Kinetic visual acuity was correlated with functional visual acuity and binocular summation.

Abstract

Purpose : We measured the kinetic visual acuity (KVA), the functional visual acuity (FVA), the photostress recovery time (PRT) under binocular and monocular condition (non-dominant eye shielding) for healthy subjects, and related ocular parameters to explore their correlation and implication in aspect of integrated visual function.

Methods : The mean age of 28 participants was 38.6 ± 8.9 y (23y – 57y, six females). KVA meter (AS-4Fα, Kowa) measured the visual acuity to recognize a Landolt ring at three speeds. FVA was evaluated with the integrated value of visual acuity for 1 minute and its maintenance rate using FVA meter (AS-28, Kowa). PRT was defined as the duration (sec) until 0.3 conversion Landolt ring was visible at 0.1 cd / m² after light exposure for 30 sec at 5700 cd / m², measured with PRT meter (AS-14Bα, Kowa). We conducted multiple regression analysis to explore correlation among measured visual function and related parameters including age, binocular summation, best corrected visual acuity, refraction, and tear break-up time.

Results : The results of binocular KV were better than monocular KV at all speeds; 20 km/h: P = 0.001, 40 km/h: P <0.001, 60 km/h: P < 0.001. A strong correlation was found between monocular and binocular KV; 20 km/h: R = 0.715, P <0.001, 40 km/h: R=0.755, P <0.001, 60 km/h: R=0.694, P <0.001. Regression analysis revealed binocular KV was strongly correlated with FV; 20 km/h: R = 0.715, P < 0.001, 40 km/h: R = 0.755, P < 0.001, 60 km/h: R= 0.694, P < 0.001 and it was more prominent than the correlation with monocular KV. The results of binocular FV were better than monocular FV (P<0.001) and there was a correlation between the monocular and binocular FV (R = 0.638, P <0.001), so was the maintenance rate for FV (R = 0.228, P = 0.003).The results of binocular PT were also better than monocular PT (p <0.001) and a strong correlation was observed between monocular and binocular PT (R = 0.670, P <0.001). Regression analysis demonstrated PT was most strongly correlated with binocular summation rather than age.

Conclusions : KVA was correlated with binocular summation and FVA. PRT was strongly correlated with binocular summation. Taken together, our results suggested both binocular summation and FVA may be contributory to integrated visual function.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.