A LOCAL CHALLENGER OF OCULAR CALCIPHYLAXIS IN PATIENTS WITH CHRONIC-RENAL-FAILURE - A HYPOTHESIS

Background: It is generally accepted that the elevated calcium phospha te product in dialysis patients is associated with the development of extraskeletal calcification. There is, however, no clear association b etween the raised revels of calcium and phosphate ions and the degree of limboconjunctival calcification. This article focuses on the role o f tissue devitalisation in the development of ocular calcification. Me thods: Local injury of the outer eye can be visualised by the Lissamin e green staining test. We measured the pre- and postdialysis staining score in 38 dialysis patients. The differences between pre- and postdi alysis tear fluid secretion and tearfilm stability were also assessed, as was the degree of limboconjunctival calcification. Serum calcium a nd phosphate levels were measured in all patients. Results: In 14 of t he 38 patients, demonstrable tissue injury was present as a result of a recurrent decrease of tear secretion after each dialysis session. Th ere was a statistically significant association between the degree of limboconjunctival calcification and both the difference between the pr e- and postdialysis Lissamine green staining score and the total numbe r of haemodialysis sessions. Conclusion: Local factors, such as minor tissue injury of the limboconjunctival epithelium, referred to as ''lo cal challenger'', are more likely to determine the degree of ocular ca lcification in dialysis patients than are systemic factors. Tissue inj ury of the outer eye in these patients is the result of a chronic decr ease of tear fluid that occurs after each haemodialysis session.