Abstract
Abstract: :
Purpose:Central contrast sensitivity (CS) improves in primary open-angle glaucoma (POAG) patients following initiation of ocular hypotensive therapy. We compared the CS recovery associated with a hypotensive drug versus a drug that purportedly has both ocular hypotensive and neuroprotective properties. Methods:We performed a double-masked, randomized study comparing the CS recovery associated with brimonidine and timolol therapy in subjects with newly diagnosed and previously untreated POAG. Sixteen patients were randomized to begin treatment with brimonidine 0.2% twice daily or timolol maleate 0.5% in Gelrite once daily in the morning. Blood pressure, heart rate, IOP, CS and visual field sensitivity were assessed at baseline and after 3 months of treatment. Results:The brimonidine-treated group demonstrated a significant increase in CS at 6 (p=0.021) and 12 (p=0.008) cpd for the right eye and 3 (p=0.021) and 12 (p=0.022) cpd for the left eye. In the timolol-treated group, a marginal improvement in CS was noted for the left eye at 12 cpd (p = 0.058). Both treatments significantly decreased IOP. Conclusion:In patients with early POAG, timolol and brimonidine provided for similar IOP reduction. Only brimonidine therapy resulted in improved visual function. The recovery of visual function following the initiation of brimonidine treatment appears to involve factors other than IOP reduction and may be a manifestation of this drug's direct or indirect action on retinal ganglion cells.
Keywords: 489 neuroprotection • 368 contrast sensitivity • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials