Inter-examiner repeatability and validity of static retinoscopy

Background: Studies on inter-examiner repeatability of measurements from retinoscopy without cycloplegia are quite limited within and across individuals. Aim: To investigate the inter-examiner repeatability and validity of static retinoscopy to autorefraction in young adults. Setting: The study took place within a South African university. Methods: Convenience, non-random sampling was used to obtain a sample of 68 adult participants, predominantly male (51.5%) of African descent (60.3%). The age range was from 18 years to 25 years with the mean ± standard deviation (s.d.) of 22.5 ± 0.71 years. The right eyes of participants underwent autorefraction, and static retinoscopy was done by two different student examiners. Bland-Altman plots and multivariate analysis were applied to assess inter-examiner repeatability and validity of retinoscopy to autorefraction of sphere, cylinder, spherical equivalent refraction (SER = M), and vector components J0 and J45. Results: Stereo-pair scatter plots for the three refractive samples from both student examiners obtained for the right eye clustered within the same region, which suggested minimal variation in refractive error between the different samples. Bland-Altman plots for mean differences () were less than or equal to one clinical step (0.25 dioptre [D]) for all refractive error variables although 95% Limits of Agreement (LoA) widths were larger for the spherical equivalent coefficients (M). Conclusion: Clinically, inter-examiner retinoscopy is repeatable and comparable to autorefraction as results differed only by approximately 0.25 D. Contribution: This study will be the first in Africa to provide multivariate analysis for inter-examiner repeatability of retinoscopy.