Abstract
Purpose :
The purpose of this study is to quantify if there is a measureable difference between standard visual acuity testing and low luminance visual acuity (LL VA) testing in patients with a variety of retinal disorders.
Methods :
A prospective study was conducted to evaluate if there is a difference between standard and LL VA testing on subjects with a variety of retinal disorders in addition to age-related macular degeneration (AMD). Study eyes underwent evaluation with standard and then LL VA using the Snellen chart. LL BCVA was measured by placing a 2.0-log-unit neutral density filter over the trial frame in front of the study eye and having the participant read the normally illuminated Snellen chart. The low luminance deficit was calculated as the difference between the logMAR low luminance visual acuity and the visual acuity under standard conditions. Eyes with media opacity including cataract and corneal opacity, as well as optic nerve disease, including glaucoma were excluded from analysis. Student’s t test was used to compare the mean low luminance deficit between eyes with and without retinal pathology.
Results :
32 eyes of 18 patients were included in the study (20 with known retinal pathology and 12 controls). These eyes were diagnosed with AMD (n=6), central serous chorioretinopathy (n=2), cystoid macular edema (n=1), proliferative diabetic retinopathy (n=2), pathologic myopia (n=4), retinitis pigmentosa (n=3), epiretinal membrane (n=2), or no retinal disease (n=12). 4 eyes were excluded for glaucoma or inability to perform low luminance testing. The mean standard VA was 20/50 and the mean LL VA was 20/120, in eyes with retinal disease. In control eyes, the mean standard VA was 20/22 and the mean LL VA was 20/56. The mean LL deficit was 0.38 log units in the eyes with retinal disease and 0.32 in the control group. This difference was not statistically significant (p=0.6).
Conclusions :
Our small study population did not show a statistical difference in standard vs LL VA. We recognize our study size is not powered to detect a small change between these 2 VA measurements. Further study in a larger population is needed to determine if LL VA testing is helpful to detect retinal impairment in eyes with non-AMD retinal disorders.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.