Trifocal versus extended depth of focus (EDOF) intraocular lenses after cataract extraction

Abstract

Background: Cataract, defined as an opacity of the lens in one or both eyes, is the leading cause of blindness worldwide. Cataract may initially be treated with new spectacles, but often surgery is required, which involves removing the cataract and placing a new artificial lens, usually made from hydrophobic acrylic. Recent advancements in intraocular lens (IOL) technology have led to the emergence of a diverse array of implantable lenses that aim to minimise spectacle dependence at all distances (near, intermediate, and distance). To assess the relative merits of these lenses, measurements of visual acuity are needed. Visual acuity is a measurement of the sharpness of vision at a distance of 6 metres (or 20 feet). Normal vision is 6/6 (or 20/20). The Jaegar eye card is used to measure near visual acuity. J1 is the smallest text and J2 is considered equivalent to 6/6 (or 20/20) for near vision.

Objectives: To compare visual outcomes after implantation of trifocal intraocular lenses (IOLs) to those of extended depth of focus (EDOF) IOLs. To produce a brief economic commentary summarising recent economic evaluations that compare trifocal IOLs with EDOF IOLs.

Search methods: We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE, Embase, and three trial registries on 15 June 2022. For our economic evaluation, we also searched MEDLINE and Embase using economic search filters to 15 June 2022, and the NHS Economic Evaluation Database (EED) from 1968 up to and including 31 December 2014. We did not use any date or language restrictions in the electronic searches.

Selection criteria: We included studies comparing trifocal and EDOF IOLs in adults undergoing cataract surgery. We did not include studies involving people receiving IOLs for correction of refractive error alone (or refractive lens exchange in the absence of cataract).

Data collection and analysis: We used standard Cochrane methods. Two review authors working independently selected studies for inclusion and extracted data from the reports. We assessed the risk of bias in the studies, and we assessed the certainty of the evidence using the GRADE approach.

Main results: We included five studies that compared trifocal and EDOF lenses in people undergoing cataract surgery. Three trifocal lenses (AcrySof IQ PanOptix, ATLISA Tri 839MP, FineVision Micro F) and one EDOF lens (TECNIS Symfony ZXR00) were evaluated. The studies took place in Europe and North America. Follow-up ranged from three to six months. Of the 239 enroled participants, 233 (466 eyes) completed follow-up and were included in the analyses. The mean age of participants was 68.2 years, and 64% of participants were female. In general, the risk of bias in the studies was unclear as methods for random sequence generation and allocation concealment were poorly reported, and we judged one study to be at high risk of performance and detection bias. We assessed the certainty of the evidence for all outcomes as low, downgrading for the risk of bias and for imprecision. In two studies involving a total of 254 people, there was little or no difference between trifocal and EDOF lenses for uncorrected and corrected distance visual acuity worse than 6/6. Sixty per cent of participants in both groups had uncorrected distance visual acuity worse than 6/6 (risk ratio (RR) 1.06, 95% confidence intervals (CI) 0.88 to 1.27). Thirty-one per cent of the trifocal group and 38% of the EDOF group had corrected distance visual acuity worse than 6/6 (RR 1.04, 95% CI 0.78 to 1.39). In one study of 60 people, there were fewer cases of uncorrected near visual acuity worse than J2 in the trifocal group (3%) compared with the EDOF group (30%) (RR 0.08, 95% CI 0.01 to 0.65). In two studies, participants were asked about spectacle independence using subjective questionnaires. There was no evidence of either lens type being superior. One further study of 60 participants reported, "overall, 90% of patients achieved spectacle independence", but did not categorise this by lens type. All studies included postoperative patient-reported visual function, which was measured using different questionnaires. Irrespective of the questionnaire used, both types of lenses scored well, and there was little evidence of any important differences between them. Two studies included patient-reported ocular aberrations (glare and halos). The outcomes were reported in different ways and could not be pooled; individually, these studies were too small to detect meaningful differences in glare and halos between groups. One study reported no surgical complications. Three studies did not mention surgical complications. One study reported YAG capsulotomy for posterior capsular opacification (PCO) in one participant (one eye) in each group. One study reported no PCO. Two studies did not report PCO. One study reported that three participants (one trifocal and two EDOF) underwent laser-assisted subepithelial keratectomy (LASEK) to correct residual myopic refractive error or astigmatism. One study reported a subset of participants who were considering laser enhancement at the end of the study period (nine trifocal and two EDOF). Two studies did not report laser enhancement rates. No economic evaluation studies were identified for inclusion in this review.

Authors' conclusions: Distance visual acuity after cataract surgery may be similar whether the lenses implanted are trifocal IOLs or EDOF (TECNIS Symfony) IOLs. People receiving trifocal IOLs may achieve better near vision and may be less dependent on spectacles for near vision. Both lenses were reported to have adverse subjective visual phenomena, such as glare and halos, with no meaningful difference detected between lenses.