Table 4.
Relative risk (and 95% confidence interval [CI]) by patient and eye characteristics, for 52 study eyes with VA 20/50 or better
| #in subgro up |
#with >=3 lines VA change (%) |
p value |
Relative Risk for >=3 line loss [95% CI] |
||
|---|---|---|---|---|---|
| PATIENT AND FELLOW EYE CHARACTERISTICS | |||||
| Age (years) | 63–77 | 28 | 12 (43%) | 0.78 | 1.14 [0.58–2.23] |
| 78–89 | 24 | 9 (38%) | ref | ||
| Gender | Women | 31 | 13 (42%) | 1.00 | 1.10 [0.56–2.18] |
| Men | 21 | 8 (38%) | ref | ||
| Fellow Eye Diagnosis | Bilateral GA |
34 | 14 (41%) | ref | |
| Fellow eye w/CNV |
14 | 7 (50%) | 0.40 | 1.21 [0.63–2.35] | |
| Fellow eye w/ Drusen |
3 | 0 (0%) | 0 | ||
| Other | 1 | 0 (0%) | 0 | ||
| Fellow eye VA | 20/50 or better |
11 | 5 (45%) | 0.82 | 1.30 [0.54,3.13] |
| 20/51– 20/199 |
21 | 9 (43%) | 1.22 [0.56–2.66] | ||
| 20/200 or worse |
20 | 7 (35%) | ref | ||
| VISUAL FUNCTION CHARACTERISTICS OF STUDY EYE | |||||
| Visual acuity (LogMAR) |
<=0.24 | 25 | 7 (28%) | 0.10 | ref |
| >0.24 | 27 | 14 (51%) | 1.85 [0.90–3.83] | ||
| Low Luminance Deficit at baseline (LogMAR) |
−0.02 to 0.4 | 21 | 4 (19%) | 0.01 | ref |
| >0.4 to 1.31 |
31 | 17 (55%) | 2.88 [1.13–7.35] | ||
| Log Contrast Sensitivity (Pelli- Robson) |
>1.20 | 23 | 6 (26%) | ref | |
| <=1.20 | 29 | 15 (52%) | 0.09 | 1.98 [0.92–4.29] | |
|
Foveal Dark adapted sensitivity (dB) |
26–42 | 21 | 3 (14%) | ref | |
| 7–25 | 20 | 12 (60%) | 0.003 | 4.20 [1.39–12.71] | |
| Maximum Reading | 97–141 | 26 | 6 (23%) | ref | |
|
Rate (words per minute) |
|||||
| 0–96 | 25 | 14 (56%) | 0.02 | 2.43 [1.11–5.31] | |
| MEASURES OF GEOGRAPHIC ATROPHY | |||||
| Baseline area of atrophy* |
< 2.39 MPS DA |
27 | 10 (37%) | 0.48 | ref |
| >= 2.39 MPS DA |
24 | 10 (42%) | 1.13 [0.57–2.23] | ||
| Two year enlargement rate of atrophy |
< 2.54 sq mm/year |
23 | 9 (39%) | 0.54 | ref |
| >= 2.54 sq mm/year |
23 | 7 (30%) | 0.78 [0.35–1.73] | ||
| GA within 500 µm of foveal center |
No | 11 | 4 (36%) | 0.74 | ref |
| Yes | 41 | 17 (41%) | 1.14 [0.48–2.70] | ||
|
Amount of central 4 MPS DA with GA* |
<= 25% | 18 | 3 (17%) | 0.02 | ref |
| 26–74% | 26 | 15 (58%) | 3.46 [1.17–10.24] | ||
| >= 75% | 7 | 2 (29%) | 1.71 [0.36–8.17] | ||
VA=visual acuity. GA = geographic atrophy. CNV = choroidal neovascularization. MPS DA = Macular Photocoagulation Study disc area, equivalent to 2.54 mm2 on the retina. Ref = the reference subgroup for the relative risk calculations. 95% CI = the 95% confidence interval. The p values represent Fisher’s exact test for the dichotomous variables, and the Chi sq test for the others.
The measures of the area of GA atrophy include 51 patients, because the photographs for one patient were not adequate for measuring area. Reading rate could not be measured for one patient, so 51 patients are included. Foveal dark adapted sensitivity was measured only in patients who had stable central fixation who could view the fixation diamond, and included 41 patients.