Ocular injectable treatment options for postcataract macular edema: systematic review

Author: Ahmadyar G, Hansen R

Geographical coverage: Not reported

Sector: Pos-cataract surgery

Sub-sector: Injectable therapy

Equity focus: Not reported

Study population: Patients with pseudophakic cystoid macular oedema (PCME)

Review type: Effectiveness review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background:

Cataract surgery is among the most frequently performed ocular procedures worldwide. In the United States alone, about two million operations are undertaken annually, a figure set to rise as populations age. Despite surgical advances, pseudophakic cystoid macular oedema (PCME) remains a recognised complication. Incidence varies with diagnostic criteria and surgical technique; although most cases resolve spontaneously, persistent PCME can impair vision and increase healthcare costs. Topical non-steroidal anti-inflammatory drugs and corticosteroids are often first-line therapy, yet their long-term effectiveness is uncertain. This review evaluates evidence for injectable pharmacological treatments.

Objective:

To assess the literature on intravitreal and sub-Tenon injectable treatments for PCME.

Main findings: The review included 18 studies. Of which, two were randomised controlled trials, 5 prospective case series, and 11 retrospective case series. The mean sample size in the included studies was 19 eyes (range: 3-59 eyes), and the mean follow-up duration was 9.7 months. However, only 39% of the studies included at least 12 months of follow-up. Of the 11 studies that reported duration of PCME, the mean was 12.5 months. Regarding study quality, 15 studies (83%) were rated to have a high risk for bias using the Cochrane Collaboration risk of bias tools. None of the studies were classified as having a low risk for bias.

All studies reported improvements in visual acuity and/or anatomical outcomes following injectable therapy, though 83% were found to have a high risk of bias. Only three studies included comparators: one showed intravitreal ranibizumab significantly improved outcomes over sham injections, while another found no significant difference between sub-Tenon triamcinolone and topical nepafenac. Similarly, a third study found no significant difference between sub-Tenon triamcinolone and retrobulbar triamcinolone injections. The majority of included studies were uncontrolled and retrospective, further limiting the strength of the evidence.

Methodology:

PubMed and Embase were searched to 9 August 2021 for English-language studies of PCME treated with intravitreal or sub-Tenon injections that reported visual or anatomical outcomes. A single reviewer screened, extracted data and assessed quality using Cochrane tools for randomised and observational studies; results were synthesised narratively.

Applicability / external validity:

Generalisability is constrained by small, often retrospective studies, heterogeneous diagnostic definitions and scant reporting of surgical details, PCME duration or prior treatments. Well-designed, adequately powered randomised trials with long-term follow-up are required to establish real-world effectiveness and safety.

Geographic focus:

No geographical limits were applied; the distribution of included studies was not stated.

Summary of quality assessment:

Overall confidence in the review’s conclusion is low. Searches were limited to two databases and English-language publications; only one reviewer conducted screening and extraction; an excluded-studies list and grey-literature search were absent. Nevertheless, inclusion/exclusion criteria were explicit, and appropriate quality-assessment tools were used.