Levels of prostaglandin E2 and leukotriene B4 in tears of vernal conjunctivitis patients during a therapeutic trial with indomethacin.

A therapeutic trial of 1% indomethacin (Indoptic) eye drops was carried out in 21 children. Looking for possible mediators of inflammation in vernal conjunctivitis, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4 levels in the tears of 9 patients were measured and the effect of the treatment on them examined. A control group of 10 unaffected children was added. Out of 42 eyes in which indomethacin treatment was instilled, only 17 remained in treatment through a 6-week follow-up period. In a few of them a moderate improvement was obtained. The mean level of PGE2 in the patients before treatment was found to be slightly lower than that in the control group, and it dropped even lower during treatment. The average LTB4 level found in patients before treatment was significantly higher than the control group; it decreased somewhat following treatment, but not significantly. This is the first report of elevated LTB4 levels in vernal conjunctivitis, previously not recorded in the literature, it points to the possible role of LTB4 in the pathogenesis of the disease. A constant relationship was observed between low PGE2 levels and high LTB4 content in the patients' tears during highly inflamed states of the eye. We conclude that: (a) indomethacin did not prove to be a highly effective topical treatment for vernal conjunctivitis; (b) PGE2 does not seem to be a dominant mediator of inflammation in this disease; and (c) LTB4, on the other hand, apparently has a role in the mechanism of inflammation of the disease, thus raising hopes for future addition to therapy.