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 66.5years (range 23-90years). For the 124 eyes, the mean spherical equivalent of the sample at baseline visit was -3.59±6.28D (range -21.00D to +4.44D).

METHODS

Automated refraction was performed on follow-up visits 1day and weekly for 4weeks. Retinoscopy and subjective refraction were conducted at the Week 4 follow up.

MAIN OUTCOME MEASURES: Automated refraction.

RESULTS

Sphere, cylinder and mean spherical equivalent, J(0) and J(45) 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±0.53D (P=0.031) and 0.23±0.42D (P<0.001), respectively. Comparison between autorefraction and retinoscopy showed a similar trend with the sphere and cylinder differences, 0.32±0.77D and 0.38±0.43D (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.