Distance and near visual acuity improvement after implementation of multifocal intraocular lenses in cataract patients with presbyopia: a systematic review

Methodological quality of the review: Low confidence

Author: Agresta B, Knorz MC, Kohnen T, Donatti C, Jackson D.

Region: Details not provided

Sector: Uncorrected visual acuity

Sub-sector: Distance visual acuity, near visual acuity, presbyopic cataract patients, presbyopia.

Equity focus: None specified

Review type: Effectiveness review

Quantitative synthesis method: Narrative analysis

Qualitative synthesis methods: Not applicable

Background

Presbyopia is an age-related loss of lens accommodation that results in an inability to focus at near distances. Presbyopia and cataract reduce patients’ quality of life (QOL). The use of multifocal intraocular lens (IOL) is designed to replace the cataract lens of an eye and reduce presbyopia by factoring change in the focal point created by the lens. Thus, if multifocal IOLs are safe and efficient, an increase of QOL should be observed in cataract patients with presbyopia.

Research objectives

To evaluate uncorrected distance visual acuity (UDVA) as well as uncorrected near visual acuity (UNVA) as outcomes in treating presbyopic cataract patients to assist clinicians and ophthalmologists in their decision-making process regarding available interventions.

Main findings

Twenty-nine studies were identified that reported uncorrected visual acuities, including one study that reported uncorrected intermediate visual acuity. These included five randomized controlled trials, 10 observational studies, 11 prospective cohort studies and two retrospective observational studies.

Nine brands of multifocal IOLs were identified in the search. All studies identified in the literature search reported improvements in UDVA and UNVA following multifocal IOL implantation. The largest improvements in visual acuity were reported using the Rayner M-Flex lens (Rayner Intraocular Lenses Ltd) (UDVA, binocular: 1.05 logMAR, monocular: 0.92 logMAR; UNVA, binocular and monocular: 0.83 logMAR) and the smallest improvements were reported using the Acri.LISA lens (Carl Zeiss Meditec) (UDVA, 0.21 decimal; UNVA, 0.51 decimal).

The results of this systematic review showed the aggregate of studies reporting a beneficial increase in UDVA and UNVA with the use of multifocal IOLs in cataract patients with presbyopia, hence provided evidence to support the hypothesis that multifocal IOLs increase UDVA and UNVA in cataract patients.

The authors noted that an analysis of studies reporting the association between QOL and uncorrected visual acuity was needed and also that further analyses were needed on studies reporting spectacle independence and QOL in regards to multifocal IOL implantation.

Methodology

The authors excluded studies using the Quality of Reporting meta-analyses chart. Studies were excluded that did not report on relevant population (presbyopic patients with cataracts), interventions (multifocal IOL implantation) comparators (other multifocal IOL implantation) or outcomes (uncorrected visual acuity). Only studies written in English were included in the review. No restriction was applied in regards to study design.

Databases used in the search included: Medline, Embase and ACP Journal Club from inception to 2011 and Cochrane databases including Cochrane database of systematic reviews (2005-2011), Cochrane central register of controlled trials (fourth quarter -2010), Cochrane Methodology Register (first quarter -2010) and other relevant electronic databases.

The authors did not report the methods used to screen studies for selection and methods used to extract data of included studies. Additionally, they did not conduct an assessment of quality and risk of bias of included studies.

The authors conducted a narrative synthesis of included studies, which seemed appropriate due the diversity of studies included in the review.

Applicability/external validity

The authors did not discuss the generalizability of the results due to the heterogeneity of included studies.

Geographic focus

The authors did not report the geographical location of studies included, as such it is not possible to determine the applicability of the results to low- and middle-income settings.

Quality assessment

There is low confidence in the conclusions about the effects of this study. The search for literature was not comprehensive so we can be confident that relevant studies were omitted. Although the authors searched relevant databases, they did not contact authors of included studies, did not review references of studies for additional studies and only studies written in English were included in the review. Additionally, the authors did not assess the quality and risk of bias of included studies, therefore, we cannot be assertive that findings of this review are reliable and robust.