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Investigative Ophthalmology & Visual... Jun 2020To evaluate the nature and extent of functional abnormality in X-linked retinoschisis (XLRS) by comparing three dark-adapted, full-field measures: the electroretinogram...
PURPOSE
To evaluate the nature and extent of functional abnormality in X-linked retinoschisis (XLRS) by comparing three dark-adapted, full-field measures: the electroretinogram (ERG), pupillary light reflex (PLR), and luminance threshold.
METHODS
ERGs, PLRs (pupil constriction due to light stimulation), and luminance thresholds were measured from seven XLRS subjects and from 10 normally sighted, age-similar controls. ERGs and PLRs were obtained for a range of flash strengths, and these data were fit with Naka-Rushton functions to derive the maximum saturated b-wave (Vmax) and PLR (Pmax) amplitudes. Additionally, semi-saturation constants were obtained for the b-wave (σ) and PLR (s). Values of 1/σ and 1/s provide sensitivity measures. Full-field, dark-adapted luminance thresholds were measured using 465-nm and 642-nm flash stimuli.
RESULTS
Vmax and 1/σ were significantly reduced in XLRS compared to the controls (both t ≥ 5.33, P < 0.001). In comparison, Pmax was normal in the XLRS subjects (t = 1.39, P = 0.19), but 1/s was reduced (t = 7.84, P < 0.001). Luminance thresholds for the control and XLRS groups did not differ significantly (F = 3.57, P = 0.08). Comparisons among measures indicated that pupil sensitivity was correlated with luminance threshold for the long- and short-wavelength stimuli (both, r ≥ 0.77, P ≤ 0.04). Correlations among all other measures were not statistically significant.
CONCLUSIONS
The results indicate that the presumed bipolar cell dysfunction in XLRS, indicated by b-wave abnormalities, has complex downstream effects: Dark-adapted luminance threshold and maximum pupil responses are not significantly affected, but pupil sensitivity is reduced.
Topics: Adult; Dark Adaptation; Electroretinography; Female; Humans; Male; Photic Stimulation; Pupil; Retinal Cone Photoreceptor Cells; Retinoschisis; Young Adult
PubMed: 32579680
DOI: 10.1167/iovs.61.6.53 -
Seminars in Pediatric Neurology May 2017In this article, we review the following 3 common juvenile macular degenerations: Stargardt disease, X-linked retinoschisis, and Best vitelliform macular dystrophy.... (Review)
Review
In this article, we review the following 3 common juvenile macular degenerations: Stargardt disease, X-linked retinoschisis, and Best vitelliform macular dystrophy. These are inherited disorders that typically present during childhood, when vision is still developing. They are sufficiently common that they should be included in the differential diagnosis of visual loss in pediatric patients. Diagnosis is secured by a combination of clinical findings, optical coherence tomography imaging, and genetic testing. Early diagnosis promotes optimal management. Although there is currently no definitive cure for these conditions, therapeutic modalities under investigation include pharmacologic treatment, gene therapy, and stem cell transplantation.
Topics: Child; Humans; Macula Lutea; Macular Degeneration; Retinoschisis; Stargardt Disease; Vitelliform Macular Dystrophy
PubMed: 28941524
DOI: 10.1016/j.spen.2017.05.005 -
Tzu Chi Medical Journal 2022Hereditary retinal dystrophies (HRDs), such as retinitis pigmentosa, Leber's congenital amaurosis (LCA), Usher syndrome, and retinoschisis, are a group of genetic... (Review)
Review
Hereditary retinal dystrophies (HRDs), such as retinitis pigmentosa, Leber's congenital amaurosis (LCA), Usher syndrome, and retinoschisis, are a group of genetic retinal disorders exhibiting both genetic and phenotypic heterogeneity. Symptoms include progressive retinal degeneration and constricted visual field. Some patients will be legal or completely blind. Advanced sequencing technologies improve the genetic diagnosis of HRD and lead to a new era of research into gene-targeted therapies. Following the first Food and Drug Administration approval of gene augmentation therapy for LCA caused by mutations, multiple clinical trials are currently underway applying different techniques. In this review, we provide an overview of gene therapy for HRD and emphasize four distinct approaches to gene-targeted therapy that have the potential to slow or even reverse retinal degeneration: (1) viral vector-based and nonviral gene delivery, (2) RNA-based antisense oligonucleotide, (3) genome editing by the Clustered Regularly Interspaced Short Palindromic Repeat/cas9 system, and (4) optogenetics gene therapy.
PubMed: 36578644
DOI: 10.4103/tcmj.tcmj_78_22 -
Clinical & Experimental Optometry Sep 2020Retinoschisis can be found in the fovea or the retinal periphery, either of which may be present in isolation, or in conjunction with each other. Foveal schisis may be... (Review)
Review
Retinoschisis can be found in the fovea or the retinal periphery, either of which may be present in isolation, or in conjunction with each other. Foveal schisis may be congenital, acquired, or secondary to an associated ocular pathology such as optic pit, glaucoma, or pathological myopia. The visual acuity is dependent on the cause of the schisis and appropriate treatment is variable based on likelihood for progression and visual impact. There are many useful considerations and tools for evaluation and monitoring that can be used to determine the aetiology and prognosis of these retinal findings. Retinoschisis is a diagnosis of exclusion, and pathology must be ruled out to accurately make the diagnosis. A review of two cases and following discussion summarises the various types, manifestations, presentations, and complications of retinoschisis and their evaluation, management, and appropriate monitoring or treatment. These cases lead a dialogue on the presentation and aetiology of retinoschisis, important considerations for differential diagnoses, and appropriate management.
Topics: Fovea Centralis; Humans; Retinoschisis; Tomography, Optical Coherence; Visual Acuity
PubMed: 31663163
DOI: 10.1111/cxo.12977 -
BMC Research Notes May 2021Retinoschisis and Norrie disease are X-linked recessive retinal disorders caused by mutations in RS1 and NDP genes respectively. Both are likely to be monogenic and no...
OBJECTIVE
Retinoschisis and Norrie disease are X-linked recessive retinal disorders caused by mutations in RS1 and NDP genes respectively. Both are likely to be monogenic and no locus heterogeneity has been reported. However, there are reports showing overlapping features of Norrie disease and retinoschisis in a NDP knock-out mouse model and also the involvement of both the genes in retinoschisis patients. Yet, the exact molecular relationships between the two disorders have still not been understood. The study investigated the association between retinoschisin (RS1) and norrin (NDP) using in vitro and in silico approaches. Specific protein-protein interaction between RS1 and NDP was analyzed in human retina by co-immunoprecipitation assay and MALDI-TOF mass spectrometry. STRING database was used to explore the functional relationship.
RESULT
Co-immunoprecipitation demonstrated lack of a direct interaction between RS1 and NDP and was further substantiated by mass spectrometry. However, STRING revealed a potential indirect functional association between the two proteins. Progressively, our analyses indicate that FZD4 protein interactome via PLIN2 as well as the MAP kinase signaling pathway to be a likely link bridging the functional relationship between retinoschisis and Norrie disease.
Topics: Animals; Blindness; Eye Proteins; Genetic Diseases, X-Linked; Humans; Mice; Mutation; Nervous System Diseases; Retina; Retinal Degeneration; Retinoschisis; Spasms, Infantile
PubMed: 34039417
DOI: 10.1186/s13104-021-05617-5 -
Ophthalmology May 2022To examine the genetic and clinical features in children and adults with X-linked retinoschisis (XLRS). (Observational Study)
Observational Study
PURPOSE
To examine the genetic and clinical features in children and adults with X-linked retinoschisis (XLRS).
DESIGN
Single-center consecutive, retrospective, observational study.
PARTICIPANTS
Adults and children with molecularly confirmed XLRS followed up between 1999 and 2020.
METHODS
Analysis of genetic, clinical, and retinal imaging findings, including OCT and fundus autofluorescence (FAF), cross-sectionally and longitudinally, was performed.
MAIN OUTCOMES MEASURES
RS1, variants, type of variants and phenotype correlations, age of onset, complications rates and types, fundoscopy findings, OCT metrics, FAF patterns, correlations including between best corrected visual acuity (BCVA) and age, and OCT characteristics.
RESULTS
One hundred thirty-two male patients were identified harboring 66 retinoschisin 1 variants, with 7 being novel. The mean age at onset was 16.5 years (range, 0-58 years). Seventy-one patients (71/75 [94.7%]) were symptomatic at presentation; all had decreased best-corrected visual acuity (BCVA). Funduscopy findings were symmetric in 104 patients (104/108 [96.3%]), with the most common finding being macular schisis (82.4%), whereas peripheral retinoschisis was present in 38.9% and macular atrophy was present in 11.1%. Twenty patients (18.5%) demonstrated complications (vitreous hemorrhage, retinal detachment, or both). Mean BCVA was 0.65 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, 20/89) in the right eye and 0.64 logMAR (Snellen equivalent, 20/87) in the left eye. Mean BCVA change over a mean interval of 6.7 years was 0.04 and 0.01 logMAR for right and left eyes, respectively. A normal FAF pattern was identified in 16 of 106 eyes (15.1%); 45 eyes (42.5%) showed a spoke-wheel pattern, 13 eyes (12.3%) showed foveal hyperautofluorescence, and 18 eyes (17.0%) showed a central reduction in signal. In total, 14 patients demonstrated evidence of progression on FAF over time. On OCT, foveoschisis was observed in 172 eyes (172/215 [80%]), parafoveal schisis was observed in 171 eyes (171/215 [79.5%]), and foveal atrophy was observed in 44 eyes (44/215 [20.5%]). Cystoid changes were localized to the inner nuclear layer (172/181 eyes [95%]), the outer nuclear layer (97/181 [53.6%]), and the ganglion cell layer (92/181 [50.8%]). Null variants were associated with worse final BCVA and aforementioned complications.
CONCLUSIONS
X-linked retinoschisis is highly phenotypically variable, but with relative foveal and BCVA preservation until late adulthood, allowing more accurate prognostication. The slowly (often minimally) progressive disease course may pose a challenge in identification of early end points for therapeutic trials aimed at altering the kinetics of degeneration.
Topics: Adult; Atrophy; Electroretinography; Eye Proteins; Humans; Male; Retina; Retinoschisis; Retrospective Studies; Tomography, Optical Coherence; Vision Disorders
PubMed: 34822951
DOI: 10.1016/j.ophtha.2021.11.019 -
Asia-Pacific Journal of Ophthalmology... 2018We present an updated clinical review of the pathophysiology, progression, and current treatments in pediatric patients with congenital X-linked retinoschisis (CXLRS).... (Review)
Review
We present an updated clinical review of the pathophysiology, progression, and current treatments in pediatric patients with congenital X-linked retinoschisis (CXLRS). CXLRS is an X-linked inherited retinal degeneration characterized by splitting of the superficial layers of the retina. Most recent classification divides CXLRS into 4 distinct clinical phenotypes: type 1, foveal; type 2, foveolamellar; type 3, complex; and type 4, foveoperipheral. The majority of retinoschisis cavities remain stable throughout life and may spontaneously collapse. However, a select number of patients progress to macula-involving peripheral retinoschisis, rhegmatogenous, and combined tractional-rhegmatogenous detachments that require further intervention. Although several advances have been made over the past several decades, medical therapy remains limited to case series‒based carbonic anhydrase therapy and prophylactic laser retinopexy. Recent advances in genetic-based clinical trials with the retinoschisis gene are promising. Vitreoretinal surgical approaches remain complex, case-based, and require careful planning depending on the configuration and location of the retinoschisis cavity.
Topics: Diagnostic Imaging; Disease Management; Genetic Testing; Genetic Therapy; Humans; Retinoschisis
PubMed: 29633586
DOI: 10.22608/APO.201803 -
Indian Journal of Ophthalmology Oct 2019
Topics: Humans; Male; Middle Aged; Ophthalmoscopy; Retina; Retinoschisis; Visual Acuity
PubMed: 31546543
DOI: 10.4103/ijo.IJO_193_19 -
Indian Journal of Ophthalmology Jan 2020
Topics: Adult; Eye Proteins; Humans; Male; Retina; Retinoschisis; Tomography, Optical Coherence
PubMed: 31856528
DOI: 10.4103/ijo.IJO_1521_19