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R. A. Applegate, L. N. Thibos, J. D. Marsack, H. M. Queener, D. E. Koenig; Change in Retinal Image Quality for Physiologic Pupil Diameters Does Not Account for the Loss of logMAR Acuity With Age. Invest. Ophthalmol. Vis. Sci. 2008;49(13):2840. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
To model, using physiologic pupil diameters, whether or not decreases in retinal image quality can account for the loss in low luminance, low contrast visual acuity with increasing age.
WFE was measured on one eye of each of 148 subjects with their pupils dilated. The WFE was fit with a normalized Zernike polynomial following the recommendations of the ANSI Z80.28 standard. The Zernike coefficients were then scaled to age and luminance appropriate (9 cd/m2) physiological pupil diameters based on data from Winn et al (IOVS 35: 1132 - 37). The scaled Zernike coefficients were in turn used to calculate the 3 top retinal image quality metrics (log PFSc, log AREA OTF, and log SFc OTF) for predicting low luminance, low contrast logMAR acuity (Optom Vis Sci 83:635-40,2006) and regressed against age.
Each retinal image quality metric, when corrected for age and luminance appropriate pupil diameter, decreased slightly with increasing age over the 60 year time span (20 - 80). Age accounted for between 3 and 12% of the variance in the retinal image quality metrics. The expected average decrease in low luminance, low contrast logMAR acuity due to the decrease in retinal image quality over the 60 year time span is between 1 and 1 ½ letters.
When WFE is scaled to correct pupil diameter for luminance and age, metrics of retinal image quality decrease only slightly with age and cannot account for the loss of either low or high contrast logMAR acuity at either low or high light levels. This finding suggests that factors such as scatter and/or losses in neural processing account for the majority of acuity loss with age.
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