Abstract
Purpose :
Visual acuity (VA) is a key outcome measure in patient management and clinical, but factors that are unrelated to retinal abnormalities impact measurements. We investigated the influence of wavefront (WF) aberrations on VA, comparing real world patients to a control group, using a custom device designed to minimize wavefront errors.
Methods :
VA in MAR was measured as previously with the Potential Vision Tester (PVT™) using Maxwellian view and a 3 mm pupil to minimize the impact of WF aberrations. An E and 4 Alternative Forced Choice repeated 8 times at each size provided a mean VA and SD for each subject. WF measurements (OCULUS AXL Wave) and retinal imaging with OCT and OCTA (Heidelberg Spectralis) classified the 49 subjects into controls vs. those with retinal pathology or anterior segment changes sufficient to impact VA. For the WF analysis, root mean squared error for higher order aberrations (RMSHO) included Zernike terms greater than 3rd order. An ophthalmologist assessed the OCT and OCTA for posterior segment changes which included macular pucker, epiretinal membrane, drusen, and cystoid macular edema. Anterior segment conditions included dry eye, posterior capsular opacification, and cataract, with 2 subjects having severe dry eye that prevented useful WF measurements. This gave 29 control subjects (45.4 +/- 16.5; 22-75 yr) and 18 with pathology. All subjects were consented and tested in a manner approved by the Indiana University IRB.
Results :
The mean VA of the control subjects was 1.11 +/- 0.89 MAR (min arc). There was no association between the age and VA of the control subjects (VA= 0.014(Age in yr) + 0.44, r2=0.073, P = 0.7). VA was within the 95% confidence limits for 6 subjects with anterior segment issues and posterior segment status not expected to decrease VA: 0.62, 0.78, 1.17, 0.61, 0.59, 1.34 MAR (min arc). In contrast, a subject with cystoid macular edema and a higher RMSHO value had VA outside the confidence limits of the controls: 3.21 MAR (min arc).
Conclusions :
VA measurements can be affected by retinal pathology or optics of the anterior segment, but the method used here with small pupil and Maxwellian view led to no significant decrement with aging. Similarly, moderate posterior segment changes that were associated with measurable WF aberration did not significantly worsen VA, while retinal pathology did.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.