Abstract
To evaluate the prognostic significance of persistent choroidal hypertransmission defects (HyperTDs) detected on en face OCT imaging for predicting the progression of drusen to geographic atrophy (GA) by analyzing their association with the presence of nascent GA (nGA).
Retrospective, post hoc subgroup analysis of a prospective study.
Patients with bilateral soft drusen from a natural history study.
Participants underwent both Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany) and Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA) imaging over 36 months at 6-month intervals. The Spectralis SD-OCT B-scans were used to grade nGA. En face imaging of Cirrus SD-OCT scans was used to detect HyperTDs, masked to nGA gradings. Hypertransmission defects with greatest linear dimension (GLD) of 125 μm or more were tracked throughout visits.
The GLD at baseline for best discrimination between persistent and transient HyperTDs over 36 months and the association between these HyperTDs with nGA assessed with odds ratio.
A total of 157 eyes from 81 patients were enrolled. Cirrus SD-OCT scans were available for 133 eyes at baseline, and 39 HyperTDs lesions from 27 eyes of 22 participants were classified as either persistent (26 lesions) or transient (13 lesions) over 36 months. Receiver operating characteristic curve analysis suggested that HyperTDs with baseline GLD of 250 μm or more or 300 μm fit the definition of persistent. After grading the entire population of 157 eyes, a significant association (P < 0.001) was found between nGA gradings and masked HyperTD gradings with GLD of 250 μm or more (odds ratio, 14.5; 95% confidence interval, 4.8-54.0) or 300 μm (odds ratio, 15.2; 95% confidence interval, 5.0-56.7). Identification of HyperTDs was associated with more nGA false-positive results than false-negative results (P < 0.001). Hypertransmission defects with GLD of 250 μm or more or 300 μm showed excellent negative predictive value of 94% or more, but poor positive predictive value of 40% or less, for detecting nGA.
Choroidal HyperTDs on en face OCT imaging were associated strongly with nGA. The potential of using HyperTDs with GLD of 250 μm or more or 300 μm as a risk factor for the progression of drusen to GA is promising and requires further study.
