Abstract
Abstract: :
Purpose: To determine the most important clinical predictors of the spectacle correction which provides the greatest comfort and performance for near tasks in presbyopia. Methods: Thirty volunteers over the age of 40 years volunteered to have testing of accommodative amplitude, pupillary size, fusional vergence amplitude, interpupillary distance, arm length, preferred working distance, near and far visual acuity, and preferred reading correction in the phoropter and trial frames. The volunteers then performed near tasks including reading, writing, and counting change using various spectacle correction strengths. The clinical predictors of the spectacle correction maximizing speed, accuracy, and subjective comfort of near task performance were determined. Results:The mean age was 54.9 years (SD 7.9, range 43 to 71). Fifty–three per cent were male and 40% had diabetes. The significant predictors of the most comfortable reading correction in univariate analyses were age (p=0.002), interpupillary distance (p=0.0006), fusional vergence amplitude (p=0.01), best–corrected distance visual acuity in the better eye (p=0.008), visual acuity at 40 cm in the worse eye with distance correction (p=0.01), the preferred correction to read at 40 cm with the phoropter (p=0.0006), and the preferred correction to read with trial frames (p<0.0001). Stated dioptric working distance and arm length were not significant predictors (p>0.2). By multivariable linear regression, the preferred add wearing trial frames holding a reading target at a distance selected by the patient was the only independent predictor. Excluding this variable, corrected distance visual acuity was predictive independent of age or near visual acuity. Similar results were obtained for prediction of task performance. Conclusions: Appropriate spectacle correction for near visual tasks can be estimated by subjective refraction with trial frames. Multivariable linear regression can be used to generate novel tables based on age, near and distance visual acuity to predict appropriate near spectacle correction.
Keywords: aging: visual performance • refraction • reading