Abstract
Purpose :
Vision in glaucoma is most often tested using visual fields (VFs), visual acuity (VA), or contrast sensitivity (CS), though people with glaucoma may also experience other visual difficulties related to functional loss. Here, we determine how 3 alternative visual metrics vary with glaucoma severity (defined by VFs and the contrast sensitivity function [CSF], which integrates VA and CS results).
Methods :
We analyzed data from 183 people age 57 and older with glaucoma or suspected glaucoma. Integrated VF (IVF) sensitivity was calculated from right and left eye 24-2 VFs. The qCSF test was used to measure area under the log CSF (AULCSF). Color vision and distance stereo acuity were evaluated with the HRR plates and Distance Randot Stereotest, respectively. Vision in noise, a measure of acuity tested on pixelated noise, was assessed with the Pelli Levi Dual Acuity Chart. Separate multivariate regression models evaluated associations between either IVF sensitivity or AULCSF and vision in noise, color vision, and stereo acuity, adjusting for age, gender, race, comorbidities, and medications.
Results :
Subjects had a mean age of 70.6 (SD=7.6), IVF sensitivity of 26.1dB (IQR=25.1–29.7dB; normal value [NV]=33dB), and AULCSF of 1.2 (IQR=1.04–1.43; NV=1.6). Mean number of noisy letters read was 15.2 (IQR=13–19; NV not described) and mean color symbols seen 17.2 (IQR=18–20; NV=20). Most subjects (77%) had no detectable distance stereo acuity, while 6%, 8%, and 8% had 400, 200, and 60-100 seconds of arc, respectively. Each 5dB decrement in IVF sensitivity was associated with a 65% lower odds of having a higher level of stereo acuity (p<0.003), 2.2 fewer noisy letters read (p<0.001), and 2.9 fewer color symbols seen (p<0.001). Each 0.1 decrement in AULCSF was associated with a 40% lower odds of having a higher level of stereo acuity (p<0.001), 1.1 fewer noisy letters read (p<0.001), and 0.82 fewer color symbols seen (p<0.001). Correlations between IVF sensitivity and vision in noise, color vision, and stereo acuity were 0.54, 0.65, and 0.25, respectively.
Conclusions :
Glaucoma influences a variety of visual metrics not typically assessed, including vision in noise, color vision, and stereo acuity. Given the moderate correlations between these and traditional vision metics, further work is required to determine what better reflects functional outcomes.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.