Fundus Autofluorescence Imaging Research Articles

The impact of short-term postoperative face-up position on unintentional retinal displacement after pars plana vitrectomy for rhegmatogenous retinal detachment.

To assess the effectiveness and safety of a rigorous short-term supine position in preventing inadvertent retinal displacement after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachment (RRD). We conducted a retrospective observational analysis of a case series at two ophthalmological surgical centers. We included eyes diagnosed with macula-off RRD that maintained a strict face-up position for three hours immediately after PPV with intraoperative perfluorocarbon liquid (PFCL) and 20% sulfur hexafluoride (SF6) tamponade. Fundus autofluorescence (FAF) imaging was performed at one month post-operatively to identify unintentional retinal displacement through the detection of retinal vessel prints (RVPs) on FAF imaging using an ultrawide-field (UWF) imaging system. A total of 29 eyes with macula-off RRD were included in the study. The average age of the participants was 59.62 years. RRD involved one quadrant in two eyes, two quadrants in fourteen eyes, three quadrants in seven eyes, and four quadrants in six eyes. UWF-FAF imaging at one month follow-up after complete reattachment of the retina revealed RVPs in seven out of the 29 eyes (24.13%), with a mean displacement of 0.22 mm. In every case the displacement occurred downward. Our results suggest that adhering to a strict face-up position for three hours after PPV with PFCL and gas tamponade for macula-off RRD may lead to a low frequency and severity of inadvertent post-operative retinal displacement.

Shwachman-Diamond syndrome associated with rod-cone dystrophy.

To report a patient with Shwachman-Diamond syndrome and concomitant rod-cone dystrophy who underwent bone marrow transplantation. Retrospective single case report. A female patient with Shwachman-Diamond syndrome was referred to a tertiary hospital to investigate possible pigmentary retinopathy at the age of 16. She described poor night vision and was found to have reduced visual acuity (6/20 right, 6/38 left). Over the ten-year follow-up period, her visual acuity remained relatively stable with no new visual symptoms. Optical coherence tomography revealed progressive, diffuse outer retinal thinning with disruption of the ellipsoid zone, which initially was relatively preserved subfoveally. Fundus autofluorescence images revealed generalised areas of hypoautofluorescence beyond the vascular arcades and a perimacular ring of increased autofluorescence. The flash electroretinogram was in keeping with a severe rod-cone dystrophy. The pattern visual evoked potential was abnormal but detectable indicating macular pathway dysfunction, suggesting encroachment into central macular regions but with some functional preservation. We report a patient with Shwachman-Diamond syndrome with severe early-onset rod-cone dystrophy noted at the age of 16. Slow anatomical progression has been observed over the subsequent ten years, with relative functional macular preservation to support a visual acuity of 6/36 in both eyes.

ATXN7-Related Cone-Rod Dystrophy

Reliable biomarkers with diagnostic and prognostic values are needed for upcoming gene therapy trials for spinocerebellar ataxias. To identify ophthalmological biomarkers in a sample of spinocerebellar ataxia type 7 (SCA7) carriers. This article presents baseline data from a cross-sectional natural history study conducted in Paris, France, reference centers for rare diseases from May 2020 to April 2021. Data were analyzed from September to December 2022. Fifteen adult ATXN7 pathogenic expansion carriers (9 with preataxia and 6 with ataxia) were included, all with a Scale for the Assessment and Rating of Ataxia (SARA) score of 15 of 40 or lower. Patients were recruited at the Paris Brain Institute, and all contacted patients accepted to participate in the study. Three visits (baseline, 6 months, and 12 months) were planned, including neurological examination (SARA and Composite Cerebellar Functional Severity Score), ophthalmological examination (best-corrected visual acuity, microperimetry, full-field electroretinogram, optical coherence tomography, and fundus autofluorescence imaging), and neurofilament light chain (NfL) measurements. Here we report the baseline ophthalmic data from the cohort and determine whether there is a correlation between disease scores and ophthalmic results. Among the 15 included SCA7 carriers (median [range] age, 38 [18-60] years; 8 women and 7 men), 12 displayed cone or cone-rod dystrophy, with the number of CAG repeats correlating with disease severity (ρ, 0.73, 95% CI, 0.34 to 0.90; P < .001). Two patients with cone-rod dystrophy exhibited higher repeat numbers and greater ataxia scores (median [range] SARA score, 9 [7-15]) compared to those with only cone dystrophy (median [range] SARA score, 2 [0-5]). A correlation emerged for outer nuclear layer thickness with SARA score (ρ, -0.88; 95% CI, -0.96 to -0.59; P < .001) and NfL levels (ρ, -0.87; 95% CI, -0.86 to 0.96; P < .001). Moreover, ataxia severity was correlated with visual acuity (ρ: 0.89; 95% CI, 0.68 to 0.96; P < .001) and retinal sensitivity (ρ, -0.88; 95% CI, -0.96 to 0.59; P < .001). In this cross-sectional study, retinal abnormalities were found at preataxic stages of the disease. Most of the carriers presented with cone dystrophy and preserved rod function. The outer nuclear layer thickness correlated with SARA score and plasma NfL levels suggesting nuclear layer thickness to be a biomarker of disease severity. These findings contribute to understanding the dynamics of SCA7-related retinal dystrophy and may help lay the groundwork for future therapeutic intervention monitoring and clinical trials. ClinicalTrials.gov Identifier: NCT04288128.

Genetics, Clinical Characteristics, and Natural History of PDE6B-Associated Retinal Dystrophy

To analyze the clinical characteristics, natural history, and genetics of PDE6B-associated retinal dystrophy. Retrospective, observational cohort study. Review of medical records and retinal imaging, including fundus autofluorescence (FAF) imaging and spectral-domain optical coherence tomography (SD-OCT) of patients with molecularly confirmed PDE6B-associated retinal dystrophy in a single tertiary referral center. Genetic results were reviewed, and the detected variants were assessed. Forty patients (80 eyes) were identified and evaluated longitudinally. The mean age (±SD, range) was 42.1 years (± 19.0, 10-86) at baseline, with a mean follow-up time of 5.2 years. Twenty-nine (72.5%) and 27 (67.5%) patients had no or mild visual acuity impairment at baseline and last visit, respectively. Best-corrected visual acuity (BCVA) was 0.56 ± 0.72 LogMAR (range -0.12 to 2.80) at baseline and 0.63 ± 0.73 LogMAR (range 0.0-2.80) at the last visit. BCVA was symmetrical in 87.5% of patients. A hyperautofluorescent ring was observed on FAF in 48 and 46 eyes at baseline and follow-up visit, respectively, with a mean area of 7.11 ± 4.13 mm2 at baseline and mean of 6.13 ± 3.62 mm2 at the follow-up visit. Mean horizontal ellipsoid zone width at baseline was 1946.1 ± 917.2 µm, which decreased to 1763.9 ± 827.9 µm at follow-up. Forty-four eyes had cystoid macular edema at baseline (55%), and 41 eyes (51.3%) at follow-up. There were statistically significant changes during the follow-up period in terms of BCVA and the ellipsoid zone width. Genetic analysis identified 43 variants in the PDE6B gene, including 16 novel variants. This study details the natural history of PDE6B-retinopathy in the largest cohort to date. Most patients had mild to no BCVA loss, with slowly progressive disease, based on FAF and OCT metrics. There is a high degree of disease symmetry and a wide window for intervention.

Visual Sensitivity Loss in Geographic Atrophy: Structure-Function Evaluation Using Defect-Mapping Microperimetry.

To examine the structure-function relationship in eyes with geographic atrophy (GA) using defect-mapping microperimetry, a testing strategy optimized to quantify the spatial extent of deep visual sensitivity losses. Fifty participants with GA underwent defect-mapping microperimetry testing of the central 8°-radius region (208 locations tested once with a 10-decibel stimuli) and fundus autofluorescence imaging in one eye. The GA extent in the corresponding central 8°-radius was derived by manual annotations and image co-registration to examine the global structure-function relationship. The distance of each test location from the GA margin was also derived, and regions defined, to examine the local structure-function relationship. GA extent in the central 8° explained a substantial proportion of variance in the percentage of locations missed (nonresponse) on microperimetry at the global level (R2=0.90). At a local level, the probability of missing stimuli at the outer junctional zone (0-500 µm outside the GA margin) and GA margin (probability=7% and 34%, respectively) was higher than at the outer nonlesional zone (>500 µm outside the GA margin; probability=2%; P<0.001 for both). The probability of missing stimuli at the inner junctional zone (0-250 µm inside the GA margin) was also lower than at the inner lesional zone (>250 µm inside the GA margin; probability=64% and 88%; P<0.001). This study confirms the expected functional relevance of the region with GA on fundus autofluorescence imaging and underscores the potential effectiveness of defect-mapping microperimetry testing for capturing visual function changes when evaluating new GA treatments.

Macular pigment evaluation using dual-wavelength fundus auto-fluorescence imaging.

Macular pigment plays an important role in the reduction of oxidative stress and in preventing retinal diseases. Quick and easy measurements of the macular pigment are essential in both clinical and research settings. Dual wavelength fundus auto-fluorescence seems to be the optimal method. This study aims to investigate changes in fundus autofluorescence in patients taking daily lutein oral supplements and develop image processing methods for follow-up evaluations of the images. New devices allow us to examine fundus autofluorescence using both blue and green excitation wavelengths. This allows detection of the amount of macular pigment by subtracting these two images because the yellow pigment particles absorb blue wavelengths. We determined daily dose of 25 mg of lutein and 3 mg of zeaxanthin. Patients were followed up for 15 months at 3-month intervals. During our 15-month study, we observed a positive trend in pixel lightness values, suggesting an increase in macular pigments in the foveal area. In all patients taking daily lutein supplements, the foveal index significantly increased after six months, with a median change of 0.081. We did not observe a significant change after the first three months (0.006) and only a small change between the 6th and 12th-month visits (0.012). With appropriate patients and procedures for capturing autofluorescence images, this is a valuable technique for macular pigment evaluation in follow-up examinations using software image post-processing and analysis with commonly available hardware. To put this into everyday practice, developing tools to automate the assessment is necessary.

Characteristics of fundus autofluorescence imaging at 795 nm and its correlations with postoperative outcomes for idiopathic macular hole.

Vitrectomy combined with internal limiting membrane (ILM) peeling or ILM inverted flap greatly improves hole closure and vision prognosis for idiopathic macular holes (IMH). The application of indocyanine green (ICG) in MH surgery increases the visibility of ILM and the safety of surgery. However, the area of ILM peeling and the state of the flap and a closed hole has not been well observed. Fundus autofluorescence at 7935nm can show the range of ILM peeling and the state of the hole site and ILM flap by monitoring residual ICG postoperatively. However, the characteristics of fundus autofluorescence especially the site of the closed hole, and its relationship with vision prognosis have not been explored. The aim of this project was to find the autofluorescence features of the closed hole and their relation with vision. To investigate the characteristics of fundus autofluorescence imaging after ICG-assisted vitrectomy for IMH and to evaluate the correlations of fluorescence patterns at the MH site with visual acuity and macular anatomic outcomes. We retrospectively evaluated 33 IMH patients (33 eyes) who underwent a 25G pars plana vitrectomy (follow-up, 6-14.5 months). ICG staining (2.5 mg/mL) was either used to remove the internal limiting membrane (ILM) or the inverted ILM flap was overlaid on the hole. After surgery, fluorescence imaging of the fundus was obtained using a scanning laser ophthalmoscope at 795 nm. On fluorescence imaging, the area of ILM peeling in all eyes showed hypofluorescence with no changes over time. The inverted ILM flap (performed in 18 eyes) was positioned on the inferior retina and exhibited early mild hyperfluorescence with blurred edges. This was gradually enhanced up to 3-6 months postoperatively and was then attenuated. MHs showed two distinct patterns on optical coherence tomography: granular (21 eyes) and patchy hyperfluorescence (12 eyes). Best-corrected visual acuity improved postoperatively in all cases (p<0.001, Z=-4.744). VA was worse in the patchy (vs. granular) hyperfluorescence cases (p=0.011, Z=-2.548). The status of the ILM peeling area, ILM flap, and closed MH can be clearly observed using autofluorescence imaging at 795 nm. Fluorescence may be due to ICG staining of the ILM and accumulation in retinal pigment epithelium cells during ICG-assisted surgery. Granular hyperfluorescence at the MH site may indicate good anatomic and visual prognoses.

Lamotrigine‐associated macular phototoxicity in Asperger syndrome

Purpose: Asperger's syndrome is a neurodevelopmental disorder that falls within the autism spectrum disorder family. Comorbid conditions such as depression and anxiety are commonly associated, and lamotrigine is often prescribed off‐label for treatment. It has the capacity to absorb ultraviolet (UV) light and generate free oxygen radicals, which can potentially cause cellular damage. In this case report, we present multimodal imaging findings in a patient diagnosed with solar maculopathy.Methods: A young patient was referred to our department for bilateral visual decline and central scotoma. The patient was examined with multimodal imaging including fundus photography, fundus autofluorescence (FAF), swept‐source optical coherence tomography (SS‐OCT) and multifocal electroretinogram.Results: A 25‐year‐old patient with Asperger's syndrome treated with lamotrigine was referred to our department for bilateral visual decline and central scotoma. Best corrected visual acuity (BCVA) was 0.40 in both eyes. Dilated fundus examination revealed a bilateral yellow foveal lesion. Fundus autofluorescence (FAF) imaging showed foveal hyperautofluorescence. SS‐OCT in the macular region of both eyes showed a disruption of the ellipsoid zone and the external limiting membrane. Upon further questioning, the patient disclosed history of repeatedly gazing at the sun. The diagnosis of solar maculopathy associated with lamotrigine was established.Conclusion: This is the second report of lamotrigine associated retinal phototoxicity. Lamotrigine, recognized as a photosensitizer, may induce a photochemical response, with retinal phototoxicity. Caution must be exercised to educate patients about the importance of not gazing directly at the sun, as it van cause irreversible retinal impairment.

Morphometric Risk Factors for Drusenoid Pigment Epithelium Detachment Collapse and Retinal Pigment Epithelium Atrophy Expansion.

The purpose of this study was to investigate factors associated with drusenoid pigment epithelium detachment (dPED) growth rate, incidence of dPED collapse, and retinal pigment epithelium (RPE) atrophy enlargement rate following dPED collapse and their impact on visual acuity (VA). This was a retrospective longitudinal study on 44 eyes. Serial spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (AF) imaging were performed. Qualitative features and quantitative dPED-related metrics were assessed. The surface-to-volume ratio (S/V) was computed to evaluate dPED shape irregularity. AF imaging was utilized to measure RPE atrophy area in eyes experiencing dPED collapse. Regression models were used to analyze associations among VA, dPED growth rate, and RPE atrophy enlargement rate. Cox regression was used to identify risk factors for dPED collapse. Significant correlations were observed between dPED area, surface, and volume (P < 0.05 for all pairs). The dPED metrics were inversely correlated with the S/V. Incidence of dPED collapse was 22 per 100 eye-years over a mean follow-up of 59 ± 41 months. Eyes experiencing collapsed dPED had worse baseline VA (P < 0.001). RPE hypertransmission (hazard ratio [HR] = 3.68, P = 0.004) and hyper-reflective foci (HR = 3.45, P = 0.02) were risk factors for dPED collapse; a higher S/V ratio was protective (HR = 0.78, P = 0.03). A faster rate of RPE atrophy enlargement was associated with a faster rate of dPED volume increase (r = 0.47, P = 0.02) and worse VA over time (P = 0.02). Risk stratification in patients with dPED can be aided by identifying risk factors for dPED collapse. Identifying factors associated with RPE atrophy enlargement may have implications for treatment decision making.

Iron overload and chelation modulates bisretinoid levels in the retina.

Iron dysregulation in conjunction with other disease processes may exacerbate retinal degeneration. We employed models of iron overload and iron chelation to explore the interactions between iron-catalyzed oxidation and photoreactive bisretinoid lipofuscin. The mice were injected intravitreally with ferric ammonium citrate (FAC) or were treated using the iron chelator deferiprone (DFP) from birth to 2months of age. Short-wavelength fundus autofluorescence (SW-AF) and spectral-domain optical coherence tomography (SD-OCT) scans were acquired. The bisretinoid levels were quantified using ultra performance liquid chromatography (UPLC) and in vivo through quantitative fundus autofluorescence (qAF). In histologic sections, the photoreceptor cell viability was assessed by measuring the thickness of the outer nuclear layer (ONL). The levels of bisretinoids, all-trans-retinal dimers, and A2PE were significantly increased in the FAC-injected eyes of C57BL/6J mice. Seven days after FAC injection, hyperautofluorescent foci were visible in fundus autofluorescence (488nm) images, and in SD-OCT scans, aberrant hyperreflectivity was present in the outer retina and ONL thinning was observed. In FAC-injected Abca4-/- mice with pronounced RPE bisretinoid lipofuscin accumulation, the hyperautofluorescent puncta were more abundant than in the wild-type mice, and the extent of ONL thinning was greater. Conversely, the intravitreal injection of FAC in Mertk-/- mice led to a more modest increase in A2PE after 2 days. In contrast to the effect of iron accumulation, chelation with DFP resulted in significantly increased levels of A2E and A2-GPE and qAF due to the reduced iron-catalyzed oxidation of bisretinoids. In Mertk-/- mice, the A2E level was significantly lower and the ONL area was smaller than in DFP-treated mice. DFP chelation did not impair the visual cycle in BALB/cJ mice. Iron accumulation was associated with progressive impairment in photoreceptor cells that was associated with the increased formation of a bisretinoid species known to form in photoreceptor outer segments as a precursor to A2E. Additionally, disease features such as the development of hyperautofluorescence puncta in fundus AF images, hyperreflectivity in the outer retina of SD-OCT scans, and ONL thinning were more pronounced when iron was delivered to Abca4-/- mice with a greater propensity for bisretinoid formation. Higher bisretinoid levels and enhanced qAF are indicative of lesser bisretinoid loss due to oxidation.

Fundus Autofluorescence Patterns in Subretinal Hemorrhages Associated with Neovascular Age-Related Macular Degeneration

Introduction: Submacular hemorrhage (SMH) is a vision-threatening complication of neovascular age-related macular degeneration (AMD). The exact treatment scheme is not established yet. The aim of the current study was to describe surgical results and fundus autofluorescence (FAF) patterns after pars plana vitrectomy (ppV) + subretinal tissue plasminogen activator (tPA) + anti-vascular endothelial growth factor (VEGF) and intravitreal tPA + anti-VEGF + sulfur hexafluoride (SF6) tamponade and to compare them to intravitreal tPA + anti-VEGF + SF6 in the treatment of SMH in the course of AMD. Materials and Methods: We performed FAF imaging in patients with a previous SMH in the course of AMD with a duration of <60 days treated with vitrectomy with subretinal anti-VEGF and tPA and intravitreal anti-VEGF, tPA, and SF6 administration (group 1) or intravitreal tPA + anti-VEGF + SF6 (group 2). In all eyes, a throughout ophthalmic examination, fluorescein angiography, and spectral domain optical coherence tomography (SD-OCT) were done for diagnosis. SD-OCT was performed monthly during treatment. Results: Three FAF patterns were observed in both groups. Pattern one (normal autofluorescence) was observed in 5/18 in group one and 5/21 group two. Pattern two was observed in 6/18 in group one and 7/21 in group two. Pattern three was noted in 7/18 in group one and 5/21 in group two. Improvement in visual acuity was statistically significant for both groups: 0.01 Snellen (2.0 logMAR) to 0.11 Snellen (0.96 logMAR) in group one (p = 0.019) and 0.11 Snellen (0.96 logMAR) to 0.33 Snellen (0.48 logMAR) in group two (p = 0.0007). Central retinal thickness also decreased with statistical significance for both groups (p < 0.05). Conclusion: FAF patterns did not depend on the treatment used, but solely on the duration of SMH before treatment. SMH if not treated prompt enough might cause long-standing photoreceptor and retinal pigment epithelium defect, which is represented by hypo- and hyperautofluorescence. Performing a subretinal injection of tPA and anti-VEGF does not cause any defects associated with the injection site. That might be associated with previous local internal limiting membrane peeling, which reduces the injection pressure. Not only prompt treatment of SMH but also further continuation of anti-VEGF treatment is mandatory to maintain vision.

Hydroxychloroquine can be resumed with close monitoring after retinopathy has developed, without major visual loss: Case Report.

To present a patient with systemic lupus erythematosus on longstanding hydroxychloroquine (HCQ) use for whom HCQ was stopped due to signs of toxicity, and then resumed four years later due to dire systemic need. Long term retrospective study. Humphrey visual fields (10-2 and 24-2), fundus autofluorescence imaging, and spectral domain OCT were used to follow progression over time. The patient was on HCQ for 26 years, with a cumulative dose over 3,000g. HCQ was stopped in 2011 due to macular toxicity. She remained off HCQ for four years, during which time she developed type 1 diabetes due to an immunologic attack on the pancreas, and then JC (John Cunningham) viremia after a period of treatment with mycophenolate, which put her at risk for progressive multifocal leukoencephalopathy. Mycophenolate was discontinued and HCQ was resumed with careful follow-up over the next 7 years. The toxic maculopathy showed only mild, slow progression since HCQ was resumed. Careful annual monitoring using HVF 10-2 and spectral domain OCT imaging remains the standard of care for patients on HCQ. However, it may be possible with close monitoring, when there is compelling systemic need, to resume HCQ after it has been stopped, with only slow progression of the retinopathy. This allowed the patient to have an improved quality of life and reduced the risk of severe morbidity and mortality.

Multimodal photoacoustic microscopy, optical coherence tomography, and fluorescence imaging of USH2A knockout rabbits

Usher syndrome type 2A (USH2A) is a genetic disorder characterized by retinal degeneration and hearing loss. To better understand the pathogenesis and progression of this syndrome, animal models such as USH2A knockout (USH2AKO) rabbits have been developed. In this study, we employed multimodal imaging techniques, including photoacoustic microscopy (PAM), optical coherence tomography (OCT), fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography (ICGA) imaging to evaluate the retinal changes in the USH2AKO rabbit model. Twelve New Zealand White rabbits including USH2AKO and wild type (WT) were used for the experiments. Multimodal imaging was implemented at different time points over a period of 12 months to visualize the progression of retinal changes in USH2AKO rabbits. The results demonstrate that ellipsoid zone (EZ) disruption and degeneration, key features of Usher syndrome, began at the age of 4 months old and persisted up to 12 months. The EZ degeneration areas were clearly observed on the FAF and OCT images. The FAF images revealed retinal pigment epithelium (RPE) degeneration, confirming the presence of the disease phenotype in the USH2AKO rabbits. In addition, PAM images provided high-resolution and high image contrast of the optic nerve and the retinal microvasculature, including retinal vessels, choroidal vessels, and capillaries in three-dimensions. The quantification of EZ fluorescent intensity using FAF and EZ thickness using OCT provided comprehensive quantitative data on the progression of degenerative changes over time. This multimodal imaging approach allowed for a comprehensive and non-invasive assessment of retinal structure, microvasculature, and degenerative changes in the USH2AKO rabbit model. The combination of PAM, OCT, and fluorescent imaging facilitated longitudinal monitoring of disease progression and provided valuable insights into the pathophysiology of USH2A syndrome. These findings contribute to the understanding of USH2A syndrome and may have implications for the development of diagnostic and therapeutic strategies for affected individuals. The multimodal imaging techniques employed in this study offer a promising platform for preclinical evaluation of potential treatments and may pave the way for future clinical applications in patients with Usher syndrome.

Longitudinal Changes of Retinal Structure in Molecularly Confirmed C1QTNF5 Patients With Late-Onset Retinal Degeneration.

The purpose of this study was to present our findings on the natural history of late-onset retinal degeneration (LORD) in patients with molecularly confirmed C1QTNF5 heterozygous pathogenic variants and assess suitability of retinal structure parameters for disease monitoring. Sixteen patients with C1QTNF5-LORD were retrospectively identified from Moorfields Eye Hospital, UK. Fundus autofluorescence (FAF), optical coherence tomography (OCT) scans, and best-corrected visual acuity (BCVA) were collected. Area of atrophy (AA) was manually drawn in FAF images. Ellipsoid zone (EZ) width and foveal retinal thickness of the whole retina and outer retina were extracted from OCT scans. Age-related changes were tested with linear-mixed models. Patients had median age of 62.3years (interquartile range [IQR]=58.8-65.4years) at baseline, and median follow-up of 5.1years (IQR=2.6-7.6years). AA, EZ width, and retinal thickness parameters remained unchanged until age 50years, but showed significant change with age thereafter (all P < 0.0001). AA and EZ width progressed rapidly (dynamic range normalized rates=4.3-4.5%/year) from age 53.9 and 50.8years (estimated inflection points), respectively. Retinal thickness parameters showed slower progression rates (range=1.6-2.5%/year) from age 60 to 62.3. BCVA (median=0.3 LogMAR, IQR=0.0-1.0 at baseline) showed a rapid decline (3.3%) from age 70years. Findings from patients with earlier disease showed FAF atrophy manifests in the temporal retina initially, and then progresses nasally. Patients with LORD remained asymptomatic until age 50years, before suffering rapid outer retinal degeneration. EZ width and AA showed rapid progression and high interocular correlation, representing promising outcome metrics. Clinical measures also capturing the temporal retina may be preferable, enabling earlier detection and better disease monitoring. Area of atrophy in FAF images and OCT-measured EZ width represent promising outcome metrics for disease monitoring in patients with C1QTNF5-LORD.

Discovery of Novel Ophthalmic Imaging Biomarkers for Neurodegenerative Disease

AbstractBackgroundThe retina is increasingly investigated as a site of Alzheimer’s Disease (AD) manifestation, with amyloid β (Aβ) plaques being found in the retina of AD and mild cognitively impaired (MCI) patients, however functional changes in the retina are poorly understood. Retinal imaging techniques can be utilized for neurodegenerative biomarkers, since the retina is the only CNS organ available for noninvasive tracking.MethodRetinal imaging techniques were using to compare the retina of wild‐type (WT) or AD transgenic mice containing the APP: Swedish and Indiana mutation expressed under the prion promoter (TgCRND8) at 20 and 30 weeks of age (n = 10 mice per genotype). Optical coherence tomography (OCT) for retinal thickness assessment, Fundus Autofluorescence Imaging (FAF) for aggregate visualization, and electroretinogram (ERG) for retinal neuronal electrical activity were performed. Aβ ELISA was also performed on retina and cortex to evaluate amyloid burden correlation.ResultMean retinal insoluble Aβ 1‐42 was significantly elevated in TgCRND8 mice relative to WT at 23 weeks (35 vs 4.2 pg/mL, P&lt;0.05) and 42 weeks (77.9 vs 7.5 pg/mL, P&lt;0.05), and correlated with insoluble cortical brain Aβ 1‐42 (Pearson’s r = 0.847, P = 0.001). Total retinal thickness was significantly higher in TgCRND8 mice relative to WT (233 µm vs 225 µm, P&lt;0.01). Specifically, the retinal nerve fiber layer (RNFL) was thicker in TgCRND8 mice (28.5 vs 22.9 µm, P&lt;0.01). FAF imaging revealed significant autofluorescent aggregate detection in TgCRND8 mice both in the RNFL (94.3 vs 59.8 spots, P&lt;0.01) and outer plexiform layer (OPL) (87.8 vs 49.3 spots, P&lt;0.01). Lastly ERG revealed reduced b wave amplitude in TgCRND8 mice relative to WT (197.45 vs 457.9 µV, P&lt;0.001) and photopic negative response (PhNR) wave amplitude (8.2 µm vs 25.7 457.9 µV, P&lt;0.001). These values are indicative of dysfunctional bipolar and retinal ganglion cell electrical activity.ConclusionTgCRND8 mice have functional changes in retina thickness, FAF lipofuscin deposition, and ERG, which may prove invaluable as biomarkers for pre‐clinical AD diagnosis, monitoring and drug efficacy trials.

Deep learning model for automatic differentiation of EMAP from AMD in macular atrophy

To create a deep learning (DL) classifier pre-trained on fundus autofluorescence (FAF) images that can assist the clinician in distinguishing age-related geographic atrophy from extensive macular atrophy and pseudodrusen-like appearance (EMAP). Patients with complete outer retinal and retinal pigment epithelium atrophy secondary to either EMAP (EMAP Group) or to dry age related macular degeneration (AMD group) were retrospectively selected. Fovea-centered posterior pole (30° × 30°) and 55° × 55° degree-field-of-view FAF images of sufficiently high quality were collected and used to train two different deep learning (DL) classifiers based on ResNet-101 design. Testing was performed on a set of images coming from a different center. A total of 300 patients were recruited, 135 belonging to EMAP group and 165 belonging to AMD group. The 30° × 30° FAF based DL classifier showed a sensitivity of 84.6% and a specificity of 85.3% for the diagnosis of EMAP. The 55° × 55° FAF based DL classifier showed a sensitivity of 90% and a specificity of 84.6%, a performance that was significantly higher than that of the 30° × 30° classifer (p = 0.037). Artificial intelligence can accurately distinguish between atrophy caused by AMD or by EMAP on FAF images. Its performance are improved using wide field acquisitions.

Ocular manifestation of an adult Niemann-Pick disease type B

Niemann-Pick disease is a rare, autosomal recessive inherited lysosomal storage disorder. The pathophysiological background for this condition is the deficiency or reduced function of the enzyme sphingomyelinase, as well as a deficiency in the intracellular cholesterol transporter protein. Due to the breakdown defect, sphingomyelin and cholesterol accumulate in the lysosomes of cells. The disease is divided into 5 subtypes (A, A/B, B, C, D). The authors present the case of a 24-year-old young man diagnosed with Niemann-Pick disease type B as a child, focusing on the ophthalmic manifestation of the disease. During the examination of the patient, fundus photographs and fundus autofluorescence imaging were taken, and optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and visual field (perimetry) examinations were performed. The characteristic macular halo and the cherry-red spot in the fovea were clearly visible during ophthalmoscopy and on the fundus photographs. The OCT images showed focal thickening with high reflectivity in the ganglion cell layer corresponding to the macular halo, and the area of the foveola was spared. With visual field examination, an intact field of vision was found on both eyes. Similar to the presented patient, symptoms in patients with the B subtype are milder, and besides the visceral symptoms, there are no neurological symptoms, and the specific ophthalmic abnormalities do not cause visual impairment. Currently, Niemann-Pick disease is considered a rare disease, and the diagnosis of the patients is often delayed or even missed due to non-specific or mild symptoms. Through consultation between medical specialties, ophthalmological examination can also contribute to the correct diagnosis in cases with mild general symptoms. Timely diagnosis can potentially lead to mitigation of symptoms thanks to the ever-expanding therapeutic options, stabilization of the disease progression, and increase of the patients' life expectancy. Orv Hetil. 2023; 164(46): 1838-1844.

RP2-Associated X-linked Retinopathy: Clinical Findings, Molecular Genetics, and Natural History in a Large Cohort of Female Carriers

RP2-associated retinopathy typically causes severe early onset retinitis pigmentosa (RP) in affected males. However, there is a scarcity of reports describing the clinical phenotype of female carriers. We tested the hypothesis that RP2 variants manifest in female carriers with a range of functional and anatomic characteristics. Retrospective case series. Females with disease-causing variants in RP2 were identified from investigation of pedigrees affected by RP2 retinopathy. All case notes and results of molecular genetic testing, retinal imaging (fundus autofluorescence imaging, optical coherence tomography (OCT)), and electrophysiology were reviewed. Forty pedigrees were investigated. Twenty-nine pedigrees had obligate carriers or molecularly confirmed female members with recorded relevant history and/or examination. For 8 pedigrees, data were available only from history, with patients reporting affected female relatives with RP in 4 cases and unaffected female relatives in the other 4 cases. Twenty-seven females from 21 pedigrees were examined by a retinal genetics specialist. Twenty-three patients (85%) reported no complaints and had normal vision and 4 patients had RP-associated complaints (15%). Eight patients had normal fundus examination (30%), 10 had a tapetal-like reflex (TLR; 37%), 5 had scattered peripheral pigmentation (19%), and the 4 symptomatic patients had fundus findings compatible with RP (15%). All asymptomatic patients with normal fundus, TLR, or asymptomatic pigmentary changes had a continuous ellipsoid zone on OCT when available. The electroretinograms revealed mild to severe photoreceptor dysfunction in 9 of 11 subjects, often asymmetrical, including 5 with pattern electroretinogram evidence of symmetrical (n = 4) or unilateral (n = 1 subject) macular dysfunction. Most carriers were asymptomatic, exhibiting subclinical characteristics such as TLR and pigmentary changes. However, female carriers of RP2 variants can manifest RP. Family history of affected females with RP does not exclude X-linked disease. The phenotypic spectrum as described herein has prognostic and counselling implications for RP2 carriers and patients.

Changes in Optical Coherence Tomography and Fundus Autofluorescence Findings in Acute Zonal Occult Outer Retinopathy

We report a case of peripapillary acute zonal occult outer retinopathy (AZOOR) in a 43-year-old woman. Fundus photographs showed no specific abnormal findings, while blue-light fundus autofluorescence (FAF) imaging revealed well-defined hyperfluorescent areas in the peripapillary region, excluding the macula. The ellipsoid zone (EZ) was absent on optical coherence tomography (OCT) images of this area. Visual field testing with Goldmann perimetry showed blind spot enlargement and multifocal electroretinogram showed corresponding amplitude reductions. Three months after the initial visit, the EZ had reappeared and both FAF and visual field had improved. FAF together with OCT may be useful in the evaluation and monitoring of AZOOR.

A deep learning model for generating fundus autofluorescence images from color fundus photography

BackgroundFundus Autofluorescence (FAF) is a valuable imaging technique used to assess metabolic alterations in the retinal pigment epithelium (RPE) associated with various age-related and disease-related changes. The practical uses of FAF are ever-growing. This study aimed to evaluate the effectiveness of a generative deep learning (DL) model in translating color fundus (CF) images into synthetic FAF images and explore its potential for enhancing screening of age-related macular degeneration (AMD). MethodsA generative adversarial network (GAN) model was trained on pairs of CF and FAF images to generate synthetic FAF images. The quality of synthesized FAF images was assessed objectively by common generation metrics. Additionally, the clinical effectiveness of the generated FAF images in AMD classification was evaluated by measuring the area under the curve (AUC), using the LabelMe dataset. ResultsA total of 8410 FAF images from 2586 patients were analyzed. The synthesized FAF images exhibited an impressive objectively assessed quality, achieving a multi-scale structural similarity index (MS-SSIM) of 0.67. When evaluated on the LabelMe dataset, the combination of generated FAF images and CF images resulted in a noteworthy improvement in AMD classification accuracy, with the AUC increasing from 0.931 to 0.968. ConclusionsThis study presents the first attempt to use a generative deep learning model to create authentic and high-quality FAF images from CF images. The incorporation of the translated FAF images on top of CF images improved the accuracy of AMD classification. Overall, this study presents a promising approach to enhance large-scale AMD screening.