A Correlation Between Latanoprost-induced Conjunctival Hyperemia and Intraocular Pressure-lowering Effect

Purpose: To study any correlation between a short-term change in conjunctival hyperemia severity and the intraocular pressure-lowering effect induced by latanoprost. Patients and Methods: A 114 patients (56 females and 58 males) with open-angle glaucoma or ocular hypertension were studied. Their mean age was 60.9 +/- 15.0 years (range, 25 to 87 y). The primary outcome measure was the change in conjunctival hyperemia grade at 2 days and the change in intraocular pressure at 6 months after the start of latanoprost administration. Results: Mean intraocular pressure before and 6 months after latanoprost administration was 22.5 +/- 3.8 mm Hg and 16.5 +/- 2.9 mm Hg, respectively (P< 0.0001). Mean conjunctival hyperemia grade before and 2 days after the administration of latanoprost was 0.32 +/- 0.58 and 1.74 +/- 1.11, respectively (P< 0.0001). Mean change in intraocular pressure was - 1.7 +/- 1.2 mm Hg (- 6.6 +/- 5.1%) in eyes with no hyperemia grade change, - 5.2 +/- 2.2 mm Hg (- 21.5 +/- 7.6%) in eyes with a hyperemia grade change of 1, - 7.3 +/- 2.8 mm Hg (- 32.0 +/- 8.9%) in eyes with a change of 2, and - 10.8 +/- 2.7 mm Hg (- 46.1 +/- 8.6%) in eyes with a change of 3 or 4 (P< 0.0001). There was a significant correlation between intraocular pressure change and hyperemia grade change (intraocular pressure: r= 0.535, P= 0.0001; percent of intraocular pressure: r= 0.755, P= 0.0001). Conclusion: A statistically significant correlation was found between a change in intraocular pressure and conjunctival hyperemia severity induced by latanoprost.