Canine corneal endothelial dystrophy: a retrospective analysis of 99 dogs (1991-2014)

Abstract

Purpose : Corneal endothelial dystrophy (CED) is a canine disease characterized by primary degeneration of the corneal endothelium, corneal edema, and subsequent vision impairment. Canine CED represents a spontaneous model for Fuchs’ endothelial corneal dystrophy (FECD), warranting further characterization of this disease in canine patients. Thus, the purpose of this study was to retrospectively evaluate case details, outcomes, and risk factors for dogs with CED when compared to a control population.

Methods : Medical records of 99 dogs diagnosed with CED at the University of California-Davis Veterinary Medical Teaching Hospital were reviewed and compared to the general hospital population (n=458,680) during the study period (1991-2014). Retrieved data included signalment, exam findings, diagnoses, treatments, and outcomes associated with CED. Exact Pearson’s chi squared test or exact Kruskal-Wallis test were used to statistically compare parameters between groups. A Kaplan-Meier (KM) curve was generated to demonstrate the progression of corneal edema in affected eyes across visits.

Results : Dogs diagnosed with CED during the study period represented 36 breeds in addition to mixed breeds. Ten breeds were significantly overrepresented in comparison to the reference population (Table 1), several of which had not previously been reported to have higher incidences of CED. Dogs over 11 years of age were significantly overrepresented (P<0.001), and intact dogs were underrepresented (P<0.05) in the CED population. Surgical interventions included superficial keratectomy and conjunctival advancement hood flap (n=7), enucleation (n=3), and corneal transplant (n=1). A KM curve including patients with follow up visits estimated the median time to progression of corneal edema to be 687 days in dogs without surgical intervention.

Conclusions : Canine CED is a progressive disease in which several breeds are predisposed, suggesting an underlying genetic component. Like FECD, CED typically presents in older patients. While human patients with FECD experience gradual disease progression over decades, we have shown that many dogs with CED progress in months to years without surgical intervention, making dogs with CED a useful model for the investigation of novel therapies.

This is a 2020 ARVO Annual Meeting abstract.

 

Table 1. Distribution of CED diagnosed in significantly overrepresented breeds. A Pearson’s exact chi squared test was performed. *P < 0.05. O:E=observed:expected.