Spectrally resolved autofluorescence imaging in posterior uveitis

Abstract

Clinical discrimination of posterior uveitis entities remains a challenge. This exploratory, cross-sectional study investigated the green (GEFC) and red emission fluorescent components (REFC) of retinal and choroidal lesions in posterior uveitis to facilitate discrimination of the different entities. Eyes were imaged by color fundus photography, spectrally resolved fundus autofluorescence (Color-FAF) and optical coherence tomography. Retinal/choroidal lesions’ intensities of GEFC (500–560 nm) and REFC (560–700 nm) were determined, and intensity-normalized Color-FAF images were compared for birdshot chorioretinopathy, ocular sarcoidosis, acute posterior multifocal placoid pigment epitheliopathy (APMPPE), and punctate inner choroidopathy (PIC). Multivariable regression analyses were performed to reveal possible confounders. 76 eyes of 45 patients were included with a total of 845 lesions. Mean GEFC/REFC ratios were 0.82 ± 0.10, 0.92 ± 0.11, 0.86 ± 0.10, and 1.09 ± 0.19 for birdshot chorioretinopathy, sarcoidosis, APMPPE, and PIC lesions, respectively, and were significantly different in repeated measures ANOVA (p < 0.0001). Non-pigmented retinal/choroidal lesions, macular neovascularizations, and fundus areas of choroidal thinning featured predominantly GEFC, and pigmented retinal lesions predominantly REFC. Color-FAF imaging revealed involvement of both, short- and long-wavelength emission fluorophores in posterior uveitis. The GEFC/REFC ratio of retinal and choroidal lesions was significantly different between distinct subgroups. Hence, this novel imaging biomarker could aid diagnosis and differentiation of posterior uveitis entities.

White Dot Syndromes: Report of Three Cases

“…Wintergerst et al [ 7 ] and Yeh et al [ 4 ] emphasized the utility of FAF in the ocular examination of white dot syndromes. It is a rapid and noninvasive tool to monitor lesions, guide treatment, detect recurrences, and evaluate patient’s response to the treatment.…”

“…While traditional ophthalmic assessments, fundus photography, and FFA played crucial roles in white dot syndrome evaluation, FAF imaging emerged as a valuable tool for emphasizing areas of disease activity and facilitating distinctions between different conditions. Wintergerst et al noted that foveal hypoautofluorescence seemed to serve as an indicator for moderate to severe visual impairment [ 7 ].…”

“…Wintergerst et al [ 7 ] introduced the green emission fluorescent component/red emission fluorescent component ratio as a novel imaging biomarker for inflammatory chorioretinopathies using spectrally resolved FAF. It provides means for differentiation of posterior uveitis entities, which can be difficult to distinguish otherwise [ 7 ]. Besides, Yeh et al [ 4 ] observed the correlation between vision loss and foveal hypoautofluorescence.…”

Fundus Autofluorescence in Posterior and Panuveitis—An Under-Estimated Imaging Technique: A Review and Case Series

“…Interestingly, macular hyperfluorescent lesions are not associated with worse LogMAR visual acuity [43]. Also, spectrally resolved autofluorescence imaging can aid in diagnosing BSCR as distinct from similar posterior uveitis entities utilizing the ratio between green and red emission fluorescent components [44].…”

“…Ocular involvement is observed in about 30-50% of patients with sarcoidosis [7]. Inflammatory lesions involving RPE can present as hyperautofluorescent, while healed lesions can present as hypoautofluorescence due to atrophy of the RPE and the overlying photoreceptors [7,44,48]. These findings, observed on swBAF (450 nm excitation wavelength), corresponded to choroidal thinning on OCT and white dots in CFP [44].…”