Research focus: Brachycephaly, Epidemiology

The below abstract was presented at the 2021 American College of Veterinary Ophthalmologists' conference in Indianapolis. It is a 2-centre study, with cases from the RVC and eye clinic in Berlin.

PRIMARY GLAUCOMA IN THE FRENCH BULLDOG (UM Dietrich 1; SL Priestnall 2; E Ludwig 3 and I Allgoewer 4) 1 The London Cat Clinic, London, U.K.; 2 The Royal Veterinary College, U.K.; 3 Fachpraxis fuer Tierpathologie, Munich, Germany; 4 Animal Eye Practice, Berlin, Germany

Purpose.

To describe ocular, gonioscopic and histopathologic findings in a series of French Bulldogs with glaucoma.

Methods.

Dogs underwent a complete ocular examination including slit lamp biomicroscopy, rebound tonometry and gonioscopy in the affected and/or opposite eye if possible. Histopathology was performed in enucleated, blind eyes.

Results.

A total of 27 dogs (31 eyes) with 14 female and 13 male dogs were included. Mean age at onset of glaucoma was 7.12 years. The right eye was affected in 11, the left eye in 12 and both eyes in 4 dogs. All eyes were buphthalmic and blind with variable amount of corneal oedema. Mean IOP at presentation was 61 mmHg. Gonioscopy performed in 17/27 dogs revealed goniodysgenesis characterized by a narrow/closed angle, sheets, flow holes and thickened trabeculae. Histopathological examination of 23 eyes showed a closed or collapsed iridocorneal angle (21/23) with arborized termination of Descemet’s membrane in 11/23. Pigment invasion of the ICA, uvea, and sclera with melanomacrophages as predominant cell type was found in 21/23. Iridociliary cysts were detected in 10/23 eyes and neutrophilic inflammation with PIFM formation in 11/23 eyes. All 23 eyes had various degrees of retinal degeneration, optic nerve atrophy and cupping.

Conclusion.

French Bulldogs with glaucoma were found to have goniodysgenesis, with narrow or closed angles and varying degrees of pectinate ligament dysplasia suggestive of primary glaucoma. IOP spikes predominantly occurred in middle-aged to older dogs and appeared to be associated with progressive pigment invasion of the iridocorneal angle, uvea and sclera in most of dogs