Summary of findings for the main comparison. Low‐ versus high‐energy diode trans‐scleral cyclophotocoagulation for non‐refractory glaucoma.
| Low‐ versus high‐energy diode transscleralcyclophotocoagulation for non‐refractory glaucoma | ||||||
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Population: people with primary open‐angle glaucoma and no previous glaucoma surgery Settings: ophthalmology clinics Intervention: low energy; 1.5 watts for 1.5 seconds x 20 spots over 360 ° (45.0 J) Comparison: high energy; 1.25 watts for 2.5 seconds x 20 spots over 360 ° (62.5 J) | ||||||
| Outcomes* | Illustrative comparative risks** (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| High‐energy diode transscleralcyclophotocoagulation | Low‐energy diode transscleralcyclophotocoagulation | |||||
| Control of intraocular pressure | 462 per 1000 | 475 per 1000 (295 to 762) | RR 1.03 (0.64 to 1.65) | 79 (1 study) | ⊕⊕⊝⊝ low1, 2 | Control of intraocular pressure defined as a decrease in IOP by 20% from baseline value |
| Mean change in intraocular pressure | On average intraocular pressure in the high energy group dropped by 3 mmHg | On average intraocular pressure in the low‐energy group was 0.5 mmHg lower than the IOP in the high‐energy group (5.79 mmHg lower to 4.79 mmHg higher) | ‐ | 79 (1 study) | ⊕⊕⊝⊝ low1, 2 | ‐ |
| Decrease in visual acuity | 205 per 1000 | 250 per 1000 (111 to 566) | RR 1.22 (0.54 to 2.76) | 79 (1 study) | ⊕⊕⊝⊝ low1, 2 | Decrease in visual acuity defined as a decrease of 2 or more lines on the Snellen chart or one or more categories of visual acuity if unable to read the eye chart |
| Mean visual field | No visual field outcomes reported | ‐ | ‐ | ‐ | ‐ | ‐ |
| Number of glaucoma medications after treatment | The mean number of glaucoma medications in the high energy group was 1.3 | The mean number of glaucoma medications in the low energy group was 0.10 more (0.43 fewer to 0.63 more) | ‐ | 79 (1 study) | ⊕⊕⊕⊝ moderate1 | ‐ |
| Additional glaucoma surgery | 231 per 1000 | 175 per 1000 (72 to 425) | RR 0.76 (0.31 to 1.84) | 79 (1 study) | ⊕⊕⊝⊝ low1, 2 | Additional glaucoma surgery defined as retreatment with cyclophotocoagulation according to randomized assignment |
| Adverse events: atonic pupil | 311 per 1000 | 277 per 1000 (146 to 523) | RR 0.89 (0.47 to 1.68) | 92 (1 study) | ⊕⊕⊝⊝ low1, 2 | Atonic pupil was the only adverse event reported by treatment group. Trial authors noted that most participants had mild to moderate pain for a few days following the procedure and many also had transient conjunctival burns (number not reported). Severe iritis occurred in 2 eyes and hyphema occurred in 3 eyes. No instances of hypotony or phthisis bulbi were reported |
| *All outcomes are reported for participants with at least 3 months follow‐up; mean follow‐up was 13.2 months. **The basis for the assumed risk is the risk in the comparison group. 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). J: joule; CI: confidence interval; RR: risk ratio; mmHg: millimeter of mercury | ||||||
| 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. | ||||||
1Downgraded for risk of bias in the trial (unmasked outcome assessors and 14% attrition). 2Downgraded for imprecision in the effect estimate (wide confidence interval).