Bilateral anterior segment dysgenesis in a 7-week-old domestic shorthaired cat.

A 7-week-old, intact, female domestic shorthaired cat was presented to the Atlantic Veterinary College (AVC) Ophthalmology service for a 1-week history of buphthalmia in the left eye and bilateral elevated intraocular pressures. Ocular examination revealed bilateral non-visual glaucomatous eyes. Bilateral enucleations were performed without complications and histopathology revealed anterior segment dysgenesis of varying degrees in both eyes. Key clinical message: Anterior segment dysgenesis is a developmental condition that can result in primary congenital glaucoma for which the best course of treatment is enucleation.

Dysgénésie bilatérale du segment antérieur chez un chat domestique à poils courts de 7 semaines. Une chatte domestique à poil court femelle intacte âgée de 7 semaines a été présentée au service d'ophtalmologie du Atlantic Veterinary College pour une histoire d'une semaine de buphtalmie dans l'æil gauche et de pressions intraoculaires bilatérales élevées. L'examen oculaire a révélé des yeux glaucomateux non visuels bilatéraux. Les énucléations bilatérales ont été réalisées sans complications et l'histopathologie a révélé une dysgénésie du segment antérieur à des degrés divers dans les deux yeux.Message clinique clé :La dysgénésie du segment antérieur est une affection du développement qui peut entraîner un glaucome congénital primaire pour lequel le meilleur traitement est l'énucléation.(Traduit par Dr Serge Messier).

Severe unilateral buphthalmos in a 4-month-old kitten.

A 4-month-old kitten was presented with unilateral buphthalmos. The eye was blind with no menace response, but intraocular pressure was normal. A trans-palpebral enucleation was performed on the affected eye and the globe was submitted for histology. There was a suppurative, lympho-plasmacytic panophthalmitis with inflammatory exudate in the iridocorneal angle.

Buphthalmie unilatérale grave chez un chaton âgé de 4 mois. Un chaton âgé de 4 mois a été présenté avec de la buphtalmie unilatérale. L'œil était aveugle sans réponse à la menace, mais la pression intraoculaire était normale. Une énucléation trans-palpébrale a été réalisée sur l'œil affecté et le globe a été soumis pour examen histologique. Il y avait une panophtalmitie lympho-plasmacytique avec de l'exsudat inflammatoire dans l'angle irido-cornéen.(Traduit par Isabelle Vallières).

The location of sites and effect of semiconductor diode trans-scleral cyclophotocoagulation on the buphthalmic equine globe.

PURPOSE: To determine appropriate location and energy settings for trans-scleral cyclophotocoagulation (TSCPC) for buphthalmic equine globes. ANIMALS: Eleven horses with a buphthalmic eye blinded by glaucoma presented for enucleation. METHODS: Globe and corneal dimensions were measured via ultrasonography and calipers, and TSCPC was performed under general anesthesia immediately prior to enucleation. Part 1: In nine globes, sixty sites were lasered 4 mm posterior to the limbus in the dorsotemporal and ventrotemporal quadrants at settings of 1500 milliwatts and 1500 ms. Globes were processed and sectioned sagitally over the temporal aspect in two blocks, each with five histologic sections examined by light microscopy. A digital imaging system was used to determine the location and length of the pars plicata on one slide from each block. Part 2: Based on results in Part 1, two globes were measured and lasered using the same time and energy settings at the following distances posterior to the limbus: 8 mm dorsally, 6 mm dorsotemporally, 5 mm ventrotemporally, and 5 mm ventrally. RESULTS: Globe and corneal dimensions exceeded normal values in all globes. Part 1: In all nine globes, photocoagulation affected the anterior ciliary processes and iris base and in 8/9 coagulation of the pectinate ligaments was noted. Part 2: In both globes, coagulation was confined to the pars plicata. CONCLUSIONS: The previously recommended TSCPC sites are located too far anteriorly for a buphthalmic globe. Buphthalmic equine globes should have TSCPC performed at the following distances posterior to the limbus: 6-8 mm dorsally, 5-6 mm dorsotemporally, 4-5 mm ventrotemporally, and 4-5 mm ventrally.

Bilateral buphthalmia in a 4-month-old Texas longhorn steer.

Congenital ocular disease occurs uncommonly in cattle, with multiple abnormalities reported only sporadically in the literature. This report describes a case of anterior segment dysgenesis resulting in glaucoma in a 4-month-old Texas Longhorn steer. On clinical exam, bilateral buphthalmia was present and intraocular pressures exceeded 47 mm Hg in both eyes. On histopathologic examination, the iridocorneal angle and filtration apparatus were distorted due to collapse of the ciliary cleft and anterior displacement of the anterior portion of the ciliary body. No evidence of inflammation or other causes of glaucoma were recognized.

[Experiences with the intraocular silicon prosthesis as an alternative to enucleation in dogs and cats]. / Erfahrungen mit der intraokulären Silikonprothese als Alternative zur Bulbusexstirpation bei Hund und Katze.

The intraocular implantation of a silicone prosthesis fulfills all important requirements to be used in dogs and cats. Given the appropriate indication including glaucoma in the first place, this method should be preferred to enucleation. The operation procedure is described and clinical observations in 14 dogs and 6 cats are reported. All animals tolerated the implant well and appeared to be pain-free. The cosmetic results depended on the correct size of the implant and on the nature of the corneal response. Final evaluation of the cosmetic effect was only possible one year or even more after operation.

Photoinduced buphthalmic avian eyes: II. Continuous darkness.

Chickens raised from 2 to 14 weeks of age in continuous darkness (OL:24D) developed shallow anterior chambers and buphthalmos (megaloglobus). Chickens raised in continuous darkness developed ocular changes similar to that reported in chickens raised in continuous fluorescent and incandescent light and in dim light. Corneal diameters and axial globe lengths were an inconsistent means of documenting ocular enlargement. Iridocorneal angles were narrowed on scanning electron microscopy (SEM). Intraocular pressure (IOP) was not different from control chickens. The chicken is proposed as a model to study ocular development, the effects of lid suture on infants, axial myopia, preglaucomatous changes, and possibly pharmacologic effects of antiglaucoma preparations.

Quantitation of uveoscleral outflow in normotensive and glaucomatous Beagles by 3H-labeled dextran.

In uveoscleral outflow, aqueous humor leaves the anterior chamber and passes caudally through the trabecular meshwork and the sclerociliary cleft to enter the supraciliary and suprachoroidal spaces. The fluid is then absorbed by choroidal and scleral circulations. Using 3H-labeled dextran, uveoscleral outflow was quantitated in normotensive and glaucomatous Beagles under general anesthesia. The intrascleral plexus was isolated and 3H-labeled dextran was injected into the anterior chamber. Intrascleral plexus contents were sampled every 5 minutes over a 30- to 60-minute period. The eyes were enucleated, sectioned, and prepared for scintillation counting. Uveoscleral outflow accounted for 15% and 3% of the total aqueous humor outflow in the normotensive dogs and in the advanced glaucomatous dogs, respectively. In the advanced glaucomatous Beagle, conventional and uveoscleral outflow pathways were reduced and contributed to the etiopathogenesis of glaucoma.

Morphologic studies of uveoscleral outflow in normotensive and glaucomatous beagles with fluorescein-labeled dextran.

Aqueous humor leaves the anterior chamber through 2 pathways: the trabecular meshwork of the iridocorneal angle and the unconventional uveoscleral route. In the latter route, aqueous humor leaves the anterior chamber, passes caudally through the trabecular meshwork and sclerociliary cleft to enter the supraciliary and suprachoroidal spaces. The fluid is absorbed by the choroidal and scleral circulation. Fluorescein-labeled dextran was slowly infused into the posterior chamber of healthy and glaucomatous Beagles for 30 minutes. The eyes were fixed in a mixture of 70% alcohol and formalin, placed in epoxy resin for histologic evaluation, and examined by fluorescent microscopy. Fluorescence was detected in the healthy dogs throughout the uveoscleral pathway. In the glaucomatous dogs, the uveoscleral outflow was decreased or completely absent.

Photoinduced buphthalmic avian eyes. 1. Continuous fluorescent light.

Numerous investigations of light induced avian buphthalmia using incandescent light have not defined an etiology. Chickens raised from 2 weeks of age in continuous fluorescent light developed shallow anterior chambers and buphthalmos within the first month of treatment. Chickens raised in continuous fluorescent light developed ocular enlargement similar to that reported in chickens raised in continuous incandescent light. Corneal diameters and axial globe lengths were an inconsistent means of documenting ocular enlargement. Iridocorneal angles were narrowed on scanning electron microscopy.