Summary of findings for the main comparison. Toric intraocular lens (IOL) compared to limbal relaxing incisions (LRIs) for corneal astigmatism after cataract surgery (phacoemulsification).
| Toric IOL compared to LRIs for corneal astigmatism after cataract surgery (phacoemulsification) | ||||||
| Patient or population: people with astigmatism who are having cataract surgery (phacoemulsification) Setting: eye hospital Intervention: toric IOL Comparison: LRIs | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Risk with LRIs | Risk with toric IOL | |||||
|
Postoperative residual refractive astigmatism of less than 0.50 D Follow‐up: ≥ 6 months |
500 per 1000 | 700 per 1000 (550 to 890) | RR 1.40 (1.10 to 1.78) | 262 eyes (5 RCTs) | ⊕⊕⊕⊝ Moderatea | — |
|
Postoperative residual refractive astigmatism in dioptres Follow‐up: ≥ 6 months |
The mean postoperative residual refractive astigmatism ranged from 0.23 D to 1.23 D | MD 0.32 D less astigmatism (0.48 D less to 0.15 D less) | — | 620 eyes (10 RCTs) | ⊕⊕⊝⊝ Lowb | — |
|
Uncorrected postoperative distance visual acuity (logMAR) LogMAR score ranges from –1.3 to +1.3 with lower scores representing better vision (logMAR of 0 = 6/6 visual acuity) Follow‐up: ≥ 6 months |
The mean uncorrected postoperative distance visual acuity (logMAR) ranged from 0.09 to 0.336 logMAR | MD 0.04 logMAR lower (0.07 lower to 0.02 lower) | — | 474 eyes (8 RCTs) | ⊕⊕⊕⊝ Moderatea | — |
|
Spectacle independence for distance as reported by the participant Follow‐up: ≥ 6 months |
500 per 1000 | 780 per 1000 (570 to 1000) | RR 1.56 (1.14 to 2.15) | 100 people (2 RCTs) | ⊕⊕⊝⊝ Lowc | — |
|
Vision‐related quality of life measured using the VF‐14 index Scale 0–100: 0 = unable to do all applicable activities because of vision and 100 = able to do all applicable activities because of vision) Follow‐up: ≥ 6 months |
The mean vision‐related quality of life score was 93.7 | MD 3.01 lower (8.56 lower to 2.54 higher) | — | 40 people (1 RCT) | ⊕⊕⊝⊝ Lowd | — |
|
Adverse effects: postoperative lens rotation requiring second procedure to re‐align toric IOL Follow‐up: any time point |
There were no events. | 318 (5 RCTs) | ⊕⊝⊝⊝ Very lowe | — | ||
| Adverse effects: other | 6 studies commented on adverse effects including corneal oedema, endophthalmitis and corneal ectasia. All reported no events with the exception of 1 study (40 eyes) where 1 participant in the LRI group had a central de‐epithelialisation which recovered over 10 days and 1 study (70 eyes) where there was 1 case of dry eye in the LRI group which resolved after 3 months and 1 case of cystoid macular oedema in the toric IOL group which resolved after 3 months with medical treatment, and 1 case of posterior capsular opacification, which underwent Nd:YAG capsulotomy. | 410 (6 RCTs) | ⊕⊝⊝⊝ Very lowf | — | ||
| *The basis for the assumed risk is the pooled risk in the LRI groups in the included 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; IOL: intraocular lens; LRI: limbal relaxing incision; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High‐certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate‐certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low‐certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low‐certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aDowngraded one level for risk of bias (studies were poorly reported and some studies were at high risk of performance and detection bias). bDowngraded one level for risk of bias (studies were poorly reported and some studies were at high risk of performance and detection bias) and one level for serious inconsistency (study effect sizes ranged from –0.71 D to –0.02 D and I² = 87%). cDowngraded one level for risk of bias (both studies were poorly reported and at high risk of bias in one or more domain) and one level for publication bias (this outcome was only reported by 2/10 studies and unclear if it was collected by the other studies). dDowngraded one level for risk of bias (study was poorly reported) and one level for serious imprecision (confidence intervals included 0 and could not exclude important differences). eDowngraded one level for risk of bias (studies were poorly reported and some studies were at high risk of performance and detection bias) and two levels for very serious imprecision (studies were underpowered to address this rare event and there were no events). fDowngraded one level for risk of bias (studies were poorly reported and some studies were at high risk of performance and detection bias) and two levels for very serious imprecision (studies were underpowered to address adverse effects).