Abstract
Purpose :
To determine if the detection of choroidal hyper-transmission defects (hyperTDs) on en face OCT images serve as a risk factor for the formation of nascent geographic atrophy (nGA) or GA in eyes with intermediate AMD (iAMD), we compared the onset and persistence of hyperTDs with the gold-standard detection of nGA using averaged OCT B-scans
Methods :
Patients with bilateral large drusen were enrolled in a natural history study and imaged with both Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany) and Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA) instruments at 6-month interval over 36 months. The Spectralis SD-OCT B-scans were used to grade for nGA at the Centre for Eye Research Australia. En face Cirrus SD-OCT images were graded for the presence of hyperTDs in a masked fashion at the Bascom Palmer Eye Institute. HyperTDs with greatest linear dimensions (GLDs) ≥ 125µm were measured and tracked throughout all available visits. The size cut-off for persistent and non-persistent hyperTDs was determined based on baseline GLD measurements. Over 36 months, the association between these HTDs and the presence of nGA was assessed.
Results :
A total of 157 eyes from 81 patients were available to be graded. At baseline, Cirrus SD-OCT scans were available on 133 eyes, and 39 hyperTDs from 27 eyes of 22 subjects were classified as either persistent (26 lesions) or non-persistent (13 lesions) over 36 months. Receiver Operating Characteristic curve analysis suggested hyperTDs with baseline GLDs above a threshold of 250µm to 300µm fulfilled the definition of persistent lesions. After grading the entire population of 157 eyes, a significant association (p < 0.001) was found between nGA gradings and the masked gradings of hyperTDs with GLD ≥ 250µm (OR, 14.5, 95% CI: 4.8, 54.0) or 300µm (OR, 15.2, 95% CI: 5.0, 56.7). HyperTDs with GLD ≥ 250 or 300µm had an excellent negative predictive value of ≥ 94%, but a poor positive predictive value (PPV) of ≤ 40% for detecting nGA. The poor PPV appeared to be due to the earlier detection of lesions that would become nGA.
Conclusions :
Choroidal hyperTDs detected on en face SD-OCT images with a GLD ≥ 250µm or 300µm were strongly associated with the presence of nGA and may serve as a useful risk factor for the early detection of disease progression of iAMD to GA.
This is a 2021 ARVO Annual Meeting abstract.