Brown et al (1999)8 | 100 patients (28–87 years; 95 white and 5 black) with diabetic retinopathy and best corrected visual acuity decreased to 20/40 or worse in at least one eye | 0.77 (0.73 to 0.81) | 0.88 (0.84 to 0.92) |
Brown et al (2000)9 | 85 white patients (56–85 years) with unilateral or bilateral macular degeneration in one or both eyes, with visual loss of a minimum of at least 20/40 in 1 eye | 0.72 (0.66 to 0.78) | 0.81 (0.76 to 0.86) |
Brown et al (2001)10 | Adult patients from Wills Eye Hospital including 15 patients with complete absence of vision (NLP), 17 patients with light perception to counting fingers in the better eye (LP-CF), 33 patients with 20/200 to 20/400 in the better eye (20/200–20/400) | 0.26 (0.19 to 0.33) for NLP | 0.32 (0.20 to 0.44) for NLP |
| | 0.47 (0.33 to 0.61) for LP-CF | 0.60 (0.46 to 0.74) for LP-CF |
| | 0.65 (0.58 to 0.72) for 20/200–20/400 | 0.80 (0.73 to 0.87) for 20/200–20/400 |