Histological effects in the iris after 3 months of latanoprost therapy: the Mainz 1 study

To determine whether 3 months of topical latanoprost treatment caused proliferative or degenerative effects on the peripheral iris of patients with glaucoma.

Seventeen patients requiring filtering surgery for primary open-angle glaucoma or pseudoexfoliation glaucoma were randomized to receive topical latanoprost for 3 months (n = 8) or alternative medication (n = 9) before surgery. A trabeculectomy and a peripheral iridectomy specimen was obtained from each patient during surgery. The tissue was subjected to histological and immunohistochemical evaluation using 2 cell cycle markers: proliferating cell nuclear antigen and nuclear-associated protein (Ki-67).

No degenerative or pathological changes were seen in the latanoprost-treated irides, including the one specimen in this series in which there was an eye color change. Proliferating cell nuclear antigen and nuclear-associated protein markers were negative for changes in all the test specimens.

Short-term treatment with latanoprost does not produce morphological changes or cellular proliferation changes in the iris.