Phenotypic characterization of predictors for development and progression of geographic atrophy using optical coherence tomography.

PURPOSE: To evaluate the impact of optical coherence tomography (OCT) phenotypes preceding atrophy related to age-related macular degeneration (AMD) on the progression of atrophic lesions. METHODS: In this observational retrospective cohort study, a total of 70 eyes of 60 consecutive patients with intermediate AMD with a minimum follow-up of 24 months were included. The atrophy was quantified using fundus autofluorescence, also considering the directionality of atrophy as centrifugal and centripetal progression rates.Main outcome measures were geographic atrophy (GA) progression rate (mm2/year) and square root-transformation GA (mm2/year). RESULTS: The best-fit model for GA (OR: 1.81, p<0.001) and square root-transformation GA (OR: 1.36, p<0.001) areas revealed that the main baseline predictor was the presence of an RPE-basal lamina-(BL)-Bruch's membrane (BrM) splitting. Large drusen at baseline appeared protective for the GA area lesion expansion over time (OR: 0.52, p<0.001) when considered with other confounders. CONCLUSION: A thin RPE-BL-BrM splitting without evidence of neovascularization on OCT angiography likely represents an OCT signature for late basal laminar deposits. Identifying this phenotype can help identify individuals with a higher risk of rapid progression and atrophy expansion.

Gender differences in retinal diseases: A review.

Gender medicine is a medical specialty that addresses gender differences in health and disease. Traditionally, medical research and clinical practice have often been focused on male subjects and patients. As a result, gender differences in medicine have been overlooked. Gender medicine considers the biological, psychological, and social differences between the genders and how these differences affect the development, diagnosis, treatment, and prevention of disease. For ophthalmological diseases epidemiological differences are known. However, there are not yet any gender-based ophthalmic treatment approaches for women and men. This review provides an overview of gender differences in retinal diseases. It is intended to make ophthalmologists, especially retinologists, more sensitive to the topic of gender medicine. The goal is to enhance comprehension of these aspects by highlighting fundamental gender differences. Integrating gender medicine into ophthalmological practice helps promote personalized and gender-responsive health care and makes medical research more accurate and relevant to the entire population.

Fluorescence lifetime imaging ophthalmoscopy and the influence of oral lutein/zeaxanthin supplementation on macular pigment (FLOS) - A pilot study.

BACKGROUND & AIMS: Oral lutein (L) and zeaxanthin (Z) supplementation enhances macular pigment optical density (MPOD) and plays a protective role in the development of age-related macular degeneration (AMD). Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a novel in vivo retinal imaging method that has been shown to correlate to classical MPOD measurements and might contribute to a metabolic mapping of the retina in the future. Our aim was to show that oral supplementation of L and Z affects the FLIO signal in a positive way in patients with AMD. METHODS: This was a prospective, single center, open label cohort study. Patients with early and intermediate AMD received oral L and Z supplementation during three months, and were observed for another three months after therapy termination. All visits included measurements of clinical parameters, serum L and Z concentration, MPOD measurements using heterochromatic flicker photometry, dual wavelength autofluorescence imaging, and FLIO. Correlation analysis between FLIO and MPOD were performed. RESULTS: Twenty-one patients completed the follow up period. Serum L and Z concentrations significantly increased during supplementation (mean difference 244.8 ng/ml; 95% CI: 81.26-419.9, and 77.1 ng/ml; 95% CI: 5.3-52.0, respectively). Mean MPOD units significantly increased (mean difference 0.06; 95% CI: 0.02-0.09; at 0.5°, 202; 95% CI: 58-345; at 2°, 1033; 95% CI: 288-1668; at 9° of eccentricity, respectively) after three months of supplementation with macular xanthophylls, which included L and Z. Median FLIO lifetimes in the foveal center significantly decreased from 277.3 ps (interquartile range 230.2-339.1) to 261.0 ps (interquartile range 231.4-334.4, p = 0.027). All parameters returned to near-normal values after termination of the nutritional supplementation. A significant negative correlation was found between FLIO and MPOD (r2 = 0.57, p < 0.0001). CONCLUSIONS: FLIO is able to detect subtle changes in MPOD after L and Z supplementation in patients with early and intermediate AMD. Our findings confirm the previous described negative correlation between FLIO and MPOD. Macular xanthophylls seem to contribute to short foveal lifetimes. This study is registered at ClinicalTrials.gov (identifier number NCT04761341).

Fluorescence lifetime distribution in phakic and pseudophakic healthy eyes.

PURPOSE: To investigate the influence of the lens status and to describe fundus autofluorescence lifetimes (FLT) in a large cohort of healthy eyes across a wide age range. MATERIALS AND METHODS: FLT data were acquired from healthy phakic and pseudophakic eyes using fluorescence lifetime imaging ophthalmoscopy (FLIO). Retinal autofluorescence was excited with a 473 nm laser and emitted autofluorescence was detected in a short and a long spectral channel (SSC: 498-560 nm; LSC: 560-720 nm). RESULTS: 141 healthy eyes from 141 participants (56 ± 18 years) were included. The shortest mean FLTs were measured within the macular center, followed by the temporal inner and outer ETDRS (Early Treatment Diabetic Retinopathy Study) grid segments, and the remaining areas of the inner and the outer ETDRS ring. In phakic participants (81%), mean, short and long FLTs correlated with the age (SSC: r2 = 0.54; LSC: r2 = 0.7; both p<0.0001) with an increase of about 33 ps in the SSC resp. 28 ps in the LSC per decade. In pseudophakic subjects (19%), mean FLTs only correlated with age in the long spectral channel (r2 = 0.44; p = 0.0002) but not in the short spectral channel (r2 = 0.066; p = 0.2). CONCLUSIONS: Fundus autofluorescence lifetimes are age dependent. FLTs in the SSC are more susceptible to lens opacities but less dependent on age changes, whereas FLTs in the LSC are largely independent of the lens status but display a higher degree of age dependency. STUDY REGISTRY: ClinicalTrials.gov NCT01981148.

Imaging in retinal vascular disease: A review.

Retinal vascular diseases represent a broad field of ocular pathologies. Retinal imaging is an important tool for diagnosis, prognosis and follow up of retinal vascular diseases. It includes a wide variety of imaging techniques ranging from colour fundus photography and optical coherence tomography to dynamic diagnostic options such as fluorescein angiography, and optical coherence tomography angiography. The newest developments in respective imaging techniques include widefield imaging to assess the retinal periphery, which is of especial interest in retinal vascular diseases. Automatic image analysis and artificial intelligence may support the image analysis and may prove valuable for prognostic purposes. This review provides a broad overview of the imaging techniques that have been used in the past, today and maybe in the future to stage and monitor retinal vascular disease with focus on the main disease entities including diabetic retinopathy, retinal vein occlusion, and retinal artery occlusion.

FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY AS PREDICTOR OF LONG-TERM FUNCTIONAL OUTCOME IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To assess whether macular fluorescence lifetimes may serve as a predictor for long-term outcomes in macula-off rhegmatogenous retinal detachment. METHODS: A single-center observational study was conducted. Patients with pseudophakic macula-off rhegmatogenous retinal detachment were included and evaluated 1 and 6 months after successful reattachment surgery. Fluorescence lifetime imaging ophthalmoscopy lifetimes in the central Early Treatment Diabetic Retinopathy Study grid subfield, in two distinct channels (short spectral channel and long spectral channel) were analyzed. Best-corrected visual acuity optical coherence tomography of the macula and fluorescence lifetimes were measured at month 1 and month 6. RESULTS: Nineteen patients were analyzed. Lifetimes of the previously detached retinas were prolonged compared with the healthy fellow eyes. Short lifetimes at month 1 were associated with better best-corrected visual acuity improvement (short spectral channel: r2 = 0.27, P < 0.05, long spectral channel: r2 = 0.23, P < 0.05) and with good final best-corrected visual acuity (short spectral channel: r2 = 0.43, P < 0.01, long spectral channel: r2 = 0.25, P < 0.05). Lifetimes were prolonged in some cases of outer retinal damage in optical coherence tomography scans. CONCLUSION: Fluorescence lifetime imaging ophthalmoscopy might serve as a prediction tool for functional recovery in pseudophakic macula-off rhegmatogenous retinal detachment. Retinal fluorescence lifetimes could give insight in molecular processes after rhegmatogenous retinal detachment.

Spectrally resolved autofluorescence imaging in posterior uveitis.

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.

Modern Imaging Techniques for Visualising Choroidal Morphology and Function. / Moderne bildgebende Verfahren zur Darstellung der Morphologie und Funktion der Aderhaut.

The choroid is directly adjacent to the retina and consists of a dense vascular network that supplies the outer retina. Pathologies in the choroid can lead to changes in the retinal pigment epithelium (RPE) and photoreceptors. Thus, the choroid plays a crucial role in the development of retinal diseases such as age-related macular degeneration (AMD), central serous chorioretinopathy (CSCR), pathologic myopia, and inflammatory diseases such as Vogt-Koyanagi-Harada syndrome (VKH). Basic knowledge of the structure and physiology of the choroid, as well as diagnostic options for visualizing choroidal changes, provides a better understanding of the physiology and pathology of choroidal processes. This review provides an overview of the anatomy and function of the choroid, and describes the diagnostic techniques currently available to characterize and visualize the choroid. It also includes an overview of various retinal conditions, which are associated with choroidal changes.

LONGITUDINAL FOVEAL FLUORESCENCE LIFETIME CHARACTERISTICS IN GEOGRAPHIC ATROPHY USING FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY.

PURPOSE: Short foveal fluorescence lifetimes (fFLT) in geographic atrophy are typically found in eyes with foveal sparing (FS) but may also occur in eyes without FS. We investigated whether short fFLT could serve as a functional biomarker for disease progression in geographic atrophy. METHODS: Thirty three eyes were followed over the course of 4 to 6 years. Foveal sparing was assessed using fluorescence lifetime imaging ophthalmoscopy, optical coherence tomography, fundus Autofluorescence, and macular pigment optical density. RESULTS: Eyes with FS exhibited shorter fFLT compared with eyes without FS. Short fFLT (<600 ps) were measured in all eyes with FS and half of the eyes without FS. Eyes with FS showed a bigger increase in fFLT per year (+39/+30 ps (short spectral channel/long spectral channel) in FS versus +29/+22 ps (short spectral channel/long spectral channel) in non FS). The best-corrected distance visual acuity correlated significantly with fFLT (P = 0.018 and P = 0.005 for short spectral channel/long spectral channel). Macular pigment optical density measurements correlated significantly with fFLT but not in all spectral channels (P ranging from 0.018 to 0.077). CONCLUSION: In geographic atrophy, shorter fFLT are associated with FS but they can also be observed in eyes without FS. Our longitudinal data suggest that shorter fFLT features in eyes with loss of FS represent an earlier stage of disease and may be more prone to loss of the visual acuity.

IMAGING ARTIFACTS IN FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY.

PURPOSE: To investigate and quantify the influence of imaging artifacts on retinal fluorescence lifetime (FLIO) values and to provide helpful hints and tricks to avoid imaging artifacts and to improve FLIO image acquisition quality. METHODS: A systematic analysis of potential parameters influencing FLIO quality and/or fluorescence lifetime values was performed in a prospective systematic experimental imaging study in five eyes of five healthy subjects. For image acquisition, a fluorescence lifetime imaging ophthalmoscope (Heidelberg Engineering) was used. Quantitative analysis of FLIO lifetime changes due to imaging artifacts was performed. RESULTS: Imaging artifacts with significant influence on fluorescence lifetimes included too short image acquisition time, insufficient illumination, ocular surface problems, and image defocus. Prior use of systemic or topical fluorescein makes analysis of retinal fluorescence lifetimes impossible. CONCLUSION: Awareness of possible sources of imaging artifacts is important for FLIO image acquisition and analysis. Therefore, standardized imaging and analysis procedure in FLIO is crucial for high-quality image acquisition and the possibility for systematic quantitative fluorescence lifetime analysis.

The Influence of Cataract on Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO).

Purpose: To investigate the influence of lens opacifications on fluorescence lifetime imaging ophthalmoscopy (FLIO). Methods: Forty-seven eyes of 45 patients were included. Mean fluorescence lifetimes (Tm) were recorded with a fluorescence lifetime imaging ophthalmoscope in a short spectral channel (SSC) and a long spectral channel (LSC). Retinal and lens autofluorescence lifetimes were measured in subjects before and after cataract surgery. Lens opacification was graded using the Lens Opacities Classification System III (LOCS III) classification. Results: The retinal Tm decreased significantly after cataract surgery in both spectral channels (SSC: -53%, P < 0.0001; LSC: -26%, P = 0.0041). The lens Tm differed significantly between the crystalline and the artificial lens in both spectral channels (P < 0.0001). The "nuclear opacity" and "nuclear color" score of the LOCS III classification correlated significantly with the mean Tm difference in both spectral channels (P < 0.0001). Conclusions: Lens opacification results in significantly longer retinal Tm. Therefore the lens status has to be considered when performing cross-sectional fluorescence lifetime analysis. Cataract-formation and cataract-surgery needs to be considered when conducting longitudinal studies. Grading of nuclear opacity following the LOCS III classification provides an approximate conversion formula for the mean change of lifetimes, which can be helpful in the interpretation of data in patients with lens opacities. Translational Relevance: FLIO is significantly influenced by lens opacities. Using a lens opacity grading scheme and measuring fluorescence lifetimes before and after cataract surgery, an approximative conversion formula can be calculated, which enables the comparison of lifetimes after cataract surgery or over the course of time.

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

PURPOSE: 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. DESIGN: Prospective, observational case series. METHODS: 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. RESULTS: 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. CONCLUSIONS: "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.

Intravitreal Injections with Vascular Endothelial Growth Factor Inhibitors: A Practical Approach.

Intravitreal injections with vascular endothelial growth factor inhibitors constitute the most prevalent ophthalmic procedure in developed countries. Historically, there has been steady growth in the number of treatments performed of this kind, and projection studies estimate further growth in such treatments in the future. We provide a practical approach to intravitreal injections and discuss important aspects relating to the setting, the patient, the procedure, and the information given to the patient.

FLUORESCENCE LIFETIME PATTERNS IN MACULAR TELANGIECTASIA TYPE 2.

PURPOSE: 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. PARTICIPANTS: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

FLUORESCENCE LIFETIME IMAGING OPHTHALMOSCOPY: Findings After Surgical Reattachment of Macula-Off Rhegmatogenous Retinal Detachment.

PURPOSE: The purpose of this study was to investigate fluorescence lifetime imaging ophthalmoscopy lifetimes after macula-off rhegmatogenous retinal detachment (RRD) repair. METHODS: Fifty-eight patients with successful macula-off RRD reattachment surgery were included. Retinal autofluorescence was excited with 470 nm, and amplitude-weighted mean fluorescence lifetimes (Tm) were measured in a short spectral channel (SSC, 498-560 nm) and a long spectral channel (LSC, 560-720 nm). Tm were obtained within a standardized Early Treatment Diabetic Retinopathy Study grid and correlated with Tm. The unaffected fellow eye served as control. RESULTS: Fifty-eight patients (age: 65 ± 1.6 years, 11 women) were imaged at median 1.5 months postoperatively. Tm were significantly prolongxxxed within areas of previously detached retina in the long spectral channel and particularly in the central subfield in the short spectral channel. Short lifetimes in the center of the Early Treatment Diabetic Retinopathy Study grid correlated with better visual acuity (short spectral channel; r = 0.18, P = 0.001, long spectral channel; r = 0.08, P = 0.03). Areas of residual subretinal fluid pockets in four RRD eyes displayed short fluorescence lifetimes. CONCLUSION: Areas of previously detached retina exhibit significant fluorescence lifetime changes. We found a significant correlation of fluorescence lifetimes within the fovea with visual acuity after successful RRD repair. Our data suggests that the prolongation of fluorescence lifetimes in the fovea is mainly driven by loss of macular pigment. Therefore, fluorescence lifetime imaging ophthalmoscopy may be useful in the prediction of long-term functional outcomes after macula-off RRD surgery.

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.

Type 1 Choroidal Neovascularization Is Associated with Reduced Localized Progression of Atrophy in Age-Related Macular Degeneration.

PURPOSE: To investigate the association between the presence of type 1 choroidal neovascularization (CNV) and the localized progression of atrophy in age-related macular degeneration (AMD). DESIGN: Analysis of patients' data collected in the context of 2 noninterventional, prospective studies conducted at the Department of Ophthalmology, University of Bonn, Germany. PARTICIPANTS: A total of 98 eyes diagnosed with AMD of 59 patients (40 female, 19 male) with a mean (±standard deviation) age at baseline of 76.60±6.65 years and median (interquartile range) review period of 1.17 years (1.01-1.55) were included. Eyes were subdivided into 3 categories based on multimodal imaging and ocular history: retinal pigment epithelium (RPE) atrophy with treatment-naïve quiescent CNV (n=7), RPE atrophy with a history of exudative CNV (n=10), and RPE atrophy without evidence of coexisting CNV (n=81). METHODS: Retinal pigment epithelium atrophy was delineated on the basis of serial fundus-autofluorescence and infrared-reflectance images. If CNV was detected by OCT angiography (OCTA), its location and dimension were spatially mapped to RPE atrophy. The localized progression of RPE atrophy in topographic relation to the CNV lesion was then analyzed using mixed-effects logistic regression. The spatial overlap (Dice coefficient) between predicted and observed RPE atrophy progression was evaluated to estimate the model accuracy. MAIN OUTCOME MEASURES: Odds ratio (OR) for localized RPE atrophy progression in areas overlying type 1 CNV. RESULTS: The prediction model achieved a high overlap between predicted and observed RPE atrophy progression with a cross-validated Dice coefficient of 0.87 (95% confidence interval [CI], 0.85-0.89) reflecting a high accuracy. The odds for future RPE atrophy involvement were reduced by a factor of 0.21 (95% CI, 0.19-0.24) in the presence of treatment-naïve quiescent type 1 CNV and by a factor of 0.46 (95% CI, 0.41-0.51) in the presence of exudative type 1 CNV. CONCLUSIONS: The results indicate that there is markedly reduced RPE atrophy progression in areas co-localizing with quiescent and exudative type 1 CNV. This observation is compatible with a potential protective effect of type 1 CNV on the RPE and overlying neurosensory retina. These results may have relevant clinical implications for the management of CNV and lead to new therapeutic strategies to prevent atrophy progression.

SPECTRAL FUNDUS AUTOFLUORESCENCE EXCITATION AND EMISSION IN ABCA4-RELATED RETINOPATHY.

PURPOSE: To systematically and longitudinally investigate the characteristics of flecks in ABCA4-related retinopathy under different fundus autofluorescence (AF) excitation and emission spectra. METHODS: A total of 132 eyes of 66 patients with ABCA4-related retinopathy were investigated using multimodal AF imaging and spectral domain optical coherence tomography. Autofluorescence imaging with blue (BAF), green (GAF), and near-infrared (NIR-AF) excitation wavelengths obtained by a confocal scanning laser ophthalmoscope was compared with AF imaging obtained by an innovative confocal light-emitting diode-based retinal imaging system (Color-AF) that allows for separation of short (green emission fluorescent component) and long (red emission fluorescent component) autofluorescence emission components. RESULTS: Color-AF, BAF, and GAF, overall, revealed similar presentation of hyperautofluorescent flecks. Flecks that showed predominantly red emission fluorescent component matched with hyperautofluorescent flecks in NIR-AF. Over the observation time of 5 to 14 months, flecks showed a transition in the AF emission spectrum to shorter wavelengths (red emission fluorescent component to green emission fluorescent component), associated with a progressed disruption of overlaying outer retinal bands in optical coherence tomography. Newer hyperautofluorescent flecks usually revealed predominantly red emission fluorescent component. CONCLUSION: By separation of the AF spectra, the remodeling of fluorophores and associated structural changes can be monitored over time indicating a novel and susceptible surrogate marker for disease progression and potential therapeutic effects.

Light Sensitivity Within Areas of Geographic Atrophy Secondary to Age-Related Macular Degeneration.

Purpose: To investigate residual sensitivity within geographic atrophy (GA) secondary to age-related macular degeneration. Methods: Mesopic and dark-adapted (DA) cyan and red light sensitivity (Goldmann III) were investigated using fundus-controlled perimetry (microperimetry). Test points were placed within GA along an "iso-hull" with a distance of -0.645° to the atrophy boundary. The false-positive response rate was determined with suprathreshold stimuli to the optic disc (Heijl-Krakau method) and used to compute the expected sensitivity measurements for the assumption of absolute scotomata. The outermost visible retinal layer on spectral-domain optical coherence tomography at the location of each test point was determined. Results: Thirty eyes of 36 patients (75.55 ± 7.93 years; 19 female) from the prospective natural history study Directional Spread in Geographic Atrophy (NCT02051998), with a total of 1380 threshold determinations were analyzed. The measured sensitivities were significantly (P < 0.01) higher than the expected values for absolute scotomata (mean ± standard error of +6.92 ± 0.86 dB for mesopic, +2.57 ± 0.56 dB for DA cyan, and +4.93 ± 0.74 dB for DA red testing). For mesopic testing and DA red testing, the presence of a residual outer nuclear layer had a significant effect on this discrepancy (P < 0.001). There was no effect of fixation stability or any other reliability index on this discrepancy. Conclusions: Measured sensitivities within the inner junctional zone of GA may not be purely explained by patient-specific false-positive response rates or other reliability indices. The marked influence of the outer retinal configuration on measured sensitivity may be indicative of residual cone function within GA at the inner junctional zone.

Artificial intelligence for morphology-based function prediction in neovascular age-related macular degeneration.

Spatially-resolved mapping of rod- and cone-function may facilitate monitoring of macular diseases and serve as a functional outcome parameter. However, mesopic and dark-adapted two-color fundus-controlled perimetry (FCP, also called "microperimetry") constitute laborious examinations. We have devised a machine-learning-based approach to predict mesopic and dark-adapted (DA) retinal sensitivity in eyes with neovascular age-related macular degeneration (nAMD). Extensive psychophysical testing and volumetric multimodal retinal imaging data were acquired including mesopic, DA red and DA cyan FCP, spectral-domain optical coherence tomography and confocal scanning laser ophthalmoscopy infrared reflectance and fundus autofluorescence imaging. With patient-wise leave-one-out cross-validation, we have been able to achieve prediction accuracies of (mean absolute error, MAE [95% CI]) 3.94 dB [3.38, 4.5] for mesopic, 4.93 dB [4.59, 5.27] for DA cyan and 4.02 dB [3.63, 4.42] for DA red testing. Partial addition of patient-specific sensitivity data decreased the cross-validated MAE to 2.8 dB [2.51, 3.09], 3.71 dB [3.46, 3.96], and 2.85 dB [2.62, 3.08]. The most important predictive feature was outer nuclear layer thickness. This artificial intelligence-based analysis strategy, termed "inferred sensitivity", herein, enables to estimate differential effects of retinal structural abnormalities on cone- and rod-function in nAMD, and may be used as quasi-functional surrogate endpoint in future clinical trials.