Neuropathy target esterase activity defines phenotypes among PNPLA6 disorders.

Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism and hair anomalies. PNPLA6 encodes neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a systematic evidence-based review of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6-associated clinical diagnoses unambiguously reclassified 36 variants as pathogenic and 10 variants as likely pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship, and the generation of a preclinical animal model, pave the way for therapeutic trials, using NTE as a biomarker.

Quantification of Fundus Autofluorescence Features in a Molecularly Characterized Cohort of More Than 3000 Inherited Retinal Disease Patients from the United Kingdom.

Purpose: To quantify relevant fundus autofluorescence (FAF) image features cross-sectionally and longitudinally in a large cohort of inherited retinal diseases (IRDs) patients. Design: Retrospective study of imaging data (55-degree blue-FAF on Heidelberg Spectralis) from patients. Participants: Patients with a clinical and molecularly confirmed diagnosis of IRD who have undergone FAF 55-degree imaging at Moorfields Eye Hospital (MEH) and the Royal Liverpool Hospital (RLH) between 2004 and 2019. Methods: Five FAF features of interest were defined: vessels, optic disc, perimacular ring of increased signal (ring), relative hypo-autofluorescence (hypo-AF) and hyper-autofluorescence (hyper-AF). Features were manually annotated by six graders in a subset of patients based on a defined grading protocol to produce segmentation masks to train an AI model, AIRDetect, which was then applied to the entire imaging dataset. Main Outcome Measures: Quantitative FAF imaging features including area in mm 2 and vessel metrics, were analysed cross-sectionally by gene and age, and longitudinally to determine rate of progression. AIRDetect feature segmentation and detection were validated with Dice score and precision/recall, respectively. Results: A total of 45,749 FAF images from 3,606 IRD patients from MEH covering 170 genes were automatically segmented using AIRDetect. Model-grader Dice scores for disc, hypo-AF, hyper-AF, ring and vessels were respectively 0.86, 0.72, 0.69, 0.68 and 0.65. The five genes with the largest hypo-AF areas were CHM , ABCC6 , ABCA4 , RDH12 , and RPE65 , with mean per-patient areas of 41.5, 30.0, 21.9, 21.4, and 15.1 mm 2 . The five genes with the largest hyper-AF areas were BEST1 , CDH23 , RDH12 , MYO7A , and NR2E3 , with mean areas of 0.49, 0.45, 0.44, 0.39, and 0.34 mm 2 respectively. The five genes with largest ring areas were CDH23 , NR2E3 , CRX , EYS and MYO7A, with mean areas of 3.63, 3.32, 2.84, 2.39, and 2.16 mm 2 . Vessel density was found to be highest in EFEMP1 , BEST1 , TIMP3 , RS1 , and PRPH2 (10.6%, 10.3%, 9.8%, 9.7%, 8.9%) and was lower in Retinitis Pigmentosa (RP) and Leber Congenital Amaurosis genes. Longitudinal analysis of decreasing ring area in four RP genes ( RPGR, USH2A, RHO, EYS ) found EYS to be the fastest progressor at -0.18 mm 2 /year. Conclusions: We have conducted the first large-scale cross-sectional and longitudinal quantitative analysis of FAF features across a diverse range of IRDs using a novel AI approach.

Towards Uncovering the Role of Incomplete Penetrance in Maculopathies through Sequencing of 105 Disease-Associated Genes.

Inherited macular dystrophies (iMDs) are a group of genetic disorders, which affect the central region of the retina. To investigate the genetic basis of iMDs, we used single-molecule Molecular Inversion Probes to sequence 105 maculopathy-associated genes in 1352 patients diagnosed with iMDs. Within this cohort, 39.8% of patients were considered genetically explained by 460 different variants in 49 distinct genes of which 73 were novel variants, with some affecting splicing. The top five most frequent causative genes were ABCA4 (37.2%), PRPH2 (6.7%), CDHR1 (6.1%), PROM1 (4.3%) and RP1L1 (3.1%). Interestingly, variants with incomplete penetrance were revealed in almost one-third of patients considered solved (28.1%), and therefore, a proportion of patients may not be explained solely by the variants reported. This includes eight previously reported variants with incomplete penetrance in addition to CDHR1:c.783G>A and CNGB3:c.1208G>A. Notably, segregation analysis was not routinely performed for variant phasing-a limitation, which may also impact the overall diagnostic yield. The relatively high proportion of probands without any putative causal variant (60.2%) highlights the need to explore variants with incomplete penetrance, the potential modifiers of disease and the genetic overlap between iMDs and age-related macular degeneration. Our results provide valuable insights into the genetic landscape of iMDs and warrant future exploration to determine the involvement of other maculopathy genes.

Central serous chorioretinopathy: An evidence-based treatment guideline.

Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and it is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.

Outcomes and Adverse Effects of Voretigene Neparvovec Treatment for Biallelic RPE65-Mediated Inherited Retinal Dystrophies in a Cohort of Patients from a Single Center.

Our study evaluated the morphological and functional outcomes, and the side effects, of voretigene neparvovec (VN) gene therapy for RPE65-mediated inherited retinal dystrophies (IRDs) in 12 eyes (six patients) at the Oxford Eye Hospital with a mean follow-up duration of 8.2 (range 1-12) months. All patients reported a subjective vision improvement 1 month after gene therapy. Best-corrected visual acuity (BCVA) remained stable (baseline: 1.28 (±0.71) vs. last follow-up: 1.46 (±0.60); p = 0.25). Average white Full-Field Stimulus Testing (FST) showed a trend towards improvement (baseline: -4.41 (±10.62) dB vs. last follow-up: -11.98 (±13.83) dB; p = 0.18). No changes in central retinal thickness or macular volume were observed. The side effects included mild intraocular inflammation (two eyes) and cataracts (four eyes). Retinal atrophy occurred in 10 eyes (eight mild, two severe) but did not impact FST measurements during the follow-up period. Increased intraocular pressure (IOP) was noted in three patients (six eyes); four eyes (two patients) required glaucoma surgery. The overall safety and effectiveness of VN treatment in our cohort align with previous VN clinical trials, except for the higher occurrence of retinal atrophy and increased IOP in our cohort. This suggests that raised IOP and retinal atrophy may be more common than previously reported.

The Role of Inflammation in Age-Related Macular Degeneration-Therapeutic Landscapes in Geographic Atrophy.

Age-related macular degeneration (AMD) is the leading cause of vision loss and visual impairment in people over 50 years of age. In the current therapeutic landscape, intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapies have been central to the management of neovascular AMD (also known as wet AMD), whereas treatments for geographic atrophy have lagged behind. Several therapeutic approaches are being developed for geographic atrophy with the goal of either slowing down disease progression or reversing sight loss. Such strategies target the inflammatory pathways, complement cascade, visual cycle or neuroprotective mechanisms to slow down the degeneration. In addition, retinal implants have been tried for vision restoration and stem cell therapies for potentially a dual purpose of slowing down the degeneration and restoring visual function. In particular, therapies focusing on the complement pathway have shown promising results with the FDA approved pegcetacoplan, a complement C3 inhibitor, and avacincaptad pegol, a complement C5 inhibitor. In this review, we discuss the mechanisms of inflammation in AMD and outline the therapeutic landscapes of atrophy AMD. Improved understanding of the various pathway components and their interplay in this complex neuroinflammatory degeneration will guide the development of current and future therapeutic options, such as optogenetic therapy.

Retinal Angiomatous Proliferation in a Patient with Retinitis Pigmentosa.

Retinal angiomatous proliferation (RAP) and other types of choroidal neovascularization (CNV) are very rarely reported in patients with retinitis pigmentosa (RP). We present a case report of a 91-year-old patient with an obvious RP phenotype, who presented with a sudden onset of vision worsening and metamorphopsia in the left eye. Genetic testing on the UK inherited retinal disease panel did not identify a pathogenic variant. Multimodal imaging comprising optical coherence tomography (OCT), OCT angiography, and fluorescein and indocyanine green angiography showed a RAP lesion in the left macula. The patient received three treatments of monthly injections of aflibercept, with excellent morphological and functional outcomes. Taking into account the patient's age at presentation of the RAP lesion, it is not clear whether the RAP was associated or coincidental with RP. This case report highlights the importance of possessing an awareness that RAP lesions can occur in RP. Moreover, due to a good response and potential safety concerns with continuous anti-VEGF injections in RP patients, a pro re nata (PRN) regimen might be the safest option.

New Imaging Technology for Simultaneous Multiwavelength-UWF Fundus Fluorescein Angiography and Indocyanine Green Angiography With Navigated Central and Peripheral SS-OCT.

OBJECTIVE: Our aim was to assess central and peripheral retinal and choroidal diseases using novel simultaneous multiwavelength-ultra-widefield (MW-UWF) fundus fluorescein angiography (FFA)/indocyanine green angiography (ICGA) with navigated central and peripheral swept-source optical coherence tomography (SS-OCT) technology. METHODS: Retrospective evaluation was carried out of 30 consecutive patients (60 eyes) who underwent UWF red/green (RG), infrared (IR), FFA and ICGA with simultaneous navigated SS-OCT using Optos Silverstone (Optos PLC). Angiographic retinal and choroidal findings in vascular pathologies and their relationship with the vitreoretinal interface (VRI) were assessed. RESULTS: Simultaneous FFA with navigated SSOCT was performed in all patients and simultaneous FFA-ICGA with SS-OCT in 18 eyes (30%). Cross-sectional central and peripheral changes in the retina, choroid, and VRI corresponding with angiographic findings in several diseases were imaged. CONCLUSION: First-in-human study of a new technology providing UWF RG/FFA/ICGA with simultaneous navigated central and peripheral SS-OCT can guide clinical management and provide new insights and understanding of central and peripheral retinal and choroidal disease. [Ophthalmic Surg Lasers Imaging Retina 2023;54:401-410.].

Combined central serous chorioretinopathy, hypermetropia, short axial length, chorioretinal folds, enlarged/thickened ocular coats, with varying association of scleral changes (CHAFES).

PURPOSE: To describe a condition with the following features: chronic central serous chorioretinopathy (CCSC), chorioretinal folds, scleral changes (including any of the following flattened or 'squared off' posterior pole, 'T sign', or thickened ocular coats), accompanied by a short axial length and hypermetropia in a series of 7 patients. METHODS: The case notes of 7 patients presenting with a combination of CSC, choroidal folds scleral changes and hypermetropia were reviewed as part of a retrospective case series. Corrected visual acuities, serial refraction, colour imaging, fluorescein and indocyanine green angiography findings, together with B-ultrasound scan features were recorded, with axial length measurements as available (< 23.3 mm was defined as short). RESULTS: The study included 14 eyes of 7 subjects (2 females and 5 males) with a primary presentation of central vision disturbance. All patients showed signs of previous or current episodes of the following features in at least one eye: CSC (5/7 bilateral); choroidal folds (6/7 bilateral), thickening of ocular coats in the 5 in whom this was measured, at least one scleral abnormality on ultrasound in at least one eye. A short axial length at final appointment was recorded in 13/14 eyes. CONCLUSIONS AND RELEVANCE: The combination of CCSC with choroidal folds, hypermetropia with apparent shortening of the eyeball associated with one or more scleral abnormalities such as a flattened or 'squared off 'appearance of the B ultrasound may be a specific ocular condition. The aetiology of this particular combination of posterior segment manifestations is unknown; the choroid could be the primary focus of disease with secondary involvement of the sclera. Alternatively, the features observed may result from a chronic inflammatory process affecting the sclera with secondary effects on the choroid, retinal pigment epithelium and retina. In our case series, the final vision was not significantly different from vision at presentation.

Neuropathy target esterase activity predicts retinopathy among PNPLA6 disorders.

Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism, and hair anomalies. PNPLA6 encodes Neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a clinical meta-analysis of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6 -associated clinical diagnoses unambiguously reclassified 10 variants as likely pathogenic and 36 variants as pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship and the generation of a preclinical animal model pave the way for therapeutic trials, using NTE as a biomarker.

A Carrier Female Manifesting an Unusual X-Linked Retinoschisis Phenotype Associated with the Pathogenic Variant c.266delA, p.(Tyr89LeufsTer37) in RS1, and Skewed X-Inactivation.

X-linked retinoschisis (XLRS) is the most common juvenile macular degeneration in males. Unlike most other X-linked retinal dystrophies, carrier heterozygous females are very rarely reported to show clinical features of the disease. Herein, we describe unusual retinal features in a 2-year-old female infant with family history and genetic testing consistent with XLRS.

Can artificial intelligence accelerate the diagnosis of inherited retinal diseases? Protocol for a data-only retrospective cohort study (Eye2Gene).

INTRODUCTION: Inherited retinal diseases (IRD) are a leading cause of visual impairment and blindness in the working age population. Mutations in over 300 genes have been found to be associated with IRDs and identifying the affected gene in patients by molecular genetic testing is the first step towards effective care and patient management. However, genetic diagnosis is currently slow, expensive and not widely accessible. The aim of the current project is to address the evidence gap in IRD diagnosis with an AI algorithm, Eye2Gene, to accelerate and democratise the IRD diagnosis service. METHODS AND ANALYSIS: The data-only retrospective cohort study involves a target sample size of 10 000 participants, which has been derived based on the number of participants with IRD at three leading UK eye hospitals: Moorfields Eye Hospital (MEH), Oxford University Hospital (OUH) and Liverpool University Hospital (LUH), as well as a Japanese hospital, the Tokyo Medical Centre (TMC). Eye2Gene aims to predict causative genes from retinal images of patients with a diagnosis of IRD. For this purpose, 36 most common causative IRD genes have been selected to develop a training dataset for the software to have enough examples for training and validation for detection of each gene. The Eye2Gene algorithm is composed of multiple deep convolutional neural networks, which will be trained on MEH IRD datasets, and externally validated on OUH, LUH and TMC. ETHICS AND DISSEMINATION: This research was approved by the IRB and the UK Health Research Authority (Research Ethics Committee reference 22/WA/0049) 'Eye2Gene: accelerating the diagnosis of IRDs' Integrated Research Application System (IRAS) project ID: 242050. All research adhered to the tenets of the Declaration of Helsinki. Findings will be reported in an open-access format.

Intraretinal Microvascular Abnormalities and Venous Beading Have Different Genetic Profiles in Caucasian Patients with Non-Proliferative Diabetic Retinopathy.

Diabetic Retinopathy (DR) is a leading cause of preventable visual impairment in the working age population. Despite the increasing prevalence of DR, there remain gaps in our understanding of its pathophysiology. This is a prospective case-control study comparing the genetic profiles of patients with no DR vs. non-proliferative DR (NPDR) focusing on intraretinal microvascular abnormalities (IRMA) and venous beading (VB) in Caucasians. A total of 596 participants were recruited to the study; 199 with moderate/severe NPDR and 397 with diabetes for at least 5 years without DR. Sixty-four patients were excluded due to technical issues. In total, 532 were analysed; 181 and 351 were in the NPDR group and no DR group, respectively. Those with severe IRMA and VB had distinctly different genetic profiles from each other and from the no DR group, which further supports the theory that these two features of DR might have different etiologies. This also suggests that IRMA and VB are independent risk factors for the development of PDR and may have different pathophysiologies. If these findings are confirmed in larger studies, this could pave the way for personalised treatment options for those more at risk of developing different features of NPDR.

Faricimab in neovascular AMD: first report of real-world outcomes in an independent retina clinic.

PURPOSE: Assess short-term real-world outcomes in neovascular aged-related macular degeneration (nAMD) treated with novel faricimab. METHODS: Retrospective case series of nine patients with nAMD (11 eyes) treated with faricimab between May and November 2022. Treatment-naïve patients and non-naïve patients underwent logMAR best corrected visual acuity (BCVA), optical coherence tomography (OCT) DRI OCT-1 Triton (Topcon Corp, Tokyo, Japan), ultra-widefield (UWF) and fundus autofluorescence (FAF) (California Optomap, Optos plc, Dunfermline, Scotland, UK). Previous treatment intervals, number of intravitreal injections, sub/intra retinal fluid (SRF/IRF), central retinal thickness (CRT) and presence/changes in pigment epithelial detachments (PEDs) were recorded. RESULTS: Mean baseline BCVA and CRT values of patients who switched from other agents were 0.612 ± 0.75 logMAR and 256.16 ± 12.98 µm respectively, with a mean 36-day previous treatment interval. The median number of other previous anti-VEGF intravitreal injections was 8. Mean BCVA at one month significantly improved to 0.387 ± 0.54 logMAR, as well as CRT values which decreased to 245.43 ± 15.34 µm. In the 3 naïve patients, mean baseline BVCA and CRT values were 0.33 ± 0.29 and 874.67 ± 510.86 µm, respectively. At one month follow-up, mean BCVA improved to 0.30 ± 0.29 logMAR and mean CRT was 536.04 ± 36.15 µm. Overall, a significant improvement in BCVA of 0.21 ± 41 logMAR and 238.44 ± 114.9 µm was achieved at one month after the first faricimab intravitreal injection. In addition, a complete resolution of SRF was observed in 6 out of 8 eyes (75%) and of IRF in 2 out of 3 eyes (66.67%), respectively. Drusenoid PED morphology changes were observed in all patients and no drug-related adverse events were observed. CONCLUSION: Real-world outcomes showed improvement in BCVA and anatomic parameters at an early timepoint, demonstrating the efficacy and durability of faricimab in nAMD patients. Larger numbers of patients and longer follow-up are needed to determine whether the loading dose is required in all, what percentage of patients experience an improvement, and whether improvement it is maintained.

Sudden Gross Visual Deterioration: Importance of Examining the Whole Eye.

A 75-year-old caucasian female presented with sudden severe visual deterioration in one eye reduced from 6/9 to counting fingers (CF), with second eye reduction in vision from 6/9 to CF three months later. Past medical history included a background of proliferative diabetic retinopathy, uncontrolled blood pressure, and a 44-year history of poorly controlled type 1 diabetes mellitus (T1DM). Previous ocular history included bilateral pan-retinal photocoagulation for proliferative diabetic retinopathy, followed by bilateral vitrectomies, with subsequent bilateral cataract surgery with intraocular lens implants. A diagnosis of anterior ischemic optic neuropathy (AION) was thought to be the most likely diagnosis due to sudden visual loss, pale discs, and previous long-term history of diabetes and blood pressure with variable control in the absence of a raised erythrocyte sedimentation rate (ESR). However, at the time of the second eye visual loss, the inferior peripheral retina examination revealed bilateral pseudophakic intraocular lens dislocations. With spectacle correction of +11.50/-1.00 x 75 right eye and +11.50/-1.00 x 65 left eye, her visual acuities were 6/12 right eye and 6/9 left eye, and subsequent secondary intraocular lens insertion was planned. This case highlights the importance of a careful review of the whole eye to ensure that remediable causes of visual loss are not missed.

INCREASING EVIDENCE FOR THE SAFETY OF FOVEA-INVOLVING HALF-DOSE PHOTODYNAMIC THERAPY FOR CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: A retrospective study was performed with data from the prospective randomized controlled trials, PLACE and SPECTRA, assessing the risk of foveal atrophy and the likelihood of structural and functional improvement on optical coherence tomography, after foveal half-dose photodynamic therapy in chronic central serous chorioretinopathy. METHODS: A total of 57 chronic central serous chorioretinopathy patients received a single half-dose photodynamic therapy with a treatment spot that included the fovea. Optical coherence tomography scans and fundus autofluorescence images were analyzed for structural improvement and possible atrophy development, at baseline and at several visits after treatment. Main outcome measures were integrity of the external limiting membrane and ellipsoid zone on optical coherence tomography and hypoautofluorescence on fundus autofluorescence. RESULTS: The subfoveal external limiting membrane was graded as continuous in 21 of 57 of patients (36.8%) at baseline, and the subfoveal ellipsoid zone was graded as continuous in 5 of 57 patients (8.8%) at first visit, which improved to 50 of 51 (98.0%) and 32 out of 51 (62.7%) at the final visit at 2 years, respectively (both P < 0.001). Hypoautofluorescent changes on fundus autofluorescence were present in 25 of 55 patients (45.5%) at baseline and in 23 of 51 patients (45.1%) at the final visit ( P = 0.480). CONCLUSION: In patients with chronic central serous chorioretinopathy who received a single, foveal, half-dose photodynamic therapy, a significant improvement in structure and function was seen at the final follow-up. None of the patients developed foveal atrophy.

A nationwide survey of hydroxychloroquine retinopathy presenting to the hospital eye service in the United Kingdom.

BACKGROUND: The risk of developing hydroxychloroquine retinopathy is considered sufficient to justify national monitoring programmes. There are an estimated 71,144-77,170 long-term hydroxychloroquine users in the UK. However, the number of patients diagnosed with retinopathy is unknown. This study aimed to identify the number of cases and clinical characteristics of hydroxychloroquine retinopathy diagnosed annually in hospital eye services across the UK. METHODS: A nationwide, prospective case ascertainment study was undertaken using the British Ophthalmological Surveillance Unit, which sends approximately 1420 reporting cards to UK Ophthalmologists monthly. The case definition was two abnormal tests suggestive of hydroxychloroquine retinopathy. Demographic and clinical data relating to hydroxychloroquine use and retinopathy were collected from identified cases using a standardised questionnaire over a 1-year period (2018-2019). RESULTS: Sixty-six cases of hydroxychloroquine retinopathy were reported, and 46 questionnaires were received (73% response rate). Twenty-four incident cases of hydroxychloroquine retinopathy were identified (24-43 cases following adjustment). The median duration of drug therapy was 19 years (range: 4-50 years, IQR: 14.5-23 years). Fourteen patients were asymptomatic, and 9 symptomatic at diagnosis. A trend towards a lower mean deviation on visual field testing was observed in the symptomatic group (-11.55 dB versus -6.9 dB; P = 0.15). CONCLUSION: Between 1 in 1655 and 3215 (0.03-0.06%) long-term hydroxychloroquine users were diagnosed with retinopathy over the study period. We estimate that monitoring was available for 1.9-3.8% of long-term users, accounting for a lower than expected incidence. The high proportion of symptomatic retinopathy at diagnosis underlines the importance of monitoring to detect pre-symptomatic disease.

Multimodal Analysis of the Visual Pathways in Friedreich's Ataxia Reveals Novel Biomarkers.

BACKGROUND: Optic neuropathy is a near ubiquitous feature of Friedreich's ataxia (FRDA). Previous studies have examined varying aspects of the anterior and posterior visual pathways but none so far have comprehensively evaluated the heterogeneity of degeneration across different areas of the retina, changes to the macula layers and combined these with volumetric MRI studies of the visual cortex and frataxin level. METHODS: We investigated 62 genetically confirmed FRDA patients using an integrated approach as part of an observational cohort study. We included measurement of frataxin protein levels, clinical evaluation of visual and neurological function, optical coherence tomography to determine retinal nerve fibre layer thickness and macular layer volume and volumetric brain MRI. RESULTS: We demonstrate that frataxin level correlates with peripapillary retinal nerve fibre layer thickness and that retinal sectors differ in their degree of degeneration. We also shown that retinal nerve fibre layer is thinner in FRDA patients than controls and that this thinning is influenced by the AAO and GAA1. Furthermore we show that the ganglion cell and inner plexiform layers are affected in FRDA. Our MRI data indicate that there are borderline correlations between retinal layers and areas of the cortex involved in visual processing. CONCLUSION: Our study demonstrates the uneven distribution of the axonopathy in the retinal nerve fibre layer and highlight the relative sparing of the papillomacular bundle and temporal sectors. We show that thinning of the retinal nerve fibre layer is associated with frataxin levels, supporting the use the two biomarkers in future clinical trials design. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Morphological and functional parameters in X-linked retinoschisis patients-A multicentre retrospective cohort study.

Introduction: X-linked retinoschisis (XLRS) is a potential target for gene supplementation approaches. To establish potential structural and functional endpoints for clinical trials, a comprehensive understanding of the inter-eye symmetry, relationship between structural and functional parameters, and disease progression is vital. Methods: In this retrospective multicentre study, 118 eyes of 59 XLRS patients with RS1 mutations were assessed. Information from center databases included: RS1 variant; age at presentation; best-corrected visual acuity (BCVA), central retinal thickness (CRT), macular volume (MV) at presentation and at the last follow up; full-field electroretinogram (ERG) findings; presence of peripheral retinoschisis and complications (vitreous hemorrhage, retinal detachment); treatment with systemic or topical carbonic anhydrase inhibitors (CAI). Results: Inter-eye symmetry revealed strong correlation in CRT (r = 0.77; p < 0.0001) and moderate correlations in MV (r = 0.51, p < 0.0001) and BCVA (r = 0.49; p < 0.0001). Weak or no correlations were observed between BCVA and structural parameters (CRT, MV). Peripheral retinoschisis was observed in 40 (68%), retinal detachment in 9 (15%), and vitreous hemorrhage in 5 (8%) patients, respectively. Longitudinal examinations (mean, 4.3 years) showed no BCVA changes; however, a reduction of the CRT (p = 0.02), and MV (p = 0.01) was observed. Oral and/or topical CAI treatment did not significantly alter the CRT (p = 0.34). Discussion: The XLRS phenotype demonstrates a strong CRT symmetry between the eyes within individual patients and stable BCVA over several years. BCVA exhibits a weak correlation with the morphological parameters of retinal thickness (CRT MV). In our cohort, longitudinal functional changes were not significant, likely attributed to the short average follow-up period. Furthermore, CAI treatment didn't influence both morphological and functional outcomes.