Is there a correlation between the severity of diabetic retinopathy and keratoconjunctivitis sicca?

Patients with diabetic retinopathy (DRP) seldom report symptoms of ocular surface irritation, but evaluations of dryness are pathologic. This study was designed to evaluate the correlation between the severity of DRP and dry eyes.

We included 144 eyes of 72 patients. Severity of retinopathy was graded according to the Early Treatment Diabetic Retinopathy Study. The examinations for dry eyes included Schirmer's test, break-up time, lipid layer thickness, fluorescein and rose bengal staining of the cornea, impression cytology, and a questionnaire. A sicca severity score was calculated using a point system of the results of these tests. Patients were divided into three groups: postpanretinal laser coagulation (PPL), postcentral laser coagulation (PCL), and those with no laser treatment (0-L). For statistics, we used the correlation coefficient to determine relationships and the unpaired Student t test for statistical difference.

The correlation (c) of keratoconjunctivitis sicca (KCS) and DRP after laser treatment was c = 0.24 and after central laser treatment was c = 0.22; the correlation without laser treatment was 0.54. The best correlation is 1 or -1, the worst was 0. The score of those patients with mild to moderate retinopathy was compared to that of patients with severe to proliferative disease. There was a significant statistical difference in the sicca severity score between both groups, (p < 0.006. Student t test).

KCS represents another manifestation of diabetes mellitus and its severity--measured by a many-membered score--correlates with the severity of the DRP.