Objective measurement of accommodation function using an autorefractometer

PURPOSE: To evaluate accommodation function among refractive surgery candidates. METHODS: Autorefraction was measured using a Speedy-K autorefractometer (Right MFG, Tokyo, Japan) in 15 corneal refractive surgery candidates (Age 21 to 38). Repeated measurements of refraction 8.5/sec for 10 sec were performed in various accommodative target distances (+0.5 to −3.0 diopters) in the Speedy-K. Accommodation functions were described as accommodation lag and high frequency component (HFC) of accommodation microfluctuation. HFC was reported as a single number ranging from 30 to 70 on the MF-1 accommodation analysis system. RESULTS: Accommodation lag at −3.0D of accommodative demand was 1.88±0.33 diopters and had significant correlation with level of spherical equivalent refraction (R2=0.427, p=0.008). HFC reached minimum at −0.5 diopters of target distance and increased with the accommodation demand up to −3.0 diopters. CONCLUSIONS: The preoperative spherical equivalent refraction in refractive surgery candidates can affect accommodation function and is anticipated to correlate with the symptoms of near vision disturbances immediately after refractive surgery.