Objective Accommodation Amplitude Measurements Using a New Autorefractometer Device

To measure the value of objective accommodation amplitude (AA) in patients using the new autorefractometer device and to evaluate the effects of age, refraction errors, pupil diameter on objective AA measurements.

Three hundred subjects who were divided into five groups according to age were enrolled in this study. AA and pupil diameter were measured three times from both eyes using Tonoref III (NIDEK Co., Ltd.).

The mean AA was 1.6325±0.061 Diopter (D) (0.13-9.11 D). The mean AA values were statistically significantly different between the groups (p=0.000). It was not observed gender effect on AA (p=0.115). Although there was no significant difference between emmetropic and myopic groups, there were significant differences between emmetropic and hyperopic groups and also between myopic and hyperopic groups concerning AA (p=0.000, for both). A statistically significant difference was found for the mean AA between the groups with and without refractive surgery (p=0.028). Correlation analysis revealed that AA is increased as the mean pupil diameter increases (p=0.000, r=0.202) and the mean pupil diameter decreases with increasing age (p=0.000, r=-0.308). When the AA obtained from the patients in group 1 were compared with the AA values obtained by subjective accommodation tests, the AA values obtained by autorefractometer device were found to be correlated with push up, push down and minus lens tests (r=0.577, r=0.682, r=0.427) AA values obtained by autorefractometer device were found to be statistically significantly lower than other subjective tests (p<0.001).

The Tonoref III device seems to provide objective AA measurements in presbyopic or non-presbyopic individuals. Age, refractive error, pupil diameter and history of refractive surgery were effective on AA values, while the gender was not effective.