threshold retinopathy of prematurity. Of the 10 eyes with cataract, five eyes were treated with a diode laser and five with an argon laser. The stage and zone of the retinopathy of prematurity, number of burns applied, time of onset of the cataract, clinical findings at the time of cataract surgery, and the course after cataract surgery were reviewed. RESULTS: Six eyes had zone 1 disease and four had zone 2 disease. The mean number of burns applied per eye was 2532 +/- 856 (range, 1400 to 4500). A cataract was diagnosed a median of 3 [corrected] weeks (range, 1 to 28 weeks) after laser photoablation. Nine of the 10 cataracts were sufficiently dense to preclude a view of the fundus. All 10 eyes had clinical signs suggestive of an inflammatory or ischemic process that included one or more of the following findings: corneal edema, pupillary membrane, iris atrophy, depigmentation of ciliary processes, pigment on the anterior lens surface, posterior synechiae, hyphema, and shallow anterior chamber. Nine eyes underwent cataract surgery. Five of the 10 eyes had retinal detachment ranging in severity from stage 4A to stage 5 at the time of cataract surgery. Nine of the 10 eyes progressed to phthisis bulbi and no light perception. CONCLUSIONS: A dense cataract developing in the eye of an infant after laser photoablation for threshold retinopathy of prematurity is associated with a poor visual prognosis. The constellation of associated clinical findings appears to be most consistent with anterior segment ischemia.

Correlation of histologic 2-dimensional reconstruction and confocal scanning laser microscopic imaging of choroidal neovascularization in eyes with age-related maculopathy.

OBJECTIVE: To topographically localize vascular channels, macrophages, and retinal pigment epithelium and other components of choroidal neovascularization (CNV) associated with age-related maculopathy. METHODS: Two postmortem eyes with age-related maculopathy and CNV were evaluated. The formalin-fixed CNV complex was excised and processed for confocal scanning laser microscopy including immunostaining for factor VIII-related antigen and incubation with Ig fluorescein isothiocyanate. After confocal microscopy, the specimens were serial step sectioned, stained, and 2-dimensional topographic reconstructions were made. The confocal images were compared with the 2-dimensional reconstructions. RESULTS: Both specimens contained central disciform scars surrounded by areas of intact retinal pigment epithelium. The first specimen was more atrophic and contained fewer choroidal neovascular channels than the second specimen. The topographic arrangement of the CNV and retinal pigment epithelial changes in the confocal images corresponded with the 2-dimensional reconstructions. Macrophages were concentrated around areas of vascularization. CONCLUSION: Confocal scanning laser microscopy of excised CNV simulates fluorescein angiography and topographic localization of the components of CNV provides insight into the pathogenesis of CNV.

Age-related changes of glycosidases in human retinal pigment epithelium.

This study was undertaken to determine whether there are age-related changes in the specific activities of several glycosidases in fresh retinal pigment epithelial cells (RPE) isolated from the posterior pole of human donor eyes. One hundred and twenty-one pairs of eyes from human donors, between the ages of 43 and 95 years, were obtained from the National Disease Research Interchange (NDRI, Philadelphia, PA) and the Cleveland Ohio Eye Bank within 18 to 24 h of death. None had histories of diabetes, hepatitis, HIV infection, intraocular surgery, or documented age-related macular degeneration, although several older donors with evidence of drusen were included in the study. RPE cells were isolated from the posterior third of the retina using the conventional rush method and homogenized with a glass, Broeck tissue grinder. All post-nuclear supernatants were analyzed for glycosidase activity; a smaller number of nuclear pellets were assayed to verify that the majority of the enzyme activity was associated with the post-nuclear sypernatants. Glycosidase activity was quantitated fluorometrically by measuring the enzymatic release of umbelliferone from synthetic substrate preparations, specific for each enzyme. Total protein was determined by a micro BCA protein assay. Regression analysis revealed statistically significant age-related decreases for the specific activities of alpha-mannosidase (p = 0.0001), beta-galactosidase (p = 0.0001), N-acetyl-beta-glucosaminidase (p = 0.0001), and N-acetyl beta galactosaminidase (p = 0.0001) in fresh human donor RPE cells taken from the region of the posterior third of the retina that included the macula. Mannose and N-acetyl-glucosamine are major carbohydrate monomers of the oligosaccaride chains of human rhodopsin, and a relatively high percentage of the oligosaccharide chains are galactosylated. Defects in their degradation may lead to the accumulation of undigested residual material in the RPE.