Comparative analysis of cycloplegic and non-cycloplegic refraction techniques for assessing refractive error in adults: a population-based study.

Abstract

Clinical relevance: Accurate determination of refractive error is essential for optimal vision correction. However, the necessity of performing cyclo-refraction in adults remains a subject of ongoing ‎debate.‎.

Background: This study aimed to assess the agreement between cycloplegic retinoscopy, non-cycloplegic objective refraction methods (autorefraction and retinoscopy) and subjective refraction, in adults aged 40 to 64 years.

Methods: In this population-based cross-sectional study, ‎a multi-stage sampling technique was employed to select the sample from this population. Measurements of uncorrected distance visual acuity, followed by autorefraction, retinoscopy, subjective refraction, and cycloplegic refraction (using cyclopentolate 1%) were performed for all participants. Cycloplegic refraction obtained through retinoscopy was established as the gold standard.

Results: The spherical equivalent (SE) obtained from cycloplegic retinoscopy, non-cycloplegic retinoscopy, non-cycloplegic autorefraction, and subjective refraction were + 0.07 ± 1.07, -0.21 ± 1.03, -0.28 ± 1.09, and -0.24 ± 0.99 D, respectively (p < 0.001). Cycloplegia resulted in a hyperopic shift in the spherical component (p < 0.001‎), with a reduction in magnitude as age increased. Subjective refraction produced the smallest absolute cylinder values (least negative) compared to all other methods (p < 0.001). In the age group of 40 to 44 years, the prevalence of hyperopia (SE ≥  +0.50 D) detected through cycloplegic retinoscopy was 42%, while the prevalence determined by non-cycloplegic autorefraction, subjective refraction, and non-cycloplegic retinoscopy was 4.9%, 2.2%, and 7.2%, respectively (p < 0.001). The prevalence of myopia (SE ≤  -0.50 D) within the same age group was 44.8%, 41.4%, 33.4%, and 34.9%, respectively (p < 0.001). The disparity in the prevalence of refractive errors identified through various refractive methods diminished progressively with advancing age.

Conclusion: Cycloplegic refraction is essential for assessing refractive errors, especially in individuals younger than 50 years. Furthermore, subjective refraction in older adults is influenced by numerous confounding variables and should be approached with caution.