In patients with proliferative diabetic retinopathy (PDR), the absence of panretinal photocoagulation (PRP) laser treatment was identified as the primary risk factor for requiring pars plana vitrectomy, according to a San Francisco-based study.
Study Design
This retrospective, single-center, case control study evaluated risk factors for diabetic vitrectomy in patients with PDR in an urban, safety-net hospital system. A total of 111 patients with PDR who required diabetic vitrectomy were compared to a matched cohort of 111 patients with PDR who did not require vitrectomy. The study included patients over a 5-year period (2017–2022). The main outcome of interest was the odds of developing vision-threating PDR complications requiring vitrectomy.
Outcomes
The absence of panretinal photocoagulation laser treatment (OR 4.78, p = 0.011), longer interval between PDR diagnosis and initial treatment (OR 1.06, p = 0.024), and greater cumulative duration of loss to follow-up (OR 1.10, p = 0.002) were risk factors for diabetic vitrectomy. Greater duration of care in the ophthalmology department was the only protective factor identified (OR 0.75, p = 0.035). Route of referral to the ophthalmology department (telemedicine vs primary physician vs emergency visit) and duration of care in non-ophthalmology departments were not significantly associated with odds of requiring diabetic vitrectomy.
Limitations
Limitations include the relatively moderate sample size and retrospective nature of data collection. Indications for diabetic vitrectomy (including tractional retinal detachment and vitreous hemorrhage) were pooled and not distinguished by severity. As this study evaluated patients enrolled in a county/safety-net healthcare system, results may not be applicable to different care settings.
Clinical Significance
Modifiable risk factors, including establishing care with departments of ophthalmology and limiting duration of loss to follow-up, remain important in preventing vision-threatening complications of PDR and the need to perform diabetic surgery. Early treatment of PDR, including completion of PRP laser in high-risk cases, appears critical in this safety-net setting.
Financial Disclosures: Dr. M. Ali Khan discloses financial relationships with Allergan, Apellis Pharmaceuticals, Genentech (Consultant/Advisor); Regeneron Pharmaceuticals (Grant Support).