Visual performance in emmetropia and low myopia after correction of high-order aberrations.
Myopic observers may not benefit to the same extent as emmetropes from adaptive optics (AO) correction in a visual acuity (VA) task. To investigate this, we measured AO-corrected VA in 10 low myopes and 9 emmetropes. Subjects were grouped by refractive error. Mean spherical equivalent refractive error was -2.73 D (SEM = 0.35) for the myopes and 0.04 D (SEM = 0.1) for the emmetropes. All subjects had best corrected VA of 20/20 or better. The AO scanning laser ophthalmoscope was used to project ultrasharp stimuli onto the retina of each observer. High-contrast photopic acuity was measured using a tumbling E test with and without AO correction. AO-corrected minimum angle of resolution was 0.61' (SEM = 0.02') for the myopes and 0.49' (SEM = 0.03') for the emmetropes. The difference between groups is significant (p = .0017). This effect is even greater (p = .00013) when accounting for spectacle magnification and axial length, with myopes and emmetropes able to resolve critical features on the retina with a mean size of 2.87 mum (SEM = 0.07) and 2.25 mum (SEM = 0.1), respectively. Emmetropes and low myopes will both benefit from AO correction in a VA task but not to the same extent. Optical aberrations do not limit VA in low myopia after AO correction. There is no difference in the high-order aberrations of emmetropes and low myopes. Retinal and/or cortical factors limit VA in low myopes after AO correction.
Rossi
Ethan A
EA
School of Optometry, University of California, Berkeley, CA 94720, USA. earossi@berkeley.edu
Weiser
Pinky
P
Tarrant
Janice
J
Roorda
Austin
A
D000328:Adult; D005139:Eyeglasses; D006801:Humans; D009216:Myopia / Q000175:diagnosis / Q000503:physiopathology* / Q000534:rehabilitation*; D009887:Ophthalmoscopy; D012029:Refraction, Ocular; D012720:Severity of Illness Index; D014787:Vision Tests; D014792:Visual Acuity