Vitrectomised eyes had nearly four times the risk of macular oedema after cataract surgery

Design

Retrospective propensity-matched cohort (TriNetX US network)

Population

7318 matched pairs of adults having cataract surgery with vs without prior vitrectomy

Primary outcome

Cystoid macular oedema 30–90 days after cataract surgery

Effect

4.59% vs 1.23%; difference 3.36% (2.82–3.90); RR 3.73 (2.97–4.70)

Whether a previous pars plana vitrectomy raises the risk of cystoid macular oedema after cataract surgery has been debated. This retrospective cohort used the US TriNetX network (2005 to 2025), excluding eyes with pre-existing CME or known risk factors, and propensity-matched 7318 patients with a vitrectomy at least six months earlier to 7318 without.

CME within 30 to 90 days occurred in 4.59% of vitrectomised eyes and 1.23% of controls (absolute difference 3.36%, 95% CI 2.82 to 3.90; RR 3.73, 2.97 to 4.70). The excess held whether the vitrectomy had been for retinal detachment (5.65% vs 1.22%) or other indications (3.99% vs 1.23%), and after excluding complicated cataract surgery (4.59% vs 1.26%).

For surgeons, a vitrectomised eye should be counselled and followed as higher risk. Whether prophylactic topical NSAIDs or routine OCT change outcomes was not tested, and the diagnosis rests on billing codes without visual acuity. Many Indian patients who have had vitrectomy for diabetic retinopathy will later need cataract surgery, and diabetes adds its own CME risk.

• Record previous vitrectomy as a CME risk factor in pre-operative cataract assessment.
• Counsel patients with a vitrectomised eye that macular oedema after cataract surgery is about three to four times more likely.
• Consider a topical NSAID alongside steroid after cataract surgery in a vitrectomised eye, particularly with diabetes.
• Arrange OCT at the one-month review if vision is below expectation.
• Refer promptly if blurred vision recurs after initial improvement.

Why it matters

It quantifies a debated risk factor with a large matched cohort, for use in consent.

Don't overread it

Diagnoses come from billing codes without visual outcomes; the study cannot say whether prophylaxis or OCT monitoring helps.

The statistics, in plain English

A risk ratio of 3.73 sounds large, but the absolute difference is about 3.4 percentage points: roughly one extra case of CME for every 30 vitrectomised eyes operated.

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