Purpose
To determine whether individuals with diabetes mellitus (DM) who undergo cataract surgery are at increased risk of being diagnosed with diabetic retinopathy (DR) relative to diabetic patients with cataracts who do not undergo surgery.
Methods
This is a longitudinal cohort study, that includes all beneficiaries with diabetes but no pre-existing DR, >30 years old, who were continuously enrolled in a managed care network for at least 2 years and who had ≥2 visits to an eye care provider from 2001-2009. Insurance billing codes were used to identify individuals with DM who were newly diagnosed with DR and those requiring interventions for DR. Multivariable Cox regression analyses were used to determine whether receipt of cataract surgery affected the risk of getting diagnosed with non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), or receiving medical or surgical interventions for DR. Adjusted hazard ratios (HR) with 95% confidence intervals (CI) of being diagnosed with NPDR, PDR, or requiring a medical or surgical intervention for DR were calculated. Regression models adjusted for sociodemographic factors, medical and ocular co-morbidities.
Results
Among the 431,310 enrollees with DM who met the study inclusion criteria, 17,269 (4.0%) were diagnosed with NPDR and 5,419 (1.3%) received a diagnosis of PDR during a mean follow-up of 4.4 ± 2.0 years. During the study period, 47,186 individuals (10.9%) underwent ≥ 1 cataract surgeries. After adjustment for potential confounders, individuals with DM who underwent cataract surgery had a 34% increased hazard of getting diagnosed with NPDR (adjusted HR = 1.34, 95% CI 1.20-1.50), a 70% increased hazard of getting diagnosed with PDR (adjusted HR = 1.70, 95% CI 1.45-2.00), and a 66% increased hazard of undergoing a medical or surgical intervention for diabetic retinopathy (adjusted HR = 1.66, 95% CI 1.46-1.90) relative to those with DM who did not undergo cataract surgery.
Conclusions
Individuals with DM who undergo cataract surgery are at increased risk of getting diagnosed with DR and undergoing interventions for DR. Efforts should be made to identify factors that may predispose patients with DM to retinopathy after cataract surgery and surgeons should reduce modifiable risk factors before recommending cataract surgery to patients with DM.
Keywords: 464 clinical (human) or epidemiologic studies: risk factor assessment •
499 diabetic retinopathy •
445 cataract