| Medication given before LTP compared with the same medication given after LTP for temporarily increased IOP after LTP | ||||||
|---|---|---|---|---|---|---|
| Participant or population: people with glaucom a receiving LTP Intervention: medication before LTP Comparison: medication after LTP | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Medication after LTP | Medication before LTP | |||||
| IOP increase of ≥ 5 mmHg within 2 hours | See comment | - | - | - | 1 study comparing apraclonidine given before and after surgery reported no participants had an increase of ≥ 5 mmHg. Another study reported that 5.3% of participants given brimonidine before surgery had an IOP increase of ≥ 5 mmHg, compared with 7.5% of participants given brimonidine after surgery (RR0.70, 95%CI 0.16 to 2.97) | |
| IOP increase of ≥ 10 mmHg within 2 hours | See comment | - | - | - | 1 study comparing apraclonidine given before and after surgery reported no participants had an increase of ≥10 mmHg. Another study reported that only 1 study participant had this high of an increase, and they had been randomized to brimonidine before surgery | |
| Mean change in IOP from pre-LTP within 2 hours | See comment | - | - | - | Mean change in IOP from pre-LTP to measurements taken within 2 hours after LTP was not reported in any study, but 1 study did report the mean IOP for the 2 study arms within 2 hours and it was not statistically different between the 2 groups | |
| IOP increase of ≥ 5 mmHg between 2 and 24 hours | 38 per 1000 | 31 per 1000 (9 to 100) | RR 0.82 (0.25 to 2.63) | 319 (4 RCTs) | ⊕⊕⊕○1 Moderate |
- |
| IOP increase of ≥ 10 mmHg between 2 and 24 hours | 6 per 1000 | 10 per 1000 (1 to 79) | RR 1.55 (0.19 to 12.43) | 319 (4 RCTs) | ⊕○○○1,2 Very low |
- |
| Mean change in IOP from pre-LTP between 2 and 24 hours | The mean change in IOP was only reported in 1 study: −3.4 mmHg. The other 2 studies reported only the mean IOP at a time point rather than the mean change: range was13.0 mmHg to 18.6 mmHg | The mean change in IOP in the intervention groups was 1.07 mmHg lower (2.51 lower to 0. 37 higher) | - | 198 (3 RCTs) | ⊕⊕⊕○3 Moderate |
- |
| Adverse events - during study period | This outcome was not reported for this comparison. | |||||
The basis for the assumed risk is the control group risk across studies. 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; IOP: intraocular pressure; LTP: laser trabeculoplasty; RCT: randomized controlled trial; RR: risk ratio.
| GRADE Working Group grades of evidence High-certainty: Further research is very unlikely to change our confidence in the estimate of effect. Moderate-certainty: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low-certainty: 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-certainty: We are very uncertain about the estimate. |
The certainty of the evidence was downgraded due to concerns of plausible bias: masking of outcomes assessors was difficult and the authors of two studies work with the company making the study drug; one study had a high risk of selective reporting bias.
The certainty of the evidence was downgraded two levels due to imprecision: the included studies for which data were available had very wide confidence intervals.
The certainty of the evidence was downgraded due to inconsistency: of the three included studies, two favored medication given before surgery, and the other favored medication given after surgery.