Short posterior ciliary artery anatomy in normal and acutely glaucomatous dogs.

Abstract

OBJECTIVE: To quantify the total number and luminal areas of the short posterior ciliary arteries (SPCA) surrounding the canine optic nerve at the level of the sclera/lamina cribrosa in normal dogs and compare this data to dogs with a history of acute (≤7 days) glaucoma. PROCEDURES: Twelve normal globes were obtained through Harlan Laboratories, the UW-Madison School of Veterinary Medicine necropsy service and via enucleation submissions to the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW). Ten globes with a history of acute glaucoma were obtained from submissions to the COPLOW. Optic nerves were cross-sectioned in 20 micron steps, and five distinct levels were identified: the retinal nerve fiber layer; the retinal pigmented epithelium and neural canal opening; the choroid/pre-lamina; the sclera/lamina cribrosa; and the retro-lamina. At the level of the sclera/lamina cribrosa, SPCA profiles were counted and the luminal area was measured using Cell Sens software. Normal and glaucomatous globes were compared using ANOVA. RESULTS: Statistically significant smaller luminal areas and fewer numbers of arteries were recorded between normal and glaucomatous globes. CONCLUSIONS: The glaucomatous eyes in this study have SPCA with decreased lumina, suggestive of a vascular pathology present at the early stages of clinical glaucoma. Smaller lumina may be a contributing factor to the ischemia, necrosis, and the eventual full-thickness retinal atrophy often seen in glaucomatous dogs.