Normal Range of Ocular Ductions in Various Age Brackets by Prism Shifting Light-Reflex Test

Abstract

ABSTRACT Purpose To introduce a new direct measurement method for ocular ductions by shifting light reflex with plastic prism [Prism Shifting Light-Reflex Test (PLR test)]. We used it to establish normative values of ocular ductions in each age bracket defined by decade and to investigate the change of ocular ductions with aging. Methods Participants aged 21–80 years old without paralytic or restrictive eye disease were examined. The ocular ductions were measured by PLR test. Normal range of ocular ductions and rate of change with aging were evaluated. Results Of 123 participants, the mean ± standard deviation of ocular ductions in all age groups were 60 ± 12, 86 ± 9, 102 ± 9, and 123 ± 9 prism diopters for supraduction, adduction, abduction, and infraduction. From regression analysis, the ocular supraduction, adduction, abduction, and infraduction significantly decreased with aging (P < .0001) by the rate of −0.66, −0.33, −0.27, and −0.25% per year. Conclusion PLR test is a new technique for ocular duction measurement. Supraduction had the smallest range of ductions followed by adduction, abduction, and infraduction. Aging has the largest decremental effect on supraduction and the smallest decremental effect on infraduction. The normative values of ocular ductions by age in each decade were established.