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

Abstract

Purpose: This study compares retinoscopy in infants using a near noncycloplegic technique, cycloplegia with tropicamide 1%, and cycloplegia with cyclopentolate 1%. The study sample included 29 healthy, nonstrabismic infants 4 to 7 months of age (mean 5.71 months).

Methods: Each study subject was examined at two separate visits an average of 2 weeks apart (mean [+/-SD] 14 +/- 9 days). The examiner completed a case history, iris color grading, confrontation tests, and noncycloplegic near retinoscopy in a dark room and then 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 min after the first drops were instilled. The bottles were masked, and the drop administered at the first visit was randomly assigned.

Results: On a scale of 0 to 4.9, the median iris grade was 4.0, which corresponds to a brown or darkly pigmented iris. All reported retinoscopy results are for the horizontal meridian of the right eye. The mean refractive error using noncycloplegic 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 cyclopentolate. 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 cycloplegic 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 with either agent, although one infant temporarily developed redder than normal cheeks after instillation of cyclopentolate.

Conclusion: Our results suggest that tropicamide is as effective as cyclopentolate for the measurement of refractive error in most healthy, nonstrabismic infants.