Fundus Autofluorescence Intensity Research Articles

Morphological and functional involvement of the inner retina in retinitis pigmentosa.

To investigate the morphological retinal parameters associated with retinal sensitivity status in retinitis pigmentosa (RP) through a quantitative multimodal imaging approach. The study was designed as an observational, prospective case series, including RP patients and healthy controls. Multimodal imaging included fundus autofluorescence (FAF), structural optical coherence tomography (OCT), OCT angiography (OCTA) and microperimetry (MP). The follow-up lasted 12 months. For each imaging modality, we performed an overall quantitative analysis and a detailed investigation based on the ETDRS-9 sectors grid. Quantitative parameters included the thickness of each retinal and choroidal layer, vessel density (VD), choriocapillaris porosity (CCP), FAF intensity and MP retinal sensitivity. We included 40 eyes (40 patients) affected by RP and 40 healthy eyes (40 controls). Mean baseline BCVA was 0.14 ± 0.18 LogMAR, with 0.18 ± 0.24 LogMAR after 1-year of follow-up. RP eyes showed statistically significant alterations of retinal and choroidal layers on the ETDRS-9 sectors grid, significant reduction of VD values and MP retinal sensitivity, and significantly higher CCP than controls. The inner retinal layers proved closely associated with the functional integrity of the posterior pole. In addition, our ROC analysis provided quantitative cutoffs connected significantly with a high probability of observing a partial sparing of MP retinal sensitivity. The inner retinal layers are closely associated with the functional integrity of the posterior pole in RP. FAF intensity reduction may be interpreted as lipofuscin metabolism impairment inducing increased phototoxic distress for retinal structures. Vascular involvement contributes to the morpho-functional deterioration of the macular region in RP.

Spectral fundus autofluorescence peak emission wavelength in ageing and AMD.

To investigate the spectral characteristics of fundus autofluorescence (FAF) in AMD patients and controls. Fundus autofluorescence spectral characteristics was described by the peak emission wavelength (PEW) of the spectra. Peak emission wavelength (PEW) was derived from the ratio of FAF recordings in two spectral channels at 500-560 nm and 560-720 nm by fluorescence lifetime imaging ophthalmoscopy. The ratio of FAF intensity in both channels was related to PEW by a calibration procedure. Peak emission wavelength (PEW) measurements were done in 44 young (mean age: 24.0 ± 3.8 years) and 18 elderly (mean age: 67.5 ± 10.2 years) healthy subjects as well as 63 patients with AMD (mean age: 74.0 ± 7.3 years) in each pixel of a 30° imaging field. The values were averaged over the central area, the inner and the outer ring of the ETDRS grid. There was no significant difference between PEW in young and elderly controls. However, PEW was significantly shorter in AMD patients (ETDRS grid centre: 571 ± 26 nm versus 599 ± 17 nm for elderly controls, inner ring: 596 ± 17 nm versus 611 ± 11 nm, outer ring: 602 ± 16 nm versus 614 ± 11 nm). After a mean follow-up time of 50.8 ± 10.8 months, the PEW in the patients decreased significantly by 9 ± 19 nm in the inner ring of the grid. Patients, showing progression to atrophic AMD in the follow up, had significantly (p ≤ 0.018) shorter PEW at baseline than non-progressing patients. Peak emission wavelength (PEW) is related to AMD pathology and might be a diagnostic marker in AMD. Possibly, a short PEW can predict progression to retinal and/or pigment epithelium atrophy.

Choroideremia Gene Therapy.

Choroideremia Gene Therapy.

Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) in Patients with Choroideremia.

PurposeTo provide a detailed characterization of choroideremia (CHM) using fluorescence lifetime imaging ophthalmoscopy (FLIO) and to provide a deeper understanding of disease-related changes and progression.MethodsTwenty-eight eyes of 14 patients with genetically confirmed CHM (mean age, 28 ± 14 years) and 14 age-matched healthy subjects were investigated in this study. FLIO images of a 30° retinal field were collected at the Moran Eye Center using a Heidelberg Engineering FLIO device. FLIO lifetimes were recorded in short spectral channels (SSC; 498–560 nm) and long spectral channels (LSC; 560–720 nm), and mean autofluorescence lifetimes (τm) were calculated. Optical coherence tomography (OCT) scans were recorded for each patient. Three patients were re-imaged after a year.ResultsPatients with CHM exhibit specific FLIO lifetime patterns. Prolonged FLIO lifetimes (around 600–700 ps) were found in the peripheral macula corresponding to atrophy in OCT imaging. In the central macula, τm was unrelated to autofluorescence intensity. Some areas of persistent retinal pigment epithelial islands had prolonged FLIO lifetimes, whereas other areas of hypofluorescence had short FLIO lifetimes. At 1-year follow-up, FLIO lifetimes were significantly prolonged within atrophic areas (P < 0.05).ConclusionsFLIO shows distinct patterns in patients with CHM, indicating lesions of atrophy and areas of preserved function in the presence or absence of findings in fundus autofluorescence intensity images. FLIO may provide differentiated knowledge about pathophysiology and atrophy progression in CHM compared to conventional imaging modalities.Translational RelevanceFLIO shows distinctive lifetime patterns that potentially identify areas of function, atrophy, and disease progression in patients with CHM.

Determinants of Cone and Rod Functions in Geographic Atrophy: AI-Based Structure-Function Correlation

To investigate the association between retinal microstructure and cone and rod function in geographic atrophy (GA) secondary to age-related macular degeneration (AMD) by using artificial intelligence (AI) algorithms. Prospective, observational case series. A total of 41 eyes of 41 patients (75.8 ± 8.4 years old; 22 females) from a tertiary referral hospital were included. Mesopic, dark-adapted (DA) cyan and red sensitivities were assessed by using fundus-controlled perimetry ("microperimetry"); and retinal microstructure was assessed by using spectral-domain optical-coherence-tomography (SD-OCT), fundus autofluorescence (FAF), and near-infrared-reflectance (IR) imaging. Layer thicknesses and intensities and FAF and IR intensities were extracted for each test point. The cross-validated mean absolute error (MAE) was evaluated for random forest-based predictions of retinal sensitivity with and without patient-specific training data and percentage of increased mean-squared error (%IncMSE) as measurement of feature importance. Retinal sensitivity was predicted with a MAE of 4.64 dB for mesopic, 4.89 dB for DA cyan, and 4.40 dB for DA red testing in the absence of patient-specific data. Partial addition of patient-specific sensitivity data to the training sets decreased the MAE to 2.89 dB, 2.86 dB, and 2.77 dB. For all 3 types of testing, the outer nuclear layer thickness constituted the most important predictive feature (35.0, 42.22, and 53.74 %IncMSE). Spatially resolved mapping of "inferred sensitivity" revealed regions with differential degrees of mesopic and DA cyan sensitivity loss outside of the GA lesions. "Inferred sensitivity" accurately reflected retinal function in patients with GA. Mapping of "inferred sensitivity" could facilitate monitoring of disease progression and serve as "quasi functional" surrogate outcome in clinical trials, especially in consideration of retinal regions beyond areas of GA.

Quantifying lipofuscin in retinal pigment epithelium in vivo by visible-light optical coherence tomography-based multimodal imaging

Lipofuscin in the retinal pigment epithelium (RPE) is the major source of fundus autofluorescence (FAF). A technical challenge to accurately quantify the FAF intensities, thus the lipofuscin concentration, is to compensate the light attenuation of RPE melanin. We developed the VIS-OCT-FAF technology to accomplish optical coherence tomography (OCT) and FAF simultaneously with a single broadband visible light source. We demonstrated that light attenuation by RPE melanin can be assessed and corrected using the depth-resolved OCT signals. FAF images from albino and pigmented rats showed that without compensation, FAF signals from pigmented rats are lower than that from albinos. After compensation, however, FAF signals from pigmented rats are higher. This finding is supported by measurements of lipofuscin fluorophore A2E in the RPE using liquid chromatography/mass spectrometry (LC/MS) showing that compensated FAF intensities correlate linearly with A2E contents. The present work represents an important step toward accurately assessing RPE lipofuscin concentrations by FAF.

Fluorescence Lifetime Patterns of Retinal Pigment Epithelium Atrophy in Patients with Stargardt Disease and Age-Related Macular Degeneration

Purpose: To investigate whether autofluorescence lifetime patterns within retinal pigment epithelium (RPE) atrophy differ between age-related macular degeneration (AMD) and Stargardt disease (STGD). Methods: Mean retinal autofluorescence lifetimes were measured in a short and a long spectral channel (SSC: 498–560 nm; LSC: 560–720 nm). Mean retinal fluorescence lifetimes were analyzed with corresponding clinical features, fundus images, fundus autofluorescence intensity images, and optical coherence tomography. Mean fluorescence lifetime values of atrophic areas were compared between the two cohorts and within the same patient to adjacent nonatrophic regions. Results: Mean fluorescence lifetimes within areas with RPE atrophy of 13 patients with STGD (mean age ± SEM 43.7 ± 5 years) and 30 patients with geographic atrophy (mean age: 78 ± 2 years) were analyzed and compared to age-matched healthy participants. The mean area of RPE atrophy in STGD and AMD was 6.6 ± 2.3 mm² (range: 0.66–33.17 mm²) and 17.5 ± 3.8 mm² (range: 0.58–50.02 mm²), respectively. In patients with AMD, atrophic areas revealed significantly longer mean fluorescence lifetime values as compared with patients with STGD (SSC: 997 ± 60 vs. 363 ± 26 ps; LSC: 880 ± 46 vs. 393 ± 23 ps; p < 0.0001). Conclusions: This study established that RPE atrophy in patients secondary to STGD and AMD display distinctive mean fluorescence lifetime characteristics. As retinal fluorescence lifetimes within areas of RPE atrophy were significantly longer in AMD patients, the analysis of specific lifetime patterns may provide additional insight into the disease processes and the pathogenetic mechanisms in the development of atrophic patches in AMD and STGD.

Characteristics and Utility of Fundus Autofluorescence in Congenital Aniridia Using Scanning Laser Ophthalmoscopy.

To investigate fundus autofluorescence (FAF) and other fundus manifestations in congenital aniridia. Fourteen patients with congenital aniridia and 14 age- and sex-matched healthy controls were examined. FAF images were obtained with an ultra-widefield scanning laser ophthalmoscope. FAF intensity was quantified in the macular fovea and in a macular ring surrounding fovea and related to an internal reference within each image. All aniridia patients underwent an ophthalmologic examination, including optical coherence tomography and slit-lamp biomicroscopy. Mean age was 28.4 ± 15.0 years in both the aniridia and control groups. Fovea could be defined by subjective assessment of FAF images in three aniridia patients (21.4%) and in all controls (P = 0.001). Mean ratio between FAF intensity in the macular ring and fovea was 1.01 ± 0.15 in aniridia versus 1.18 ± 0.09 in controls (P = 0.034). In aniridia, presence of foveal hypoplasia evaluated by biomicroscopy correlated with lack of foveal appearance by subjective analyses of FAF images (P = 0.031) and observation of nystagmus (P = 0.009). Aniridia patients present a lower ratio between FAF intensity in the peripheral and central macula than do healthy individuals. Both subjective and objective analyses of FAF images are useful tools in evaluation of foveal hypoplasia in aniridia.

Outer Retinal Thickness and Fundus Autofluorescence in Geographic Atrophy

Most studies of fundus autofluorescence (FAF) in geographic atrophy (GA) have been nonquantitative, with inadequate registration of image modalities. Furthermore, as pointed out in the recent Consensus Definition for Atrophy Associated with Age-Related Macular Degeneration on OCT, it is unclear whether decreased FAF would be correlated exclusively with a single category of OCT-defined atrophy. We sought to determine how FAF intensity in eyes with GA correlates with structural changes of the outer retina and choroid as seen on co-registered spectral domain OCT (SD-OCT) images. Retrospective cross-sectional. Twenty eyes of 11 patients with GA secondary to non-neovascular age-related macular degeneration (AMD). Spectral domain OCT and FAF images for each eye were co-registered using MATLAB (MathWorks Inc, Natick, MA). On B-scans, the choroid, retinal pigment epithelium (RPE), photoreceptor (PR) layer, and outer nuclear layer (ONL) were segmented. Regions of interest (ROIs) including all atrophic and border regions were selected manually on the FAF scans. Regions of interest were subdivided into quartiles of FAF level to correlate with retinal thickness measurements taken along the B-scans. Mean choroid, RPE, PR, and ONL thicknesses were compared across quartiles using an analysis of variance factorial design testing for interaction effects, adjusted for repeated measures (on both eyes) with a within-subjects factor. Seventeen eyes of 10 patients were selected for analysis. The mean choroidal thicknesses were not significantly different across FAF quartiles, but the overall differences in mean RPE, PR layer, and ONL thicknesses across quartiles were statistically significant (analysis of variance, P < 0.001, P < 0.001, and P=0.015, respectively). Post hoc analysis demonstrated significant differences in thickness among quartiles 1, 2, and 3 for the RPE and PR layers (Tukey, P < 0.01 in each case). The FAF quartiles within GA did not correlate exclusively with single categories of Consensus Definition for Atrophy Associated with Age-Related Macular Degeneration-defined atrophy. Not only RPE but also PR layer thickness on SD-OCT varies significantly with FAF levels in GA. This suggests that although the RPE cells are losing thickness and function, evidenced by decreased FAF from fluorophores, delicate PR cells also succumb early in the disease process. These relationships should be pursued as a possibly better-detailed mechanism in GA.

Fluorescence Lifetimes in Patients With Hydroxychloroquine Retinopathy.

To investigate fundus autofluorescence lifetime features in patients with hydroxychloroquine (HCQ) retinopathy, and to identify early markers of retinal alterations in patients due to HCQ. Patients attending screening for HCQ retinopathy were imaged with a fluorescence lifetime imaging ophthalmoscope. Mean retinal fluorescence lifetimes (Tm) were obtained in a short spectral channel (SSC, 498-560 nm) and a long spectral channel (LSC, 560-720 nm). Screening modalities included fundus images, fundus autofluorescence intensity images (FAF), spectral-domain optical coherence tomography (SD-OCT), visual fields, and multifocal electroretinogram (mfERG). Forty-two eyes of 21 patients on HCQ therapy and 40 eyes of 20 healthy age-matched controls were included. Fourteen eyes of 7 patients with HCQ retinopathy (mean age, 66.1 [SD, 7.7] years) and 28 eyes of 14 patients (mean age, 46.1 [SD, 7.9] years) receiving HCQ without retinopathy were identified. Patients with HCQ retinopathy showed a parafoveal ring-shaped or oval area of prolonged mean fluorescence lifetimes. In these areas, mean (±SEM) lifetimes were 374 ± 7 ps in the SSC, and on average 19.4% longer compared to the control group (P = 0.0001). Patients on HCQ without retinopathy had retinal fluorescence lifetimes that were similar to the control group. This study shows that HCQ retinopathy displays characteristic mean fluorescence lifetimes.

Spectrally Resolved Fundus Autofluorescence in ABCA4-Related Retinopathy.

To investigate the green and red fluorescence emission component of hyperautofluorescent flecks in patients with ABCA4-related retinopathy. A confocal light-emitting diode (LED)-based retinal imaging system (EIDON) was used for image acquisition of patients with genetically confirmed ABCA4 mutations. Using 450-nm excitation wavelengths, spectrally resolved retinal autofluorescence images were acquired in two wavelength ranges: green emission fluorescent component (GEFC, 500-560 nm), and red emission fluorescent component (REFC, 560-700 nm). Image analysis included comparison of the two emission spectra, correlation with confocal EIDON LED color fundus images, and spectral-domain optical coherence tomography (OCT). Eighty eyes of 40 patients with ABCA4-related retinopathy were examined. A characteristic distribution of flecks with distinct pattern of fluorescence emission components was detected and quantified. Independent from disease manifestation, different proportions of GEFC and REFC were identified within single flecks. Centrally located flecks showed a higher proportion of GEFC and were characterized by local disruption of outer retinal bands in OCT. More peripheral flecks were more prominent in the REFC and correlated to subretinal hyperreflective deposits with only minor pathologic alterations of outer retinal layers. Individual flecks even showed spatial differences of the predominant fluorescent component. Spectrally resolved fundus autofluorescence intensity images feature characteristic distribution of GEFC and REFC in flecks, highlighting the heterogeneity of fluorophore distribution and providing more insight into the pathogenesis of ABCA4-related retinopathy. In view of upcoming therapeutic trials, longitudinal analysis of fluorescent components might facilitate monitoring of subtle disease progression and/or treatment effects.

FLUORESCENCE LIFETIME PATTERNS IN MACULAR TELANGIECTASIA TYPE 2.

Type 2 idiopathic macular telangiectasia (MacTel) is a rare bilateral neurodegenerative disease characterized by alterations in the macular capillary network leading to central vision loss. The purpose of this study was to quantify disease-specific retinal fluorescence lifetime patterns in patients with MacTel using fluorescence lifetime imaging ophthalmoscopy. Both eyes of 14 patients (mean age ± SEM, 67.8±6.4 years) with a clinical diagnosis of MacTel Type 2 and 14 healthy age-matched controls (age 69.8±6.4 years) were included in this study. All participants were imaged with a fluorescence lifetime imaging ophthalmoscope (Heidelberg Engineering, Germany). Mean retinal fluorescence lifetimes (Tm) were obtained in the short spectral channels (498-560 nm) and long spectral channels (560-720 nm). Clinical features, fundus images, fundus autofluorescence intensity images, spectral domain optical coherence tomography, and corresponding macular pigment optical density measurements using a modified confocal scanning laser ophthalmoscope (mpHRA) were further analyzed. Patients were classified into five phenotypic subgroups using the Gass and Blodi classification. Mean fluorescence lifetimes were significantly prolonged temporal to the fovea in patients with MacTel compared with healthy controls (mean ± SEM: short spectral channels 543 ± 61 ps vs. 304 ± 9 ps; P < 0.0001; long spectral channels: 447 ± 26 ps vs. 348 ± 11 ps; P < 0.0001), and appeared as a crescent or ring-shaped pattern. Prolonged lifetime patterns correlated with decreased macular pigment density on macular pigment optical density measurements. Follow-up examinations were performed in four MacTel patients, which revealed an increase of short spectral channel Tm of 22% over 2.1 years in the temporal fovea. This study confirms that fundus autofluorescence lifetimes display characteristic patterns in patients with MacTel Type 2 disease and provide information about macular pigment and possibly photoreceptor loss. Fluorescence lifetime prolongation correlates with disease severity and may therefore be a useful addition to other imaging modalities for assessing disease progression in MacTel Type 2.

Visible-light optical coherence tomography-based multimodal system for quantitative fundus autofluorescence imaging.

Quantitative fundus autofluorescence imaging with simultaneous visible-light optical coherence tomography-based multimodal technology has potential significant impact on the diagnosis and monitoring the progression of retinal diseases.

Fundus autofluorescence beyond lipofuscin: lesson learned from ex vivo fluorescence lifetime imaging in porcine eyes.

Fundus autofluorescence (FAF) imaging is a well-established method in ophthalmology; however, the fluorophores involved need more clarification. The FAF lifetimes of 20 post mortem porcine eyes were measured in two spectral channels using fluorescence lifetime imaging ophthalmoscopy (FLIO) and compared with clinical data from 44 healthy young subjects. The FAF intensity ratio of the short and the long wavelength emission (spectral ratio) was determined. Ex vivo porcine fundus fluorescence emission is generally less intense than that seen in human eyes. The porcine retina showed significantly (p<0.05) longer lifetimes than the retinal pigment epithelium (RPE): 584 ± 128 ps vs. 121 ± 55 ps 498-560 nm, 240 ± 42 ps vs. 125 ± 20 ps at 560-720 nm. Furthermore, the lifetimes of the porcine RPE were significantly shorter (121 ± 55 ps and 125 ± 20 ps) than those measured from human fundus in vivo (162 ± 14 ps and 179 ± 13 ps, respectively). The fluorescence emission of porcine retina was shifted towards a shorter wavelength compared to that of RPE and human FAF. This data shows the considerable contribution of fluorophores in the neural retina to total FAF intensity in porcine eyes.

Fundus Autofluorescence Lifetime Patterns in Retinitis Pigmentosa.

We investigated whether fundus autofluorescence (FAF) lifetimes in patients with retinitis pigmentosa display a disease-specific lifetime pattern. Fundus autofluorescence lifetime imaging ophthalmoscopy (FLIO) was performed in two spectral channels (498-560 and 560-720 nm) after excitation with a 473 nm pulsed laser in patients with retinitis pigmentosa and compared to healthy controls of a similar age range. Corresponding FAF intensity and spectral domain optical coherence tomography (OCT) data, as well as best corrected visual acuity (BCVA) were acquired and compared to fluorescence lifetime data. We investigated 43 eyes from 43 patients with retinitis pigmentosa (mean age 45 ± 15 years) and compared them to eyes of 13 age-matched healthy participants. Mean FAF lifetimes were prolonged in areas of photoreceptor atrophy with preserved retinal pigment epithelium (RPE) (P = 0.0036) and even longer in areas with total atrophy of photoreceptors and RPE (P = 0.0002). The prevalence of perifoveal ring structures characterized by prolonged fluorescence lifetimes in FLIO was higher (63% vs. 49%) and the rings were wider compared to the hyperautofluorescent rings in qualitative fundus autofluorescence intensity images. In the central fovea with intact retinal layer structure identified by OCT, fluorescence lifetimes were slightly prolonged compared to those of age-matched healthy controls (short spectral channel [SSC], P = 0.0044; long spectral channel [LSC], P = 0.0128). Short lifetimes within the macular center were negatively correlated with BCVA (R2 = 0.33, P < 0.0001) as well as the greatest diameter of the ellipsoid band in OCT. FLIO in retinitis pigmentosa reveals characteristic patterns that allow identification of areas of photoreceptor atrophy, RPE atrophy, and remaining photoreceptor segments in areas of RPE atrophy. Fluorescence lifetimes can be used to identify ellipsoid zone loss that correlates with functional parameters.

In Vivo Multimodal Imaging of Drusenoid Lesions in Rhesus Macaques

Nonhuman primates are the only mammals to possess a true macula similar to humans, and spontaneously develop drusenoid lesions which are hallmarks of age-related macular degeneration (AMD). Prior studies demonstrated similarities between human and nonhuman primate drusen based on clinical appearance and histopathology. Here, we employed fundus photography, spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), and infrared reflectance (IR) to characterize drusenoid lesions in aged rhesus macaques. Of 65 animals evaluated, we identified lesions in 20 animals (30.7%). Using the Age-Related Eye Disease Study 2 (AREDS2) grading system and multimodal imaging, we identified two distinct drusen phenotypes – 1) soft drusen that are larger and appear as hyperreflective deposits between the retinal pigment epithelium (RPE) and Bruch’s membrane on SD-OCT, and 2) hard, punctate lesions that are smaller and undetectable on SD-OCT. Both exhibit variable FAF intensities and are poorly visualized on IR. Eyes with drusen exhibited a slightly thicker RPE compared with control eyes (+3.4 μm, P=0.012). Genetic polymorphisms associated with drusenoid lesions in rhesus monkeys in ARMS2 and HTRA1 were similar in frequency between the two phenotypes. These results refine our understanding of drusen development, and provide insight into the absence of advanced AMD in nonhuman primates.

Fluorescence Lifetimes of Drusen in Age-Related Macular Degeneration.

The purpose of this study was to characterize fundus autofluorescence lifetimes of retinal drusen in patients with AMD. Patients with AMD and retinal drusen and healthy controls of similar age were examined. A fluorescence lifetime imaging ophthalmoscope was used. Retinal autofluorescence was excited using a 473-nm pulsed laser, and fundus autofluorescence lifetimes of the central retina (30°) were measured in two distinct spectral channels (short: 498 to 560 nm [SSC]; long: 560 to 720 nm [LSC]). Mean retinal autofluorescence lifetimes, corresponding fundus autofluorescence intensity images, spectral domain optical coherence tomography, color fundus images, and clinical data were investigated. Patients were analyzed in two distinct groups (soft drusen and reticular pseudodrusen) and compared with control subjects. Sixty-four eyes of 64 patients with AMD and retinal drusen (age: mean ± SD, 78 ± 8.5 years; range, 59 to 94 years) were investigated and compared with a control group of 20 age-matched healthy subjects. Mean retinal autofluorescence lifetimes in patients with AMD was significantly prolonged compared with the healthy control eyes (mean ± SEM: SSC, 486 ± 18 vs. 332 ± 11 ps, P < 0.0001; LSC: 493 ± 9 vs. 382 ± 17 ps, P < 0.0001). Areas of drusen featured a wide range of fluorescence lifetime values. Long lifetimes were identified in areas of atrophy and in areas of intraretinal hyperreflective deposits. Short lifetimes corresponded to deposits within the photoreceptor outer segment band. Mean retinal autofluorescence lifetimes in AMD patients are significantly prolonged. Intraretinal deposits cause prolonged lifetimes, whereas deposits in the area of the outer photoreceptor segments lead to short fluorescence lifetimes.

Fundus autofluorescence imaging patterns in central serous chorioretinopathy according to chronicity.

PurposeTo investigate the time-period characteristics associated with morphologic changes in central serous chorioretinopathy (CSC) using fundus autofluorescence (FAF).Patients and methodsRetrospective, cross-sectional observational case series. Patients were classified into three groups: acute and chronic according to the onset of subjective symptoms of 6 weeks and sequelae patients who have history and symptoms but no serous retinal detachment (SRD). We compared FAF images to obtain characteristic findings according to the chronicity.ResultsA total of 52 eyes were included in this study. Acute CSC eyes were characterized by decreased FAF intensity at the leakage point in 13/22 eyes (56.5%) and staining patterns with various levels of fluorescence signal (hyperautofluorescent (10 eyes, 43.5%), hypoautofluorescent (1 eye, 4.3%), and minimal changes (12 eyes, 52.2%)) in the area of SRD. In chronic CSC eyes, hyperautofluorescent (14 eyes, 63.6%) or minimal changes (8 eyes, 36.4%) were observed in the area of SRD. Discrete dots with increased FAF intensity were observed in chronic CSC eyes (P<0.001). Eyes with sequelae of CSC had mixed FAF patterns over areas of retinal pigment epithelium (RPE) atrophy in seven eyes (100%, P<0.001)) and descending tracts which showed various FAF intensities according to the RPE and photoreceptor status (P<0.001).ConclusionFAF imaging patterns in CSC eyes differ according to the course of the disease, reflecting RPE and outer retinal changes. Detailed investigation using FAF could help to estimate the duration of CSC and determine the proper treatment modality.

Outer Retinal Layers Alterations in Chronic Central Serous Chorioretinopathy: Spectral Domain-OCT and Fundus Autofluorescence Findings

Purpose: To document alteration of the outer retinal layers and fundus autofluorescence (FAF) change in eyes with chronic central serous chorioretinopathy (CSCR). Methods: Seventeen eyes of fifteen patients diagnosed with chronic CSCR from January 2014 to March 2015 with at least 6 months of follow-up and no history of surgery were enrolled in this study. Morphologic alterations in the retinal pigment epithelium (RPE), the photoreceptor inner segment/outer segment (IS/OS) junction layer, and the outer retina were evaluated by Spectral domain optical coherence tomography (SD-OCT). The FAF images were obtained via Heidelberg Retina Angiogram using a view mode of 30° and were described using distribution patterns of retinal autofluorescence compared to background autofluorescence. After tomographic alignment of the FAF intensities with the OCT findings, we analyzed and assessed the alteration of the outer retinal layers and the characteristics of retinal autofluorescence. Results: RPE detachment lesions in SD-OCT showed little or no change in autofluorescence pattern. Five of seven eyes with RPE humps in SD-OCT showed hyper-fluorescence in FAF. All of the eyes with defects or changes of the reflective line representing the IS/OS junction in SD-OCT correlated with hyper-fluorescence in FAF. Seven of nine eyes with persistent subretinal detachment (SRD) showed specific ring-shaped hyper-fluorescence in FAF matching up with the border of the SRD, and five eyes with photoreceptor OS elongation within SRD showed a granular type of hyper-fluorescence within the ring-shaped hyper-fluorescence in FAF. Conclusions: In chronic CSCR, we found that RPE humps, the lesion IS/OS junction defect, the border of SRD, photoreceptor OS elongation in SD-OCT correlate with hyper-fluorescence lesions in FAF. The areas of the autofluorescence changes in the FAF images are associated with the extent of change in the RPE and outer retina. J Korean Ophthalmol Soc 2016;57(5):763-771

Long-Term Follow-Up of Fundus Autofluorescence Imaging Using Wide-Field Scanning Laser Ophthalmoscopy

Aim: To evaluate the variation of peripheral alterations in different retinal diseases over a period of >3 years by using wide-field fundus autofluorescence (FAF) scanning laser ophthalmoscopy (SLO). Methods: A total of 26 eyes from 13 patients (median age 66 years, range 19-80) with age-related macular degeneration and other retinal degenerations were examined. In 2009, the Optos P200CAF prototype and from 2012 onwards, the Optos 200Tx (Optos plc, Scotland) were used for wide-field FAF SLO (excitation 532 nm). Results: The area involvement in outer retinal pathological alterations, such as atrophy and mottling of the retinal pigment epithelium far beyond the vascular arcades, was readily and better visualized within one image frame using wide-field FAF as compared to pseudocolor SLO of the same device. Over time, progression of existing and the development of de novo peripheral lesions were recorded with a concomitant enlargement of central lesions. In two cases (unilateral paravenous pigmented choroidal atrophy and suspected phenocopy of retinal dystrophy), no longitudinal changes of the topographic distribution of peripheral FAF intensities were noted. Conclusions: Wide-field FAF SLO allows the mapping of dynamic changes at the outer retina far beyond the vascular arcades. While its ability to detect and monitor these changes appears to be better than that of pseudocolor imaging, wide-field FAF SLO may not only be helpful to assess more widespread retinal dysfunction, but may also be useful for longitudinal assessments in natural history studies and interventional clinical trials.