Retrospective study of the prevalence of keratoconjunctivitis sicca in diabetic and nondiabetic dogs after phacoemulsification

ObjectiveTo evaluate the prevalence of keratoconjunctivitis sicca (KCS) in diabetic and nondiabetic dogs following phacoemulsification. ProceduresMedical records were reviewed for signalment, body weight, diabetes status, and STT at the preoperative and all postoperative examinations. A clinical diagnosis of KCS was defined as a STT <15mm/min with compatible clinical signs. Schirmer tear test values and the prevalence of KCS based on STT <15mm/min were evaluated at 2-4, 5-8, 9-14, 15-20, and 41-52weeks postoperatively. Size of dog (large, >10kg; small, 10kg) and STT ranges (<15mm/min, 15-22mm/min and >22mm/min) were categorized for analysis of effect of body weight and STT on prevalence of KCS. ResultsOne hundred and seventeen nondiabetic (198 eyes) and 118 diabetic dogs (228 eyes) were evaluated. KCS was diagnosed in nearly twice as many diabetics as nondiabetics (27.4% vs. 15.4%) within 2weeks postoperatively (P=0.0088). Percentage of eyes with KCS among all dogs decreased over time and did not differ significantly after the first postoperative visit. Diabetic small dogs were 1.7 times more likely to have KCS than nondiabetic small dogs (P=0.0052). Preoperative STT was significantly associated with likelihood of postoperative KCS among large (P<0.0001), but not small dogs (P=0.0781). Among large dogs, eyes with STTs between 15 and 22mm/min were approximately 3 times more likely to be diagnosed with KCS after surgery than those with STT >22mm/min. ConclusionThe greatest risk for KCS for all dogs is during the first 2weeks postoperatively. Populations at greatest risk for postoperative KCS are small dogs, small diabetic dogs, and large dogs with preoperative STT 22.