Postoperative glaucoma in the Labrador Retriever: incidence, risk factors, and visual outcome following routine phacoemulsification

Abstract

To evaluate the incidence and risk factors associated with development of postoperative glaucoma in the Labrador Retriever following routine phacoemulsification. Medical records from Labradors and a randomly selected population of non-Labradors were retrospectively evaluated. Signalment, diabetic status, cataract stage, gonioscopic findings, presence of preoperative lens-induced uveitis, development of postoperative hypertension (POH), postoperative glaucoma and postoperative visual status were recorded for each patient. Survival curves were developed using the Cox proportional hazards model. Forty-two Labradors (66 eyes) and 199 non-Labradors (314 eyes) were included. The incidence of POH was significantly higher in Labradors (33%) than non-Labradors (18%). Labradors were at significantly increased risk of postoperative glaucoma and blindness compared to non-Labradors. Estimated probabilities of postoperative glaucoma in Labradors were 23%, 25%, 30% and 35% at weeks 4, 26, 52 and 104, respectively, compared with 5%, 6%, 7% and 9% at weeks 4, 26, 52 and 104, respectively, in non-Labradors. Estimated probabilities of postoperative blindness in Labradors were 5%, 9%, 15% and 27% at weeks 4, 26, 52 and 104, respectively, compared with 2%, 3%, 5% and 10% at weeks 4, 26, 52 and 104, respectively, in non-Labradors. Risk factors for the development of glaucoma in Labradors included increasing age and development of POH. No statistically significant risk factors for the development of glaucoma were identified in non-Labradors. Labradors are at increased risk of glaucoma and blindness following phacoemulsification compared with non-Labradors. POH and increasing age represent risk factors for the development of postoperative glaucoma in Labradors.