Short-wavelength Autofluorescence Research Articles

Fundus Autofluorescence in Diabetic Retinopathy.

Diabetic retinopathy is a leading cause of visual morbidity worldwide. Fundus autofluorescence is a rapid, non-invasive imaging modality that has gained increased popularity in recent years in the multimodal evaluation of diabetic retinopathy and, in particular, of diabetic macular oedema. Acquired using either a fundus camera or the confocal scanning laser ophthalmoscope, short-wavelength and near-infrared autofluorescence are the most used techniques in diabetic retinopathy. In diabetic macular oedema, short-wavelength autofluorescence, in its cystoid pattern, is useful for detecting cystoid macular oedema. Increased spot hyperautofluorescence in short-wavelength and granular changes in near-infrared autofluorescence correlate well with other imaging findings, indicating photoreceptor and retinal pigment epithelium damage and being associated with decreased visual acuity. While also being a marker of oxidative stress, increased short-wavelength autofluorescence in the setting of diabetic macular oedema appears to be a prognostic factor for poor visual outcome, even after the resolution of the intraretinal fluid. Autofluorescence also helps in the assessment of diabetic retinal pigment epitheliopathy and choroidopathy. Fundus autofluorescence is an evolving technology that will assist in gaining further insight into the pathophysiology of diabetic retinopathy and allow for a more comprehensive evaluation of these patients.

Multimodal imaging analysis of autosomal recessive bestrophinopathy: Case series.

Autosomal recessive bestrophinopathy (ARB) is a subtype of bestrophinopathy caused by biallelic mutations of the BEST1 gene, which affect the retinal pigment epithelium (RPE). Studying RPE abnormalities through imaging is essential for understanding ARB. This case series involved the use of multimodal imaging techniques, namely autofluorescence (AF) imaging at 488 nm [short-wavelength AF] and 785 nm [near-infrared AF (NIR-AF)] and polarization-sensitive optical coherence tomography (PS-OCT), to investigate RPE changes in 2 siblings with ARB. Two Japanese siblings (Case 1: male, followed for 20-23 years; Case 2: female, followed for 13-17 years) carried compound heterozygous mutations of the BEST1 gene. Both siblings were diagnosed with ARB. Multimodal imaging techniques were used to evaluate RPE changes. Both siblings had funduscopic changes similar to those seen in the vitelliruptive stage of Best vitelliform macular dystrophy during the follow-up period. NIR-AF imaging showed hypo-AF of the entire macular lesion in both cases, and this hypo-AF remained stable over time. PS-OCT confirmed reduced RPE melanin content in these hypo-AF areas. Additionally, hyper-NIR-AF dots were observed within hypo-NIR-AF areas. Concomitant identification of focally thickened RPE melanin on PS-OCT imaging and hyper-AF on short-wavelength AF imaging at the sites containing hyper-NIR-AF dots indicated that the hyper-NIR-AF dots had originated from either stacked RPE cells or RPE dysmorphia. We confirmed RPE abnormalities in ARB, including diffuse RPE melanin damage in the macula alongside evidence of RPE activity-related changes. This case series demonstrates that multimodal imaging, particularly NIR-AF and PS-OCT, provides detailed insights into RPE alterations in ARB.

Multimodal in-vivo maps as a tool to characterize retinal structural biomarkers for progression in adult-onset Stargardt disease.

To characterize retinal structural biomarkers for progression in adult-onset Stargardt disease from multimodal retinal imaging in-vivo maps. Seven adult patients (29-69 years; 3 males) with genetically-confirmed and clinically diagnosed adult-onset Stargardt disease and age-matched healthy controls were imaged with confocal and non-confocal Adaptive Optics Scanning Light Ophthalmoscopy (AOSLO), optical coherence tomography (OCT), fundus infrared (FIR), short wavelength-autofluorescence (FAF) and color fundus photography (CFP). Images from each modality were scaled for differences in lateral magnification before montages of AOSLO images were aligned with en-face FIR, FAF and OCT scans to explore changes in retinal structure across imaging modalities. Photoreceptors, retinal pigment epithelium (RPE) cells, flecks, and other retinal alterations in macular regions were identified, delineated, and correlated across imaging modalities. Retinal layer-thicknesses were extracted from segmented OCT images in areas of normal appearance on clinical imaging and intact outer retinal structure on OCT. Eccentricity dependency in cell density was compared with retinal thickness and outer retinal layer thickness, evaluated across patients, and compared with data from healthy controls. In patients with Stargardt disease, alterations in retinal structure were visible in different image modalities depending on layer location and structural properties. The patients had highly variable foveal structure, associated with equally variable visual acuity (-0.02 to 0.98 logMAR). Cone and rod photoreceptors, as well as RPE-like structures in some areas, could be quantified on non-confocal split-detection AOSLO images. RPE cells were also visible on dark field AOSLO images close to the foveal center. Hypo-reflective gaps of non-waveguiding cones (dark cones) were seen on confocal AOSLO in regions with clinically normal CFP, FIR, FAF and OCT appearance and an intact cone inner segment mosaic in three patients. Dark cones were identified as a possible first sign of retinal disease progression in adult-onset Stargardt disease as these are observed in retinal locations with otherwise normal appearance and outer retinal thickness. This corroborates a previous report where dark cones were proposed as a first sign of progression in childhood-onset Stargardt disease. This also supports the hypothesis that, in Stargardt disease, photoreceptor degeneration occurs before RPE cell death.

Extensive Macular Atrophy with Pseudodrusen-like appearance: Progression Kinetics and Late-Stage Findings

To describe the clinical outcome and late-stage findings of extensive macular atrophy with pseudodrusen-like appearance (EMAP). Retrospective cohort study. Seventy-eight patients (156 eyes) affected by EMAP. We collected data on best-corrected visual acuity, kinetic perimetry, OCT, short-wavelength autofluorescence, and near-infrared autofluorescence findings. Genetic testing for the TIMP3 and C1QTNF5 genes was performed via Sanger sequencing for 58 patients, with no pathogenic variants identified. The primary outcomes were best-corrected visual acuity at the last examination, visual field at the last examination, and incidence rates and time-to-event curves for blindness with the United States Social Security Administration and World Health Organization (WHO) criteria, foveal involvement, and atrophy enlargement beyond the 30° and 55° field of view. Imaging findings at the last examination were secondary outcomes. At the most recent visit, mean age was 70.9 ± 5.2 years. Using United States criteria, 58.1% of the patients were blind, and 25.8% were blind according to WHO criteria. All eyes showed large central scotomas, which were associated with visual field constriction in 22.2% of eyes. We detected focal openings or large dehiscences of Bruch's membrane (BM) in 25.4% of eyes. Near-infrared autofluorescence showed increased visibility of the choroidal vessels beyond the atrophy in 87.2% of eyes. The incidence rates for blindness were 3.95 per 100 patient-years with United States criteria and 1.54 per 100 patient-years according to WHO criteria. The incidence rates were 22.8 per 100 eye-years for foveal involvement, 12.0 per 100 eye-years for atrophy enlargement beyond 30°, and 6.6 per 100 eye-years for atrophy enlargement beyond 55°. The estimates were not influenced by the age at onset. We identified characteristic imaging findings, including BM ruptures, in elder patients with EMAP and calculated incidence rates for different functional and anatomic outcomes. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The Peripapillary Retina - A Common Juncture in Stargardt Disease and Idiopathic Intracranial Hypertension.

To present the multimodal imaging and functional exam findings in a case of combined Stargardt disease and idiopathic intracranial hypertension. The patient was evaluated with multimodal imaging including color fundus photography, short wavelength autofluorescence, spectral domain optical coherence tomography as well as functional testing such as Humphrey visual fields and full-field electroretinogram. A 35-year-old woman was referred for evaluation of bilateral transient visual obscurations over the course of 2 months. Optic disc edema was observed in both eyes as well as a bulls-eye maculopathy with pisciform flecks. Magnetic resonance imaging and subsequent lumbar puncture confirmed a diagnosis of idiopathic intracranial hypertension. Fundus autofluorescence demonstrated hyperautofluorescent flecks surrounding both the macula and the disc. Genetic testing and full-field electroretinogram confirmed a diagnosis of Stargardt disease. Notably, the peripapillary retina was not spared as is frequently seen in Stargardt disease, possibly due to the impact of disc edema in the area. The patient was treated with increasing doses of acetazolamide and familial testing for Stargardt disease was recommended. Both Stargardt disease and idiopathic intracranial hypertension are separately rare diseases with common anatomic intersection at the peripapillary retina. Stargardt disease typically spares the peripapillary retina; however, in the present case shows some evidence of peripapillary involvement. This finding suggests some relationship between disc edema due to idiopathic intracranial hypertension and the natural history of Stargardt disease.

Macular dystrophy in Kabuki syndrome due to de novo KMT2D variants: refining the phenotype with multimodal imaging and follow-up over 10 years: insight into pathophysiology

BackgroundKabuki Syndrome is a rare and genetically heterogenous condition with both ophthalmic and systemic complications and typical facial features. We detail the macular phenotype in two unrelated patients with Kabuki syndrome due to de novo nonsense variants in KMT2D, one novel. A follow-up of 10 years is reported. Pathogenicity of both de novo nonsense variants is analyzed.MethodsFour eyes of two young patients were studied by full clinical examination, kinetic perimetry, short wavelength autofluorescence, full field (ff) ERGs, and spectral-domain optical coherence tomography (SD-OCT). One patient had adaptive optic (AO) imaging. Whole exome sequencing was performed in both patients.ResultsBoth patients had de novo nonsense variants in KMTD2. One patient had c.14843C>G; p. (Ser4948ter) novel variant and the second c.11119C>T; p. (Arg3707ter). Both had a stable Snellen visual acuity of 0.2–0.3. The retinal multimodal imaging demonstrated abnormalities at the fovea in both eyes: hyperreflectivity to blue light and a well-delimited gap—disruption of ellipsoid and interdigitation layer on OCT. The dark area on AO imaging is presumed to be absent for, or with structural change to photoreceptors. The ff ERGs and kinetic visual fields were normal. The foveal findings remained stable over several years.ConclusionKabuki syndrome–related maculopathy is a distinct loss of photoreceptors at the fovea as shown by multimodal imaging including, for the first time, AO imaging. This report adds to the literature of only one case with maculopathy with two additional macular dystrophies in patients with Kabuki syndrome. Although underestimated, these cases further raise awareness of the potential impact of retinal manifestations of Kabuki syndrome not only among ophthalmologists but also other healthcare professionals involved in the care of patients with this multisystem disorder.

Localised loss of sheen in Optos pseudocolour images in Oguchi disease following prior short wavelength autofluorescence imaging

Aims/Purpose: Oguchi disease is characterized by night blindness and a striking golden retinal sheen in the light‐adapted state which disappears following prolonged dark adaptation (Mizuo‐Nakamura phenomenon). The sheen is observable clinically and on colour and pseudocolour (Optos plc) imaging. We observed a localized loss of sheen in a patient on colour/pseudocolour imaging in an area corresponding to the 30 degree square illuminated by short wavelength (488 nm) autofluorescence (AF) imaging (Heidelberg Spectralis). We explored whether other cases showed this phenomenon.Methods: Patients in our service with Oguchi disease (diagnosed phenotypically and/or with genetic confirmation) who had undergone colour or pseudocolour imaging were identified. In these patients, note was made of whether prior 30 degree short wavelength autofluorescence images had been undertaken and whether a localized square‐shaped loss of sheen was observed.Results: We identified 13 patients who had undergone colour or pseudocolour imaging. Of these, 4 patients (2 males, 2 females) had undergone prior 30 degree (and not 55 degree) short wavelength AF imaging at the same visit (ages ranging from 12 to 67). In 2 patients (a 12 year old, with variants in GRK1, and a 67 year old, not yet genotyped), a clear central square in which the sheen was absent was observed in the colour or pseudocolour images.Conclusions: The phenomenon of disappearance of the sheen in Oguchi disease following prolonged darkness is well‐described. Paradoxically, we observed loss of the sheen in 2 patients in a defined area corresponding to the field of illumination by bright blue light in 30 degree AF imaging. The blue light is preferentially absorbed by rhodopsin, which becomes bleached. It is possible that the sheen (at least in some patients) is dependent on there being a large proportion of unbleached rhodopsin as well as deficient shut‐off of activated rhodopsin.

Correlation Between Fundus Autofluorescence Pattern and Retinal Function on Microperimetry in Choroideremia.

In patients with choroideremia, it is not known how smooth and mottled patterns on short-wavelength fundus autofluorescence (AF) imaging relate to retinal function. A retrospective case-note review was undertaken on 190 patients with choroideremia at two specialist centers for retinal genetics. Twenty patients with both smooth and mottled zones on short-wavelength AF imaging and concurrent mesopic microperimetry assessments were included. Mean retinal sensitivities within the smooth and mottled zones were compared between choroideremia patients, and identical points on mesopic microperimetry collected from 12 age-matched controls. Longitudinal analyses were undertaken at 2 and 5years in a subset of patients. In patients with choroideremia, mean retinal sensitivities at baseline were significantly greater in the smooth zone (26.1 ± 2.0 dB) versus the mottled zone (20.5 ± 4.2 dB) (P < 0.0001). Mean retinal sensitivities at baseline were similar in the smooth zone between choroideremia patients and controls (P = 0.054) but significantly impaired in the mottled zone in choroideremia compared to controls (P < 0.0001). The rate of decline in total sensitivity over 5 years was not significant in either the smooth or mottled zone in a small subset of choroideremia patients (n = 7; P = 0.344). In choroideremia, retinal sensitivity as determined by microperimetry correlates with patterns on AF imaging: retinal function in the smooth zone, where the retinal pigment epithelium is anatomically preserved, is similar to controls, but retinal sensitivity in the mottled zone is impaired. Patterns on AF imaging may represent a novel, objective outcome measure for clinical trials in choroideremia as a surrogate for retinal function.

Hyperautofluorescent Ring Pattern in Retinitis Pigmentosa: Clinical Implications and Modifications Over Time.

The purpose of this study was to investigate the relation among hyperautofluorescent ring patterns, visual acuity (VA), and optical coherence tomography (OCT) features in patients with retinitis pigmentosa (RP), and to describe its modifications over time. This was a retrospective, longitudinal, and observational study. Clinical and imaging data from the first and last available visits of patients with a clinical diagnosis of RP were reviewed. The ellipsoid zone (EZ) width was measured on OCT acquisitions. Short-wavelength autofluorescence (SW-AF) images were classified based on the hyperautofluorescent ring pattern as absent, regular, and irregular, and their modifications over the follow-up were described. The VA, EZ width, and progression rate were compared among the three groups. One hundred eight eyes from 54 subjects were included in the study. The hyperautofluorescent ring was not present in 28 eyes (25.9%), appeared regular in 45 eyes (41.7%), and had an irregular pattern in 35 eyes (32.4%). The three groups differed in terms of age, VA, and EZ width (all P < 0.05). Additionally, the absence of a hyperautofluorescent ring indicated a faster rate of progression (P < 0.001). Throughout the follow-up period, 17 eyes (15.7%) experienced a change in the AF pattern, with irregular rings being more commonly affected. The hyperautofluorescent ring is a useful tool to frame patients based on their EZ width and VA. We described its possible modifications over time, the knowledge of which can aid clinicians in the interpretation of imaging finding changes of their patients.

Insights Into PROM1-Macular Disease Using Multimodal Imaging.

To describe the features of genetically confirmed PROM1-macular dystrophy in multimodal images. Thirty-six (36) eyes of 18 patients (5-66 years; mean age, 42.4 years) were prospectively studied by clinical examination and multimodal imaging. Short-wavelength autofluorescence (SW-AF) and quantitative fundus autofluorescence (qAF) images were acquired with a scanning laser ophthalmoscope (HRA+OCT, Heidelberg Engineering) modified by insertion of an internal autofluorescent reference. Further clinical testing included near-infrared autofluorescence (NIR-AF; HRA2, Heidelberg Engineering) with semiquantitative analysis, spectral domain-optical coherence tomography (HRA+OCT) and full-field electroretinography. All patients were genetically confirmed by exome sequencing. All 18 patients presented with varying degrees of maculopathy. One family with individuals affected across two generations exhibited granular fleck-like deposits across the posterior pole. Areas of granular deposition in SW-AF and NIR-AF corresponded to intermittent loss of the ellipsoid zone, whereas discrete regions of hypoautofluorescence corresponded with a loss of outer retinal layers in spectral-domain optical coherence tomography scans. For 18 of the 20 eyes, qAF levels within the macula were within the 95% confidence intervals of healthy age-matched individuals; nor was the mean NIR-AF signal increased relative to healthy eyes. Although PROM1-macular dystrophy (Stargardt disease 4) can exhibit phenotypic overlap with recessive Stargardt disease, significantly increased SW-AF levels were not detected. As such, elevated bisretinoid lipofuscin may not be a feature of the pathophysiology of PROM1 disease. The qAF approach could serve as a method of early differential diagnosis and may help to identify appropriate disease targets as therapeutics become available to treat inherited retinal disease.

Fundus Photography Methodologies to Assess RP Patients.

The development of fundus photography and imaging has improved our ability to diagnose and monitor inherited retinal degenerations. Nowadays, color fundus photography has become a staple in evaluating patients with retinitis pigmentosa (RP). Other important multimodal forms of fundus photography used today include red-free fundus photography, short-wavelength autofluorescence, and near-infrared autofluorescence. These photography methodologies provide valuable information on the natural history of disease progression, which in turn can lead to the identification of viable outcome measurements for current and future therapeutic trials. Further advances and developments in the field of fundus imaging will help in our understanding of RP and allied disorders.

Association of Missense Variants in VSX2 With a Peculiar Form of Congenital Stationary Night Blindness Affecting All Bipolar Cells

Congenital stationary night blindness (CSNB) is an inherited stationary retinal disorder that is clinically and genetically heterogeneous. To date, the genetic association between some cases with CSNB and an unusual complex clinical picture is unclear. To describe an unreported CSNB phenotype and the associated gene defect in 3 patients from 2 unrelated families. This retrospective case series was conducted in 2021 and 2022 at a national referral center for rare ocular diseases. Data for 3 patients from a cohort of 140 genetically unsolved CSNB cases were analyzed clinically and genetically. Complete ocular examination including full-field electroretinography and multimodal fundus imaging (spectral-domain optical coherence tomography, color, infrared reflectance, and short-wavelength autofluorescence photographs) were performed. The gene defect was identified by exome sequencing and confirmed by Sanger sequencing and co-segregation analysis in 1 family. Screening was performed for genetically unsolved CSNB cases for VSX2 variants by direct Sanger sequencing. Ocular and molecular biology findings. The series included 3 patients whose clinical investigations occurred at ages in the early 30s, younger than 12 years, and in the mid 40s. They had nystagmus, low stable visual acuity, and myopia from birth and experienced night blindness. Two older patients had bilateral lens luxation and underwent lens extraction. Full-field electroretinography revealed an electronegative Schubert-Bornschein appearance, combining characteristics of incomplete and complete CSNB, affecting the function of rod and cone ON- and OFF-bipolar cells. Exome sequencing and co-segregation analysis in a consanguineous family with 2 affected members identified a homozygous variant in VSX2. Subsequently, screening of the CSNB cohort identified another unrelated patient harboring a distinct VSX2 variant. This case series revealed a peculiar pan-bipolar cell retinopathy with lens luxation associated with variants in VSX2. Clinicians should be aware of this association and VSX2 added to CSNB diagnostic gene panels.

Near-Infrared Confocal Reflectance Scanning Laser Ophthalmoscopy (SLO) and Short-Wavelength Autofluorescence Imaging in Cystic Diabetic Macular Edema.

Objective To characterize results of short-wavelength autofluorescent (SW-AF) and near-infrared confocal reflectance scanning laser ophthalmoscopy (NIR-cR SLO) imaging in cystic diabetic macular edema (DME). Design Cross-sectional study. Participants: 104 eyes from 52 naïve treatment patients with DME and mild to moderate nonproliferative diabetic retinopathy (NPDR) Methods: complete ocular examination, best-corrected visual acuity (BCVA), and imaging were performed. Results In NIR-cR SLO, small/medium and large-sized cysts presented with decreased and increased reflectance, respectively. In SW-AF, increased and decreased autofluorescence, corresponding to medium-/large- and small-sized cysts were noted. Mainly, the lower NIR reflectance was associated with petaloid edema pattern in SW-AF (P=0.011), BCVA (logMAR) (P=0.056), subretinal fluid (P=0.035), and the involved layers of retina by cysts (P < 0.001) in Pearson chi-square test. Fair agreement of 0.31 (P < 0.001) between NIR-cR SLO and late FA leakage was found by the weighted kappa test. In regression analysis, NIR-cR SLO abnormality is highly correlated with outer and inner nuclear layers location of the cystic changes. Conclusions The size of cysts and involved layers affect presenting features of SW-AF and NIR reflectance.

Quantitative autofluorescence findings in patients undergoing hydroxychloroquine treatment.

BackgroundTo measure quantitative autofluorescence (qAF) in patients under treatment with hydroxychloroquine (HCQ) and at risk of retinal toxicity but with no apparent signs of retinal toxicity and to compare it with that of untreated subjects.MethodsConsecutive patients at risk for the development of HCQ retinal toxicity (duration of treatment >5 years or daily HCQ dose >5 mg/kg of actual body weight [ABW]) but no alterations on spectral domain—optical coherence tomography, short‐wavelength autofluorescence and 10–2 visual field examination were recruited. Healthy subjects matched by age and sex were also enrolled in the study. All subjects underwent qAF measurements in one eye. Images were analysed using the conventional qAF grid by Delori calculating the qAF of eight sectors of the intermediate ring and the mean of those values (qAF8).ResultsThirty‐nine patients treated with HCQ (38 females, mean age 52.1 ± 8.6 years) and 39 untreated subjects (38 females, mean age 51.2 ± 8.6 years) were included. In both HCQ patients and untreated subjects, qAF8 was positively correlated with age (p = 0.004). Although HCQ patients showed a higher mean qAF8 compared with untreated subjects (294.7 ± 65.3 vs. 268.9 ± 57.5), the difference was not significant (p = 0.068). HCQ patients showed significantly higher mean qAF values in the inferior‐temporal, inferior and inferior‐nasal sectors of the intermediate ring of qAF grid compared with untreated subjects (all p < 0.05).ConclusionsThese results suggest a possible preclinical increase of qAF values in inferior parafoveal sectors probably induced by HCQ exposure.

Retinal pigment epithelium melanin imaging using polarization-sensitive optical coherence tomography for patients with retinitis pigmentosa

This study aimed to evaluate the distribution of retinal pigment epithelium (RPE) melanin in patients with retinitis pigmentosa (RP) using entropy measurements by custom-made polarization-sensitive optical coherence tomography (PS-OCT) images, and compare entropy with the intensity of short-wavelength (SW) and near-infrared (NIR) autofluorescence (AF). We retrospectively reviewed the retinal images, including PS-OCT, SW-AF, and NIR-AF of patients with RP who had a hyperautofluorescent ring on AF. A total of 12 eyes of 12 patients (8 women and 4 men; mean age: 37.9 years) were included. There was a strong positive correlation between entropy value and NIR-AF intensity (r = 0.626, p < 0.001), and there was a very weak negative correlation between entropy value and SW-AF (r = − 0.197, p = 0.001). The mean values of the entropy in the foveal, temporal (2 mm from the fovea), and nasal (2 mm from the fovea) sections were 0.41 (± 0.09), 0.29 (± 0.08), and 0.26 (± 0.08), respectively. The entropy was significantly higher in the foveal section than in the temporal and nasal sections (p = 0.002 and p = 0.003, respectively). There was no significant difference between the entropies values for the temporal and nasal sections (p = 0.157). Age, logMAR best-corrected visual acuity, ellipsoid zone width, and central retinal thickness were not correlated with foveal entropy. We presented RPE melanin imaging in patients with RP using PS-OCT for the first time. PS-OCT can be a useful tool for monitoring patients with RP.

Prevalence, multimodal imaging and genotype-phenotype assessment of trauma related subretinal fibrosis in stargardt disease.

Stargardt disease produces lipofuscin accumulation predisposing to subretinal fibrosis (SRFib) after ocular trauma. Noninvasive imaging techniques allow in vivo assessment. The purpose of this study is to determine the prevalence of SRFib in a cohort of Stargardt patients, the presence of history of ocular trauma, the clinical features and possible genotype-phenotype associations in Stargardt patients with SRFib. We evaluated retrospectively 106 Stargardt patients and analysed the multimodal imaging and the genotype of patients with SRFib. Six patients exhibited SRFib, three of them with history of ocular trauma. Multimodal imaging showed extensive SRFib principally in the temporal midperipheral retina with no fluid associated. SRFib was better defined by short wavelength autofluorescence and spectral domain optical coherence tomography and appeared clinically stable over time. There was no particular genotype associated to SRFib. SRFib occurs in a significant percentage of patients with Stargardt disease and can be diagnosed through multimodal imaging regardless the history of trauma, further sustaining the importance of an appropriate imaging in such patients. No genotype-phenotype association has been established, supporting the traumatic etiology in half of cases. The remaining cases may be classified as idiopathic or have a minimal trauma occurring early in life that may be not recalled by the patients.

Expanding the phenotype of TTLL5-associated retinal dystrophy: a case series

BackgroundInherited retinal dystrophies describe a heterogeneous group of retinal diseases that lead to the irreversible degeneration of rod and cone photoreceptors and eventual blindness. Recessive loss-of-function mutations in Tubulin Tyrosine Ligase Like 5 (TTLL5) represent a recently described cause of inherited cone–rod and cone dystrophy. This study describes the unusual phenotypes of three patients with autosomal recessive mutations in TTLL5. Examination of these patients included funduscopic evaluation, spectral-domain optical coherence tomography, short-wavelength autofluorescence, and full-field electroretinography (ffERG). Genetic diagnoses were confirmed using whole exome capture. Protein modeling of the identified variants was performed to explore potential genotype–phenotype correlations.ResultsGenetic testing revealed five novel variants in TTLL5 in three unrelated patients with retinal dystrophy. Clinical imaging demonstrated features of sectoral cone–rod dystrophy and cone dystrophy, with phenotypic variability seen across all three patients. One patient also developed high-frequency hearing loss during a similar time period as the onset of retinal disease, potentially suggestive of a syndromic disorder. Retinal structure findings were corroborated with functional measures including ffERG findings that supported these diagnoses. Modeling of the five variants suggest that they cause different effects on protein function, providing a potential reason for genotype–phenotype correlation in these patients.ConclusionsThe authors report retinal phenotypic findings in three unrelated patients with novel mutations causing autosomal recessive TTLL5-mediated retinal dystrophy. These findings broaden the understanding of the phenotypes associated with TTLL5-mediated retinal disease and suggest that mutations in TTLL5 should be considered as a potential cause of sectoral retinal dystrophy in addition to cone–rod and cone dystrophies.

Mitochondrial Retinopathy

To report the retinal phenotype and the associated genetic and systemic findings in patients with mitochondrial disease. Retrospective case series. Twenty-three patients with retinopathy and mitochondrial disease, including chronic progressive external ophthalmoplegia (CPEO), maternally inherited diabetes and deafness (MIDD), mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), Kearns-Sayre syndrome, neuropathy, ataxia, and retinitis pigmentosa (NARP) syndrome, and other systemic manifestations. Review of case notes, retinal imaging, electrophysiologic assessment, molecular genetic testing including protein modeling, and histologic analysis of muscle biopsy. Phenotypic characteristics of mitochondrial retinopathy. Genetic testing identified sporadic large-scale mitochondrial DNA deletions and variants in MT-TL1, MT-ATP6, MT-TK, MT-RNR1, or RRM2B. Based on retinal imaging, 3 phenotypes could be differentiated: type 1 with mild, focal pigmentary abnormalities; type 2 characterized by multifocal white-yellowish subretinal deposits and pigment changes limited to the posterior pole; and type 3 with widespread granular pigment alterations. Advanced type 2 and 3 retinopathy presented with chorioretinal atrophy that typically started in the peripapillary and paracentral areas with foveal sparing. Two patients exhibited a different phenotype: 1 revealed an occult retinopathy, and the patient with RRM2B-associated retinopathy showed no foveal sparing, no severe peripapillary involvement, and substantial photoreceptor atrophy before loss of the retinal pigment epithelium. Two patients with type 1 disease showed additional characteristics of mild macular telangiectasia type 2. Patients with type 1 and mild type 2 or 3 disease demonstrated good visual acuity and no symptoms associated with the retinopathy. In contrast, patients with advanced type 2 or 3 disease often reported vision problems in dim light conditions, reduced visual acuity, or both. Short-wavelength autofluorescence usually revealed a distinct pattern, and near-infrared autofluorescence may be severely reduced in type 3 disease. The retinal phenotype was key to suspecting mitochondrial disease in 11 patients, whereas 12 patients were diagnosed before retinal examination. Different types of mitochondrial retinopathy show characteristic features. Even in absence of visual symptoms, their recognition may facilitate the often challenging and delayed diagnosis of mitochondrial disease, in particular in patients with mild or nebulous multisystem disease.

POS1393 QUANTITATIVE AUTOFLUORESCENCE FINDINGS IN PATIENTS UNDERGOING HYDROXYCHLOROQUINE TREATMENT

Background:Hydroxychloroquine (HCQ) is a relatively safe and effective drug widely used as primary or adjunctive treatment for several rheumatological and dermatological disorders1. HCQ modulates immune response through several mechanisms and has a tropism for pigmented ocular tissues, particularly retinal pigment epithelium (RPE)2. Its accumulation within RPE cells can lead to sight threatening retinal toxicity, with bull’s eye maculopathy (BEM) representing its advanced phenotype. 3 Quantitative Auto-Fluorescence (qAF) is an imaging modality that allows the measurement of retinal auto-fluorescence following short-wavelength light (488nm) excitation of retinal fluorophores (lipofuscin). 4 Two recent studies have focused on qAF values in patients treated with HCQ 5,6. In both cases qAF was increased in eyes with BEM. Furthermore, Reichel et al.6 were able to detect increased values of qAF in patients without BEM as early as 6 months after the start of HCQ treatment using an experimental imaging analysis procedure.Objectives:To measure quantitative autofluorescence (qAF) in patients under treatment with hydroxychloroquine (HCQ) with no apparent signs of retinal toxicity and to compare it with that of untreated subjects.Methods:Consecutive patients at risk for the development of HCQ retinal toxicity (duration of treatment &gt;5 years or daily HCQ dose &gt;5 mg/kg of actual body weight (ABW) and/or renal insufficiency)7 but no alterations on Spectral Domain - Optical Coherence Tomography, Short-Wavelength Autofluorescence and 10-2 Visual Field examination were recruited. Healthy subject matched by age and sex were also enrolled in the study. All subjects underwent qAF measurements in one eye. Images were analyzed using the conventional qAF grid by Delori calculating the qAF of 8 sectors of the intermediate ring and the mean of those values (qAF8).Results:Thirty-nine patients treated with HCQ (38 females, mean age 52,1 ± 8,6 years) and 39 untreated subjects (38 females, mean age 51,2 ± 8,6 years). In both HCQ patients and untreated subjects, qAF8 was positively correlated with age (p=0.004) (Figure 1). Although HCQ patients showed a higher mean qAF8 compared to untreated subjects (294,7 ±65,3 vs 268,9 ± 57,5), the difference was not significant (p=0.068). HCQ patients showed significantly higher mean qAF values in the inferior-temporal, inferior and inferior-nasal sectors of the intermediate ring of qAF grid compared to untreated subjects (all p&lt;0.05).Figure 1.Visual representation of a model predicting the standardized qAF values as influenced by age and HCQ daily dose/ABW, calculated for a treatment duration of 15 years.Conclusion:These results suggest a possible preclinical increase of qAF values in inferior parafoveal sectors probably induced by HCQ exposure. Further studies are required to improve our understanding of preclinical stages of HCQ retinopathy and the possible role of qAF in the HCQ toxicity screening.

Long-term follow-up of a patient with JAG1-associated retinopathy

To report the long-term structural and functional changes in the posterior segments of an adult with an unusual retinal dystrophy caused by a novel mutation in JAG1. A 33-year-old female underwent comprehensive ophthalmic examination, including best corrected visual acuity (BCVA) measurement, dilated fundus imaging (wide-angle fundus colour and short wavelength autofluorescence imaging), macular and peripheral spectral-domain optical coherence tomography (SD-OCT) and electroretinography (ERG) at baseline and 10years later at the age of 43. The patient also underwent systemic review with detailed cardiac, brain and renal investigations. During follow-up, genetic analysis using whole-exome sequencing was performed on the patient and her parents to identify disease-causing variants. The patient's main complaint was of a recent onset of bilateral photophobia and blurred vision in the left eye. On examination, the most striking retinal finding was of bilateral well-demarcated, anterior circumferential chorioretinal atrophy with scattered pigment clumping from the mid periphery to the ora. In addition, she had posterior pole RPE hypopigmentation, peripapillary chorioretinal atrophy, left macular choroidal folds and retinal vasculature tortuosity with atypical branching. Her retinal electrophysiology was consistent with a cone rod photoreceptor dystrophy and left macular dysfunction. Ten years later, her BCVA, the anterior circumferential chorioretinal atrophy and her visual field constriction all remained stable. Her retinal electrophysiology demonstrated deterioration of left rod function, while cone dysfunction remained stable. Macular function deteriorated in both eyes. During follow-up, she was also noted to have progressive aortic root dilatation, posterior embryotoxon and an x ray diagnosis of butterfly vertebrae. Whole-exome sequencing revealed a novel c.2412C > A p.(Tyr804Ter) truncating mutation in JAG1 that was predicted to be pathogenic and suggested a diagnosis of Alagille syndrome. This is the first report of the long-term detailed follow-up of a patient with Alagille syndrome whose most striking ophthalmic finding was bilateral well-demarcated, anterior circumferential chorioretinal atrophy. During follow-up, this finding remained stable, suggesting that this may be developmental in origin. This is in contrast with the progressive deterioration in the posterior pole retinal and macular function.