Table 1. The demographic characteristics of participants, mean subscale and composite score of IVI in all subjects.
| Participants | Normal | Cataracts | AMD | Diabetic Retinopathy | Glaucoma | |
|---|---|---|---|---|---|---|
| No. | 30 | 30 | 30 | 30 | 30 | |
| Age range (yr.) | 41–70 | 32–88 | 47–85 | 32–80 | 18–85 | |
| (mean ± S.D.) | 52.8 ± 6.7 | 69.4 ± 11.8 | 69.7 ± 9.5 | 62.5 ± 9.3 | 59.8 ± 17.6 | |
| Gender (male; No.,%) | 8 (26.7) | 11 (36.7) | 21 (70.0) | 11 (36.7) | 14 (46.7) | |
| Visual acuity, logMAR (range) | 0.0–0.1 | 0.0–0.7 | 0.0–1.0 | 0.0–1.3 | 0.0–1.0 | |
| (mean ± S.D.) | 0.02 ± 0.04 | 0.29 ± 0.16 | 0.31 ± 0.29 | 0.27 ± 0.28 | 0.24 ± 0.25 | |
| Vision impairment (No., %) | ||||||
| Good reading vision (20/20–20/25) | 30 (100) | 8 (26.7) | 15 (50.0) | 14 (46.7) | 14 (46.7) | |
| Legal driving vision (20/30–20/40) | 0 | 10 (33.3) | 6 (20.0) | 6 (20.0) | 9 (30.0) | |
| Moderate visual loss (20/50–20/100) | 0 | 12 (40.0) | 5 (16.7) | 8 (26.7) | 5 (16.7) | |
| Legal blindness (≤ 20/200) | 0 | 0 | 4 (13.3) | 2 (6.7) | 2 (6.7) | |
| Summary IVI scales | ||||||
| Reading and accessing information | 3.83 ± 1.13 | 13.30 ± 1.76† | 14.07 ± 1.67† | 11.70 ± 1.33† | 13.00 ± 1.97† | |
| Mobility and independence | 3.20 ± 0.73 | 13.97 ± 1.90† | 12.67 ± 1.51† | 14.07 ± 1.70† | 11.03 ± 1.58† | |
| Emotional well-being | 0.83 ± 0.37 | 5.47 ± 1.17† | 7.00 ± 1.06† | 5.93 ± 1.30† | 4.37 ± 0.96† | |
| Composite score | 7.87 ± 2.01 | 32.73 ± 4.32† | 33.73 ± 3.53† | 31.70 ± 3.31† | 28.40 ± 3.74† | |
| Rasch-transformed IVI scores (in logits) | ||||||
| Reading and accessing information | -1.49 ± 1.84 | -0.21 ± 2.41** | 0.18 ± 1.51*** | -0.07 ± 1.83*** | -0.21 ± 2.17** | |
| Mobility and independence | -2.20 ± 1.76 | -0.58 ± 2.25*** | -0.20 ± 1.41*** | -0.21 ± 1.81*** | -1.11 ± 1.92** | |
| Emotional well-being | -2.86 ± 1.97 | -1.67 ± 2.52* | -0.96 ± 2.16*** | -1.47 ± 3.04** | -2.17 ± 2.27 | |
| Composite score | -1.01 ± 1.44 | -0.20 ± 1.58*** | 0.54 ± 1.14*** | 0.36 ± 1.45*** | -0.09 ± 1.42** | |
AMD: Age-related macular degeneration. Visual acuity, log(MAR) in the better eye. Data are expressed at the mean ± SD.
† Significant differences between this group and normal at baseline (P-value < 0.001).
***, **, and * denote statistical significance level of the difference from the reference (Normal) group, at 1%, 5%, and 10% respectively.