A preliminary risk-benefit assessment of latanoprost and unoprostone in open-angle glaucoma and ocular hypertension.

Latanoprost and unoprostone (isopropyl unoprostone) represent the first commercially available prostaglandin analogues to be used for the treatment of glaucoma. Both compounds reduce intraocular pressure by enhancing uveoscleral outflow. Latanoprost, when used once daily in the evening, produces a greater reduction in pressure than timolol. Latanoprost produces mild conjunctival hyperaemia compared with timolol in some patients. Darkening of the irides has been reported, especially in green-brown, yellow-brown and blue/grey-brown irides. Hypertrichosis and hyperpigmentation of the eyelashes have also been demonstrated. Although latanoprost has not been proven to cause uveitis or cystoid macular oedema, case reports of an association exist. Latanoprost does not produce systemic adverse effects nor does it alter routine blood analyses. Unoprostone, when given twice daily, produces less of a reduction in intraocular pressure than timolol or latanoprost. Three times daily use may be required to approach the effectiveness of timolol. Unoprostone may have a similar adverse effect profile to latanoprost, but may to cause more corneal epithelial problems. Unoprostone is also not known to cause systemic adverse effects. Both agents are welcome additions to the treatment of glaucoma. However, additional studies and more experience are needed with each agents.