Glaucoma surgery linked to incidence of early endophthalmitis

The incidence of early endophthalmitis was higher for both glaucoma and combined cataract/glaucoma surgeries than for cataract surgery alone, reveals a study. The incidence was highest among tube shunts.

This retrospective, longitudinal study determined early endophthalmitis incidence and risk factors following glaucoma surgeries among Medicare Fee-for-Service (FFS) and Medicare Advantage beneficiaries in the US aged ≥65 years undergoing surgery.

Researchers used Medicare claims to determine all patients who underwent surgery from 2016 to 2019 and diagnostic codes to identify endophthalmitis cases within 42 days of the index surgery. Finally, they used multivariable logistic regression models to assess factors contributing to postoperative endophthalmitis.

Of the 466,928 glaucoma surgeries performed, 310,823 (66.6 percent) were combined with cataract surgery. A total of 8,460,360 cataract surgeries alone served as reference. Most glaucoma procedures done were microinvasive (67.8 percent), while the rest were by trabeculectomy (14.0 percent), tube shunt (10.9 percent), and others (7.3 percent).

Following all these glaucoma procedures, endophthalmitis developed in 572 patients. Incidence of endophthalmitis was 1.5 per 1,000 procedures (95 percent confidence interval [CI], 1.3‒1.7) after glaucoma surgery, 1.1 (95 percent CI, 1.0‒1.2) after combined cataract glaucoma surgery, and 0.8 (95 percent CI, 0.8‒0.8) after cataract surgery alone.

Diagnosis of endophthalmitis was much earlier for combined cataract/glaucoma or cataract surgeries alone than for glaucoma surgeries (8 and 6 vs 16.5 days, respectively).

Notably, tube shunts were found to be the only risk factor for endophthalmitis for both stand-alone (adjusted odds ratio [aOR], 1.8; p=0.002) and combined surgery (aOR, 1.8; p=0.047). Charlson Comorbidity Index was another predictor for both stand-alone (aOR, 1.1; p=0.001) and combined surgeries (aOR, 1.06; p=0.049).

For combined cataract/glaucoma surgeries, age (aOR, 1.03; p=0.004) and male gender (aOR, 1.46; p=0.001) were significant risk factors for endophthalmitis.