Prostaglandin Analogs and Blood-Aqueous Barrier Integrity: A Flare Cell Meter Study

Purpose: To study, with an objective method, inflammation of the anterior segment of the glaucomatous eye after treatment with latanoprost, travoprost and bimatoprost. Materials and Methods: Sixty patients with chronic open-angle glaucoma aged between 38 and 76 years (mean 64.0 ± 12.2) were randomly assigned to latanoprost 0.005, travoprost 0.004 and bimatoprost 0.03%. The study period lasted 6 months. Intraocular pressure (IOP) was measured every 2 weeks. We studied the intraocular inflammation before and after 3 and 6 months of therapy with an instrument composed of a He-Ne laser beam system, a photomultiplier mounted on a slitlamp microscope and a computer. This flare meter allows objective determination of the flare and the number of cells in the aqueous of the anterior chamber. Results: At the baseline, IOP was 26.4 ± 3.6 mm Hg. After 3 months of treatment, mean IOP in the latanoprost group was 17.9 ± 0.3 mm Hg (p < 0.001) with a mean cellularity of 12.638 ± 3.284 photons/ms (p < 0.001). The travoprost group had an IOP of 17.2 ± 0.3 mm Hg (p < 0.001) with a cellularity of 9.719 ± 1.927 photons/ms (0.001). Finally, IOP in the bimatoprost group was 17.6 ± 0.5 mm Hg (p < 0.001) with a cellularity of 6.138 ± 1.475 photons/ms (p < 0.032). After 6 months of treatment, IOP in the latanoprost group was 18.1 ± 0.3 (p < 0.001), in the travoprost group 17.3 ± 0.3 (p < 0.001) and in the bimatoprost group 17.7 ± 0.5 mm Hg (p < 0.001), whereas cellularity was 11.838 ± 3.218 (p < 0.001), 8.950 ± 3.692 (p < 0.001) and 7.617 ± 2.603 photons/ms (p < 0.001), respectively. After 3 months, the travoprost (p < 0.013) and the bimatoprost groups (p < 0.001) had less flare compared with the latanoprost group and this remained so even at 6 months. When we compared the travoprost group with the bimatoprost group, we found significantly less flare at 3 months in the bimatoprost group (p < 0.001) but not at 6 months (p < 0.246). Conclusions: The flare meter analysis shows that the eyes treated with bimatoprost and travoprost have a less significantly broken blood-aqueous barrier and their anterior chamber is also significantly less inflamed.