Repeatability and agreement of ARK-30 autorefraction after cataract surgery

Background: To evaluate the intra‐test variability of ARK‐30 handheld autorefractor and the agreement with subjective refraction and retinoscopy after uneventful cataract surgery. Design: Prospective and non‐randomized study that included 6 visits by patients undergoing uneventful cataract surgery at IOBA (Instituto de Oftalmobiología Aplicada) Eye Institute (University of Valladolid). Participants: The mean age of the 79 patients was 66.5 years (range 23–90 years). For the 124 eyes, the mean spherical equivalent of the sample at baseline visit was ?3.59 ± 6.28 D (range ?21.00 D to +4.44 D). Methods: Automated refraction was performed on follow‐up visits 1 day and weekly for 4 weeks. Retinoscopy and subjective refraction were conducted at the Week 4 follow up. Main Outcome Measures: Automated refraction. Results: Sphere, cylinder and mean spherical equivalent, J₀ and J₄₅ coefficient variabilities were low in all visits. Standard deviations and the limits of agreement were smallest for the last visit. Subjective refraction sphere and cylinder values were more positive than autorefraction by 0.12 ± 0.53 D (P = 0.031) and 0.23 ± 0.42 D (P < 0.001), respectively. Comparison between autorefraction and retinoscopy showed a similar trend with the sphere and cylinder differences, 0.32 ± 0.77 D and 0.38 ± 0.43 D (P < 0.05), respectively. Conclusions: The ARK‐30 is sufficiently accurate and repeatable for automated refraction after uneventful cataract surgery. This instrument may be useful for monitoring refractive outcome in these patients.