Systematic Review of the Use of Supplemental Multifocal Intraocular Lenses in the Ciliary Sulcus for Presbyopia Correction

Author: Carlos Rocha-de-Lossa

Geographical coverage: Search not restricted geographically. No information included on countries in which included studies were undertaken. 

Sector: Biomedical

Sub-sector: Treatment

Equity focus: None

Study population: Patients with presbyopia who had had the insertion of a supplemental multifocal IOL (SMIOL) in the ciliary sulcus.

Review type: Effectiveness review

Quantitative synthesis method: if applicable: e.g.: narrative/thematic synthesis; meta-analysis etc?

Qualitative synthesis method:

Background: Presbyopia and cataract are unavoidable age-related conditions and their importance is growing, due to an aging population and increasing demand for quality of vision with spectacle independence. The options to correct presbyopia at the intraocular level are based on two approaches: the replacement of a monofocal IOL previously implanted with another MIOL in the capsular bag, and the insertion of a supplemental multifocal IOL (SMIOL) in the ciliary sulcus.

Objectives: To conduct a critical review of the peer-reviewed literature on the use of supplemental multifocal intraocular lenses in the ciliary sulcus.

Main findings:

One line summary: Supplemental multifocal intraocular lenses (SMIOL) seem to offer good distance and near visual results, leading to high levels of spectacle independence and patients’ satisfaction, with limited associated complications.

Evidence base: A total of 141 articles were identified, which were evaluated and selected according to the inclusion and exclusion criteria. A total of 15 articles were included that were published between 2006 and 2021. Most were case studies or case reports, except for four clinical trials. Data for 384 eyes from 227 patients was considered in this review, and consequently some studies included both eyes of the same patient in their analyses. Most of the studies reviewed had a short follow-up (ranging from 3 to 60 months) and poor or limited design.

Post-operative uncorrected distance and near visual acuity ranged from 20/40 to 20/20 and from 0.4 to 0.02 logMAR, respectively. Pigment dispersion (12 eyes) and deposits (13 eyes) were the most described complication. Dysphotopsia, glare and halos were the more frequently reported visual disturbances. However, most of the patients reported a high level of satisfaction with their surgery. Most articles reviewed (13 of 15) achieved a risk of bias score between 6 and 8, representing a high level of evidence despite the study design limitations.

This is the first systematic review that describes the refractive and visual outcomes, patient satisfaction and complications of SMIOL implantation. Authors indicate that the main limitation is that most of the studies included are case reports or case series, many of them having a retrospective design and short follow-up periods. Only four clinical trials were included and did not clearly specify how the randomisation was achieved, which makes it difficult to obtain robust evidence. Another limitation is that different articles included used different ways to study the visual results of MIOL implantation, some of them including the evaluation of contrast sensitivity, defocus curves, or positive dysphotopsias, which caused considerable heterogeneity between the results, making the synthesis of data difficult and limiting the possibility of providing a robust estimation of the effect. A clear problem of heterogeneity was observed in the mode of reporting the uncorrected near visual acuity outcomes, which complicates the standardisation of the data. Another limitation is that some studies used both eyes for the statistical analysis of data. Using the data from both eyes could duplicate information, because they are normally correlated, so some of the results reported could be biased. Therefore, although the results from this systematic review generally seem good, caution should be taken because there is a lack of homogeneity when reporting several key elements and several studies present a low level of evidence due to their methodological structure.

Authors note the need of randomised controlled trials to compare the results of SMIOLs between them, including comparison with MIOLs and other surgical techniques to correct presbyopia. More studies with a more robust design are needed to confirm these preliminary trends reported here.

Methodology:

Inclusion criteria were: (1) original articles; (2) case reports and case series studies. Exclusion criteria were: (1) narrative reviews; (2) artificial eye studies; (3) non-English publications; (4) animal eye studies; (5) studies that excluded monofocal IOL implantation in the capsular bag and MIOL implantation in the sulcus; (6) studies that included MIOL and monofocal IOL implantation as piggyback but with both IOLs in the capsular bag; and (7) supplementary toric IOL.

This systematic review study was performed by searching PubMed on 17 May 2021. An initial search was conducted, focused on obtaining case studies of refractive and visual outcomes, patient satisfaction and complications of non-toric SMIOLs combined with MIOL implantation in the bag or MIOL and monofocal IOL both implanted in the capsular bag (piggyback). The article cites details of search terms used.

Risk of bias of the included studies was assessed using the Quality Assessment Tool for Case Series Studies from the National Heart, Lung, and Blood Institute. Questions included in the tool were: (1) Is the study oriented to a clear question?; (2) Were all patients’ results taken into account?; (3) Was the follow-up complete?; (4) Were the same conditions used in surgical treatment?; (5) Was the intervention clearly described?; (6) Was the duration of follow-up adequate?; and (7) Were the results described correctly? The following question was also included: (8) Was a declaration of conflict of interest included? Risk of bias was assessed by two of the authors, with no disagreement found between both evaluators.

Narrative analysis was undertaken, although there are no details provided regarding how this was done in practice.

Applicability/external validity: Authors draw attention to various limitations to the evidence generated from the included studies, which contribute to a high degree of heterogeneity and may limit their applicability/external validity overall.

Geographic focus: No geographic restrictions to the search – but no individuation of where the included studies were undertaken. Therefore, it is unclear how applicable the reported findings are to a LMIC context.

Summary of quality assessment:

There were a number of limitations to the approaches used to identify, include and critically appraise articles for this review. The search was limited to one database and to studies produced in English, and there is no evidence of unpublished material being considered for inclusion. In addition, there is no indication that the search was performed by more than one of the authors.  While the approach to the narrative review of the data was generally robust, there is no evidence that data was extracted by more than one author, although it is clear that each of the studies were risk assessed by two individuals. For these reasons, we have “low confidence” in the findings of this review.