Cycloplegia improves the inter-optometrist repeatability of subjective refraction

Abstract

Background: Since accommodation may be a source of error affecting the inter-optometrist repeatability of subjective refraction, this study investigated whether the use of cycloplegia could improve this repeatability. Methods: A randomized cross-sectional study was conducted on 42 young hyperopes (18.2 ± 7.7 years, range 6 to 31 years). Subjective refraction was performed by two different optometrists in two measurement sessions: one day without cycloplegia and, on a different day, with cycloplegia, in random order. The inter-optometrist repeatability of all refractive variables (M, J0, and J45) was analyzed, selecting one eye randomly, in terms of the 95% confidence interval of repeatability (r). Results: No statistically significant differences were found between the optometrists for any refractive variable, both with and without cycloplegia (p ≥ 0.05). Furthermore, no correlation was found between participants’ age and the refractive differences between optometrists under both cycloplegic conditions (p ≥ 0.05). However, the use of cycloplegia improved the inter-optometrist repeatability of M (r = 0.37 D) compared to the non-cycloplegic measurements (r = 0.62 D). Conclusions: These results suggest that accommodation in young hyperopes is likely a primary source of error that could explain the discrepancies in subjective refraction between optometrists.