Blue-light Autofluorescence Research Articles

Use digital subtraction images of blue-light and near-infrared autofluorescence for the assessment of irregular foveal contour.

The aims of this study are to generate subtraction images of blue-light autofluorescence (BL-AF) and near-infrared autofluorescence (NIR-AF) from normal eyes, eyes with full thickness macular holes, and eyes with irregular foveal contour, and to compare their autofluorescence patterns. This retrospective study included 44 normal eyes of 22 health individuals, 32 eyes with full thickness macular holes of 32 patients, and 36 eyes with irregular foveal contour of 36 patients. BL-AF and NIR-AF were obtained from all patients and used to generate subtraction images using the Image J software. The decreased signal of central patch was recorded. The central foveal thickness (CFT) and outer nucleus layer (ONL) thickness of fovea were measured to calculate the ONL thickness/CFT ratio. The subtraction images showed regularly increased signal in the central macula of all normal eyes. In contrast, decreased signal of central patch was detected in all full thickness macular holes eyes and 26 out of 36 eyes with irregular foveal contour. No significant difference of the ONL thickness/CFT ratio (F = 2.32, P = 0.113) was observed between normal and irregular foveal contour eyes with or without decreased signal of central patch. Both regularly increased signal and decreased signal of central patch were detected in the eyes with irregular foveal contour. Our results suggest that subtraction images are useful for the assessment of certain macular conditions by providing supplementary information to the green-light autofluorescence and BL-AF.

An update on the ocular phenotype in patients with pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is an inherited multi-system disorder characterized by ectopic mineralization and fragmentation of elastic fibers in the skin, the elastic laminae of blood vessels and Bruch’s membrane in the eye. Biallelic mutations in the ATP-binding cassette (ABC) transporter gene ABCC6 on chromosome 16 are responsible for the disease. The pathophysiology is incompletely understood. However, there is consent that a metabolic alteration leads to dysfunction in extracellular calcium homeostasis and subsequent calcification of connective tissues rich in elastic fibers. This review summarizes and aims at explaining the variety of phenotypic ocular findings in patients with PXE. Specialized imaging techniques including white light fundus photography, blue light autofluorescence, near-infrared confocal reflectance imaging, high resolution optical coherence tomography, fluorescein and indocyanine green (ICG) angiography have revealed characteristic lesions at the ocular fundus of PXE patients. These include the classic signs of angioid streaks, peau d’orange, comet lesions, and choroidal neovascularizations (CNVs), but also the more recently recognized features such as chorioretinal atrophy, subretinal fluid independent from CNV, pattern dystrophy-like changes, debris accumulation under the retinal pigment epithelium, reticular drusen and a decreased fluorescence on late phase ICG angiography.

Near-Infrared Autofluorescence and Indocyanine Green Angiography in Central Serous Chorioretinopathy

Purpose: To evaluate the diagnostic potential of near-infrared (NIR) autofluorescence (AF) in central serous chorioretinopathy (CSC) and to present a method to analyze NIR-AF findings quantitatively. Procedures: NIR-AF images, indocyanine green (ICG) angiograms, blue-light autofluorescence (BL-AF) images and fluorescein angiograms were recorded with the use of a confocal scanning laser ophthalmoscope in 19 eyes of 17 patients with CSC. Gray-value ratios were calculated to compare the methods. Results: Using NIR-AF, hypofluorescent spots were observed at the leakage site in 18 of 19 eyes (94.7%). The mean gray-value ratio (±SD) was 0.55 ± 0.22 for the site of the leakage point with NIR-AF and 0.65 ± 0.35 with BL-AF. ICG angiography showed a gray-value ratio of 2.37 ± 2.07. Fluorescein angiography had the best contrast, with a gray-value ratio of 13.44 ± 15.02. Conclusion: NIR-AF demonstrated CSC in 94.7% of the cases. NIR-AF may be a noninvasive alternative to detect CSC.

Macular Congenital Hypertrophy of the Retinal Pigment Epithelium: A Case Report

To describe autofluorescence, microperimetry, and electrophysiology findings in a case of macular congenital hypertrophy of the retinal pigment epithelium (CHRPE). A 58-year-old man was referred to the Department of Ophthalmology of the University of Udine for the evaluation of a pigmented macular lesion in the right eye. The patient underwent blue-light autofluorescence (BL-AF), near-infrared autofluorescence (NIR-AF), electrooculogram, full-field electroretinogram and multifocal electroretinogram (mfERG), microperimetry, computerized visual field, and optical coherence tomography (OCT). BL-AF performed using Heidelberg Retinal Angiograph II revealed a homogeneous hypoautofluorescence, surrounded by a hyperautofluorescent halo. NIR-AF showed a heterogeneous response combining an increased signal in the center of the lesion bordered by a decreased and darker signal. Electrooculogram and full-field electroretinogram were normal in both eyes. mfERG revealed only a limited area of reduced function in the right eye, which matched to location of CHRPE. The segments most functionally altered on mfERG corresponded to the area showing an increased signal in the NIR-AF, possibly reflecting the presence of increased pigment density within a more viable retinal pigment epithelium-Bruch membrane complex. In essence, macular CHRPE is associated with slight defect in retinal sensitivity and outer retinal dysfunction secondary to the anatomic changes characteristic of the lesion.

AUTOFLUORESCENCE IN ADULT-ONSET FOVEOMACULAR VITELLIFORM DYSTROPHY

To describe fundus autofluorescence (FAF) characteristics of adult-onset foveomacular vitelliform dystrophy (AOFVD) and to perform a comparative evaluation of FAF patterns and functional response. Fifteen patients with AOFVD and 10 healthy volunteers underwent complete ophthalmic examination, including visual acuity determination (Early Treatment Diabetic Retinopathy Study charts), blue-light autofluorescence (BL-AF) analysis, near-infrared autofluorescence (NIR-AF) analysis, and microperimetry. : Three different patterns of BL-AF (normal, focal, and patchy) and two of NIR-AF (focal and patchy) were identified in AOFVD. Abnormal BL-AF and NIR-AF patterns were detectable in 86% and 100% of cases, respectively. Patchy BL-AF and NIR-AF patterns are associated with the worst functional outcomes. AOFVD can be associated with different FAF patterns. A functional correlate with visual acuity and retinal sensitivity, measured by means of microperimetry, can be found.