2.5% v 10% Phenylephrine in Maintaining Mydriasis During Cataract Surgery

A 10% viscous solution of phenylephrine hydrochloride was more effective than a 2.5% aqueous solution of phenylephrine hydrochloride in maintaining mydriasis during extracapsular cataract surgery. The pupil area after nucleus expression was 57% larger with the stronger phenylephrine concentration. The difference in pupil area was greater in darkly pigmented irides (114%) than in moderately pigmented (70%) or lightly pigmented irides (12%). Mean BP elevations following phenylephrine administration were not higher in the group receiving the 10% solution than in the group receiving the 2.5% solution. In darkly pigmented irides, a 10% viscous solution of phenylephrine hydrochloride is more effective than a 2.5% concentration in maintaining mydriasis during cataract surgery.