Normal Range of Ocular Duction in Various Age Brackets by Prism Shifting Light-Reflex Test
Worawalun Honglertnapakul, MD; Pokpong Praneeprachachon, MD; Parnchat Pukrushpan, MD
Chulalongkorn University and King Chulalongkorn Memorial Hospital the Thai Red Cross Society
Introduction: To introduce a new direct measurement method for ocular duction by shifting light reflex with plastic prism. We named this method Prism Shifting Light-Reflex Test (PLR test). We used it to establish normative values of ocular duction in each age bracket defined by decade and investigate the change of ocular duction with aging.
Methods: Participants aged between 21 and 80 years old without history of significant ophthalmologic, neurologic, and thyroidal diseases were examined. All participants had best corrected visual acuity better than 20/70 in both eyes. The ocular adduction, abduction, supraduction and infraduction were measured separately by PLR test.
Results: Of 123 participants included in this study, majority are female (82%). There were 20 to 23 participants in each ten-year age bracket. From regression analysis, the 95% predictive intervals for ocular adduction, abduction, supraduction and infraduction in the youngest and the oldest groups were [78,109] and [64,95], [92,126] and [78,112], [50,88] and [31,70], and [115,146] and [100,131] prism diopters, respectively. With aging, the ocular adduction, abduction, supraduction and infraduction were significantly decreased (P<0.0001) by the rate of -0.33%, -0.27%, -0.66% and -0.25% per year, respectively.
Discussion: The normative values of ocular duction by age in each decade was established as reference range from 95% predictive interval. Aging has the largest and smallest decremental effect on supraduction and infraduction, respectively.
Conclusion: PLR test is a novel technique in ocular duction measurement. This test is applicable in clinical practice due to its practicality and ease of use.
References: 1. Urist MJ. A lateral version light-reflex test. Am J Ophthalmol. 1967;63(4):808-815.
2. Clark RA, Isenberg SJ. The range of ocular movements decreases with aging. J AAPOS. 2001;5(1):26-30.
3. Kang N-Y. Changes of Ocular Version with Aging in Normal Korean Population. Journal of Korean Medical Science. 2009;24(4):708.