Abstract
Purpose :
To determine which psychophysical measures of foveal function can distinguish among three groups of eyes with moderate-severe diabetic retinopathy: eyes with No Edema, eyes with clinically significant macular edema (CSME), and eyes with diabetic macular edema elsewhere in the macula (DME-E).
Methods :
Eyes were classified into 1 of the 3 groups according to the grading of dilated color fundus photographs by a retinal specialist. Fifty-five eyes (34 No Edema; 5 DME-E; 16 CSME) are included in the analyses. Foveal function was assessed using several simple, rapid, clinically practicable tests: standard (high contrast) visual acuity (VA); low contrast VA (LCVA); low contrast acuity at reduced luminance measured using the dark chart of the SKILL card (SKD); contrast sensitivity (CS; Pelli-Robson chart); and color vision (color confusion score [CCS] of the Adams desaturated D-15). Testing was monocular. A non-parametric test (Kruskal-Wallis) was used to evaluate potential differences among groups. For significant differences, post-hoc pairwise comparisons were carried out using the Mann-Whitney U test.
Results :
Neither VA nor LCVA differs among the 3 groups (p>0.05). CS and SKD show marginally significant differences among the groups (p= 0.04 and 0.02, respectively). However, given the multiple comparisons, only the D15 CCS differs significantly among groups (p<0.002). The median CCS of the CSME group is highest (76.00) and is significantly different (P=0.004) from the No Edema group (CCS= 17.18) , but neither of these groups differ significantly from the DME-E group, which has a median CCS between the other 2 groups (CCS=42.81). A CCS of ≥ 30 was considered to be abnormal. Using this criterion, the frequency of abnormalities for the CSME group and the DME-E group are very similar (62.5% vs 60% respectively) and 3 times the rate of abnormalities seen in the No Edema group (20.6%). Among those that fail, approximately 60% of each group show a blue-yellow defect pattern in each group. These findings suggest that edema outside the fovea may also affect color vision.
Conclusions :
Color vision, assessed with the Adams desaturated D-15 test is sensitive to the presence of CSME, and is also affected by more peripheral edema (DME-E).
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.