Quality of life in patients with CRB1-associated retinal dystrophies: A longitudinal study

PURPOSE

To assess the longitudinal vision-related quality of life among patients with CRB1-associated inherited retinal dystrophies.

METHODS

In this longitudinal questionnaire study, the National Eye Institute Visual Function Questionnaire (39 items, NEI VFQ-39) was applied at baseline, two-year follow-up, and 4-year follow-up in patients with pathogenic CRB1 variants. [Correction added on 20 November 2023, after first online publication: The preceding sentence has been updated in this version.] Classical test theory was performed to obtain subdomain scores and in particular 'near activities' and 'total composite' scores. The Rasch analysis based on previous calibrations of the NEI VFQ-25 was applied to create visual functioning and socio-emotional subscales.

RESULTS

In total, 22 patients with a CRB1-associated retinal dystrophy were included, […] with a median age of 25.0 years (interquartile range: 13-31 years) at baseline and mean follow-up of 4.0 ± 0.3 years. [Correction added on 20 November 2023, after first online publication: The preceding sentence has been updated in this version.] A significant decline at 4 years was observed for 'near activities' (51.0 ± 23.8 vs 35.4 ± 14.7, p = 0.004) and 'total composite' (63.0 ± 13.1 vs 52.0 ± 12.1, p = 0.001) subdomain scores. For the Rasch-scaled scores, the 'visual functioning' scale significantly decreased after 2 years (-0.89 logits; p = 0.012), but not at 4-year follow-up (+0.01 logits; p = 0.975). [Correction added on 20 November 2023, after first online publication: In the preceding sentence, "…after 4 years…" has been corrected to "…after 2 years…" in this version.] The 'socio-emotional' scale also showed a significant decline after 2 years (-0.78 logits, p = 0.033) and 4 years (-0.83 logits, p = 0.021).

CONCLUSION

In the absence of an intervention, a decline in vision-related quality of life is present in patients with pathogenic CRB1 variants at 4-year follow-up. Patient-reported outcome measures should be included in future clinical trials, as they can be a potential indicator of disease progression and treatment efficacy.

Relapse in ocular tuberculosis: relapse rate, risk factors and clinical management in a non-endemic country

AIMS

To assess the risk of uveitis relapse in ocular tuberculosis (OTB) following clinical inactivity, to analyse clinical factors associated with relapses and to describe the management strategies for relapses.

METHODS

A retrospective study was conducted on a 10-year patient registry of patients with OTB diagnosed at Erasmus MC in Rotterdam, The Netherlands. Time-to-relapse of uveitis was evaluated with Kaplan-Meier curve and risk factors for relapses were analysed.

RESULTS

93 OTB cases were identified, of which 75 patients achieved clinical inactivity following treatment. The median time to achieve uveitis inactivity was 3.97 months. During a median follow-up of 20.7 months (Q1-Q3: 5.2-81.2) after clinical inactivity, uveitis relapse occurred in 25 of these 75 patients (33.3%). Patients who were considered poor treatment responders for their initial uveitis episode had a significantly higher risk of relapse after achieving clinical inactivity than good responders (adjusted HR=3.84, 95% CI: 1.28 to 11.51). 13 of the 25 relapsed patients experienced multiple uveitis relapse episodes, accounting for 78 eye-relapse episodes during the entire observation period. Over half (46 out of 78, 59.0%) of these episodes were anterior uveitis. A significant number of uveitis relapse episodes (31 episodes, 39.7%) were effectively managed with topical corticosteroids.

CONCLUSIONS

Our results suggest that approximately one-third of patients with OTB will experience relapse after achieving clinical inactivity. The initial disease course and poor response to treatment predict the likelihood of relapse in the long-term follow-up. Topical corticosteroids were particularly effective in relapse presenting as anterior uveitis.

KCNV2-associated retinopathy: genotype-phenotype correlations - KCNV2 study group report 3

BACKGROUND/AIMS

To investigate genotype-phenotype associations in patients with KCNV2 retinopathy.

METHODS

Review of clinical notes, best-corrected visual acuity (BCVA), molecular variants, electroretinography (ERG) and retinal imaging. Subjects were grouped according to the combination of KCNV2 variants-two loss-of-function (TLOF), two missense (TM) or one of each (MLOF)-and parameters were compared.

RESULTS

Ninety-two patients were included. The mean age of onset (mean±SD) in TLOF (n=55), TM (n=23) and MLOF (n=14) groups was 3.51±0.58, 4.07±2.76 and 5.54±3.38 years, respectively. The mean LogMAR BCVA (±SD) at baseline in TLOF, TM and MLOF groups was 0.89±0.25, 0.67±0.38 and 0.81±0.35 for right, and 0.88±0.26, 0.69±0.33 and 0.78±0.33 for left eyes, respectively. The difference in BCVA between groups at baseline was significant in right (p=0.03) and left eyes (p=0.035). Mean outer nuclear layer thickness (±SD) at baseline in TLOF, MLOF and TM groups was 37.07±15.20 µm, 40.67±12.53 and 40.38±18.67, respectively, which was not significantly different (p=0.85). The mean ellipsoid zone width (EZW) loss (±SD) was 2051 µm (±1318) for patients in the TLOF, and 1314 µm (±965) for MLOF. Only one patient in the TM group had EZW loss at presentation. There was considerable overlap in ERG findings, although the largest DA 10 ERG b-waves were associated with TLOF and the smallest with TM variants.

CONCLUSIONS

Patients with missense alterations had better BCVA and greater structural integrity. This is important for patient prognostication and counselling, as well as stratification for future gene therapy trials.

Association of Risk Variants in the CFH Gene With Elevated Levels of Coagulation and Complement Factors in Idiopathic Multifocal Choroiditis

Importance

Idiopathic multifocal choroiditis (MFC) is poorly understood, thereby hindering optimal treatment and monitoring of patients.

Objective

To identify the genes and pathways associated with idiopathic MFC.

Design, Setting, and Participants

This was a case-control genome-wide association study (GWAS) and protein study of blood plasma samples conducted from March 2006 to February 2022. This was a multicenter study involving 6 Dutch universities. Participants were grouped into 2 cohorts: cohort 1 consisted of Dutch patients with idiopathic MFC and controls, and cohort 2 consisted of patients with MFC and controls. Plasma samples from patients with idiopathic MFC who had not received treatment were subjected to targeted proteomics. Idiopathic MFC was diagnosed according to the Standardization of Uveitis Nomenclature (SUN) Working Group guidelines for punctate inner choroidopathy and multifocal choroiditis with panuveitis. Data were analyzed from July 2021 to October 2022.

Main outcomes and measures

Genetic variants associated with idiopathic MFC and risk variants associated with plasma protein concentrations in patients.

Results

This study included a total of 4437 participants in cohort 1 (170 [3.8%] Dutch patients with idiopathic MFC and 4267 [96.2%] controls; mean [SD] age, 55 [18] years; 2443 female [55%]) and 1344 participants in cohort 2 (52 [3.9%] patients with MFC and 1292 [96.1%] controls; 737 male [55%]). The primary GWAS association mapped to the CFH gene with genome-wide significance (lead variant the A allele of rs7535263; odds ratio [OR], 0.52; 95% CI, 0.41-0.64; P = 9.3 × 10-9). There was no genome-wide significant association with classical human leukocyte antigen (HLA) alleles (lead classical allele, HLA-A*31:01; P = .002). The association with rs7535263 showed consistent direction of effect in an independent cohort of 52 cases and 1292 control samples (combined meta-analysis OR, 0.58; 95% CI, 0.38-0.77; P = 3.0 × 10-8). In proteomic analysis of 87 patients, the risk allele G of rs7535263 in the CFH gene was strongly associated with increased plasma concentrations of factor H-related (FHR) proteins (eg, FHR-2, likelihood ratio test, adjusted P = 1.1 × 10-3) and proteins involved in platelet activation and the complement cascade.

Conclusions and relevance

Results suggest that CFH gene variants increase systemic concentrations of key factors of the complement and coagulation cascades, thereby conferring susceptibility to idiopathic MFC. These findings suggest that the complement and coagulation pathways may be key targets for the treatment of idiopathic MFC.

Myopia control in Mendelian forms of myopia

PURPOSE

To study the effectiveness of high-dose atropine for reducing eye growth in Mendelian myopia in children and mice.

METHODS

We studied the effect of high-dose atropine in children with progressive myopia with and without a monogenetic cause. Children were matched for age and axial length (AL) in their first year of treatment. We considered annual AL progression rate as the outcome and compared rates with percentile charts of an untreated general population. We treated C57BL/6J mice featuring the myopic phenotype of Donnai-Barrow syndrome by selective inactivation of Lrp2 knock out (KO) and control mice (CTRL) daily with 1% atropine in the left eye and saline in the right eye, from postnatal days 30-56. Ocular biometry was measured using spectral-domain optical coherence tomography. Retinal dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured using high-performance liquid chromatography.

RESULTS

Children with a Mendelian form of myopia had average baseline spherical equivalent (SE) -7.6 ± 2.5D and AL 25.8 ± 0.3 mm; children with non-Mendelian myopia had average SE -7.3 ± 2.9 D and AL 25.6 ± 0.9 mm. During atropine treatment, the annual AL progression rate was 0.37 ± 0.08 and 0.39 ± 0.05 mm in the Mendelian myopes and non-Mendelian myopes, respectively. Compared with progression rates of untreated general population (0.47 mm/year), atropine reduced AL progression with 27% in Mendelian myopes and 23% in non-Mendelian myopes. Atropine significantly reduced AL growth in both KO and CTRL mice (male, KO: -40 ± 15; CTRL: -42 ± 10; female, KO: -53 ± 15; CTRL: -62 ± 3 μm). The DA and DOPAC levels 2 and 24 h after atropine treatment were slightly, albeit non-significantly, elevated.

CONCLUSIONS

High-dose atropine had the same effect on AL in high myopic children with and without a known monogenetic cause. In mice featuring a severe form of Mendelian myopia, atropine reduced AL progression. This suggests that atropine can reduce myopia progression even in the presence of a strong monogenic driver.

Cost-effective sequence analysis of 113 genes in 1,192 probands with retinitis pigmentosa and Leber congenital amaurosis

Introduction: Retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) are two groups of inherited retinal diseases (IRDs) where the rod photoreceptors degenerate followed by the cone photoreceptors of the retina. A genetic diagnosis for IRDs is challenging since >280 genes are associated with these conditions. While whole exome sequencing (WES) is commonly used by diagnostic facilities, the costs and required infrastructure prevent its global applicability. Previous studies have shown the cost-effectiveness of sequence analysis using single molecule Molecular Inversion Probes (smMIPs) in a cohort of patients diagnosed with Stargardt disease and other maculopathies. Methods: Here, we introduce a smMIPs panel that targets the exons and splice sites of all currently known genes associated with RP and LCA, the entire RPE65 gene, known causative deep-intronic variants leading to pseudo-exons, and part of the RP17 region associated with autosomal dominant RP, by using a total of 16,812 smMIPs. The RP-LCA smMIPs panel was used to screen 1,192 probands from an international cohort of predominantly RP and LCA cases. Results and discussion: After genetic analysis, a diagnostic yield of 56% was obtained which is on par with results from WES analysis. The effectiveness and the reduced costs compared to WES renders the RP-LCA smMIPs panel a competitive approach to provide IRD patients with a genetic diagnosis, especially in countries with restricted access to genetic testing.

Long-term data on efficacy and safety of adalimumab in Behçet's disease

INTRODUCTION

Behçet's disease (BD) is a systemic, inflammatory disorder affecting multiple organ systems, frequently treated with TNF-α blocking agents, as infliximab and adalimumab. Insights about long-term use of adalimumab are lacking. Therefore, we conducted a study into the long-term efficacy and safety of adalimumab in BD.

METHODS

A retrospective cohort study from patients with BD treated with adalimumab in the Erasmus Medical Center was performed. Patients included were at least 18 years of age, diagnosed according to ISG criteria, and uninterruptedly used adalimumab for at least 36 months.

RESULTS

In a population of 39 BD patients using adalimumab, 29 patients persisted treatment >36 months (range 37-206 months). Indications for treatment were uveitis (n = 15) 51.7%, mucocutaneous involvement (n = 9) 31%, arthritis (n = 2) 6.9%, intestinal disease (n = 3) 10.3%. Overall, adalimumab decreased the occurrence of flares from 0.64 to 0.17 flares per year and BCVA improved subsequently. Also, a steady decline in BDCAF is reported over the course of at least 5 years. Subsequently, 79% was able to reduce their use of immunosuppressive agents aside from adalimumab. Adverse effects were reported in, (n = 15) 51.7% of which (n = 13) 86.6% were infectious complications. Two of those required inpatient hospital care.

CONCLUSION

Our study illustrates durable long-term efficacy of adalimumab treatment in patients with BD. In our patient cohort long-term adalimumab treatment is safe, with a low incidence of serious adverse events.

Outcome of Cataract Surgery in Patients With Retinitis Pigmentosa

PURPOSE

To assess the visual outcome of cataract surgery in patients with retinitis pigmentosa (RP).

DESIGN

Retrospective, noncomparative clinical study.

METHODS

Preoperative, intraoperative, and postoperative data of patients with RP who were undergoing cataract surgery were collected from several expertise centers across Europe.

RESULTS

In total, 295 eyes of 226 patients were included in the study. The mean age at surgery of the first eye was 56.1 ± 17.9 years. Following surgery, best-corrected visual acuity (BCVA) improved significantly from 1.03 to 0.81 logMAR (ie, 20/214 to 20/129 Snellen) in the first treated eye (-0.22 logMAR; 95% CI = -0.31 to -0.13; P < .001) and from 0.80 to 0.56 logMAR (ie, 20/126 to 20/73 Snellen) in the second treated eye (-0.24 logMAR; 95% CI = -0.32 to -0.15; P < .001). Marked BCVA improvements (postoperative change in BCVA of ≥0.3 logMAR) were observed in 87 of 226 patients (39%). Greater odds for marked visual improvements were observed in patients with moderate visual impairment or worse. The most common complications were zonular dialysis (n = 15; 5%) and (exacerbation of) cystoid macular edema (n = 14; 5%), respectively. Postoperative posterior capsular opacifications were present in 111 of 295 eyes (38%).

CONCLUSION

Significant improvements in BCVA are observed in most patients with RP following cataract surgery. Baseline BCVA is a predictor of visual outcome. Preoperative evaluation should include the assessment of potential zonular insufficiency and the presence of CME, as they are relatively common and may increase the risk of complications.

The Natural History of Leber Congenital Amaurosis and Cone-Rod Dystrophy Associated with Variants in the GUCY2D Gene

OBJECTIVE

To describe the spectrum of Leber congenital amaurosis (LCA) and cone-rod dystrophy (CORD) associated with the GUCY2D gene and to identify potential end points and optimal patient selection for future therapeutic trials.

DESIGN

International, multicenter, retrospective cohort study.

SUBJECTS

Eighty-two patients with GUCY2D-associated LCA or CORD from 54 families.

METHODS

Medical records were reviewed for medical history, best-corrected visual acuity (BCVA), ophthalmoscopy, visual fields, full-field electroretinography, and retinal imaging (fundus photography, spectral-domain OCT [SD-OCT], fundus autofluorescence).

MAIN OUTCOMES MEASURES

Age of onset, evolution of BCVA, genotype-phenotype correlations, anatomic characteristics on funduscopy, and multimodal imaging.

RESULTS

Fourteen patients with autosomal recessive LCA and 68 with autosomal dominant CORD were included. The median follow-up times were 5.2 years (interquartile range [IQR] 2.6-8.8 years) for LCA and 7.2 years (IQR 2.2-14.2 years) for CORD. Generally, LCA presented in the first year of life. The BCVA in patients with LCA ranged from no light perception to 1.00 logarithm of the minimum angle of resolution (logMAR) and remained relatively stable during follow-up. Imaging for LCA was limited but showed little to no structural degeneration. In patients with CORD, progressive vision loss started around the second decade of life. The BCVA declined annually by 0.022 logMAR (P < 0.001) with no difference between patients with the c.2513G>A and the c.2512C>T GUCY2D variants (P = 0.798). At the age of 40 years, the probability of being blind or severely visually impaired was 32%. The integrity of the ellipsoid zone (EZ) and that of the external limiting membrane (ELM) on SD-OCT correlated significantly with BCVA (Spearman ρ = 0.744, P = 0.001, and ρ = 0.712, P < 0.001, respectively) in those with CORD.

CONCLUSIONS

Leber congenital amaurosis associated with GUCY2D caused severe congenital visual impairment with relatively intact macular anatomy on funduscopy and available imaging, suggesting long preservation of photoreceptors. Despite large variability, GUCY2D-associated CORD generally presented during adolescence, with a progressive loss of vision, and culminated in severe visual impairment during mid-to-late adulthood. The integrity of the ELM and EZ may be suitable structural end points for therapeutic studies of GUCY2D-associated CORD.

Whole exome sequencing of known eye genes reveals genetic causes for high myopia

High myopia (refractive error ≤ -6 diopters (D)) is a heterogeneous condition, and without clear accompanying features it can be difficult to pinpoint a genetic cause. This observational study aimed to evaluate the utility of whole exome sequencing (WES) using an eye disorder gene panel in European patients with high myopia. Patients with high myopia were recruited by ophthalmologists and clinical geneticists. Clinical features were categorized into isolated high myopia, high myopia with other ocular involvement or with systemic involvement. WES was performed and an eye disorder gene panel of ~ 500 genes was evaluated. 113 patients with high myopia (mean (SD) refractive error - 11.8D (5.2) were included. Of these, 53% were children younger than 12 years of age (53%), 13.3% were 12-18 years, and 34% were adults (aged over 18 years). 23 out of 113 patients (20%) received a genetic diagnosis of which 11 patients displayed additional ocular or systemic involvement. Pathogenic variants were identified in retinal dystrophy genes (e.g.GUCY2D, CACNA1F), connective tissue disease genes (e.g. COL18A1, COL2A1), non-syndromic high myopia genes (ARR3), ocular development genes (e.g. PAX6) and other genes (ASPH, CNNM4). In 20% of our high myopic study population WES using an eye gene panel enabled us to diagnose the genetic cause for this disorder. Eye genes known to cause retinal dystrophy, developmental or syndromic disorders can cause high myopia without apparent clinical features of other pathology.

CRB1-Associated Retinal Dystrophies: A Prospective Natural History Study in Anticipation of Future Clinical Trials

PURPOSE

To investigate the natural disease course of retinal dystrophies associated with crumbs cell polarity complex component 1 (CRB1) and identify clinical end points for future clinical trials.

DESIGN

Single-center, prospective case series.

METHODS

An investigator-initiated nationwide collaborative study that included 22 patients with CRB1-associated retinal dystrophies. Patients underwent ophthalmic assessment at baseline and 2 years after baseline. Clinical examination included best-corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study charts, Goldmann kinetic perimetry (V4e isopter seeing retinal areas), microperimetry, full-field electroretinography, full-field stimulus threshold (FST), fundus photography, spectral-domain optical coherence tomography, and fundus autofluorescence imaging.

RESULTS

Based on genetic, clinical, and electrophysiological data, patients were diagnosed with retinitis pigmentosa (19 [86%]), cone-rod dystrophy (2 [9%]), or isolated macular dystrophy (1 [5%]). Analysis of the entire cohort at 2 years showed no significant changes in BCVA (P = .069) or V4e isopter seeing retinal areas (P = .616), although signs of clinical progression were present in individual patients. Macular sensitivity measured on microperimetry revealed a significant reduction at the 2-year follow-up (P < .001). FST responses were measurable in patients with nonrecordable electroretinograms. On average, FST responses remained stable during follow-up.

CONCLUSION

In CRB1-associated retinal dystrophies, visual acuity and visual field measures remain relatively stable over the course of 2 years. Microperimetry showed a significant decrease in retinal sensitivity during follow-up and may be a more sensitive progression marker. Retinal sensitivity on microperimetry may serve as a functional clinical end point in future human treatment trials for CRB1-associated retinal dystrophies.

Early onset X-linked female limited high myopia in three multigenerational families caused by novel mutations in the ARR3 gene

This study describes the clinical spectrum and genetic background of high myopia caused by mutations in the ARR3 gene. We performed an observational case series of three multigenerational families with high myopia (SER≤-6D), from the departments of Clinical Genetics and Ophthalmology of a tertiary Dutch hospital. Whole-exome sequencing (WES) with a vision-related gene panel was performed, followed by a full open exome sequencing. We identified three Caucasian families with high myopia caused by three different pathogenic variants in the ARR3 gene (c.214C>T, p.Arg72*; c.767+1G>A; p.?; c.848delG, p.(Gly283fs)). Myopia was characterized by a high severity (<-8D), an early onset (<6 years), progressive nature, and a moderate to bad atropine treatment response. Remarkably, a female limited inheritance pattern was present in all three families accordant with previous reports. The frequency of a pathogenic variant in the ARR3 gene in our diagnostic WES cohort was 5%. To conclude, we identified three families with early onset, therapy-resistant, high myopia with a female-limited inheritance pattern, caused by a mutation in the ARR3 gene. The singular mode of inheritance might be explained by metabolic interference due to X-inactivation. Identification of this type of high myopia will improve prompt myopia treatment, monitoring, and genetic counseling.

CAUSES AND CLINICAL MANIFESTATIONS OF MASQUERADE SYNDROMES IN INTRAOCULAR INFLAMMATORY DISEASES

OBJECTIVE

To identify the clinical characteristics and prevalence of neoplastic and nonneoplastic inflammatory masquerade syndromes (IMSs) in a tertiary center and determine the useful diagnostic tests.

METHODS

A retrospective cohort study of consecutive 1906 patients diagnosed with intraocular inflammatory disease.

RESULTS

Of all patients initially diagnosed with intraocular inflammatory disease, we identified 116 (6%) patients with noninflammatory causes (neoplastic IMSs in 36/116; 31% and nonneoplastic IMSs in 52/116; 45%). In addition, 26 patients (22%, 1.4% of all) had drug-induced uveitis and 2 (2%, 0.1% of all) had paraneoplastic uveitis. The large B-cell lymphoma was the most common neoplastic IMS (78%), and the major clinical features were presence of cells and floaters in the vitreous (69%) and chorioretinal lesions (33%). The causes of nonneoplastic IMSs included retinal vascular disorders (38%), hereditary retinal diseases (31%), and degenerative ocular disorders (19%). The common clinical manifestations consisted of chorioretinal scars (27%), small white-yellow retinal lesions (17%), and leaking vessels on fluorescein angiography (14%).

CONCLUSION

Noninflammatory causes were determined in 6% of a large population with initial diagnosis of intraocular inflammatory disease. Although neoplastic IMS was commonly characterized by vitreous cells and opacities, most common definitive diagnoses in nonneoplastic IMS encompassed diverse retinal disorders.

Differences in clinical presentation of primary open-angle glaucoma between African and European populations

Purpose

Primary open‐angle glaucoma (POAG) has been reported to occur more frequently in Africans, and to follow a more severe course compared to Europeans. We aimed to describe characteristics of POAG presentation and treatment across three ethnic groups from Africa and one from Europe.

Methods

We ascertained 151 POAG patients from South African Coloured (SAC) and 94 South African Black (SAB) ethnicity from a university hospital in South Africa. In Tanzania, 310 patients were recruited from a university hospital and a referral hospital. In the Netherlands, 241 patients of European ancestry were included. All patients were over 35 years old and had undergone an extensive ophthalmic examination. Patients were diagnosed according to the ISGEO criteria. A biogeographic ancestry analysis was performed to estimate the proportion of genetic African ancestry (GAA).

Results

The biogeographic ancestry analysis showed that the median proportion of GAA was 97.6% in Tanzanian, 100% in SAB, 34.2% in SAC and 1.5% in Dutch participants. Clinical characteristics at presentation for Tanzanians, SAB, SAC and Dutch participants, respectively: mean age: 63, 57, 66, 70 years (p < 0.001); visual acuity in the worse eye: 1.78, 1.78, 0.3, 0.3 LogMAR (p < 0.001); maximum intraocular pressure of both eyes: 36, 34, 29, 29 mmHg (p_anova < 0.001); maximum vertical cup to disc ratio (VCDR) of both eyes: 0.90, 0.90, 0.84, 0.83 (p < 0.001); mean central corneal thickness: 506, 487, 511, 528 μm (p < 0.001). Fourteen percent of Tanzanian patients presented with blindness (<3/60 Snellen) in the better eye in contrast to only 1% in the Dutch.

Conclusion

In this multi‐ethnic comparative study, Sub‐Saharan Africans present at a younger age with lower visual acuity, higher IOP, larger VCDR, than SAC and Dutch participants. This indicates the more progressive and destructive course in Sub‐Saharan Africans.

Correction: Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images

[This corrects the article DOI: 10.1371/journal.pgen.1009497.].

Cystoid maculopathy is a frequent feature of Cohen syndrome-associated retinopathy

Cohen syndrome (CS) is a rare syndromic form of rod-cone dystrophy. Recent case reports have suggested that cystoid maculopathy (CM) could affect CS patients with an early onset and high prevalence. Our study aims at improving our understanding and management of CM in CS patients through a retrospective case series of ten CS patients with identified pathogenic variants in VPS13B. Longitudinal optical coherence tomography (OCT) imaging was performed and treatment with carbonic anhydrase inhibitors (CAI) was provided to reduce the volume of cystoid spaces. CM affected eight out of ten patients in our cohort. The youngest patient showed a strong progression of macular cysts from the age of 4.5 to 5 years despite oral CAI medication. Other teenage and young adult patients showed stable macular cysts with and without treatment. One patient showed a moderate decrease of cystoid spaces in the absence of treatment at 22 years of age. Through a correlative analysis we found that the volume of cystoid spaces was positively correlated to the thickness of peripheral and macular photoreceptor-related layers. This study suggests that CAI treatments may not suffice to improve CM in CS patients, and that CM may resolve spontaneously during adulthood as photoreceptor dystrophy progresses.

Clinical Phenotype and Course of PDE6A-Associated Retinitis Pigmentosa Disease, Characterized in Preparation for a Gene Supplementation Trial

Importance

Treatment trials require sound knowledge on the natural course of disease.

Objective

To assess clinical features, genetic findings, and genotype-phenotype correlations in patients with retinitis pigmentosa (RP) associated with biallelic sequence variations in the PDE6A gene in preparation for a gene supplementation trial.

Design, Setting, and Participants

This prospective, longitudinal, observational cohort study was conducted from January 2001 to December 2019 in a single center (Centre for Ophthalmology of the University of Tübingen, Germany) with patients recruited multinationally from 12 collaborating European tertiary referral centers. Patients with retinitis pigmentosa, sequence variants in PDE6A, and the ability to provide informed consent were included.

Exposures

Comprehensive ophthalmological examinations; validation of compound heterozygosity and biallelism by familial segregation analysis, allelic cloning, or assessment of next-generation sequencing-read data, where possible.

Main Outcomes and Measures

Genetic findings and clinical features describing the entire cohort and comparing patients harboring the 2 most common disease-causing variants in a homozygous state (c.304C>A;p.(R102S) and c.998 + 1G>A;p.?).

Results

Fifty-seven patients (32 female patients [56%]; mean [SD], 40 [14] years) from 44 families were included. All patients completed the study. Thirty patients were homozygous for disease-causing alleles. Twenty-seven patients were heterozygous for 2 different PDE6A variants each. The most frequently observed alleles were c.304C>A;p.(R102S), c.998 + 1G>A;p.?, and c.2053G>A;p.(V685M). The mean (SD) best-corrected visual acuity was 0.43 (0.48) logMAR (Snellen equivalent, 20/50). The median visual field area with object III4e was 660 square degrees (5th and 95th percentiles, 76 and 11 019 square degrees; 25th and 75th percentiles, 255 and 3923 square degrees). Dark-adapted and light-adapted full-field electroretinography showed no responses in 88 of 108 eyes (81.5%). Sixty-nine of 108 eyes (62.9%) showed additional findings on optical coherence tomography imaging (eg, cystoid macular edema or macular atrophy). The variant c.998 + 1G>A;p.? led to a more severe phenotype when compared with the variant c.304C>A;p.(R102S).

Conclusions and Relevance

Seventeen of the PDE6A variants found in these patients appeared to be novel. Regarding the clinical findings, disease was highly symmetrical between the right and left eyes and visual impairment was mild or moderate in 90% of patients, providing a window of opportunity for gene therapy.

Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images

Optical Coherence Tomography (OCT) enables non-invasive imaging of the retina and is used to diagnose and manage ophthalmic diseases including glaucoma. We present the first large-scale genome-wide association study of inner retinal morphology using phenotypes derived from OCT images of 31,434 UK Biobank participants. We identify 46 loci associated with thickness of the retinal nerve fibre layer or ganglion cell inner plexiform layer. Only one of these loci has been associated with glaucoma, and despite its clear role as a biomarker for the disease, Mendelian randomisation does not support inner retinal thickness being on the same genetic causal pathway as glaucoma. We extracted overall retinal thickness at the fovea, representative of foveal hypoplasia, with which three of the 46 SNPs were associated. We additionally associate these three loci with visual acuity. In contrast to the Mendelian causes of severe foveal hypoplasia, our results suggest a spectrum of foveal hypoplasia, in part genetically determined, with consequences on visual function.

KCNV2-Associated Retinopathy: Genetics, Electrophysiology, and Clinical Course-KCNV2 Study Group Report 1

PURPOSE

To investigate genetics, electrophysiology, and clinical course of KCNV2-associated retinopathy in a cohort of children and adults.

STUDY DESIGN

This was a multicenter international clinical cohort study.

METHODS

Review of clinical notes and molecular genetic testing. Full-field electroretinography (ERG) recordings, incorporating the international standards, were reviewed and quantified and compared with age and recordings from control subjects.

RESULTS

In total, 230 disease-associated alleles were identified from 117 patients, corresponding to 75 different KCNV2 variants, with 28 being novel. The mean age of onset was 3.9 years old. All patients were symptomatic before 12 years of age (range, 0-11 years). Decreased visual acuity was present in all patients, and 4 other symptoms were common: reduced color vision (78.6%), photophobia (53.5%), nyctalopia (43.6%), and nystagmus (38.6%). After a mean follow-up of 8.4 years, the mean best-corrected visual acuity (BCVA ± SD) decreased from 0.81 ± 0.27 to 0.90 ± 0.31 logarithm of minimal angle of resolution. Full-field ERGs showed pathognomonic waveform features. Quantitative assessment revealed a wide range of ERG amplitudes and peak times, with a mean rate of age-associated reduction indistinguishable from the control group. Mean amplitude reductions for the dark-adapted 0.01 ERG, dark-adapted 10 ERG a-wave, and LA 3.0 30 Hz and LA3 ERG b-waves were 55%, 21%, 48%, and 74%, respectively compared with control values. Peak times showed stability across 6 decades.

CONCLUSION

In KCNV2-associated retinopathy, full-field ERGs are diagnostic and consistent with largely stable peripheral retinal dysfunction. Report 1 highlights the severity of the clinical phenotype and established a large cohort of patients, emphasizing the unmet need for trials of novel therapeutics.

Genome-wide meta-analysis identifies 127 open-angle glaucoma loci with consistent effect across ancestries

Primary open-angle glaucoma (POAG), is a heritable common cause of blindness world-wide. To identify risk loci, we conduct a large multi-ethnic meta-analysis of genome-wide association studies on a total of 34,179 cases and 349,321 controls, identifying 44 previously unreported risk loci and confirming 83 loci that were previously known. The majority of loci have broadly consistent effects across European, Asian and African ancestries. Cross-ancestry data improve fine-mapping of causal variants for several loci. Integration of multiple lines of genetic evidence support the functional relevance of the identified POAG risk loci and highlight potential contributions of several genes to POAG pathogenesis, including SVEP1, RERE, VCAM1, ZNF638, CLIC5, SLC2A12, YAP1, MXRA5, and SMAD6. Several drug compounds targeting POAG risk genes may be potential glaucoma therapeutic candidates.

Are Patients at Risk for Recurrent Disease Activity After Switching From Remicade® to Remsima®? An Observational Study

Background: Since the late ‘90s, infliximab (Remicade^®) is being used successfully to treat patients with several non-infectious immune mediated inflammatory diseases (IMIDs). In recent years, infliximab biosimilars, including Remsima^® were introduced in clinical practice.

Aim: To investigate the interchangeability of Remicade^® (originator infliximab) and its biosimilar Remsima^® in patients with rare immune-mediated inflammatory diseases (IMIDs).

Methods: This two-phased prospective open label observational study was designed to monitor the transition from Remicade^® to Remsima^® in patients with rare IMIDs. All included patients were followed during the first 2 years. The primary endpoint was the demonstration of non-difference in quality of life and therapeutic efficacy, as measured by parameters including a safety monitoring program, physicians perception of disease activity (PPDA) and patient self-reported outcomes (PSROs). Secondary outcomes included routine blood analysis, pre-infusion serum drug concentration values and anti-drug antibody formation.

Results: Forty eight patients treated with Remicade^® were switched to Remsima^® in June-July 2016 and subsequently monitored during the first 2 years. The group consisted of patients with sarcoidosis (n = 17), Behçet's disease (n = 12), non-infectious uveitis (n = 11), and other diagnoses (n = 8). There were no significant differences in PPDA, PSROs, clinical and laboratory assessments and pre-infusion serum drug concentrations between the groups. De novo anti-drug antibodies were observed in two patients. Seven patients with sarcoidosis and five with another diagnosis developed a significant disease relapse (n = 7) or adverse events (n = 5) within 2 years; 10 of these patients discontinued Remsima^® treatment, one withdrew from the study and one received additional corticosteroid therapy.

Conclusions: We observed no significant differences in PSROs, PPDA and laboratory parameters after treatment was switched from Remicade^® to Remsima^®. However, disease relapse or serious events were observed in 12 out of 48 patients when treatment was switched from Remicade^® to Remsima^®. The choice to switch anti-TNF alpha biologics in patients with rare IMIDs, particularly in sarcoidosis, requires well-considered decision-making and accurate monitoring due to a possibly higher incidence of disease worsening.

Multi-trait genome-wide association study identifies new loci associated with optic disc parameters

A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH.

Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry

IMPORTANCE

Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders.

OBJECTIVES

To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma.

DESIGN, SETTINGS, AND PARTICIPANTS

A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14 917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma.

EXPOSURES

Genetic variants associated with primary open-angle glaucoma.

MAIN OUTCOMES AND MEASURES

Presence of primary open-angle glaucoma. Genome-wide significance was defined as P < 5 × 10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data.

RESULTS

A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-β A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; P = 2 × 10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14 917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; P < .001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; P = 4 × 10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry.

CONCLUSIONS AND RELEVANCE

In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies.

Extending the Spectrum of EYS-Associated Retinal Disease to Macular Dystrophy

Purpose

To assess the phenotypic variability and natural course of inherited retinal diseases (IRDs) caused by EYS mutations.

Methods

Multiethnic cohort study (N = 30) with biallelic EYS variants from a clinical IRD database (retinitis pigmentosa [RP], N = 27; cone-rod dystrophy [CRD], N = 1; and macular dystrophy, N = 2). In vitro minigene splice assay was performed to determine the effect on EYS pre-mRNA splicing of the c.1299+5_1299+8del variant in macular dystrophy patients.

Results

We found 27 different EYS variants in RP patients and 7 were novel. The rate of visual field loss of the V4e isopter area was -0.84 ± 0.44 ln(deg2) per year, and the rate of visual acuity loss was 0.75 Early Treatment Diabetic Retinopathy Study letters per year. Ellipsoid zone width was correlated with area of the hyperautofluorescent ring, with rs = 0.78 and P < 0.001. Rate of decline in ellipsoid zone width was -57 ± 17 μm per year (P < 0.01) (n = 14) or -3.69% ± 0.51% from baseline per year (P < 0.001). An isolated CRD patient carried a homozygous EYS variant (c.9405T>A), previously identified in RP patients. Two siblings with macular dystrophy carried compound heterozygous EYS variants: c.1299+5_1299+8del and c.6050G>T. The former was novel and shown to result in skipping of exon 8, and the latter was a known RP variant.

Conclusions

We report on EYS-associated macular dystrophy, extending the spectrum of EYS-associated IRDs. We observed heterogeneity between RP patients in age of onset and disease progression. Identical EYS variants were found in cases with RP, CRD, and macular dystrophy. Screening for EYS variants in CRD and macular dystrophy patients might increase the diagnostic yield in previously unsolved cases.

The Common ABCA4 Variant p.Asn1868Ile Shows Nonpenetrance and Variable Expression of Stargardt Disease When Present in trans With Severe Variants

Purpose

To assess the occurrence and the disease expression of the common p.Asn1868Ile variant in patients with Stargardt disease (STGD1) harboring known, monoallelic causal ABCA4 variants.

Methods

The coding and noncoding regions of ABCA4 were sequenced in 67 and 63 STGD1 probands respectively, harboring monoallelic ABCA4 variants. In case p.Asn1868Ile was detected, segregation analysis was performed whenever possible. Probands and affected siblings harboring p.Asn1868Ile without additional variants in cis were clinically evaluated retrospectively. Two asymptomatic siblings carrying the same ABCA4 variants as their probands were clinically examined. The penetrance of p.Asn1868Ile was calculated using allele frequency data of ABCA4 variants in non-Finnish European individuals.

Results

The p.Asn1868Ile variant was found in cis with known variants in 14/67 probands. In 27/67 probands, we identified p.Asn1868Ile without additional variants in cis, in combination with known, mainly severe ABCA4 variants. In 23/27 probands, the trans configuration was established. Among 27 probands and 6/7 STGD1 siblings carrying p.Asn1868Ile, 42% manifested late-onset disease (>44 years). We additionally identified four asymptomatic relatives carrying a combination of a severe variant and p.Asn1868Ile; ophthalmologic examination in two persons did not reveal STGD1. Based on ABCA4 allele frequency data, we conservatively estimated the penetrance of p.Asn1868Ile, when present in trans with a severe variant, to be below 5%.

Conclusions

A significant fraction of genetically unexplained STGD1 cases carries p.Asn1868Ile as a second variant. Our findings suggest exceptional differences in disease expression or even nonpenetrance of this ABCA4 variant, pointing toward an important role for genetic or environmental modifiers in STGD1.

Heterozygous deep-intronic variants and deletions in ABCA4 in persons with retinal dystrophies and one exonic ABCA4 variant

Variants in ABCA4 are responsible for autosomal-recessive Stargardt disease and cone-rod dystrophy. Sequence analysis of ABCA4 exons previously revealed one causative variant in each of 45 probands. To identify the "missing" variants in these cases, we performed multiplex ligation-dependent probe amplification-based deletion scanning of ABCA4. In addition, we sequenced the promoter region, fragments containing five deep-intronic splice variants, and 15 deep-intronic regions containing weak splice sites. Heterozygous deletions spanning ABCA4 exon 5 or exons 20-22 were found in two probands, heterozygous deep-intronic variants were identified in six probands, and a deep-intronic variant was found together with an exon 20-22 deletion in one proband. Based on ophthalmologic findings and characteristics of the identified exonic variants present in trans, the deep-intronic variants V1 and V4 were predicted to be relatively mild and severe, respectively. These findings are important for proper genetic counseling and for the development of variant-specific therapies.

Causes and consequences of inherited cone disorders

Hereditary cone disorders (CDs) are characterized by defects of the cone photoreceptors or retinal pigment epithelium underlying the macula, and include achromatopsia (ACHM), cone dystrophy (COD), cone-rod dystrophy (CRD), color vision impairment, Stargardt disease (STGD) and other maculopathies. Forty-two genes have been implicated in non-syndromic inherited CDs. Mutations in the 5 genes implicated in ACHM explain ∼93% of the cases. On the contrary, only 21% of CRDs (17 genes) and 25% of CODs (8 genes) have been elucidated. The fact that the large majority of COD and CRD-associated genes are yet to be discovered hints towards the existence of unknown cone-specific or cone-sensitive processes. The ACHM-associated genes encode proteins that fulfill crucial roles in the cone phototransduction cascade, which is the most frequently compromised (10 genes) process in CDs. Another 7 CD-associated proteins are required for transport processes towards or through the connecting cilium. The remaining CD-associated proteins are involved in cell membrane morphogenesis and maintenance, synaptic transduction, and the retinoid cycle. Further novel genes are likely to be identified in the near future by combining large-scale DNA sequencing and transcriptomics technologies. For 31 of 42 CD-associated genes, mammalian models are available, 14 of which have successfully been used for gene augmentation studies. However, gene augmentation for CDs should ideally be developed in large mammalian models with cone-rich areas, which are currently available for only 11 CD genes. Future research will aim to elucidate the remaining causative genes, identify the molecular mechanisms of CD, and develop novel therapies aimed at preventing vision loss in individuals with CD in the future.

Maternal uniparental isodisomy of chromosome 6 reveals a TULP1 mutation as a novel cause of cone dysfunction

PURPOSE

The majority of the genetic causes of autosomal recessive (ar) cone dystrophy (CD) and cone-rod dystrophy (CRD) are currently unknown. We used a high-resolution homozygosity mapping approach in a cohort of patients with CD or CRD to identify new genes for ar cone disorders.

DESIGN

Case series.

PARTICIPANTS

A cohort of 159 patients with ar CD and 91 patients with CRD.

METHODS

The genomes of 83 patients with ar CD and 73 patients with CRD were analyzed for homozygous regions using single nucleotide polymorphism (SNP) microarrays. One patient showed homozygosity of SNPs across chromosome 6, and segregation analysis was performed using microsatellite markers. Direct sequencing of all retinal disease genes on chromosome 6 revealed a novel pathogenic TULP1 mutation in this patient. A cohort of 159 individuals with CD and 91 individuals with CRD was screened for this particular mutation using the restriction enzyme HhaI. The medical history of patients carrying the TULP1 mutation was reviewed and additional ophthalmic examinations were performed, including electroretinography (ERG), perimetry, optical coherence tomography (OCT), fundus autofluorescence (FAF), and fundus photography.

MAIN OUTCOME MEASURES

TULP1 mutations, age at diagnosis, visual acuity, fundus appearance, color vision defects, visual field, ERG, FAF, and OCT findings.

RESULTS

In 1 patient, homozygosity mapping and subsequent segregation analysis revealed maternal uniparental disomy (UPD) of chromosome 6. A novel homozygous missense mutation (p.Arg420Ser) was identified in TULP1, whereas no mutations were detected in other retinal disease genes on chromosome 6. The mutation affects a highly conserved amino acid residue in the Tubby domain and is predicted to be pathogenic. The same homozygous mutation was also identified in an additional, unrelated patient with CRD. Both patients carrying the p.Arg420Ser mutation presented with a bull's eye maculopathy. The first patient had progressive loss of visual acuity with a relatively preserved ERG, whereas the second patient developed loss of visual acuity, peripheral degeneration, and severely reduced ERG responses in a cone-rod pattern.

CONCLUSIONS

Maternal UPD of chromosome 6 unmasked a mutation in the TULP1 gene as a novel cause of cone dysfunction. This expands the disease spectrum of TULP1 mutations from Leber congenital amaurosis and early-onset retinitis pigmentosa to cone-dominated disease.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Cone-rod dystrophy can be a manifestation of Danon disease

BACKGROUND

Danon disease is a neuromuscular disorder with variable expression in the eye. We describe a family with Danon disease and cone-rod dystrophy (CRD).

METHODS

Affected males of one family with Danon were invited for an extensive ophthalmologic examination, including color vision testing, fundus photography, Goldmann perimetry, full-field electroretinogram (ERG), and SD-OCT. Previous ophthalmologic data were retrieved from medical charts. The LAMP2 and RPGR gene were analyzed by direct sequencing.

RESULTS

Two siblings had no ocular phenotype. The third sibling and a cousin developed CRD leading to legal blindness. Visual acuity deteriorated progressively over time, color vision was severely disturbed, and ERG showed reduced photopic and scotopic responses. SD-OCT revealed thinning of the photoreceptor and RPE layer. Visual fields demonstrated central scotoma. The causal mutation was p.Gly384Arg in LAMP2; no mutations were found in RPGR.

CONCLUSIONS

This is the first description of CRD in Danon disease. The retinal phenotype was a late onset but severe dystrophy characterized by loss of photoreceptors and RPE cells. With this report, we highlight the importance of a comprehensive ophthalmologic examination in the clinical work-up of Danon disease.

Clinical course, genetic etiology, and visual outcome in cone and cone-rod dystrophy

OBJECTIVE

To evaluate the clinical course, genetic etiology, and visual prognosis in patients with cone dystrophy (CD) and cone-rod dystrophy (CRD).

DESIGN

Clinic-based, longitudinal, multicenter study.

PARTICIPANTS

Consecutive probands with CD (N = 98), CRD (N = 83), and affected relatives (N = 41 and N = 17, respectively) from various ophthalmogenetic clinics in The Netherlands, Belgium, and the United Kingdom.

METHODS

Data on best-corrected Snellen visual acuity, color vision, ophthalmoscopy, fundus photography, Goldmann perimetry, and full-field standard electroretinogram (ERG) from all patients were registered from medical charts over a mean follow-up of 19 years. The ABCA4, CNGB3, KCNV2, PDE6C, and RPGR genes were analyzed by direct sequencing in autosomal recessive (AR) and X-linked (XL), respectively. Genotyping was not undertaken for autosomal-dominant cases.

MAIN OUTCOME MEASURES

The 10-year progression of all clinical parameters and cumulative lifetime risk of low vision and legal blindness were assessed.

RESULTS

The mean age onset for CD was 16 years (standard deviation, 11), and of CRD 12 years (standard deviation, 11; P = 0.02). The pattern of inheritance was AR in 92% of CD and 90% of CRD. Ten years after diagnosis, 35% of CD and 51% of CRD had a bull's eye maculopathy; 70% of CRD showed absolute peripheral visual field defects and 37% of CD developed rod involvement on ERG. The mean age of legal blindness was 48 (standard error [SE], 3.1) years in CD, and 35 (SE, 1.1; P<0.001) years in CRD. ABCA4 mutations were found in 8 of 90 (9%) of AR-CD, and in 17 of 65 (26%) of AR-CRD. Other mutations were detected in CNGB3 (3/90; 3%), KCNV2 (4/90; 4%), and in PDE6C (1/90; 1%). The RPGR gene was mutated in the 2 XL-CD and in 4 of 5 (80%) of XL-CRD. ABCA4 mutations as well as age of onset <20 years were significantly associated with a faster progression to legal blindness (P<0.001).

CONCLUSIONS

Although CD had a slightly more favorable clinical course than CRD, both disorders progressed to legal blindness in the majority of patients. Mutations in the ABCA4 gene and early onset of disease were independent prognostic parameters for visual loss. Our data may serve as an aid in counseling patients with progressive cone disorders.

Clinical course of cone dystrophy caused by mutations in the RPGR gene

Background

Mutations in the RPGR gene predominantly cause rod photoreceptor disorders with a large variability in clinical course. In this report, we describe two families with mutations in this gene and cone involvement.

Methods

We investigated an X-linked cone dystrophy family (1) with 25 affected males, 25 female carriers, and 21 non-carriers, as well as a small family (2) with one affected and one unaffected male. The RPGR gene was analyzed by direct sequencing. All medical records were evaluated, and all available data on visual acuity, color vision testing, ophthalmoscopy, fundus photography, fundus autofluorescence, Goldmann perimetry, SD-OCT, dark adaptation, and full-field electroretinography (ERG) were registered. Cumulative risks of visual loss were studied with Kaplan–Meier product-limit survival analysis.

Results

Both families had a frameshift mutation in ORF15 of the RPGR gene; family 1 had p.Ser1107ValfsX4, and family 2 had p.His1100GlnfsX10. Mean follow up was 13 years (SD 10). Virtually all affected males showed reduced photopic and normal scotopic responses on ERG. Fifty percent of the patients had a visual acuity of <0.5 at age 35 years (SE 2.2), and 75% of the patients was legally blind at age 60 years (SE 2.3). Female carriers showed no signs of ocular involvement.

Conclusions

This report describes the clinical course and visual prognosis in two families with cone dystrophy due to RPGR mutations in the 3’ terminal region of ORF15. Remarkable features were the consistent, late-onset phenotype, the severe visual outcome, and the non-expression in female carriers. Expression of RPGR mutations in this particular region appears to be relatively homogeneous and predisposed to cones.

Progressive loss of cones in achromatopsia: an imaging study using spectral-domain optical coherence tomography

PURPOSE

Achromatopsia (ACHM) is a congenital autosomal recessive cone disorder with a presumed stationary nature and only a few causative genes. Animal studies suggest that ACHM may be a good candidate for corrective gene therapy. Future implementation of this therapy in humans requires the presence of viable cone cells in the retina. In this study the presence of cone cells in ACHM was determined, as a function of age.

METHODS

The appearance and thickness of all retinal layers were evaluated by spectral-domain optical coherence tomography (SD-OCT) in 40 ACHM patients (age range, 4-70 years) with known mutations in the CNGB3, CNGA3, and PDE6C genes. A comparison was made with 55 healthy age-matched control subjects.

RESULTS

The initial feature of cone cell decay was loss of inner and outer segments with disruption of the ciliary layer on OCT, which was observed as early as 8 years of age. Cone cell loss further progressed with age and occurred in 8 (42%) of 19 patients below 30 years and in 20 (95%) of 21 of those aged 30+ years. Retinal thickness was significantly thinner in the fovea of all patients (126 μm in ACHM vs. 225 μm in the control; P < 0.001) and correlated with age (β = 0.065; P = 0.011). Foveal hypoplasia was present in 24 (80%) of 30 patients and in 1 of 55 control subjects.

CONCLUSIONS

ACHM is not a stationary disease. The first signs of cone cell loss occur in early childhood. If intervention becomes available in the future, the present results imply that it should be applied in the first decade.

Homozygosity mapping reveals PDE6C mutations in patients with early-onset cone photoreceptor disorders

Cone photoreceptor disorders form a clinical spectrum of diseases that include progressive cone dystrophy (CD) and complete and incomplete achromatopsia (ACHM). The underlying disease mechanisms of autosomal recessive (ar)CD are largely unknown. Our aim was to identify causative genes for these disorders by genome-wide homozygosity mapping. We investigated 75 ACHM, 97 arCD, and 20 early-onset arCD probands and excluded the involvement of known genes for ACHM and arCD. Subsequently, we performed high-resolution SNP analysis and identified large homozygous regions spanning the PDE6C gene in one sibling pair with early-onset arCD and one sibling pair with incomplete ACHM. The PDE6C gene encodes the cone alpha subunit of cyclic guanosine monophosphate (cGMP) phosphodiesterase, which converts cGMP to 5'-GMP, and thereby plays an essential role in cone phototransduction. Sequence analysis of the coding region of PDE6C revealed homozygous missense mutations (p.R29W, p.Y323N) in both sibling pairs. Sequence analysis of 104 probands with arCD and 10 probands with ACHM revealed compound heterozygous PDE6C mutations in three complete ACHM patients from two families. One patient had a frameshift mutation and a splice defect; the other two had a splice defect and a missense variant (p.M455V). Cross-sectional retinal imaging via optical coherence tomography revealed a more pronounced absence of cone photoreceptors in patients with ACHM compared to patients with early-onset arCD. Our findings identify PDE6C as a gene for cone photoreceptor disorders and show that arCD and ACHM constitute genetically and clinically overlapping phenotypes.

Coronary artery fistulas

The aetiology of congenital coronary artery fistulas remains a challenging issue. Coronary arteries with an anatomically normal origin may, for obscure reasons, terminate abnormally and communicate with different single or multiple cardiac chambers or great vessels. When this occurs, the angiographic morphological appearance may vary greatly from discrete channels to plexiform network of vessels. Coronary arteriovenous fistulas (CAVFs) have neither specific signs nor pathognomonic symptoms; the spectrum of clinical features varies considerably. The clinical presentation of symptomatic cases can include angina pectoris, myocardial infarction, fatigue, dyspnoea, CHF, SBE, ventricular and supraventricular tachyarrhythmias or even sudden cardiac death. CAVFs may, however, be a coincidental finding during diagnostic coronary angiography (CAG). CAG is considered the gold standard for diagnosing and delineating the morphological anatomy and pathway of CAVFs. There are various tailored therapeutic modalities for the wide spectrum of clinical manifestations of CAVFs, including conservative pharmacological strategy, percutaneous transluminal embolisation and surgical ligation.