Abstract
Purpose :
To compare monocular performance of monocular subjects on near chart measures of basic visual function and reading (speed and acuity) to that of normal binocular subjects and binocular subjects with retinal disease.
Methods :
Subjects were patients at the West Virginia University Eye Institute with near acuity better than 20/30 (logMAR < 0.14). There were 20 normals (age: 36.7 ± 12.7 years), 8 with retinal disease (age: 62.9 ±12.5 years) and 27 monocular (age: 51.7 ± 20.5 years). We assessed each subject’s performance on 5 near vision chart tests, ETDRS, Pelli-Robson (Precision Vision), Smith-Kettlewell Low Luminance Acuity (SKLL), and MN Read. Subjects were tested on each test monocularly at a distance of 16 inches (40 cm). Testing was performed in a well-lit room (252 lux). All charts were black type on white backgrounds with contrasts > 0.9.
Results :
Using regression analyses, best monocular acuity was the best predictor of reading acuity (p<0.001). Years of Education was the best predictor of reading speed (p=0.0007). Analyses of Covariance controlling for age, education, LogMAR, Log Contrast Sensitivity, and SKLL indicated statistically significant differences between the groups (p<0.05). For both reading acuity and reading speed posthoc analyses indicated that the best monocular reading performance was found in the binocular group (RS: 236.7 wpm; RAC: -0.08), compared to the monocular group (RS: 167.6 wpm; RAC: -0.03) or to the better eye of the binocular subjects with retinal disease (RS: 171.1; RAC: -.0.06). No statistically significant relationships were found between age of vision loss or duration of visual loss and the visual functions of the monocular group (p > 0.10).
Conclusions :
In our previous research, we found that monocular subjects scored more poorly than binocular subjects on the Role Difficulties scale of the VFQ(Kondo et al., 2013). Based on anecdotal reports of reading difficulties in monocular persons, we hypothesized that reading difficulties might partially account for role difficulties. The present results appear to support that hypothesis. Even when other monocular visual factors are controlled statistically, monocular patients need slightly larger print and read about 40 wpm more slowly than binocular subjects reading monocularly.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.