Eye examinations improve visual acuity across ages

Objective: To investigate changes in distance best corrected visual acuity (BCVA) relative to presenting visual acuity (PVA) as a function of age and the number of years between eye examinations. Design: Retrospective cross-sectional study. Participants: 6397 patient files at a large Canadian Optometric Clinic. Methods: A retrospective file review of patients aged 4 to 93 years from the University of Waterloo, Optometry Clinic was conducted. Mean decimal PVA values were calculated for all patients grouped by year of age, and a function was fit to these data using nonlinear regression. The same was done for BCVA and the functions were compared. In addition, the mean IogMAR difference between PVA and BCVA was determined for patients grouped by the length of time between the study visual assessment and their previous visual assessment independent of patient age. Results: Right and left eye functions were not significantly different from each other for either PVA or BCVA. BCVA functions were significantly greater than PVA functions for both right (F[3174] = 194.7, p < 0.0001) and left (F[3174] = 206.0, p < 0.0001) eyes. PVA differed (>= 1 line) from BCVA in at least 1 eye in 70% (n = 4054) of patients. The difference between BCVA and PVA increased as the length of time between assessments increased from 0.075 IogMAR for < 1 year to 0.107 IogMAR for >= 5 years. Conclusions: Refractive testing resulted in an improvement in BCVA over PVA in the majority of patients, over a wide range of ages.