Influence of Macular Pigment on Retinal Straylight in Healthy Eyes

PURPOSE. To study the influence of macular pigment on retinal straylight in healthy eyes. METHODS. This prospective study included 150 eyes of 75 healthy subjects between 12 and 81 years of age (mean, 46.1 years) without a history of ocular surgery or ocular disease known to influence straylight (e.g., cataract). Retinal straylight was measured with the compensation comparison technique, and the known influence of age and axial length was compensated by calculating the base, age, and axial length-corrected (BALC) straylight. Macular pigment optical density (MPOD) was measured using light-emitting diode (LED) heterochromatic flicker photometry. Axial length was determined with a partial coherence biometer and iris color by visual inspection. Data analysis consisted of studying the predictive values between these parameters, after correction for the symmetry between left and right eyes, using linear mixed models. RESULTS. Mean retinal straylight was 1.05 +/- 0.18 log units, and the mean MPOD was 0.37 +/- 0.19. Age and axial length were found to be important predictors of retinal straylight (P < 0.001 and P = 0.010, respectively) but not of MPOD (P > 0.05). The mean BALC straylight was -0.07 +/- 0.13 log units. No significant relationship was found between retinal straylight and MPOD (P > 0.05), even after correction for age and axial length. Also, no significant correlation was found between iris color and BALC straylight or MPOD. CONCLUSIONS. In healthy human eyes, retinal straylight values measured with the compensation comparison technique are not significantly correlated with macular pigment optical density.