Prior topical anesthesia reduces time to full cycloplegia in Chinese

PURPOSE: To investigate the effect of prior anesthesia on the time to full cycloplegia in young Chinese subjects. METHODS: The amplitude of accommodation was monitored over a 50-minute interval after the application of 1% cyclopentolate hydrochloride with a pretreatment of 0.4% benoxinate (oxybuprocaine) or 0.9% saline solution (control). Using a nonlinear mathematical model, the rate of accommodative loss (k) and the time required for 95% of total cycloplegia (T95%) were determined. RESULTS: Statistical analysis revealed a significantly faster rate of accommodative loss (P < .0001) after prior anesthesia (0.129 +/- 0.05) compared with the controls (0.103 +/- 0.04). T95% was noted at 26.43 +/- 10.22 minutes after prior anesthesia, which was significantly shorter (P < .0001) than that after the saline treatment (35.28 +/- 16.51 minutes). CONCLUSIONS: Prior application of topical anesthetic can shorten the time to full cycloplegia for people, such as the Chinese, with dark irides.