Association of Treatment Type and Loss to Follow-up With Tractional Retinal Detachment in Proliferative Diabetic Retinopathy

Importance The association of proliferative diabetic retinopathy (PDR) interventions of panretinal photocoagulation (PRP) and intravitreal injections (IVIs) with tractional retinal detachment (TRD) is unclear. Objectives To determine whether different treatment types or a 6-month or longer period of loss to follow-up (LTFU) is associated with TRD. Design, Setting, and Participants This nested case-control study included data from January 1, 2000, to June 30, 2021, of patients with PDR. Those who progressed to TRD were matched to non-TRD controls up to a 5:1 ratio. Exclusion criteria included 2 or fewer years in the plan, history of nondiabetic retinopathy, vitreous hemorrhage, previous RD, or any other surgically indicated diagnosis. Patient data were obtained from a deidentified commercial and Medicare Advantage medical claims database. Statistical analysis was performed from January to May 2022. Exposures Primary exposures of interest were prior treatment (PRP, IVI, both) and any period of 6 months or longer in which the patient received no eye care. Main Outcomes and Measures Odds ratios (ORs) of IVI only compared with PRP and 6-month or longer LTFU on development of TRD. Results After application of inclusion and exclusion criteria, a total of 214 patients (mean [SD] age, 55.6 [12.4] years; 115 female [53.7%]) with PDR and TRD were matched to 978 controls (mean [SD] age, 65.6 [11.3] years; 507 female [51.8%]) with only PDR. Among patients with TRD, 69 (32.2%) were treated with laser only, 17 (7.9%) were treated with injection only, 39 (18.2%) were treated with both, and 89 (41.6%) had no prior treatment. Among patients in the PDR-only group, 207 (21.2%) received laser only, 83 (8.5%) received injection only, 57 (5.8%) received both, and 631 (64.5%) received no treatment. After adjusted analysis, no difference in odds of TRD for patients who received injection only compared with patients who received laser only was found (adjusted OR [aOR], 0.56; 95% CI, 0.27-1.14). Patients who received both treatments had higher odds of TRD compared with those who received laser only (aOR, 2.33; 95% CI, 1.21-4.48), and patients who had no treatment had lower odds of TRD (aOR, 0.46; 95% CI, 0.29-0.71; P < .001 for treatment category). Similarly, no difference was seen in the odds of TRD between those with LTFU for 6 months or longer and those without LTFU (aOR, 0.72; 95% CI, 0.49-1.07; P = .11). Conclusions and Relevance Results of this case-control analysis suggest that there is no increased risk of TRD associated with IVI-only treatment or with 6-month or longer periods of LTFU, which supports the findings of other investigations. Nonetheless, LTFU rates continue to remain high in patients with PDR, which can contribute to substantial vision loss regardless of treatment regimen.