| Medication compared with placebo for preventing temporarily increased IOP after LTP | ||||||
|---|---|---|---|---|---|---|
| Participant or population: people with glaucom a receiving LTP Intervention: IOP-lowering medication (apraclonidine, acetazolamide, brimonidine, pilocarpine) Comparison: placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo | Medication | |||||
| IOP increase of ≥ 5 mmHg within 2 hours | See comment | - | 273 (2 RCTs) | ⊕⊕○○1,2 Low |
Medications in this comparison were apraclonidine and brimonidine. 2 studies reported on this outcome and 1 favored the alpha-2 agonists while the other favored placebo. Due to significant statistical heterogeneity (I2 = 70%), we did not perform a meta-analysis. | |
| IOP increase of ≥ 10 mmHg within 2 hours | 195 per 1000 | 10 per 1000 (2 to 39) | RR 0.05 (0.01 to 0.20) 446 | (4 RCTs) | ⊕⊕⊕○1 Moderate |
Medications in this comparison were acetazolamide, apraclonidine, and brimonidine |
| Mean change in IOP from pre-LTP within 2 hours | The mean change in IOP ranged across control groups from0.4 mmHg to 4.40 mmHg, for 3 included studies | The mean change in IOP in the intervention groups was 7.43 mmHg lower (10.60 lower to 4.27 lower) | - | 151 (4 studies) | ⊕⊕⊕○1 Moderate |
Each of the studies included in this outcome compared apraclonidine vs placebo |
| IOP increase of ≥ 5 mmHg between 2 and 24 hours | 280 per 1000 | 48 per 1000 (25 to 87) | RR 0.17 (0.09 to 0.31) | 634 (5 studies) | ⊕⊕○○3 Low |
Medications in this comparison were apraclonidine and brimonidine |
| IOP increase of ≥ 10 mmHg between 2 and 24 hours | 202 per 1000 | 44 per 1000 (22 to 85) | RR 0.22 (0.11 to 0.42) | 817 (9 studies) | ⊕○○○3,4 Very low |
Medications in this comparison were apraclonidine, brimonidine, dorozolamide, and pilocarpine |
| Mean change in IOP from pre-LTP between 2 and 24 hours | The mean change in IOP ranged across control groups from −2.0 mmHg to 0.63 mmHg, for 3 included studies | The mean change in IOP in the intervention groups was 5.32 mmHg lower (7.37 lower to 3.28 lower) | - | 151 (4 studies) | ⊕⊕⊕○1 Moderate |
Each of the studies included in this outcome compared apraclonidine vs placebo |
| Adverse events - conjunctival blanching during study period | See comment | - | 319 (2 studies) | ⊕⊕⊕○1 Moderate |
2 studies reported on conjunctival blanching; however, due to significant statistical heterogeneity (I2 = 95%), we did not perform a meta-analysis. In both studies, conjunctival blanching was reported in more participants in the group that received an alpha-2 agonist compared with participants who received placebo. 1 other study that reported only the range of participants who had conjunctival blanching also reported that this adverse event was more frequent in the groups receiving brimonidine vs placebo. Other adverse events reported for the comparison of medication vs placebo were lid retraction and conjunctival hyperemia, reported in 1 study each | |
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 risk of bias: masking of outcomes assessors was difficult and in one study, the authors of some studies worked with the company making the study drug.
The certainty of the evidence was downgraded due to inconsistency of the outcome measurements in the individual studies: one favored medication and one favored placebo.
The certainty of the evidence was downgraded two levels due to concerns of very serious plausible bias: some studies in these analyses had issues with masking of outcomes assessors, high risk of selective reporting, and authors associated with the manufacturer of the study drug.
The certainty of the evidence was downgraded due to imprecision: there is a small number of events in the medication groups.