In the United States, cataract surgery is usually performed with one to two weeks or more between eyes as a hedge against intraoperative complications that might impact decisions on the second-eye surgery. Many debate whether visual outcomes are better with delayed sequential bilateral cataract surgery or immediate sequential bilateral cataract surgery, during which the surgeon operates on both eyes on the same day as separate procedures. 

Using data from the American Academy of Ophthalmology’s Intelligent Research in Sight (IRIS) Registry, a recent study determined that, compared with short- and long-interval delayed procedures, immediate sequential bilateral cataract surgery is associated with worse visual outcomes, which were statistically significant but may or may not be clinically relevant, depending on patients’ additional risk factors.

The researchers analyzed data from 44,525 patients who underwent immediate bilateral cataract surgery, 897,469 patients who underwent short-interval delayed surgery (one to 14 days between operations) and 882,202 patients who underwent long-interval delayed surgery (15 to 90 days). Mean age at the first surgery for those younger than 87 was 70, and the cohort was 38% male.

After age, race, insurance status, history of AMD, diabetic retinopathy and glaucoma were controlled for, the uncorrected visual acuity (UCVA) of the first surgical eye was higher by 0.41 letters and the best-corrected visual acuity (BCVA) was higher by 0.89 letters in the short interval surgery group vs. the long-interval delayed surgery group. Compared with the long-interval delayed group’s first eye, the UCVA was lower by 2.79 letters and the BCVA by 1.64 letters in the immediate surgery group.

Although the difference was fairly small, short-interval second surgery eyes performed slightly better than the long-interval group. The UCVA was higher by 0.79 letters and the BCVA by 0.48 letters in the short-interval delayed group. Compared with long-interval second eyes, UCVA was lower by 1.67 letters and BCVA by 1.88 letters in the immediate surgery group.

“These results are consistent with the possibility that the interval between operations in the two delayed surgery groups may have allowed for adjustments that resulted in better second eye outcome,” the researchers noted in their paper. “The current study also found that race, insurance type and comorbid eye disease were associated with worse outcomes, suggesting that other factors may have influenced visual outcomes among surgery groups.”

The team believes that further studies that evaluate other potential confounders are warranted because they may explain the small outcome differences found between the surgery groups.