Various Factors Impact Visual Outcomes After Cataract Surgery in People With Diabetes

Emily Y. Chew, MD

New findings suggest the visual prognosis after cataract surgery is usually favorable in individuals with type 2 diabetes (T2D), with two-thirds of eyes achieving outcomes of 20/40 or better in the Action to Control Cardiovascular Risk in Diabetes (ACCORD)-Eye study

However, the rates observed in the study remained both comparable to previous reports on the subject and lower than the general population, despite updated clinical guidelines and medical developments presumably leading to better management of the disease.

“Notable factors associated with visual outcomes included preoperative visual acuity (VA) and diabetic retinopathy, but not HbA1c, underscoring that while certain ocular measures may help to evaluate visual potential, systemic parameters may not be as valuable,” wrote study author Emily Y. Chew, MD, National Institutes of Health.

Advances in cataract surgery and the treatment of diabetes have been associated with improved postoperative outcomes and decreased risk of diabetic complications, respectively. These advances may additionally have improved the potential for better visual outcomes after cataract surgery in people with diabetes.

Utilizing the ACCORD population, investigators set out to analyze visual outcomes after cataract surgery and further identify predictors of good visual outcomes in the ACCORD-Eye substudy. Eyes that underwent cataract surgery during the ACCORD study follow-up and had both a preoperative VA recorded within 2 years prior to surgery and a postoperative VA recorded within 2 years after surgery were included in the current analysis.

A subset of eyes received fundus photographs graded for diabetic retinopathy. The analysis examined sociodemographic, systemic and ocular factors associated with good visual outcome after cataract surgery and defined the latter as postoperative VA of 20/40 or better.

Ultimately, of the 17774 eyes for which eye-related data and VA data were collected, 1816 eyes (10.8%) underwent cataract surgery during follow-up and 1136 (62.6%) eyes of 784 participants were included in the analysis after applying the inclusion criteria. Individuals in the study reported undergoing cataract surgery at a median time of 3.0 years after randomization.

From the overall sample, 363 eyes (31.9%) of 251 participants received fundus photographs graded for diabetic retinopathy. In this subsample, data show 179 eyes (49.4%) had no diabetic retinopathy, 50 eyes (13.8%) had mild nonproliferative diabetic retinopathy (NPDR), 124 eyes (34.3%) had moderate NPDR, 3 eyes (0.8%) had severe NPDR, and 6 eyes (1.7%) had PDR.

In the overall sample, 762 eyes (67.1%) achieved a good visual outcome of 20/40 or better. In the subsample of eyes that received fundus photographs, 265 eyes (73.2%) achieved a good visual outcome. The mean change in VA score after cataract surgery was +3.7 ± 18.4 Early Treatment Diabetic Retinopathy Study (ETDRS) letters.

Moreover, the factors associated with good visual outcome were the highest level of education (college vs. some high school: odds ratio [OR], 2.35; 95% CI, 1.44 to 3.82), preoperative VA (reference, 20/20 or better vs worse than 20/200, OR, 10.59; 95% CI, 4.07 to 27.54), and bilateral cataract surgery (OR, 1.55; 95% CI, 1.14 to 2.10).

Factors including race, insurance status, diabetes duration, HbA1c, lipid levels, blood pressure, insulin, time of cataract surgery and randomization to medical treatments were not significantly associated with good visual outcomes.

In the subsample that received fundus photographs, the absence of diabetic retinopathy was associated with good visual outcome (OR, 1.73; 95% CI, 1.02 to 2.94). The presence or absence and the severity of diabetic retinopathy may be particularly important for visual outcomes, but the sample size was not large enough to detect any significant effect.

“Although the current visual prognosis after cataract surgery is usually favorable, certain factors still limit the visual potential in those with diabetes and continued efforts to improve visual outcomes are necessary,” Chew concluded.

The study, “Visual acuity outcomes after cataract surgery in type 2 diabetes: the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study,” was published in the British Journal of Ophthalmology.