To investigate the effects of homatropine eye drops before cataract surgery to prevent intraoperative floppy iris syndrome (IFIS) in patients treated with alpha blockers.

The medical records of 98 eyes from 68 patients taking alpha blockers who underwent cataract surgery were retrospectively reviewed and divided into three groups: patients with preoperative instillation of homatropine (group 1), patients with preoperative instillation of atropine (group 2), and patients without preoperative eye drops (group 3) for three days. Age, sex, underlying disease, type of alpha blocker, preoperative and postoperative pupil size, parameters of phacoemulsification, surgical complication, and the degree of IFIS of patients were measured to compare among the three groups.

No significant differences were found in age and underlying diseases. Significant differences were found in the preoperative and postoperative pupil size, cumulative dissipated energy, and the incidence rate of iris prolapse through the incision sites among the three groups, but no significant difference was detected in other findings, or with regard to intraoperative or postoperative complications. In addition, the preoperative pupil size and preoperative instillation of 1% atropine were significant factors for decreasing the degree of IFIS.

Preoperative instillation of homatropine as well as atropine before cataract surgery minimized the degree of IFIS in patients taking alpha blockers. In addition, the pupil size recovered more rapidly after surgery in the homatropine group than in the atropine group.