Efficacy of intracameral antibiotics following manual small incision cataract surgery in reducing the rates of endophthalmitis: A meta-analysis

Author: Rana K, Bahrami B, van Zyl L, Esterman A, Goggin M.

Geographical coverage: India, Pakistan, China and Nepal

Sector: Cataract surgery

Sub–sector: Antibiotics

Equity focus: Not reported

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Cataract remains a major cause of blindness in the developing world. In these countries, manual small incision cataract surgery (MSICS) is widely used because of its efficiency, low cost and minimal equipment requirements. Although MSICS offers substantial advantages, multiple studies have reported a higher incidence of postoperative endophthalmitis than that seen after phaco‑emulsification. The excess risk may reflect the larger, self‑sealing wound and the fact that patients often present with more advanced cataracts in low‑resource settings. Effective infection control during MSICS is further hindered by inconsistent peri‑operative protocols and difficulties in ensuring postoperative follow‑up. While prophylactic intracameral (IC) antibiotics have been shown to reduce endophthalmitis after phaco‑emulsification, their use during MSICS is still limited because of the paucity of supporting evidence. Given the importance of scaling up high‑volume MSICS in underserved populations, every component of the procedure—including antibiotic prophylaxis—must be critically appraised before widespread implementation.

Objective: To determine whether prophylactic intracameral antibiotics reduce the incidence of postoperative endophthalmitis after MSICS and to explore the effect of routinely placing scleral sutures on endophthalmitis risk.

Main findings: Twelve studies (eight retrospective, four prospective) comprising 1,494,307 eyes met the inclusion criteria; each enrolled at least 500 participants and collectively carried a high risk of bias. Study locations were India (n = 8), China (n = 2), Nepal (n = 1) and Pakistan (n = 1). Intracameral moxifloxacin was administered in 725,324 eyes (48.5 %). Postoperative endophthalmitis occurred in 0.02 % of treated eyes versus 0.07 % of untreated eyes, translating to a risk ratio of 2.94 for the non‑IC group (95 % CI 1.07 – 8.12; *p* = 0.037). Posterior‑capsule rupture rates did not differ between groups and were not associated with infection (coefficient 0.0006; SE 0.005; *p* = 0.91). Use of topical antibiotics showed no significant relation to endophthalmitis risk (coefficient 0.0002; SE 0.004; *p* = 0.97). Analysis of 62 studies (1,499,159 eyes) investigating scleral suturing revealed no cases of endophthalmitis among the 349 eyes in which a routine suture was placed.

Methodology:  MEDLINE and Embase were searched for English‑language articles published between October 1992 and April 2020. Randomised controlled trials and observational studies were eligible if they involved ≥ 500 MSICS cases; studies assessing scleral sutures were included regardless of sample size. Reference lists of included papers were hand‑searched. Two reviewers independently screened studies, extracted data and assessed risk of bias using the Joanna Briggs Institute checklists, resolving disagreements by discussion. Pooled estimates were generated with a random‑effects meta‑analysis; heterogeneity was quantified with the I² statistic and explored using meta‑regression. Publication bias was evaluated with funnel plots and Egger’s test.

Applicability/external validity: The predominance of non‑randomised designs increases the likelihood of bias and limits generalisability, yet the results support incorporating intracameral moxifloxacin into MSICS protocols in comparable high‑volume settings.

Geographic focus: All included studies originated from South and East Asia (India, Pakistan, China and Nepal).

Summary of quality assessment: Overall confidence in the evidence is low. Searches were systematic and eligibility clearly specified; two reviewers independently screened studies and assessed bias. Study characteristics were comprehensively reported and appropriate statistical methods used. Nonetheless, English‑language restriction, absence of an exclusion list and the reliance on non‑randomised studies constrain certainty.