To evaluate the changes of tear film and ocular surface in patients with chronic renal failure (CRF) undergoing hemodialysis.

In 50 eyes of 25 CRF patients undergoing hemodialysis and 30 eyes of 15 control subjects, tear break-up time (BUT), basal tear secretion (BST), corneal sensation, tear clearance rate (TCR), keratoepitheliopathy and impression cytology findings were compared. Correlation between the above parameters and local or systemic factors was analyzed.

Tear BUT, BST, TCR, conjunctival squamous metaplasia and conjunctival goblet cell density in the patient and control groups were 7.7±3.8 and 11.1±2.9 sec, 7.0±3.1 and 14.0±6.2 mm, 3.5±1.2 and 4.5±0.7, 1.5±0.6 and 0.3±0.5, 6.5±1.7 and 24.3±21.4 cells/mm². Osmolarity in serum and tears of the patient group was higher than that of the control group. Serum and tear osmolarity correlated with BST, corneal sensation and conjunctival goblet cell density, and serum creatine level correlated with conjunctival goblet cell density ( p <0.05).

Patients with CRF undergoing hemodialysis have an increased risk of dry eye and thus, serum and tear osmolarity in dry eye patients should be closely monitored.