[Treatment of the dry eye with vitamin A acid--an impression cytology controlled study]

To test the efficacy of topically applied tretinoin eyedrops (0.01%, twice daily, in a solution of peanut oil) in the treatment of squamous metaplasia of the conjunctival epithelium associated with dry-eye, the authors evaluated the impression cytology (IPC) of a total of 31 patients. The cytological findings were classified into four different stages with an overall range from 0 to 9 points. The average period of treatment was 12 weeks. The patients were classified into three groups: (1) Those with mucin deficiency (Mucin less than - greater than; n = 19), (2) those with Keratoconjunctivitis sicca (KSC; n = 6), and (3) a control group in whom pure peanut oil was used (n = 6). The IPC showed a considerable improvement of squamous metaplasia in the mucin less than - greater than group, by an average of 4.3 points (from 6.2 points before treatment to 1.9 points). No changes were seen in the IPC of the KCS patients or the control group. The results of this study show a good effect of tretinoin eyedrops in patients with a significant decrease in or loss of goblet cells seen in the IPC, a decreased break-up time and with no severe aqueous deficiency of tear film. These patients seem to have a "primary" mucin deficiency induced by the decrease in or loss of goblet cells. There is no indication for tretinoin treatment in patients with aqueous deficiency involving major or accessory lacrimal glands. The results of other previous and recent studies on tretinoin treatment are discussed.