Aberrant lipid accumulation and retinal pigment epithelium dysfunction in PRCD-deficient mice.

Progressive Rod-Cone Degeneration (PRCD) is an integral membrane protein found in photoreceptor outer segment (OS) disc membranes and its function remains unknown. Mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. PRCD-deficient models exhibit decreased levels of cholesterol in the plasma. However, potential changes in the retinal cholesterol remain unexplored. In addition, impaired phagocytosis observed in these animal models points to potential deficits in the retinal pigment epithelium (RPE). Here, using a Prcd-/- murine model we investigated the alterations in the retinal cholesterol levels and impairments in the structural and functional integrity of the RPE. Lipidomic and immunohistochemical analyses show a 5-fold increase in the levels of cholesteryl esters (C.Es) and lipid deposits in the PRCD-deficient retina, respectively, indicating alterations in total retinal cholesterol. Furthermore, the RPE of Prcd-/- mice exhibit a 1.7-fold increase in the expression of lipid transporter gene ATP-binding cassette transporter A1 (Abca1). Longitudinal fundus and spectral domain optical coherence tomography (SD-OCT) examinations showed focal lesions and RPE hyperreflectivity. Strikingly, the RPE of Prcd-/- mice exhibited age-related pathological features such as lipofuscin accumulation, Bruch's membrane (BrM) deposits and drusenoid focal deposits, mirroring an Age-related Macular Degeneration (AMD)-like phenotype. We propose that the extensive lipofuscin accumulation likely impairs lysosomal function, leading to the defective phagocytosis observed in Prcd-/- mice. Our findings support the dysregulation of retinal cholesterol homeostasis in the absence of PRCD. Further, we demonstrate that progressive photoreceptor degeneration in Prcd-/- mice is accompanied by progressive structural and functional deficits in the RPE, which likely exacerbates vision loss over time.

LONGITUDINAL ADAPTIVE OPTICS SCANNING LASER OPHTHALMOSCOPY REVEALS REGIONAL VARIATION IN CONE AND ROD PHOTORECEPTOR LOSS IN STARGARDT DISEASE.

PURPOSE: To investigate the temporal sequence of changes in the photoreceptor cell mosaic in patients with Stargardt disease type 1, using adaptive optics scanning laser ophthalmoscopy. METHODS: Two brothers with genetically confirmed Stargardt disease type 1 underwent comprehensive eye exams, spectral-domain optical coherence tomography, fundus autofluorescence, and adaptive optics scanning laser ophthalmoscopy imaging 3 times over the course of 28 months. Confocal images of the cones and rods were obtained from the central fovea to 10° inferiorly. Photoreceptors were counted in sampling windows at 100- µ m intervals of 200 µ m × 200 µ m for cones and 50 µ m × 50 µ m for rods, using custom cell marking software with manual correction. Photoreceptor density and spacing were measured and compared across imaging sessions using one-way analysis of variance. RESULTS: Adaptive optics scanning laser ophthalmoscopy revealed the younger brother had a 30% decline in foveal cone density after 8 months, followed by complete loss of foveal cones at 28 months; the older brother had no detectable foveal cones at baseline. In the peripheral macula, cone and rod spacings were greater than normal in both patients. The ratio of the cone spacing to rod spacing was greater than normal across all eccentricities, with a greater divergence closer to the foveal center. CONCLUSION: Cone cell loss may be an early pathogenetic step in Stargardt disease. Adaptive optics scanning laser ophthalmoscopy provides the capability to track individual photoreceptor changes longitudinally in Stargardt disease.

The Progression of Stargardt Disease as Determined by Spectral-Domain Optical Coherence Tomography over a 24-Month Period (ProgStar Report No. 18).

INTRODUCTION: The aim of this study was to evaluate the progression of atrophy as determined by spectral-domain optical coherence tomography (SD-OCT) in patients with molecularly confirmed ABCA4-associated Stargardt disease type 1 (STGD1) over a 24-month period in a multicenter prospective cohort study. METHODS: SD-OCT images from 428 eyes of 236 patients were analyzed. Change of mean thickness (MT) and intact area were estimated after semiautomated segmentation for the following individual layers in the central subfield (CS), inner ring (IR), and outer ring (OR) of the ETDRS grid: retinal pigment epithelium (RPE), outer segments (OSs), inner segments (IS), outer nuclear layer (ONL) inner retina (IR), and total retina. RESULTS: Statistically significant decreases of all outer retinal layers (RPE, OS, IS, and ONL) could be observed over a 24-month period both in decline of mean retinal thickness and intact area (p < 0.0001, respectively), whereas the IR showed an increase of retinal thickness in the CS and IR and remained unchanged in the OR. CONCLUSIONS: Significant loss could be detected in outer retinal layers by SD-OCT over a 24-month period in patients with STGD1. Loss of thickness and/or intact area of such layers may serve as potential endpoints for clinical trials that aim to slow down the disease progression of STGD1.

Late-Onset Slowly Progressing Cone/Macular Dystrophy in Patients With the Biallelic Hypomorphic Variant p.Arg1933Ter in RP1.

Purpose: Homozygous hypomorphic variants of the RP1 gene, including c.5797C>T, p.Arg1933Ter, have traditionally been considered non-pathogenic. This study aimed to elucidate the clinical manifestations of late-onset, slowly progressive cone/macular dystrophy in patients homozygous for p.Arg1933Ter in the RP1 gene. Methods: Five patients with biallelic p.Arg1933Ter in RP1 were retrospectively recruited, and their clinical profiles were analyzed. Copy number variation analysis and Alu insertion assessment of genes associated with inherited retinal diseases were conducted. The results of comprehensive ophthalmological examinations, multimodal imaging, and full-field electroretinogram tests were analyzed. Results: No specific sequencing errors or structural variations associated with the clinical phenotypes were identified. Alu element insertion in RP1 was not detected. The mean ± SD age at the first visit was 62.2 ± 9.8 years, with symptoms typically starting between 45 and 50 years of age. Two patients exhibited a mild form of cone/macular dystrophy, characterized by a relatively preserved fundus appearance and blurring of the ellipsoid zone on optical coherence tomography. Three patients had late-onset cone/macular dystrophy with significant atrophy. Conclusions: To our knowledge, this study is the first to report that a homozygous hypomorphic variant of RP1, previously considered non-pathogenic, leads to cone/macular dystrophy. Translational Relevance: The study introduces novel possibilities suggesting that the homozygous hypomorphic variant of RP1 may be linked to variant pathogenicity.

Ophthalmological findings in ectodermal dysplasia, ectrodactyly, and macular dystrophy syndrome: a case report / Achados oftalmológicos na displasia ectodérmica, ectrodactilia e síndrome da distrofia macular: relato de caso

ABSTRACT We report on a case of two sisters, daughters of consanguineous parents, presenting with a similar condition of low visual acuity associated with retinal dystrophy in both eyes associated with alopecia and bone alterations or syndactyly.

RESUMO Relatamos um caso de duas irmãs, filhas de pais consanguíneos, apresentando uma condição semelhante de baixa acuidade visual associado à distrofia retiniana em ambos os olhos associado à alopecia e alterações ósseas ou sindactilia.

Do you know this syndrome? / Voce conhece esta sindrome?

POEMS syndrome is a unique clinical entity, the diagnosis of which is made when polyneuropathy and monoclonal gammopathy occur together, associated with other changes such as organomegaly, endocrinopathy, skin changes and papilledema. Cutaneous manifestations are heterogeneous, with diffuse cutaneous hyperpigmentation, hemangiomas and hypertrichosis occurring more frequently. We report the case of a 65- year-old female patient with this syndrome, diagnosed after 15 years of disabling peripheral neuropathy.

A síndrome de POEMS é uma entidade clínica única cujo diagnóstico é colocado quando existe polineuropatia e gamapatia monoclonal associada a outras alterações tais como organomegalia, endocrinopatia, alterações cutâneas e papiledema. As manifestações cutâneas são heterogéneas, sendo as mais frequentes a hiperpigmentação cutânea difusa, os hemangiomas e a hipertricose. Relata-se o caso de uma doente de 65 anos com essa síndrome diagnosticada após 15 anos de neuropatia periférica.

Nuevas perspectivas en el abordaje de la degeneración macular asociada a la edad / New perspectives in the approach to age-related macular degeneration

La aprobación de aflibercept para el tratamiento de la forma neovascular de degeneración macular asociada a la edad ha abierto la posibilidad de tratar a los pacientes con menos inyecciones dada la bimestralidad de dosificación de aflibercept, así como rescatar pacientes con respuesta subóptima a otros tratamientos antiangiogénicos. El presente manuscrito revisa la evidencia científica existente respecto al tratamiento con aflibercept, tanto en pacientes no tratados previamente como en aquellos con respuesta insatisfactoria a los tratamientos convencionales

The approval of aflibercept for the neovascular form of age-related macular degeneration has opened up the possibility of treating patients with fewer injections, since the drug can be administered once every two months. Aflibercept can also be used as rescue therapy in patients with suboptimal response to other antiangiogenic treatments. The present study reviews the scientific evidence on aflibercept, both in treatment-naïve patients and in those with an unsatisfactory response to conventional treatments

Distrofia epitelial pigmentar central-areolar / Central areolar pigment epithelial distrophy

Relatam-se 4 casos de uma família que apresenta o aspecto clínico e os testes morfológicos sugestivos de distrofia epitelial pigmentar central-areolar (CAPED). Säo discutidos os achados clínicos e angiográficos. Tanto os mecanismos de herança quanto a forma de evoluçäo assemelham-se aos relatos internacionais. Estes säo os primeiros casos de distrofia epitelial pigmentar central-areolar documentados no IPB

Retinose pigmentar central (inversa) / Central pigmentary retinitis

Apresentam-se 14 membros de uma família, nove dos quais säo portadores de retinose pigmentar central (inversa). Comparam-se os achados clínicos desses portadores num acompanhamento de 16 anos (1977-1993) no IPB, com aqueles descritos na retinose pigmentar típica. A discussäo baseia-se na herança, diagnóstico diferencial e conduta