Primary Glaucoma in a Litter of Lop Rabbits

OBJECTIVE: To describe pectinate ligament dysplasia (PLD) and primary glaucoma in a litter of adult Lop rabbits. ANIMALS STUDIED: A litter of six adult Lop rabbits, three males and three females. PROCEDURES: The animals were surrendered to the shelter. One male appeared functionally blind with bilateral severe corneal edema, and a second male showed severe corneal edema in one eye. Based on these observations, detailed ophthalmic examinations were performed on all six animals. Digital gonioscopy and fundoscopy were performed on three females. Because the two affected males were euthanized for humane reasons, and one female arrested during general anesthesia for ovariohysterectomy, six eyes of three animals were examined by routine histopathology. RESULTS: Clinical examination revealed that the three eyes with diffuse corneal edema were affected by chronic glaucoma with intraocular pressure (IOP) elevation, buphthalmos, and severe secondary keratitis. Gonioscopy performed in the normal-appearing, normotensive female rabbits showed partial or complete closure of the iridocorneal angle (ICA). Histopathologic evaluation revealed PLD in the glaucomatous and clinically normal eyes. In the glaucomatous eyes, uvea-like tissue crossed the ICA with an indistinct to absent ciliary cleft, pectinate ligament, and scleral venous plexus. Inner-to full-thickness retinal atrophy was consistent with chronic glaucoma. In the non-glaucomatous eyes, multiple segments of uveal tissue crossed the ICA, with the trabecular meshwork partially collapsed. CONCLUSIONS: This is the first formal description of PLD and primary glaucoma in a litter of Lop rabbits.