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.