Comparison Between Retinoscopy and Autorefractometry In Determining Refractive Error Under Cycloplegia

Abstract

ABSTRACT: AIM: To compare the retinoscopy and autorefractometry in determining refractive error under cycloplegia. BACKGROUND: Visual acuity is defined as the measure of the ability of the eye to distinguish the details of the object at a certain distance. It can be measured by various methods, of which most commonly used method include Subjective refraction, Autorefraction and Retinoscopy under cycloplegia. MATERIALS AND METHODS: This is a prospective study conducted on 500 patients after obtaining clearance from the ethical committee and informed consent from the patients. The patients who met the inclusion criteria were subjected to autorefractomery, retinoscopy and subjective refraction under cycloplegia. The parameters included measuring spherical power, cylindrical power and axis of the cylinder by different methods and the data obtained is recorded on a data sheet. The results were then compared and statistical analysis was performed using standard statistical software. RESULTS: It was found that 52.8 % were females and 47.2% were males and the mean age group was found to be18.77±6.56 in males and 18.96±6.17 years in females. In both the genders, the age group which was most predominantly affected was 11-20 years. In case of type of refractive errors, Hypermetropia and hypermetropic astigmatism (53.8%) was found to be more common than myopia and myopic astigmatism (34.4%). Refraction by Autorefractometry overestimated the axis of the cylindrical power by 23.36±51.57 degrees and underestimation of spherical equivalent (S.E.) by -0.5±0.49 and this difference was found to be statistically significant. It was also observed that retinoscopy overestimated the spherical power by -0.05±0.46D, cylindrical power by -0.06±0.47D, axis of cylinder 31.35±53.65 degrees and spherical equivalent (S.E.) by -0.08±0.49 and was statistically significant. CONCLUSION: The study revealed that the retinoscopy is a superior method for assesment of refractive errors in younger age group whereas autorefractomery was better in older age group. Retinoscopy is a better method for myopia irrespective of age group.