Causes and outcomes of dogs presenting with hyphema to a referral hospital in Colorado: a retrospective analysis of 99 cases

Abstract

Objective: To investigate the causes of hyphema in dogs and identify factors associated with poor visual outcomes.

Animals studied: Ninety-nine dogs (120 eyes) that presented with hyphema.

Procedure: Medical records from the Colorado State University Veterinary Teaching Hospital between the years 2004-2015 were reviewed.

Results: Overall, 36.4% of dogs were diagnosed with hyphema from systemic causes, 32.9% due to local ocular disease, 26.1% due to trauma, and 4.5% due to idiopathic causes. Regardless of cause, 55.4% of eyes were blind at their last recheck, but the percentage of eyes that lost vision ranged from 11.1 to 100%, depending on the cause. Causes of hyphema with poor outcomes were ocular neoplasia, chronic uveitis, and trauma. Enucleation was performed or recommended in 36 eyes (39.5%), and 27 eyes (31.4%) were diagnosed with glaucoma. Initial exam findings associated with a significantly increased risk of blindness were absent consensual PLR (odds ratio (OR) = 28.6), absent dazzle (OR = 19.4), elevated intraocular pressure (IOP) (OR = 9.1), presence of a retinal detachment (OR = 7.6), unilateral hyphema (OR = 5.8), and complete hyphema (OR = 3.9). Factors associated with a significantly increased risk of glaucoma included hyphema present for 8-30 days (OR > 6), absent consensual PLR (OR = 6.4), absent dazzle (OR = 5.3), and the presence of a retinal detachment at the final evaluation (OR = 5.8).

Conclusion: Prognosis for vision is highly dependent on the cause of hyphema and initial exam findings. Poor prognostic factors on presentation include absent dazzle, absent consensual PLR, elevated IOP, unilateral hyphema, and complete hyphema.

Keywords: canine; causes; glaucoma; hyphema; prognosis.