Methodological quality of the review: Low confidence

Author:  Hahn U, Krummenauer F, Neuhann I.

Region: United Kingdom (UK), Sweden, Germany

Sector: Cataract surgery

Sub-sector: Outcome indicators, benchmarks, refractive accuracy, visual rehabilitation.

Type of cataract: Age-related cataract

Equity focus: None specified

Review type: Review of descriptive cataract audits

Quantitative synthesis method: Thematic analysis

Qualitative synthesis methods: Not applicable

Background

A systematic literature review on success rates of cataract surgery should provide a reference for eye care providers. The problem is the lack of universal cataract audit template. Limitations of indicators of success and new indicators are discussed as source for planning of future quality control systems.

Research objectives

To provide a benchmark for outcome of cataract surgery (in terms of visual rehabilitation and refractive accuracy) for institutions/surgeons who want to compare their own results but also to provide a foundation on which to build a cataract audit framework.

Main findings

In total, authors included seven studies analysing outcomes of cataract surgery conducted in the United Kingdom (UK), Sweden and Germany.

The literature review showed an overall high quality of cataract surgery results (visual acuity ≥ 6/12 and target refraction within 1 dioptre [dpt]). Nevertheless, authors noted that these success rates were easy to achieve and that measurable indicators are prone to miss the complexity of describing and evaluating success of cataract surgery (questionable validity of success criteria).

Methodology

Authors included studies on predominantly Caucasian patients who underwent phacoemulsification technique with at least 1,000 participants published between 2000 and 2011.

Authors conducted a search on PUBMED using the following search terms: “refractive outcome cataract surgery” and “visual outcome cataract surgery” and “benchmark cataract surgery”. Additionally, authors reviewed references lists in included articles. Authors did not report methods used to select studies for inclusion and extract data of included studies. Also, they did not report the criteria for assessing risk of bias. However, they described certain sources of bias of the included studies.

Authors conducted a narrative synthesis of the gathered studies, as these were too heterogeneous to be summarized in a formal meta-analysis or model.

Applicability/external validity

Authors did not discuss the applicability/external validity of findings.

Geographic focus

Although the review did not limit its search to a certain geographic area, it only considered publications from western European countries. The actual results might only be partly applicable in low- and middle-income countries, but the general conclusions of the publication are independent of the setting.

Quality assessment

This systematic review not only reported results of different publications on cataract surgeries, but also reflected on indicators used and suggests new ones. However, major limitations were identified in the review. The search strategy, although covering references in included studies, was not sufficiently comprehensive that we could be confident that relevant studies were not omitted. The authors did not state if study selection and data extraction was carried out by two reviewers independently. Therefore, it was not clear if this was conducted appropriately to avoid risk of bias. As this review was prone to bias, including publication and selection bias, low confidence was attributed in the conclusions about the effects of this study.