Adaptive Optics Retinal Imaging in RDH12-Associated Early Onset Severe Retinal Dystrophy.

Purpose: RDH12 is among the most common genes found in individuals with early-onset severe retinal (EOSRD). Adaptive optics scanning light ophthalmoscopy (AOSLO) enables resolution of individual rod and cone photoreceptors in the retina. This study presents the first AOSLO imaging of individuals with RDH12-associated EOSRD. Methods: Case series of patients who attended Moorfields Eye Hospital (London, UK). Spectral-domain optical coherence tomography, near-infrared reflectance (NIR), and blue autofluorescence imaging were analyzed. En face image sequences of photoreceptors were recorded using either of two AOSLO modalities. Cross-sectional analysis was undertaken for seven patients and longitudinal analysis for one patient. Results: Nine eyes from eight patients are presented in this case series. The mean age at the time of the assessment was 11.2 ± 6.5 years of age (range 7-29). A subfoveal continuous ellipsoid zone (EZ) line was present in eight eyes. Posterior pole AOSLO revealed patches of cone mosaics. Average cone densities at regions of interest 0.5° to the fovea ranged from 12,620 to 23,660 cells/mm2, whereas intercell spacing ranged from 7.0 to 9.7 µm. Conclusions: This study demonstrates that AOSLO can provide useful high-quality images in patients with EOSRD, even during childhood, with nystagmus, and early macular atrophy. Cones at the posterior pole can appear as scattered islands or, possibly later in life, as a single subfoveal conglomerate. Detailed image analysis suggests that retinal pigment epithelial stress and dysfunction may be the initial step toward degeneration, with NIR being a useful tool to assess retinal well-being in RDH12-associated EOSRD.

Stargardt's pigmentosa: A novel combination of two inherited retinal dystrophies.

60-year-old woman referring visual disability. She presented bone spicule pigmentation and retinal atrophy in all peripheral retina, as well as macular retinal flecks. Multimodal imaging showed typical findings of both inherited retinal dystrophies (IRD). Electroretinogram confirmed rod dysfunction. Biallelic mutations were found in ABCA4 and CNGA1 genes. Although not common, different IRDs may be present in a same patient at the same time. This is the first reported case of the combination of RP with late-onset Stargardt's disease. We propose the name 'Stargardt's pigmentosa' for this novel clinical entity.

Síndrome de Kjellin: paraparesia espástica y distrofia en patrón multifocal que simula fundus flavimaculatus / Kjellin's syndrome: Spastic paraplegia and multifocal pattern dystrophy simulating fundus flavimaculatus

El síndrome de Kjellin es un raro síndrome neurooftalmológico de herencia autosómica recesiva cuyo diagnóstico se basa en la apariencia del fondo de ojo en un paciente con paraparesia espástica, dificultad de aprendizaje, amiotrofia y cuerpo calloso delgado. Presentamos el caso de un varón de 42 años sin síntomas visuales, remitido por el Servicio de Neurología por cuadro degenerativo a estudio. En la exploración oftalmológica se objetiva una distrofia en patrón multifocal que simula fundus flavimaculatus y un retardo en la conducción de los potenciales evocados visuales. Se revisan las pruebas realizadas hasta ese momento y se solicita análisis genético para los subtipos 11 y 15 de paraparesia espástica hereditaria, que son los asociados a cambios maculares. Se demuestra una variante patogénica en el gen SPG11 que explica las manifestaciones clínicas del paciente. Los hallazgos oftalmológicos fueron clave en el diagnóstico de este raro síndrome (AU)

Kjellin's syndrome is a rare autosomal recessive hereditary neuro-ophthalmologic syndrome. The diagnosis of Kjellin's syndrome is based on the retinal appearance in a patient with spastic paraplegia, learning difficulties, amyotrophy and thin corpus callosum. We present the case of a 42-year-old man without visual symptoms, referred to study from the Neurology Service due to a degenerative condition. On ophthalmologic examination is found a multifocal pattern dystrophy simulating fundus flavimaculatus and a delay in the visual evoked potential responses. The performed tests are reviewed and a genetic analysis for subtypes 11 and 15 of hereditary spastic paraplegia are requested. These subtypes are associated with macular changes. A pathogenic variant in the SPG11 gene is identified, which explains the patient's clinical manifestations. Ophthalmological findings were key in the diagnosis of this rare syndrome (AU)

Quantitative and qualitative characterization of retinal dystrophies in canine models of inherited retinal diseases using spectral domain optical coherence tomography (SD-OCT).

The purpose of this study was to establish spectral domain optical coherence tomography (SD-OCT) assessment data in well-established canine models of inherited retinal dystrophies: PDE6B-rod-cone dysplasia 1 (RCD1: early onset retinitis pigmentosa), PRCD-progressive rod-cone degeneration (PRCD: late onset retinitis pigmentosa), CNGB3-achromatopsia, and RPE65-Leber congenital amaurosis (LCA). High resolution SD-OCT images of the retina were acquired from both eyes in 5 planes: temporal; superotemporal; superior; nasal; and inferior in adult dogs with: RCD1 (n = 4 dogs, median age: 1.5 yrs); PRCD (n = 2, 4.3 yrs); LCA (n = 3, 5.2 yrs); achromatopsia (n = 3, 4.2 yrs); and wild types (wt, n = 6, 5.5 yrs). Total, inner and outer retinal thicknesses and ellipsoid zone were analyzed. In selected animals, histomorphometric evaluations were performed. In dogs with RCD1, PRCD, and LCA, the thickness of the outer retina was, compared to wt, significantly decreased (p ≤ 0.02) in all OCT imaging planes, and in superotemporal and inferior imaging planes in dogs with achromatopsia. No significant thinning was observed in inner retina thickness in any disease model except in the inferior imaging plane in dogs with RCD1. Dogs with RCD1, PRCD, and LCA had significantly more areas with disrupted ellipsoid zone in the presumed area centralis than wt (p ≤ 0.001). OCT findings provide baseline information for research of retinal dystrophies using these canine models.

RETINAL DYSTROPHY IN JEUNE SYNDROME: A MULTIMODAL IMAGING CHARACTERIZATION.

PURPOSE: To report multimodal imaging findings in a patient affected by Jeune syndrome-associated retinal dystrophy. METHODS: Observational case report. RESULTS: An 18-year-old girl affected by Jeune syndrome was referred to our low vision unit. She presented with bilateral high myopia, reduced visual acuity, exotropia, and nystagmus. Fundus examination detected posterior myopic staphyloma and diffuse retinal dystrophy confirmed using a full-field electroretinogram as a cone-rod dystrophy. Spectral domain optical coherence tomography detected a thick anomalous hyperreflective band located beneath an irregular and disrupted external limiting membrane, showing the primary involvement of the photoreceptors outer segment with relative sparing of the retinal pigment epithelium, as confirmed by fundus autofluorescence. CONCLUSION: This is a case of Jeune syndrome with retinal abnormalities studied with fundus autofluorescence and optical coherence tomography. Retinal noninvasive multimodal imaging could provide significant insight in the retinal involvement of patients affected by Jeune syndrome and should have an essential role in the multidisciplinary diagnostic approach and follow-up.

Assessing Photoreceptor Status in Retinal Dystrophies: From High-Resolution Imaging to Functional Vision.

PURPOSE: To describe the value of integrating phenotype/genotype data, disease staging, and evaluation of functional vision in patient-centered management of retinal dystrophies. METHODS: (1) Cross-sectional structure-function and retrospective longitudinal studies to assess the correlations between standard fundus autofluorescence (FAF), optical coherence tomography, visual acuity (VA), and perimetry (visual field [VF]) examinations to evaluate photoreceptor functional loss in a cohort of patients with rod-cone dystrophy (RCD); (2) flood-illumination adaptive optics (FIAO) imaging focusing on photoreceptor misalignment and orientation of outer segments; and (3) evaluation of the impact of visual impairment in daily life activities, based on functional (visual and mobility) vision assessment in a naturalistic environment in visually impaired subjects with RCD and subjects treated with LuxturnaⓇ for RPE65-related Leber congenital amaurosis before and after therapy. RESULTS: The results of the cross-sectional transversal study showed that (1) VA and macular sensitivity were weakly correlated with the structural variables; and (2) functional impairment (VF) was correlated with reduction of anatomical markers of photoreceptor structure and increased width of autofluorescent ring. The dimensions of the ring of increased FAF evolved faster. Other criteria that differed among groups were the lengths of the ellipsoid zone, the external limiting membrane, and the foveal thickness. FIAO revealed a variety of phenotypes: paradoxical visibility of foveal cones; heterogeneous brightness of cones; dim, inner segment-like, and RPE-like mosaic. Directional illumination by varying orientation of incident light (Stiles-Crawford effect) and the amount of side illumination (gaze-dependent imaging) affected photoreceptor visibility. Mobility assessment under different lighting conditions showed correlation with VF, VA, contrast sensitivity (CS), and dark adaptation, with different predictive values depending on mobility study paradigms and illumination level. At high illumination level (235 lux), VF was a predictor for all mobility performance models. Under low illumination (1 and 2 lux), VF was the most significant predictor of mobility performance variables, while CS best explained the number of collisions and segments. In subjects treated with LuxturnaⓇ, a very favorable impact on travel speed and reduction in the number of collisions, especially at low luminance, was observable 6 months following injection, in both children and adults. CONCLUSIONS: Our results suggest the benefit of development and implementation of quantitative and reproducible tools to evaluate the status of photoreceptors and the impact of both visual impairment and novel therapies in real-life conditions. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Chorioretinal dystrophy, hypogonadotropic hypogonadism, and cerebellar ataxia: Boucher-Neuhauser syndrome due to a homozygous (c.3524C>G (p.Ser1175Cys)) variant in PNPLA6 gene.

Purpose: The current study aims to raise awareness of Boucher - Neuhauser syndrome (BNHS) that occurs as a rare phenotype due to biallelic pathogenic variants in the PNPLA6 gene.Methods: Detailed family histories and clinical data were recorded. Whole exome sequencing was performed and co-segregation analysis of the family was done by sanger sequencing. Also, review of 28 molecularly confirmed patients with BNHS from the literature was evaluated.Results: We identified a missense homozygous variant (c.3524 C > G (p.Ser1175Cys)) in the PNPLA6 gene, which explains the phenotype of the patient and neurologic, ophthalmologic, endocrine, and genetic evaluations established a diagnosis of BNHS. Symptoms, ethnicity, clinical and genetic findings of 28 molecularly confirmed patients with BNHS from the literature were also presented.Conclusion: We present the main findings of a Turkish family with BNHS together with detailed clinical and genetic profiles of patients diagnosed as BNHS that have been molecularly confirmed in the literature so far.

Multimodal imaging of an RPGR carrier female.

Background: Retinitis pigmentosa GTPase regulator (RPGR) gene mutations are a common cause of X-linked retinitis pigmentosa and X-linked cone-rod dystrophy. There have been no previous reports of association with crystalline retinopathy or pseudo-crystalline retinopathy.Materials and Methods: We describe the history, clinical findings, retinal imaging, and electrodiagnostic studies of a patient with a tapetal-like reflex (TLR) and pseudo-crystalline retinopathy secondary to RPGR mutation.Case Description: Asymptomatic TLR secondary to RPGR mutation was diagnosed in a 14-year-old African American female with a family history of retinal dystrophy and no other past ophthalmic or medical history. Pseudo-crystalline retinopathy was observed on the Optos scanning laser ophthalmoscopy (SLO) imaging system but not on color fundus photography (CFP). Evidence of a TLR secondary to RPGR mutation was confirmed by CFP, autofluorescence, and genetic testing.Conclusion: We present a case of pseudo-crystalline retinopathy seen on Optos imaging in a patient with a TLR secondary to RPGR mutation.

Biallelic CDK9 variants as a cause of a new multiple-malformation syndrome with retinal dystrophy mimicking the CHARGE syndrome.

CDK9 has been considered a candidate gene involved in the CHARGE-like syndrome in a pair of cousins. We report an 8-year-old boy with a strikingly similar phenotype including facial asymmetry, microtia with preauricular tags and bilateral hearing loss, cleft lip and palate, cardiac dysrhythmia, and undescended testes. Joint contracture, no finger flexion creases, and large halluces were the same as those of a previously reported patient with homozygous CDK9 variants. The ocular phenotype included blepharophimosis, lacrimal duct obstruction, eyelid dermoids, Duane syndrome-like abduction deficit, and congenital cataracts. Optical coherence tomography and electroretinography evaluations revealed severe retinal dystrophy had developed at an early age. Trio-based whole-exome sequencing identified compound heterozygous variants in CDK9 [p.(A288T) of maternal origin and p.(R303C) of paternal origin] in the patient. Variants' kinase activities were reduced compared with wild type. We concluded that CDK9 biallelic variants cause a CHARGE-like malformation syndrome with retinal dystrophy as a distinguishing feature.

RETINAL DYSTROPHY IN A PATIENT WITH McARDLE DISEASE.

PURPOSE: To report a case of pattern dystrophy in a patient with McArdle disease, a rare autosomal recessive disorder of glycogen metabolism. METHODS: Case report. RESULTS: A 29-year-old woman with a history of muscle biopsy-confirmed McArdle disease presented with fundus findings consistent with pattern dystrophy. Multimodal imaging, including optical coherence tomography and fundus autofluorescence, was performed. CONCLUSION: To our knowledge, this is the third reported case of pattern dystrophy in a patient with McArdle disease.

DEEP PHENOTYPING AND FURTHER INSIGHTS INTO ITM2B-RELATED RETINAL DYSTROPHY.

PURPOSE: To reappraise the presentation and the course of ITM2B-related retinal dystrophy and give further insights into ITM2B expression in the retina. METHODS: The clinical data of nine subjects with ITM2B-related retinal dystrophy were retrospectively reviewed. The genetic mutation was assessed for its influence on splicing in cultured fibroblasts. The cellular expression of ITM2B within the inner retina was investigated in wild-type mice through mRNA in situ hybridization. RESULTS: All patients complained of decreased vision and mild photophobia around their twenties-thirties. The peculiar feature was the hyperreflective material on optical coherence tomography within the inner retina and the central outer nuclear layer with thinning of the retinal nerve fiber layer. Although retinal imaging revealed very mild or no changes over the years, the visual acuity slowly decreased with about one Early Treatment Diabetic Retinopathy Study letter per year. Finally, full-field electroretinography showed a mildly progressive inner retinal and cone dysfunction. ITM2B mRNA is expressed in all cellular types of the inner retina. Disease mechanism most likely involves mutant protein misfolding and/or modified protein interaction rather than misplicing. CONCLUSION: ITM2B-related retinal dystrophy is a peculiar, rare, slowly progressive retinal degeneration. Functional examinations (full-field electroretinography and visual acuity) seem more accurate in monitoring the progression in these patients because imaging tends to be stable over the years.

Long-term follow-up of a Chinese patient with KCNV2-retinopathy.

Purpose: To characterize and monitor the clinical and electrophysiological features of a Chinese patient with KCNV2 retinopathy.Methods: A 17-year-old Chinese male with the diagnosis of cone dystrophy with supernormal rod response (CDSRR) was followed-up for 5 years, with full ophthalmological examinations, including decimal best corrected visual acuity (BCVA), fundus photography, fundus autofluorescence (FAF) imaging, spectral-domain optical coherence tomography (SD-OCT), and full-field electroretinogram (ERG). Genetic screening was performed to detect the sequence variations in the retinal dystrophy associated genes in the patient and his parents.Results: The patient demonstrated the characteristic full-field electroretinography (ERG) features of CDSRR, namely a profound enlargement of the dark-adapted ERG b-wave amplitude with increasing flash strength and a broadened a-wave trough; this case also had undetectable light-adapted ERGs. A BCVA of 0.15 was maintained over 5 years in both eyes; while progressive macular atrophy was identified. Molecular genetic analyses revealed two novel disease-causing KCNV2 variants in compound heterozygous state: c.1408 G > C (p.Gly470Arg) and c.1500 C > G (p.Tyr500Ter).Conclusions: This is the first long-term case study of an East Asian patient with molecularly confirmed CDSRR. The progressive atrophy with maintained VA demonstrated in this case will be valuable for increasing the understanding of the natural course of KCNV2 retinopathy and it will help in counselling patients with this disease.

Novel variants in PNPLA6 causing syndromic retinal dystrophy.

PNPLA6-related disorders include several phenotypes, such as Boucher-Neuhäuser syndrome, Gordon Holmes syndrome, spastic paraplegia, photoreceptor degeneration, Oliver-McFarlane syndrome and Laurence-Moon syndrome. In this study, detailed clinical evaluations and genetic testing were performed in five (4 Chinese and 1 Caucasian/Chinese) syndromic retinal dystrophy patients. Genotype-phenotype correlations were analyzed based on review of the literatures of previously published PNPLA6-related cases. The mean age of patients and at first visit were 20.8 years (11, 12, 25, 28, 28) and 14.2 years (4, 7, 11, 24, 25), respectively. They all presented with severe chorioretinal dystrophy and profoundly decreased vision. The best corrected visual acuity (BCVA) ranged from 20/200 to 20/2000. Systemic manifestations included cerebellar ataxia, hypogonadotropic hypogonadism and hair anomalies. Six novel and three reported pathogenic variants in PNPLA6 (NM_001166111) were identified. The genotypes of the five cases are: c.3134C > T (p.Ser1045Leu) and c.3846+1G > A, c.3547C > T (p.Arg1183Trp) and c.1841+3A > G, c.3436G > A (p.Ala1146Thr) and c.2212-10A > G, c.3436G > A (p.Ala1146Thr) and c.2266C > T (p.Gln756*), c.1238_1239insC (p.Leu414Serfs*28) and c.3130A > G (p.Thr1044Ala). RT-PCR confirmed that the splicing variants indeed led to abnormal splicing. Missense variants p.Thr1044Ala, p.Ser1045Leu, p.Ala1146Thr, p.Arg1183Trp and c.3846+1G > A are located in Patatin-like phospholipase (Pat) domain. In conclusion, we report the phenotypes in five patients with PNPLA6 associated syndromic retinal dystrophy with variable systemic involvement and typical choroideremia-like fundus changes. Ocular manifestations may be the first and the only findings for years. All of our patients carried one severe deleterious variant (stop-gain or splicing variant) and one milder variant (missense variant). Retinal involvement was significantly correlated with severe deleterious variants and variants in Pat domain.

Distrofia macular en patrón unilateral y enfermedad sistémica asociada / Unilateral pattern of macular dystrophy and associated systemic pathology

Las distrofias en patrón de la retina son un grupo heterogéneo de maculopatías, en general, bilaterales y simétricas, que curiosamente se pueden asociar a diferentes enfermedades sistémicas. En este artículo se describe el caso de una paciente con distrofia en patrón unilateral que presentó asociada enfermedad de McArdle y fibrosis pulmonar idiopática

Retinal pattern dystrophies are a heterogeneous group of generally bilateral and symmetrical maculopathies that, curiously, can be associated with different systemic diseases. This article describes a patient with unilateral pattern dystrophies, as well as associated McArdle disease and idiopathic pulmonary fibrosis

Novel Pathogenic Sequence Variants in NR2E3 and Clinical Findings in Three Patients.

A retrospective review of the clinical records of patients seen at the Oxford Eye Hospital identified as having NR2E3 mutations was performed. The data included symptoms, best-corrected visual acuity, multimodal retinal imaging, visual fields and electrophysiology testing. Three participants were identified with biallelic NR2E3 pathogenic sequence variants detected using a targeted NGS gene panel, two of which were novel. Participant I was a Nepalese male aged 68 years, and participants II and III were white Caucasian females aged 69 and 10 years old, respectively. All three had childhood onset nyctalopia, a progressive decrease in central vision, and visual field loss. Patients I and III had photopsia, patient II had photosensitivity and patient III also had photophobia. Visual acuities in patients I and II were preserved even into the seventh decade, with the worst visual acuity measured at 6/36. Visual field constriction was severe in participant I, less so in II, and fields were full to bright targets targets in participant III. Electrophysiology testing in all three demonstrated loss of rod function. The three patients share some of the typical distinctive features of NR2E3 retinopathies, as well as a novel clinical observation of foveal ellipsoid thickening.

Molecular and phenotypic investigation of a New Zealand cohort of childhood-onset retinal dystrophy.

Inherited retinal diseases are clinically heterogeneous and are associated with nearly 300 different genes. In this retrospective, observational study of a consecutive cohort of 159 patients (134 families) with childhood-onset (<16 years of age) retinal dystrophy, molecular investigations, and in-depth phenotyping were performed to determine key clinical and molecular characteristics. The most common ocular phenotype was rod-cone dystrophy in 40 patients. Leber Congenital Amaurosis, the most severe form of retinal dystrophy, was present in 10 patients, and early onset severe retinal dystrophy in 22 patients. Analysis has so far identified 131 pathogenic or likely pathogenic variants including 22 novel variants. Molecular diagnosis was achieved in 112 of 134 families (83.6%) by NGS gene panel investigation in 60 families, Sanger sequencing in 27 families, and Asper microarray in 25 families. An additional nine variants of uncertain significance were also found including three novel variants. Variants in 36 genes have been identified with the most common being ABCA4 retinopathy in 36 families. Five sporadic retinal dystrophy patients were found to have variants in dominant and X-linked genes (CRX, RHO, RP2, and RPGR) resulting in more accurate genetic counseling of inheritance for these families. Variants in syndromic associated genes including ALMS1, SDCCAG8, and PPT1 were identified in eight families enabling directed systemic care.

Multimodal imaging and adaptive optics in internal limiting membrane dystrophy.

An 18-year-old boy presented with a mild blurring of vision in both his eyes for the last 2 years. His best-corrected visual acuity was 20/60 in both the eyes with normal colour vision. Fundus evaluation showed exaggerated shiny reflex from the internal limiting membrane (ILM) with the wrinkled inner retinal surface at posterior pole. No vessel attenuation or retinal pigment epithelium changes were evident. Optical coherence tomography showed thickened ILM, which was appreciated in fundus photo also. The electrodiagnostic tests were normal, and the photoreceptors appeared normal in adaptive optics in the central macula at 2°-4° eccentricity. Among the very few reported cases of Muller cells sheen dystrophy, our patient was the probably the youngest and was picked up by a thoughtful ophthalmologist in detailed clinical examination. Adaptive optics in the case of ILM dystrophy is also not reported earlier.

Biallelic RP1-associated retinal dystrophies: Expanding the mutational and clinical spectrum.

Purpose: To evaluate the phenotypic spectrum of autosomal recessive RP1-associated retinal dystrophies and assess genotypic associations. Methods: A retrospective multicenter study was performed of patients with biallelic RP1-associated retinal dystrophies. Data including presenting symptoms and age, visual acuity, kinetic perimetry, full field electroretinogram, fundus examination, multimodal retinal imaging, and RP1 genotype were evaluated. Results: Nineteen eligible patients from 17 families were identified and ranged in age from 10 to 56 years at the most recent evaluation. Ten of the 21 unique RP1 variants identified were novel, and mutations within exon 2 accounted for nearly half of alleles across the cohort. Patients had clinical diagnoses of retinitis pigmentosa (13), cone-rod dystrophy (3), Leber congenital amaurosis (1), early-onset severe retinal dystrophy (1), and macular dystrophy (1). Macular atrophy was a common feature across the cohort. Symptom onset occurred between 4 and 30 years of age (mean 14.9 years, median 13 years), but there were clusters of onset age that correlated with the effects of RP1 mutations at a protein level. Patients with later-onset disease, including retinitis pigmentosa, had at least one missense variant in an exon 2 DCX domain. Conclusions: Biallelic RP1 mutations cause a broad spectrum of retinal disease. Exon 2 missense mutations are a significant contributor to disease and can be associated with a considerably later onset of retinitis pigmentosa than that typically associated with biallelic RP1 mutations.