| Outcomes at two years | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (eyes, studies) | Quality of the evidence (GRADE) | |
|---|---|---|---|---|---|
| Assumed risk | Corresponding risk | ||||
| Control | Photocoagulation | ||||
| Development of CNV | 83 per 1000 | 89 per 1000 (67 to 117) | OR 1.07 (0.79 to 1.46) | 2159 (3580 eyes, 11 studies) | ⊕⊕⊕⊕ high1 |
| Low risk population (people with bilateral drusen) | |||||
| 50 per 1000 | 54 per 1000 (40 to 73) | ||||
| High risk population (people with CNV in the fellow eye) | |||||
| 250 per 1000 | 268 per 1000 (199 to 365) | ||||
| Development of geographic atrophy | 66 per 1000 | 84 per 1000 (26 to 241) | OR 1.3 (0.38 to 4.51) | 148 (148 eyes, 2 studies) | ⊕⊕○○ low2 |
| Visual loss of 2–3+ lines of visual acuity | 150 per 1000 | 149 per 1000 (122 to 183) | OR 0.99 (0.81 to 1.22) | 2002 (3486 eyes, 9 studies) | ⊕⊕⊕○ moderate3 |
| Loss of ≥ 0.3 log units of contrast sensitivity | 119 per 1000 | 100 per 1000 (26 to 309) | OR 0.82 (0.20 to 3.31) | 82 (82 eyes, 1 study) | ⊕⊕○○ low2 |
| Reading speed in words/minute | The mean reading speed in words/minute in the control groups was100 words/minute | The mean reading speed in words/minute in the intervention groups was 12.5 lower (7.2 lower to 32.2 higher) | - | 44 (44 eyes, 1 study) | ⊕⊕○○ low2 |
| Drusen reduction | 107 per 1000 | 522 per 1000 (428 to 614) | OR 9.16 (6.28 to 13.4) | 570 (944 eyes, 3 studies) | ⊕⊕⊕⊕ high4,5 |
The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; CNV: choroidal neovascularisation; OR: odds ratio
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. |
Allocation sequence generation and allocation concealment and masking of visual acuity outcome assessors was achieved in half or less of them; however, the larger studies in this meta-analysis were good quality. Other quality items were not a problem for the primary outcome (no downgrade).
Small study yielding wide 95% confidence intervals (−2 for imprecision).
Visual acuity examiners were masked in less than half of studies (−1 for risk of bias).
The three studies included in this analysis had low risk of bias (no downgrade).
Estimates were heterogeneous but they both suggest a strong effect (no downgrade).