Retinoscopy in infants using a near noncycloplegic technique, cycloplegia with tropicamide 1%, and cycloplegia with cyclopentolate 1%

Purpose. This study compares retinoscopy in infants using a near noncyclopl egic technique, cycloplegia with tropicamide 1%, and cycloplegia with cyclo pentolate 1%. The study sample included 29 healthy, nonstrabismic infants 4 to 7 months of age (mean 5.71 months). Methods. Each study subject was exa mined at two separate visits an average of 2 weeks apart (mean [+/-SD] 14 /- 9 days). The examiner completed a case history, iris color grading, conf rontation tests, and noncycloplegic near retinoscopy in a dark room and the n instilled a drop of topical anesthetic in each eye followed by 2 drops of cycloplegic agent separated by 5 min. Retinoscopy was performed 25 to 30 m in after the first drops were instilled. The bottles were masked, and the d rop administered at the first visit was randomly assigned. Results. On a sc ale of 0 to 4.9, the median iris grade was 4.0, which corresponds to a brow n or darkly pigmented iris. All reported retinoscopy results are for the ho rizontal meridian of the right eye. The mean refractive error using noncycl oplegic near retinoscopy was +0.94 D (+/-1.19 D). The mean refractive error was +1.81 D (+/-1.19 D) with tropicamide and +1.88 D (+/-1.45 D) with cycl opentolate. There was no statistically or clinically significant difference between the two cycloplegic measurements using different diagnostic agents (t = -0.46, p = 0.65). The mean difference between noncycloplegic and cycl oplegic retinoscopy was 0.89 D (=/-0.66 D) with tropicamide (t = -6.57, p < 0.0001) and 1.04 D (+/-0.94 D) with cyclopentolate (t = -5.38, p < 0.0001; all two-sided paired t-tests). There were no serious adverse reactions wit h either agent, although one infant temporarily developed redder than norma l cheeks after instillation of cyclopentolate. Conclusion. Our results sugg est that tropicamide is as effective as cyclopentolate for the measurement of refractive error in most healthy, nonstrabismic infants.