OCT Predictors of Progression to Dry Atrophic AMD
Ophthalmology, December 2017
Certain patterns on spectral-domain optical coherence tomography (SD-OCT) have been linked to subsequent atrophy on color photography images from patients with age-related macular degeneration (AMD). Using SD-OCT findings from a previous study, Sleiman et al. sought to determine risk factors for new-onset geographic atrophy (GA) and central GA. They found that abnormal thinning volume of the retinal pigment epithelium (RPE) drusen complex was a strong predictor, as were atrophy or absence of the RPE layer.
For this prospective longitudinal study, the researchers evaluated a subset of patients from the Age-Related Eye Disease Study 2 (AREDS2). All 317 patients (317 eyes) in the study had bilateral large drusen or noncentral GA and at least 1 eye without advanced AMD. Baseline qualitative and quantitative SD-OCT variables were captured using standardized grading and semiautomated segmentation, respectively. Up to 7 years later, annual outcomes were extracted and were analyzed to fit multivariate logistic regression models, from which a risk calculator was derived.
Among 292 eyes with no advanced disease on baseline color photography, 46 (15.8%) developed central GA during the follow-up period (median, 4.0 years). Age-adjusted predictors determined from SD-OCT findings were abnormal thinning of the RPE drusen complex volume, intraretinal fluid or cystoid spaces, hyperreflective foci, and atrophy or absence of the RPE layer. Among the 265 eyes with no evidence of GA on baseline photography, 70 (26.4%) developed new-onset GA during follow-up (median, 4.1 years). Independent predictors were hyperreflective foci, RPE layer atrophy/absence, choroid thickness in the absence of subretinal drusenoid deposits, photoreceptor outer segment loss, volume of the RPE drusen complex, and abnormal thinning of the volume of this complex. The models yielded a calculator capable of computing risk probability of new-onset and central GA within 1 to 5 years.
The authors concluded that this risk-assessment model may simplify SD-OCT grading and, with future validation, could become a clinical prognostic tool. An online version of their calculator is available and will be updated as appropriate.
The original article can be found here.