Timolol transitory manifestations of dry eyes in long term treatment

In 64 patients treated with timolol eye drops (0.25% and 0.50%) seven patients developed transitory sensation of dry eyes. Two of these subjects also had xerostomia. Conjunctival and corneal defects were disclosed simultaneously with rose bengal staining. Morphologically, some of these lesions might have the same appearance as of the early stages of kerato-conjunctivitis sicca. A reduction of Schirmer test and break-up time was noted. The duration of symptoms ranged from 3 to 13 days. The mean time of treatment at the début of symptoms was 30 weeks (range 23--43 weeks). A pathogenesis of these seemingly harmless findings is at the present obscure. In none of our patients was the treatment discontinued and the symptoms did not reappear.