Pharmacological management of night vision disturbances after refractive surgery: Results of a randomized clinical trial

PURPOSE: To evaluate the efficacy and safety of diluted aceclidine eyedrops in reducing night vision disturbances after refractive surgery. SETTING: Department of Ophthalmology, Istituto Clinico Humanitas, Rozzano-Milano, Italy. METHODS: This double-masked randomized clinical trial included 30 patients (60 eyes) with chronic night vision disturbance after refractive surgery. Patients were randomly allocated to receive (1) placebo, (2) aceclidine 0.016%, or (3) aceclidine 0.032%. Drugs were administered once or twice daily. Anterior segment, haze, uncorrected visual acuity, best corrected visual acuity, intraocular pressure, corneal maps, and scotopic pupil size were determined at baseline and at follow-up examinations (15 and 30 days after inclusion). Halos and double vision 4-step scales were built to determine subjective grading of night vision disturbance, and the root mean square (RMS) was calculated to determine objective changes in night vision disturbance. RESULTS: The effect of diluted aceclidine started about 15 minutes after instillation and lasted for about 5 hours. No difference between the 2 dilutions could be found. Thirty-nine of 40 treated eyes showed a reduction in night vision disturbance. The mean reduction in halos and double vision grading was 1.42 ± 0.5 (SD) and 1.14 ± 0.4, respectively. A mean decrease in pupil size of 2.5 mm was measured. Thirty minutes after the instillation of diluted aceclidine, the topography-derived wavefront error showed a statistically significant reduction in RMS values (total, spherical, astigmatic, coma, and higher order), which was maintained for 5 hours. A transitory conjunctival hyperemia was the only side effect reported. CONCLUSION: Diluted aceclidine seemed to be an effective and safe treatment for night vision disturbance following refractive surgery.