Abstract
Purpose :
Despite optical coherence tomography (OCTA) being available in many ophthalmology units, there is controversy regarding whether it can replace fluorescent angiography (FA) in the diagnosis of wet age-related macular degeneration (wAMD). The main aim of this study is to determine whether the sensitivity and specificity of OCTA combined with Optical Coherence Tomography (OCT) is non-inferior to that of FA combined with OCT for the detection of wAMD.
Methods :
This is a non-inferiority, prospective, randomised diagnostic accuracy study. Participants are patients with a suspicion of wAMD who present to an NHS secondary care ophthalmology unit in the UK. They will be randomised to OCT+FA or OCT+OCTA trial arms. Following random allocation using a secure online randomisation system, a clinician will review the OCT with either FA or OCTA first and make an initial diagnosis (wAMD: yes/no). Then the remaining test will be reviewed to further confirm or exclude wAMD. Comparison of the two clinical diagnoses in each arm will provide evidence concerning the added value of OCTA vs FA in patients with an OCT suspicious of wAMD. According to the sample size calculation, allowing for 10% withdrawal of consent, missing data and inconclusive test results, we will aim to recruit 1,067 patients. The non-inferiority of OCTA vs FA will be evaluated with two-sided 95% confidence intervals for the differences in sensitivity and specificity.
Results :
The primary outcome of the study will be the difference in sensitivity and specificity between OCT+OCTA and OCT+FA for wAMD detection. Secondary outcomes will include sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of OCTA alone and FFA alone and PPV of OCT for the detection of wAMD. We will also evaluate the intra- and inter-rater variation and perform an economic analysis of the incremental cost per true positive detected and incremental cost per correct diagnosis for wAMD.
Conclusions :
This study will provide clinically significant information on the diagnostic suitability of OCTA vs FA for the diagnosis of wAMD and validated criteria for OCTA-based diagnosis of wAMD, which can provide evidence to change the goldstandard imaging guidelines.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.