Ultrastructural changes in the aqueous outflow apparatus of beagles with inherited glaucoma.

Spontaneous glaucoma in the beagle was exhibited after 6 months of age by elevated intraocular pressures and open iridocorneal angles followed by secondary changes. In order to appreciate alterations of the aqueous outflow apparatus in dogs with this autosomal recessive disorder, the eyes of beagles with inherited glaucoma at ages 1 day through 34 months were examined by light, scanning and transmission electron microscopy. Developmentally, no notable differences were observed between normal and preglaucomatous outflow channels through 7 months of age. In 12-month-old glaucomatous chamber angles clustered basement membrane-like material was found scattered throughout the outer corneoscleral trabecular meshwork. In this region elastin-like fibers appeared to be more numerous and arranged less regularly than age-matched normal eyes. Occasional trabecular cells within the corneoscleral trabecular meshwork possessed small clusters of serrated, opaque rods within their cytoplasm. In the older glaucomatous dogs these changes were more generalized and extensive throughout the entire corneoscleral trabecular meshwork. In some individual eyes the anterior chamber angles were observed to be narrow both clinically and histologically. These outflow apparatuses were additionally characterized by compressed, less organized trabeculae with a concomitant build-up of extracellular materials. No correlation was found between the shallowness of the iridocorneal angle and increase in intraocular pressure. Primary glaucoma in the beagle during its earlier phases compared more positively to open-angle glaucoma in man than any of the other spontaneous types in animals.

Comparison of sodium hyaluronate and methylcellulose in extracapsular cataract extraction.

Extracapsular cataract surgery with posterior chamber lens implantation was performed in a total of 30 patients. These were randomly divided into two groups. In one group sodium hyaluronate 1% (Healon) was used as a tool in surgery, in the other group methylcellulose 2% was used. The viscous substances were irrigated out of the eyes at the conclusion of surgery. Central corneal thickness, intraocular pressure, and aqueous flare were recorded until one month post-operatively. There was no difference in corneal thickness between the two groups. The mean intraocular pressure was lower than pre-operatively in both groups with a lower pressure in the methylcellulose group compared to the sodium hyaluronate group during the first part of the observation period.

Multiple dosing of prostaglandin F2 alpha or epinephrine on cynomolgus monkey eyes. II. Slit-lamp biomicroscopy, aqueous humor analysis, and fluorescein angiography.

Prostaglandin (PG) F2 alpha (250 micrograms in 50 microliters saline) or epinephrine 2% solution (50 microliters) was topically applied twice daily for 2 weeks to one eye of six cynomolgus monkeys for each agent. Contralateral control eyes received their respective vehicles. A trace aqueous humor flare response occurred in some PGF2 alpha-treated eyes, which reached significance (P less than 0.05) only when observed 4 hr after the first or seventh dose. No significant anterior chamber cellular response was observed in treated as compared to control eyes. Slit-lamp biomicroscopic evaluation of the cornea, iris, and lens showed no differences in treated as compared to control eyes throughout the study. Aqueous humor samples were obtained from all eyes 4 hr after the ninth consecutive dose. Soluble protein concentration was significantly (P less than 0.01) greater in the PGF2 alpha-treated eyes (1.22 +/- 0.30 mg/ml) as compared to control (0.56 +/- 0.17 mg/ml) or to epinephrine-treated eyes (0.59 +/- 0.18 mg/ml). Microscopic examination of sediments obtained after centrifugation of the aqueous humor revealed no cells in experimental or control samples. Both PGF2 alpha and PGE2 levels were significantly (P less than 0.025) greater in PGF2 alpha-treated eyes, and showed a trend towards being greater in epinephrine-treated compared to control eyes. Neither cystoid macular edema nor other retinal abnormalities were evident by fluorescein angiography in any eyes during the second week of treatment. Multiple dosing of PGF2 alpha in monkey eyes does not appear to produce clinically significant adverse effects in either the anterior or posterior segment which would contraindicate its use in a multiple-dose clinical trial in glaucoma patients.

Diagnostic cytopathology of ocular fluid specimens.

The brief history of the development of cytopathologic study of ocular fluids has been reviewed. The utilization of cytopathology techniques has become increasingly important with the introduction and widespread use of vitreous surgery. The cytopathologic study of ocular fluids have diagnostic value in infectious and noninfectious ocular inflammatory diseases, neoplastic lesions, some forms of secondary glaucoma, epithelial ingrowth, proliferative vitreoretinopathy, persistent hyperplastic primary vitreous and amyloidosis.

Aqueous humor cytology of pseudophakic bullous keratopathy.

The long-term effects of the interaction between an IOL and the immune system of the implanted patient are not yet clear. This study presents the results of aqueous humor (AH) cytological analysis of 51 patients undergoing intraocular surgery for cataract, and aphakic (ABK) or pseudophakic bullous keratopathy (PBK). Cataract AH was acellular (N = 8). The mean ABK AH cell count was 8.5 +/- 6.4 cells per high power field (hpf) of cytologically filtered specimens; mean PBK cell count was 30.2 +/- 13.0. If inflamed eyes are defined as those with more than one cell/hpf, a statistically significant greater number of PBK eyes than ABK eyes were inflamed (93% versus 44%, P less than 0.003 chi square). More than 99% of the nucleated cells were mononuclear histiocytes. One PBK patient had many multinucleated giant cells in the AH.

The blood-ocular barriers under osmotic stress. Studies on the freeze-dried eye.

Regional differences in the response of primate blood-ocular barriers to severe osmotic stress were measured. Marker dyes were localized by fluorescence microscopy in tissues that had been freeze-dried to prevent diffusion. Under severe osmotic stress, the form and the function of the ciliary process are grossly compromised while the iris is spared. Breakdown of the retinal pigment epithelial barrier is widespread, while the retinal blood vessels in large areas retain normal permeability characteristics. The pigment epithelial barrier mechanism is substantially more susceptible to osmotic stress in the region surrounding the optic disc than in the equatorial area.