At the American Academy of Ophthalmology annual meeting, researchers presented two retrospective analyses linking preoperative hemoglobin A1c to complications after eye surgery. One VA Health System study of more than 127,000 cataract surgeries found that cystoid macular edema incidence increased from 4.2% in patients with A1c below 6.3% to 6.9% in those with A1c at or above 8%. Each 1% increase in A1c raised the odds of CME by about 6%.
Diabetic retinopathy was the strongest predictor of post-cataract CME, tripling the odds, but A1c remained a significant and additive risk factor. The study presenter said the results support more detailed preoperative counseling for patients with higher A1c, while also calling for an interventional study to test whether lowering A1c reduces CME rates.
A separate glaucoma analysis using TriNetX data found that patients with A1c above 8.4% had a 5-year hazard of blebitis or endophthalmitis after tube-shunt surgery of 1.93 compared with patients whose A1c was below 7%. The intermediate group, with A1c between 7% and 8.4%, did not show a significantly higher risk.
Both studies are retrospective and carry limitations, including VA data skewed toward older white males and potential residual confounding. Still, they add evidence that glycemic control before eye surgery may matter for complication risk, and they point toward the need for prospective trials to guide clinical decisions.