FLUORESCEIN ANGIOGRAPHIC EVALUATION OF THE EFFECT OF LATANOPROST TREATMENT ON BLOOD-RETINAL BARRIER INTEGRITY - A REVIEW OF STUDIES CONDUCTED ON PSEUDOPHAKIC GLAUCOMA PATIENTS AND ON PHAKIC AND APHAKIC MONKEYS

Endogenous prostaglandins (PGs) have been claimed to play a role in th e development of cystoid macular edema (CME). Two fluorescein angiogra phic studies evaluating the effect of latanoprost, a new ocular hypote nsive PG analogue, on blood-retinal barrier integrity are, therefore, reviewed here. In the first study, six of eight unilaterally aphakic c ynomolgus monkeys were treated bilaterally once daily for six months w ith 0.035% latanoprost (seven times the clinically used oculohypotensi ve concentration). Two of the animals served as controls. Fluorescein angiography of the fundus after one, three and six months of treatment revealed no leakage of fluorescein in any of the 16 eyes. In another study, pseudophakic eyes of 16 glaucoma patients who received twice-da ily treatment with 0.006% latanoprost for four weeks were compared to eight patients treated with placebo. Biomicroscopic examination did no t reveal any signs of CME and only one placebo-treated eye revealed a slight perifoveal leakage of fluorescein. These studies suggest that t opically-applied latanoprost does not have a fluorescein angiographica lly detectable direct effect on the integrity of the blood-retinal bar rier system in phakic or aphakic monkey eyes or in pseudophakic human eyes. This does not rule out the occurrence of CME in eyes more suscep tible to CME, due to vitreous loss, posterior capsulotomy, or other po stoperative situations. Especially in those eyes a study with latanopr ost is proposed. Since, fluorescein angiography is a rather crude meth od of detecting abnormalities of the blood-retinal barriers, vitreous fluorometry in addition is suggested.