Summary of findings for the main comparison. Summary of findings table: photocoagulation of drusen versus control.
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 was 100 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. |
1Allocation 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). 2Small study yielding wide 95% confidence intervals (‐2 for imprecision). 3Visual acuity examiners were masked in less than half of studies (‐1 for risk of bias). 4The three studies included in this analysis had low risk of bias (no downgrade). 5Estimates were heterogeneous but they both suggest a strong effect (no downgrade).