Demographics table for poor and normal visual performers
| Measure | Poor vision (n=34) | Normal vision (n=63) | P value |
| Gender (M:F) | 20:14 | 29:34 | ns |
| Age (years) | 67.97 (7.18) | 62.27 (7.20) | *** |
| Years of education | 17.99 (2.74) | 16.44 (2.75) | ** |
| MOCA score (max. 30) | 27.27 (2.35) | 28.37 (1.68) | ** |
| UPDRS-III | 24.59 (13.83) | 21.18 (10.13) | ns |
| Pelli-Robson contrast sensitivity | 1.70 (.16) | 1.85 (.14) | *** |
| Binocular LogMAR visual acuity | −0.05 (.14) | −0.11 (.12) | ns |
| D15 hue discrimination total error score | 1.45 (3.99) | 3.26 (5.32) | ns |
| HADS depression score | 4.94 (3.33) | 3.27 (2.31) | ns |
| HADS anxiety score | 6.06 (4.15) | 6.02 (4.16) | ns |
| RBDSQ score | 4.03 (2.11) | 4.19 (2.64) | ns |
| Smell test (Sniffin’ Sticks) | 8.44 (3.14) | 7.32 (3.24) | ns |
| Disease duration (years) | 4.85 (2.91) | 3.71 (2.16) | * |
| Levodopa equivalent dose (mg) | 516.15 (222.09) | 422.78 (272.84) | ns |
Pelli-Robson: higher score is better contrast sensitivity. Binocular LogMAR: lower score is better visual acuity. D15: lower score is better colour discrimination.
***p<0.001; **p<0.01; *p<0.05.
HADS, Hospital Anxiety and Depression Scale; MoCA, Montreal Cognitive Assessment; ns, not significant; RBDSQ, REM (rapid eye movement) Sleep Behaviour Disorder Screening Questionnaire; UPDRS, Unified Parkinson's Disease Rating Scale.