Accuracy of GRK-2200T Auto-refkeratometer in Subjective Acceptance for Refractive Errors

Abstract

Introduction: Globally, the most common cause for diminution of vision is refractive errors and the number of patients with refractive errors is increasing day by day. The Auto-refraction (AR) is quick and patient friendly procedure as compared to retinoscopy and subjective refraction in finding out refractive errors. Hence, the accuracy of Auto-refractometer in terms of subjective acceptance (SA) should be taken into account before prescribing optical correction based on findings of that particular model of Auto-refractometer. So, this study is directed towards analysis of the accuracy of GRK-2200T Auto-retieratometer in terms of acceptance by comparing findings of AR with that of SC.

Objectives: The aim of this study was to assess the refractive status of patient's eyes using auto refractometer (GRK-2200T auto-retierato meter) and to estimate the agreement of it in terms of accuracy in acceptance of subjective correction by the patient.

Methodology: A hospital based prospective comparative study conducted on 226 eyes of 113 patients who visited out-patient department (OPD) of Ophthalmology at Nobel Medical College and Teaching Hospital (NoMCTH), Biratnagar diagnosed with Myopia, Hyperopia and Astigmatism. Duration of study was 4 months from 2^nd October, 2018 to 2^nd February, 2019. All data thus collected was subjected to statistical analysis by using SPSS version 22.

Result The mean age of the study subjects was 26.91±7.79 years with male to female ratio of 0.47. When spherical power, cylindrical power and the axis are taken into consideration together, only 13.3% of the total tested eyes subjectively accepted the AR values unchanged. On subjective correction, 32.7% of the tested eyes accepted spherical power while 46.5% accepted cylindrical power and 50.9% accepted axis of AR unchanged. About 52.2% of the total eyes examined fall within the deviation of spherical equivalent (SE) of ±o.25D and up to 67.3% of them fall within the deviation of ±o.50D.

Conclusion The auto refraction by GRK-2200T auto-retieratometer was found to be satisfactory for a preliminary refraction but not satisfactory as substitutes for conventional subjective refraction. However, auto refraction values obtained by GRK-2200T auto-retieratometer could be important in order to accurately prescribe the cylindrical power as well as its axis than the spherical component.