COMPARISON OF ACCURACY WITH SPHERE VERSES SPHERE CYLINDER TECHNIQUE FOR NEUTRALIZATION OF REFRACTIVE ERROR WITH RETINOSCOPE

Abstract

Background Retinoscopy is an important objective method used for assessing refractive error and determining an appropriate refractive correction. Accurate neutralization requires appropriate assessment of the spherical and cylindrical components of the refractive error. The Sphere technique primarily considers spherical power, whereas the Sphere-Cylinder technique incorporates both spherical and cylindrical components. However, there is a need to evaluate which technique provides greater accuracy during retinoscopic neutralization. Objective To compare the accuracy of the Sphere technique and Sphere-Cylinder technique for neutralization of refractive errors using retinoscopy. Methodology A comparative study was conducted to assess the accuracy of the two retinoscopic neutralization techniques. Participants underwent refractive assessment using both the Sphere and Sphere-Cylinder techniques. The obtained refractive values were compared with the reference spherical equivalent to determine the accuracy of each technique. The difference between the obtained and reference values was used to assess measurement error. Data were analyzed using SPSS, with descriptive statistics used to summarize the study variables. Normality was assessed using the Shapiro-Wilk test, and the appropriate statistical test was used to compare the two techniques. Results The findings demonstrated a statistically significant difference in accuracy between the two techniques. The Sphere-Cylinder technique showed a lower mean absolute error (0.131 ± 0.139 D) compared with the Sphere technique (0.269 ± 0.119 D). The difference between the techniques was statistically significant (p < 0.001), indicating greater accuracy of the Sphere-Cylinder technique in the studied sample. The mean difference in error between the two techniques was approximately 0.138 D, favoring the Sphere-Cylinder technique. These findings indicate that consideration of the cylindrical component may improve the precision of refractive error neutralization during retinoscopy. Conclusion The study concluded that the Sphere-Cylinder technique was more accurate than the Sphere technique for neutralization of refractive errors using retinoscopy. Incorporating the cylindrical component during retinoscopic assessment may provide a more complete representation of refractive error and reduce residual refractive error, particularly in eyes with astigmatism.