Abstract
Purpose :
Choroidal ischemia is one of the major factors in the pathogenesis of age-related macular degeneration (AMD). Studies have shown that panretinal photocoagulation (PRP) increases macular choroidal perfusion and may offer a protective effect against neovascular AMD (nAMD). We used a large health claims dataset to evaluate this hypothesis.
Methods :
Optum’s Clinformatics® Data Mart database of health claims includes records of over 57 million patients between 2007 and 2017. The database is over 70% white and given the relatively low incidence of AMD in the non-white population our analysis focused on Caucasian patients. Only patients above 50 years of age who had least one encounter with an ophthalmologist or optometrist were included. Each patient was coded based on ICD-9 diagnosis for having diabetes mellitus (250.xx), subtype of diabetic retinopathy (362.01-07), and subtype of AMD (362.50-52). Because PRP is the mainstay of treatment for proliferative diabetic retinopathy (PDR), we used PDR as a surrogate for PRP. Prevalence of AMD was compared between patients with non-PDR (NPDR) and PDR, with additional stratification by age and sex.
Results :
5,707,013 patients met the inclusion criteria and were 57.3% female and roughly evenly distributed in 10-year brackets between ages 50 to 90 years old. 30.2% of patients had DM, 4.9% with NPDR and 1% with PDR. 6.9% of patients had AMD, with 2% having nAMD. In the youngest age bracket, the prevalence of nAMD was higher in patients with PDR compared to NPDR (OR=3.47); but this OR decreased with age (OR=1.45 for the oldest bracket). High rates of co-diagnosed diabetic macular edema (DME) was seen in these nAMD patients (44% in PDR, 20% in NPDR) which could confound the diagnosis of nAMD. Excluding patients with co-morbid DME the OR decreased slightly to 3.24 in the youngest to 1.36 in the oldest age bracket. The P-values of all reported OR are <0.00001.
Conclusions :
Analysis of a large claims database was used to evaluate if PRP conferred a protection against the development of AMD, using PDR as a surrogate marker for PRP. The results show that in whites, PDR is actually a risk factor in developing nAMD, and by proxy, PRP is likely not protective. These data suggest that the microvascular insult and proclivity towards a neovascular response in PDR increases the risk of nAMD, which is not alleviated by PRP.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.