Group 1 Group  2 Group 3
Patients (n) 29 22 31
Eyes (n) 58 44 62
Sex (n)
         Male
         Female
  18
11
  17
5
  9
22
Age (yr)
         Median
         Range
  47
11-72
  48
17-65
  39
24-59
Eyes with visual acuity < 6/60 (%) 2/58 (3.4) 2/44 (4.5) 0
Eyes with color vision defect (%) 3/58 (5.1) 1/44 (2.2) 0
Eyes with visual field defect (%) 2/58 (3.4) 0/22 (0) 0
Contrast Sensitivity
 (log unit)
         Mean
         Range
  1.60
(1.35-1.95)
  1.57
(1.50-1.95)
  1.79
(1.65-1.95)
Table 1: Demographic data of the patients in 3 groups.