Abstract
Purpose :
To determine the risk factors for retinal scar development during the five year follow-up in the Comparison of Age-related Macular Degeneration Treatments Trials (CATT)
Methods :
Participants were assigned to ranibizumab or bevacizumab treatment and to 1 of 3 dosing regimens for 2 years, and were released from the clinical trial after 2 years. Study eye color fundus photographs and fluorescein angiograms at year 1, year 2 and year 5 were assessed for scar by masked readers. Incidence of scar was estimated with Kaplan-Meier curves. We evaluated the association between baseline demographic, visual acuity, morphologic features on photograph and optical coherence tomography (OCT), and drug treatment in the first 2 years and the development of retinal scar by univariate and multivariate proportional hazard models
Results :
Among 1061 study eyes, the incidence of retinal scar was 32% at 1 year, 46% at 2 years, and 56% at 5 years. (Figure 1). Increased risk of scar was observed with predominantly classic type of CNV at baseline when compared with occult CNV (adjusted Hazards Ratio (aHR)=4.49, 95% Confidence Interval (CI) 3.34, 6.04 ), larger hemorrhages of >1 disc diameter associated with the CNV lesion vs no hemorrhage (aHR=2.28, 95%CI: 1.49, 3.47), increased (>212 µm) foveal retinal thickness vs <120 µm thickness (aHR=2.58, 95% CI: 1.69, 3.94), increased thickness (>275 µm) of the subretinal tissue complex at foveal center vs ≤75 µm (aHR=2.64, 95%CI: 1.81, 3.84), the presence of sub-retinal hyper reflective material (aHR=1.72, 95% CI: 1.25, 2.36), absence of RPE elevation (aHR=1.71, 95% CI: 1.21, 2.41), and better visual acuity in the fellow eye (aHR=1.34, 95% CI: 1.00-1.79 for 20/20 or better vs. 20/50 or worse) (Table 1). Ranibizumab or bevacizumab treatment assigned in the first 2 years was not associated with development of scar in 5 years (p=0.23 in adjusted analysis).
Conclusions :
About half of the CATT subjects developed scar in five years which was apparent in most eyes by 2 years. Larger hemorrhages, classic CNV at baseline and subretinal thickness increase the risk of developing scar after initiation of anti-VEGF therapy. Risk of scar was similar between eyes treated with ranibizumab and bevacizumab during the first two years
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.