Objective: To evaluate the relationship between corneoconjunctival calcification and conjunctival squamous metaplasia in patients with chronic renal failure (CRP).
Study design: We studied impression cytology in 45 CRF patients on regular hemodialysis and 30 age- and sex-matched controls. Specimens were obtainedfrom the temporal bulbar conjunctiva using cellulose acetate filter paper. The samples were fixed in a mixture of 70% ethyl alcohol, 37% formaldehyde and glacial acetic acid and then stained with a combination of periodic acid- Schiff and Gill's modified Papanicolaou stain and graded by a masked observer. Corneoconjunctival calcification was graded by the Porter-Crombie classification.
Results: Of 45 study patients, 4 (9%) disclosed grade 0, 23 (51%) grade 1, 14 (31%) grade 2 and 4 grade 3 (9%) impression cytology changes. There was a statistically significant difference between the patient and control groups (p < 0.001). Calcium deposits were more frequent and extensive in CRF patients than in controls (p = 0.01). There was no correlation between impression cytology and calcium deposit grades (p = 0.128). However the presence of conjunctival inflammation correlated with the existence of extensive squamous metaplasia (p < 0.001).
Conclusion: The severity of conjunctival changes in CRF patients on regular hemodialysis are not related to calcium deposition but to acute conjunctival inflammation.