Swept‐source optical coherence tomography objective composite activity score for uveitis

Abstract

Purpose To develop an objective intraocular inflammation composite score. Methods Cross‐sectional study. Non‐invasive image acquisition and processing were conducted from April 2017 to April 2019. Inflammation‐grade stratified eyes from patients with active, inactive uveitis and healthy controls were recruited. After clinical assessment, four anterior and posterior segment image acquisition protocols per eye, using swept‐source optical coherence tomography (SS‐OCT), were performed at inclusion. Eight imaging biomarkers in three domains: anterior, intermediate and posterior were studied. They were ranked and selected by discriminatory power and correlation with clinical scores. A final SS‐OCT‐derived composite uveitis activity score (SS‐UAS) was developed through multiple linear regression. Results We studied 224 eyes with uveitis (165 active and 59 inactive) from 165 patients (mean age 46.6 SD 15.5 years; 55.3% women) and 38 eyes from 19 healthy controls (mean age 43.6 SD 17.1; 47% women). The selected SS‐OCT‐derived biomarkers to build the final score were anterior chamber hyper‐reflective dots (anterior), high‐definition relative vitreous intensity (intermediate) and the averaged thickened retinal index (posterior). Swept‐source (SS)‐UAS was highly discriminant between active and inactive, and between active and healthy eyes (means 2.06 SD 1.86, 0.93 SD 0.44, and 0.96 SD 0.38, respectively, both p ‐, Mann–Whitney U). Construct validity (Cronbach's alpha = 0.7), internal consistency, criterion validity and reliability (concordance correlation coefficient intra‐rater = 0.99, 95% CI: 0.98–0.99; inter‐rater = 0.98, 95% CI: 0.96–0.99) were favourable. Conclusions Global intraocular inflammation can potentially be staged and scored objectively, continuously, consistently and in a valid manner through the combined processing of SS‐OCT scans.

Non‐invasive biomarkers for close activity monitoring in birdshot chorioretinitis: Optical coherence tomography angiography and beyond

“…OCT-A all retina en face thickness maps of the fundus field were exported in colour scale for processing and calculating the averaged index of the amount of red and blue in RGB (Red-Green-Blue) units per area in pixels. The averaged thickened retinal index (ATRI) and the averaged atrophy retinal index (AARI) were studied after thickness map processing, as described elsewhere (Llorenç et al, 2021).…”

Measuring Inflammation in the Vitreous and Retina: A Narrative Review

“…Moreover, the correlation of this marker with global intraocular inflammation assessment and NEI vitreous haze scale was poor and nonsignificant. 32 The use of OCT vitreous signal intensity as an instrument-derived measure of vitreous haze was first described by Keane et al in 2014. 26 Macula-centred OCT scans were manually segmented using custom software "OCTOR" and pixel intensity summed to derive a mean OCT intensity.…”

“…[65][66][67][68] The use of thickness maps for a range of relevant structures (perivascular, macular, peripapillary, subretinal and intraretinal foci or fluid) can be used as indirect signs of chorioretinal inflammation in an holistic way. 32,69 There are however challenges. For example, the limited scanning frame of en face thickness maps and the challenge of differentiating whether persistent thickening of structures in uveitis is due to active inflammation or established complications ('damage').…”

“…Moreover, the mean choroidal thickness was not significantly different between eyes with active uveitis of various etiologies and matched inactive or healthy control eyes. 32…”