Ocular Surface Disorders in Patients with Chronic Renal Failure

Aim of the Work: To study conjunctival epithelial changes in patients with chronic renal failure (CRF), to correlate the results with the degree of corneo-conjunctival calcium deposits and to determine whether precipitation of calcium salts predispose to ocular surface changes. Methods: Impression cytology from 30 CRF patients (60 eyes) on regular haemodialysis and 20 healthy control subjects were included in the study. Specimens were obtained from temporal bulbar conjunctiva using cellulose acetate filter paper to determine the degree of conjunctival metaplasia. Impression cytology samples were graded from 0-6 according to Tseng classification. Corneo-conjunctival calcification was graded from 0-5 according to system proposed by Porter and Crombie. Results: In the study group, 3 eyes (5%) had grade I squamous metaplasia, 29 eyes (48%) grade II, 21 eyes (35%) grade III, 4 eyes (7%) grade IV, 3 eyes (5%) gradeV. The difference between the patients and the control group in impression cytology was statistically significant (p 0.001). The severity of conjunctival changes was related to the duration of renal failure, 22% of patients with CRF 10 years showed grade II-III cytological changes whereas the same grade of changes was present in 40% of patients with CRF 10 years. Calcium deposits were more frequent and extensive in CRF patients than control group (p=0.02). There was no correlation between corneo-conjunctival calcification grade and impression cytology grades. Abnormal rosebengal staining and tear film break-up time (BUT) in patients group. The grade of squamous metaplasia was correlated with abnormal rosebengal (p 0.00l). Conclusion: The ocular surface of CRF patients differ significantly from those of normal individuals. The severity of conjunctival changes are not related to the presence or extent of calcium deposits.