51
|
Birch DG, Samarakoon L, Melia M, Duncan JL, Ayala AR, Audo I, Cheetham JK, Durham TA, Iannaccone A, Pennesi ME, Stingl K. The RUSH2A Study: Dark-Adapted Visual Fields in Patients With Retinal Degeneration Associated With Biallelic Variants in the USH2A Gene. Invest Ophthalmol Vis Sci 2022; 63:17. [PMID: 35293952 PMCID: PMC8944389 DOI: 10.1167/iovs.63.3.17] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To measure visual fields using two-color dark-adapted chromatic perimetry in a subset of participants in the Rate of Progression of USH2A-related Retinal Degeneration (RUSH2A), a study of USH2A-mediated syndromic (USH2) and autosomal recessive nonsyndromic retinitis pigmentosa, determine percentage retaining rod function, and explore relationships between dark-adapted visual fields (DAVF) and rod function from ERG and full-field stimulus thresholds (FST). Methods Full-field rod mean sensitivity, number of rod loci, maximum sensitivity, DAVF full-field hill of vision (DAVF VTOT), and 30° hill of vision (DAVF V30) were measured in one eye for DAVF ancillary study participants (n = 49). Loci where cyan relative to red sensitivity was more than 5 dB on dark-adapted chromatic perimetry were considered rod mediated. Correlation coefficients between the DAVF measures and standard clinical measures were estimated, as were kappa statistics (κ) for agreement between DAVF and other measures of rod function. Results Of 49 participants tested with DAVF, 38 (78%) had evidence of rod function, whereas 15 (31%) had measurable rod ERGs. DAVF maximum sensitivity was highly correlated with FST white thresholds (r = -0.80; P < .001). Although not statistically significant, the number of rod loci and DAVF VTOT were lower in eyes with longer disease duration by 0.82 (95% confidence interval, -1.76, 0.12) loci/year and 0.59 (95% confidence interval, -1.82, 0.64) dB-steradians/year, respectively. Conclusions Rod-mediated function on FST and DAVF is present in many patients with symptomatic USH2A-related retinal degeneration, including some without measurable rod ERGs. RUSH2A longitudinal data will determine how these measures change with disease progression and whether they are useful for longitudinal studies in inherited retinal degenerations.
Collapse
|
52
|
Stingl K, Hoyng C, Kempf M, Kohl S, Jung R, Righetti G, Kühlewein L, Pohl L, Kortüm F, Kelbsch C, Wilhelm B, Peters T, Stingl K. Evaluation of Local Rod and Cone Function in Stargardt Disease. Invest Ophthalmol Vis Sci 2022; 63:6. [PMID: 35262734 PMCID: PMC8934563 DOI: 10.1167/iovs.63.3.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Purpose In this study, chromatic pupil campimetry (CPC) was used to map local functional degenerative changes of cones and rods in Stargardt disease (STGD1). Methods 19 patients (age 36 ± 8 years; 12 males) with genetically confirmed ABCA4 mutations and a clinical diagnosis of STGD1 and 12 age-matched controls (age 37 ± 11 years; 2 males) underwent scotopic (rod-favoring) and photopic (cone-favoring) CPC. CPC evaluates the local retinal function in the central 30° visual field via analysis of the pupil constriction to local stimuli in a gaze-corrected manner. Results Scotopic CPC revealed that the rod function of patients with STGD1 inside the 30° visual field was not impaired when compared with age-matched controls. However, a statistically significant faster pupil response onset time (∼ 40 ms) was observed in the measured area. Photopic CPC showed a significant reduction of the central cone function up to 6°, with a minor, non-significant reduction beyond this eccentricity. The time dynamic of the pupillary response in photopic CPC did not reveal differences between STGD1 and controls. Conclusions The functional analysis of the macular region in STGD1 disease indicates reduced central cone function, corresponding to photoreceptor degeneration. In contrast, the rod function in the central area was not affected. Nevertheless, some alteration of the time dynamics in the rod system was observed indicating a complex effect of cone degeneration on the functional performance of the rod system. Our results should be considered when interpreting safety and efficacy in interventional trials of STGD1.
Collapse
|
53
|
Girach A, Audo I, Birch DG, Huckfeldt RM, Lam BL, Leroy BP, Michaelides M, Russell SR, Sallum JM, Stingl K, Tsang SH, Yang P. RNA-based therapies in inherited retinal diseases. Ther Adv Ophthalmol 2022; 14:25158414221134602. [PMID: 36388727 PMCID: PMC9643766 DOI: 10.1177/25158414221134602] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 10/05/2022] [Indexed: 11/10/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a genetically and phenotypically heterogeneous group of genetic eye disorders. There are more than 300 disease entities, and together this group of disorders affects millions of people globally and is a frequent cause of blindness or low-vision certification. However, each type is rare or ultra-rare. Characteristically, the impaired vision in IRDs is due to retinal photoreceptor dysfunction and loss resulting from mutation in a gene that codes for a retinal protein. Historically, IRDs have been considered incurable and individuals living with these blinding conditions could be offered only supportive care. However, the treatment landscape for IRDs is beginning to evolve. Progress is being made, driven by improvements in understanding of genotype-phenotype relationships, through advances in molecular genetic testing and retinal imaging. Alongside this expanding knowledge of IRDs, the current era of precision medicine is fueling a growth in targeted therapies. This has resulted in the first treatment for an IRD being approved. Several other therapies are currently in development in the IRD space, including RNA-based therapies, gene-based therapies (such as augmentation therapy and gene editing), cell therapy, visual prosthetics, and optogenetics. RNA-based therapies are a novel approach within precision medicine that have demonstrated success, particularly in rare diseases. Three antisense oligonucleotides (AONs) are currently in development for the treatment of specific IRD subtypes. These RNA-based therapies bring several key advantages in the setting of IRDs, and the potential to bring meaningful vision benefit to individuals living with inherited blinding disorders. This review will examine the increasing breadth and relevance of RNA-based therapies in clinical medicine, explore the key features that make AONs suitable for treating genetic eye diseases, and provide an overview of the three-leading investigational AONs in clinical trials.
Collapse
|
54
|
Righetti G, Kempf M, Braun C, Jung R, Kohl S, Wissinger B, Zrenner E, Stingl K, Stingl K. Oscillatory Potentials in Achromatopsia as a Tool for Understanding Cone Retinal Functions. Int J Mol Sci 2021; 22:12717. [PMID: 34884517 PMCID: PMC8657736 DOI: 10.3390/ijms222312717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 11/25/2022] Open
Abstract
Achromatopsia (ACHM) is an inherited autosomal recessive disease lacking cone photoreceptors functions. In this study, we characterize the time-frequency representation of the full-field electroretinogram (ffERG) component oscillatory potentials (OPs), to investigate the connections between photoreceptors and the inner retinal network using ACHM as a model. Time-frequency characterization of OPs was extracted from 52 controls and 41 achromat individuals. The stimulation via ffERG was delivered under dark-adaptation (DA, 3.0 and 10.0 cd·s·m-2) to assess mixed rod-cone responses. The ffERG signal was subsequently analyzed using a continuous complex Morlet transform. Time-frequency maps of both DA conditions show the characterization of OPs, disclosing in both groups two distinct time-frequency windows (~70-100 Hz and >100 Hz) within 50 ms. Our main result indicates a significant cluster (p < 0.05) in both conditions of reduced relative power (dB) in ACHM people compared to controls, mainly at the time-frequency window >100 Hz. These results suggest that the strongly reduced but not absent activity of OPs above 100 Hz is mostly driven by cones and only in small part by rods. Thus, the lack of cone modulation of OPs gives important insights into interactions between photoreceptors and the inner retinal network and can be used as a biomarker for monitoring cone connection to the inner retina.
Collapse
|
55
|
Faber H, Ernemann U, Sachs H, Gekeler F, Danz S, Koitschev A, Besch D, Bartz-Schmidt KU, Zrenner E, Stingl K, Kernstock C. CT Assessment of Intraorbital Cable Movement of Electronic Subretinal Prosthesis in Three Different Surgical Approaches. Transl Vis Sci Technol 2021; 10:16. [PMID: 34264295 PMCID: PMC8299430 DOI: 10.1167/tvst.10.8.16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Purpose Electronic retinal implants restore some visual perception in patients blind from retinitis pigmentosa. Eye movements cause mechanical stress in intraorbital power supply cables leading to cable breaks. By using computer tomography (CT) scans at the extreme positions of the four cardinal gaze directions, this study determined in vivo, which of three surgical routing techniques results in minimal bending radius variation and favors durability. Methods Nine patients received the first-generation subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) in one eye. Three techniques for intraorbital cable routing were used (straight cable route (A), parabulbar loop (B), and encircling band (C)), each in three patients. All patients underwent computer tomography of the orbital region. The bending radius of the intraorbital cable was measured with the DICOM viewer Osirix v4.1.2 (Pixmeo SARL, Bernex, Switzerland) and served as indicator for mechanical stress. Results Average bending radius variation was 87% for method A, 11% for method B, and 16% for method C. Methods A and B (P = 0.005) and methods A and C (P = 0.007) differed significantly, while method B and C showed no statistical difference (P = 0.07). Conclusions Compared to straight routes, arcuated cable routes significantly reduce cable movement and bending. Due to an easier surgical procedure, a parabulbar loop is the preferred method to minimize bending radius variation and prolong survival time of electronic subretinal implants. Translational Relevance CT analysis of cable bending of implanted medical devices allows to determine which surgical routing technique favors durability in vivo.
Collapse
|
56
|
Iannaccone A, Brewer CC, Cheng P, Duncan JL, Maguire MG, Audo I, Ayala AR, Bernstein PS, Bidelman GM, Cheetham JK, Doty RL, Durham TA, Hufnagel RB, Myers MH, Stingl K, Zein WM. Auditory and olfactory findings in patients with USH2A-related retinal degeneration-Findings at baseline from the rate of progression in USH2A-related retinal degeneration natural history study (RUSH2A). Am J Med Genet A 2021; 185:3717-3727. [PMID: 34331386 DOI: 10.1002/ajmg.a.62437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/25/2021] [Accepted: 07/03/2021] [Indexed: 11/09/2022]
Abstract
Sensorineural hearing loss (SNHL) is characteristic of Usher syndrome type 2 (USH2), but less is known about SNHL in nonsyndromic autosomal recessive retinitis pigmentosa (ARRP) and olfaction in USH2A-associated retinal degeneration. The Rate of Progression of USH2A-related Retinal Degeneration (RUSH2A) is a natural history study that enrolled 127 participants, 80 with USH2 and 47 with ARRP. Hearing was measured by pure-tone thresholds and word recognition scores, and olfaction by the University of Pennsylvania Smell Identification Test (UPSIT). SNHL was moderate in 72% of USH2 participants and severe or profound in 25%, while 9% of ARRP participants had moderate adult-onset SNHL. Pure-tone thresholds worsened with age in ARRP but not in USH2 participants. The degree of SNHL was not associated with other participant characteristics in either USH2 or ARRP. Median pure-tone thresholds in ARRP participants were significantly higher than the normative population (p < 0.001). Among 14 USH2 participants reporting newborn hearing screening results, 7 reported passing. Among RUSH2A participants, 7% had mild microsmia and 5% had moderate or severe microsmia. Their mean (±SD) UPSIT score was 35 (±3), similar to healthy controls (34 [±3]; p = 0.39). Olfaction differed by country (p = 0.02), but was not significantly associated with clinical diagnosis, age, gender, race/ethnicity, smoking status, visual measures, or hearing. Hearing loss in USH2A-related USH2 did not progress with age. ARRP patients had higher pure-tone thresholds than normal. Newborn hearing screening did not identify all USH2A-related hearing loss. Olfaction was not significantly worse than normal in participants with USH2A-related retinal degeneration.
Collapse
|
57
|
Kuehlewein L, Zobor D, Andreasson SO, Ayuso C, Banfi S, Bocquet B, Bernd AS, Biskup S, Boon CJF, Downes SM, Fischer MD, Holz FG, Kellner U, Leroy BP, Meunier I, Nasser F, Rosenberg T, Rudolph G, Stingl K, Thiadens AAHJ, Wilhelm B, Wissinger B, Zrenner E, Kohl S, Weisschuh N. Clinical Phenotype and Course of PDE6A-Associated Retinitis Pigmentosa Disease, Characterized in Preparation for a Gene Supplementation Trial. JAMA Ophthalmol 2021; 138:1241-1250. [PMID: 33057649 DOI: 10.1001/jamaophthalmol.2020.4206] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
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.
Collapse
|
58
|
Neugebauer A, Stingl K, Ivanov I, Wahl S. Influence of Systematic Gaze Patterns in Navigation and Search Tasks with Simulated Retinitis Pigmentosa. Brain Sci 2021; 11:brainsci11020223. [PMID: 33673036 PMCID: PMC7917782 DOI: 10.3390/brainsci11020223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 12/29/2022] Open
Abstract
People living with a degenerative retinal disease such as retinitis pigmentosa are oftentimes faced with difficulties navigating in crowded places and avoiding obstacles due to their severely limited field of view. The study aimed to assess the potential of different patterns of eye movement (scanning patterns) to (i) increase the effective area of perception of participants with simulated retinitis pigmentosa scotoma and (ii) maintain or improve performance in visual tasks. Using a virtual reality headset with eye tracking, we simulated tunnel vision of 20° in diameter in visually healthy participants (n = 9). Employing this setup, we investigated how different scanning patterns influence the dynamic field of view—the average area over time covered by the field of view—of the participants in an obstacle avoidance task and in a search task. One of the two tested scanning patterns showed a significant improvement in both dynamic field of view (navigation 11%, search 7%) and collision avoidance (33%) when compared to trials without the suggested scanning pattern. However, participants took significantly longer (31%) to finish the navigation task when applying this scanning pattern. No significant improvements in search task performance were found when applying scanning patterns.
Collapse
|
59
|
Stingl K, Kempf M, Bartz-Schmidt KU, Dimopoulos S, Reichel F, Jung R, Kelbsch C, Kohl S, Kortüm FC, Nasser F, Peters T, Wilhelm B, Wissinger B, Wozar F, Zrenner E, Fischer MD, Stingl K. Spatial and temporal resolution of the photoreceptors rescue dynamics after treatment with voretigene neparvovec. Br J Ophthalmol 2021; 106:831-838. [PMID: 33472769 PMCID: PMC9132865 DOI: 10.1136/bjophthalmol-2020-318286] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
Background Voretigene neparvovec is a gene therapeutic agent for treatment of retinal dystrophies caused by bi-allelic RPE65 mutations. In this study, we report on a novel and objective evaluation of a retinotopic photoreceptor rescue. Methods Seven eyes of five patients (14, 21, 23, 24, 36 years, 1 male, 4 females) with bi-allelic RPE65 mutations have been treated with voretigene neparvovec. The clinical examinations included visual acuity testing, dark-adapted full-field stimulus threshold (FST), dark-adapted chromatic perimeter (DAC) with a 30-degree grid, and a 30 degrees grid scotopic and photopic chromatic pupil campimetry (CPC). All evaluations and spectral domain optical coherence tomography were performed at baseline, 1 month and 3 months. Results All except the oldest patient had a measurable improvement of the rod function assessed via FST, DAC or scotopic CPC at 1 month. The visual acuity improved slightly or remained stable in all eyes. A cone function improvement as measured by photopic CPC was observed in three eyes. The gain of the dark-adapted threshold with blue FST and the DAC stimuli (cyan) average correlated strongly with age (R2>0.7). The pupil response improvement in the scotopic CPC correlated with the baseline local retinal volume (R2=0.5). Conclusions The presented protocols allow evaluating the individual spatial and temporal effects of gene therapy effects. Additionally, we explored parameters that correlated with the success of the therapy. CPC and DAC present new and fast ways to assess functional changes in retinotopic maps of rod and cone function, measuring complementary aspects of retinal function.
Collapse
|
60
|
Kortüm F, Kieninger S, Mazzola P, Kohl S, Wissinger B, Prokisch H, Stingl K, Weisschuh N. X-Linked Retinitis Pigmentosa Caused by Non-Canonical Splice Site Variants in RPGR. Int J Mol Sci 2021; 22:ijms22020850. [PMID: 33467000 PMCID: PMC7830253 DOI: 10.3390/ijms22020850] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 01/13/2023] Open
Abstract
We aimed to validate the effect of non-canonical splice site variants in the RPGR gene in five patients from four families diagnosed with retinitis pigmentosa. Four variants located in intron 2 (c.154 + 3_154 + 6del), intron 3 (c.247 + 5G>A), intron 7 (c.779-5T>G), and intron 13 (c.1573-12A>G), respectively, were analyzed by means of in vitro splice assays. Splicing analysis revealed different aberrant splicing events, including exon skipping and intronic nucleotide addition, which are predicted to lead either to an in-frame deletion affecting relevant protein domains or to a frameshift of the open reading frame. Our data expand the landscape of pathogenic variants in RPGR, thereby increasing the genetic diagnostic rate in retinitis pigmentosa and allowing patients harboring the analyzed variants to be enrolled in clinical trials.
Collapse
|
61
|
Faber H, Besch D, Bartz‐Schmidt K, Eisenstein H, Roider J, Sachs H, Gekeler F, Zrenner E, Stingl K. Restriction of eye motility in patients with RETINA IMPLANT Alpha AMS. Acta Ophthalmol 2020; 98:e998-e1003. [PMID: 32304165 DOI: 10.1111/aos.14435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 03/16/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE To evaluate the motility of the eye in patients with the RETINA IMPLANT Alpha AMS. METHODS Eye motility was determined in eight gaze directions in ten blind retinitis pigmentosa patients, who had received the RETINA IMPLANT Alpha AMS, before implantation of the subretinal implant and at six time-points up to one year after. RESULTS The analysis of eye motility showed a restriction in the upgaze and gaze to the temporal side directly after surgery in eight of the nine patients included. The degree of motility restriction decreased continuously with recovery during the observation time. One year after surgery, eye motility was still restricted in the majority of patients, especially in the upgaze to the temporal side at 20° (five of seven patients). CONCLUSION Retinal implants with intraorbital parts (e.g. connecting cables) caused restriction in the temporal and superior viewing directions in the majority of patients. Although this restriction might be cosmetically visible, this limitation in eye motility has no effects on the monocular vision and the implant's efficacy for daily use.
Collapse
|
62
|
Birch DG, Cheng P, Duncan JL, Ayala AR, Maguire MG, Audo I, Cheetham JK, Durham TA, Fahim AT, Ferris FL, Heon E, Huckfeldt RM, Iannaccone A, Khan NW, Lad EM, Michaelides M, Pennesi ME, Stingl K, Vincent A, Weng CY. The RUSH2A Study: Best-Corrected Visual Acuity, Full-Field Electroretinography Amplitudes, and Full-Field Stimulus Thresholds at Baseline. Transl Vis Sci Technol 2020; 9:9. [PMID: 33133772 PMCID: PMC7552938 DOI: 10.1167/tvst.9.11.9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/06/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose The purpose of this study was to evaluate baseline best corrected visual acuity (BCVA), full-field electroretinography (ERG), full-field stimulus thresholds (FST), and their relationship with baseline demographic and clinical characteristics in the Rate of Progression in Usher syndrome type 2 (USH2A)-related Retinal Degeneration (RUSH2A) multicenter study. Methods Participants had Usher syndrome type 2 (USH2, N = 80) or autosomal recessive nonsyndromic retinitis pigmentosa (ARRP, N = 47) associated with biallelic variants in the USH2A gene. Associations of demographic and clinical characteristics with BCVA, ERG, and FST were assessed with regression models. Results In comparison to ARRP, USH2 had worse BCVA (median 79 vs. 82 letters; P < 0.001 adjusted for age), lower rod-mediated ERG b-wave amplitudes (median 0.0 vs. 6.6 µV; P < 0.001) and 30 Hz flicker cone-mediated ERG amplitudes (median 1.5 vs. 3.1 µV; P = 0.001), and higher (white, blue, and red) FST thresholds (means [−26, −31, −23 dB] vs. [−39, −45, −28 dB]; P < 0.001 for all stimuli). After adjusting for age, gender, and duration of vision loss, the difference in BCVA between diagnosis groups was attenuated (P = 0.09). Only diagnosis was associated with rod- and cone-mediated ERG parameters, whereas both genders (P = 0.04) and duration of visual loss (P < 0.001) also were associated with FST white stimulus. Conclusions USH2 participants had worse BCVA, ERG, and FST than ARRP participants. FST was strongly associated with duration of disease; it remains to be determined whether it will be a sensitive measure of progression. Translational Relevance Using standardized research protocols in RUSH2A, measures have been identified to monitor disease progression and treatment response and differentiate features of prognostic relevance between USH2 and ARRP participants with USH2A mutations.
Collapse
|
63
|
Stingl K, Stingl K, Nowomiejska K, Kuehlewein L, Kohl S, Kempf M, Strasser T, Jung R, Wilhelm B, Peters T, Kelbsch C, Bartz-Schmidt KU, Langrova H, Zrenner E. Clinical protocols for the evaluation of rod function. Ophthalmologica 2020; 244:396-407. [PMID: 32805733 DOI: 10.1159/000510888] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 08/13/2020] [Indexed: 11/19/2022]
Abstract
This work presents a fast clinical protocol for dark adapted chromatic perimetry (DAC) and a novel clinical tool: scotopic chromatic pupil campimetry (CPC). The goal of the study is to explore the applicability of these methods in a clinical setting, their test-retest repeatability and congruence of results. Local rod sensitivity was assessed at 36 locations within 30 degrees eccentricity of the visual field in fifteen healthy subjects (mean age 43±16 years; 7 females, 8 males) with DAC (red and cyan stimuli) and CPC two times in repeated measurements. The duration of individual measurements was 370±5 s for CPC, and 366±62 s for DAC. The intraclass correlation (ICC) coefficient for DAC cyan stimuli was 0.53, for red stimuli 0.67 and for CPC 0.93. However, the spatial resolution of CPC was substantially smaller than in DAC. We did not find correlation of DAC and CPC measurements on the global nor local level. In comparison to DAC, CPC shows a superior intervisit repeatability in detection of functional changes in the rod population in an objective way with lower spatial resolution. Our results also indicate that these two methods might measure the rod function in different ways and therefore could represent complementary scotopic functional diagnostics.
Collapse
|
64
|
Weisschuh N, Obermaier CD, Battke F, Bernd A, Kuehlewein L, Nasser F, Zobor D, Zrenner E, Weber E, Wissinger B, Biskup S, Stingl K, Kohl S. Genetic architecture of inherited retinal degeneration in Germany: A large cohort study from a single diagnostic center over a 9-year period. Hum Mutat 2020; 41:1514-1527. [PMID: 32531858 DOI: 10.1002/humu.24064] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/27/2020] [Accepted: 05/04/2020] [Indexed: 12/29/2022]
Abstract
We aimed to unravel the molecular genetic basis of inherited retinal degeneration (IRD) in a comprehensive cohort of patients diagnosed in the largest center for IRD in Germany. A cohort of 2,158 affected patients from 1,785 families diagnosed with IRD was analyzed by targeted next-generation sequencing (NGS). Patients with single-gene disorders (i.e., choroideremia and retinoschisis) were analyzed by Sanger sequencing and multiplex ligation-dependent probe amplification. Our study cohort accounts for ∼7% of the estimated 30,000 patients with IRD in Germany, thereby providing representative data for both the prevalence of IRDs and the mutation spectrum of IRD genes for the population in Germany. We achieved a molecular diagnostic rate of 35-95%, depending on the clinical entities, with a high detection rate for achromatopsia, retinoschisis, and choroideremia, and a low detection rate for central areolar choroidal dystrophy and macular dystrophy. A total of 1,161 distinct variants were identified, including 501 novel variants, reaffirming the known vast genetic heterogeneity of IRD in a mainly outbred European population. This study demonstrates the clinical utility of panel-based NGS in a large and highly heterogeneous cohort from an outbred population and for the first time gives a comprehensive representation of the genetic landscape of IRDs in Germany. The data are valuable and crucial for the scientific community and healthcare providers, but also for the pharmaceutical industry in the progressing field of personalized medicine and gene therapy.
Collapse
|
65
|
Faber H, Bartz-Schmidt KU, Stett A, Zrenner E, Stingl K. [Electronic Retina Implants - an Abandoned Dream?]. Klin Monbl Augenheilkd 2020; 237:288-293. [PMID: 32182631 DOI: 10.1055/a-1021-5040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Between 2005 and 2016, over 30,000 cochlear implants were implanted in Germany, while the number of retinal implants remained less than 1% of this number. The two types of retina implants that reached the market did not survive economically. The present review article discusses the impact and future of electronic retina implants in ophthalmology.
Collapse
|
66
|
Stingl KT, Kuehlewein L, Weisschuh N, Biskup S, Cremers FPM, Khan MI, Kelbsch C, Peters T, Ueffing M, Wilhelm B, Zrenner E, Stingl K. Chromatic Full-Field Stimulus Threshold and Pupillography as Functional Markers for Late-Stage, Early-Onset Retinitis Pigmentosa Caused by CRB1 Mutations. Transl Vis Sci Technol 2019; 8:45. [PMID: 31879567 PMCID: PMC6927735 DOI: 10.1167/tvst.8.6.45] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/30/2019] [Indexed: 01/08/2023] Open
Abstract
Purpose Mutations in the CRB1 gene cause early-onset retinal degeneration (EORD). Clinical disease progression markers, such as visual fields or electrophysiology, are not reliably measurable in most patients to follow the retinal function in patients with CRB1-mutations. Methods Ten patients (five females, five males; age 22–56 years) with EORD caused by CRB1 mutations were examined in a cross-sectional manner using best corrected visual acuity (BCVA), perimetry, full-field and multifocal electroretinography, full-field stimulus threshold (FST), and pupillography to red and blue light. Disease duration was defined as the difference between the age at the first symptoms to the age at examination in years. Results BCVA was quantifiable in six patients and ranged from light perception to 20/50. The visual field was measurable only in three patients who had the shortest disease duration. Full-field and multifocal electroretinography were not measurable in any patient. FST to blue and red light were measurable in all patients except the one with the longest disease duration; the thresholds ranged from −16.7 to 1.5 dB for red light and from −40.2 to 2.5 dB for blue light (0 dB = 0.01 cd.s/m2) and showed correlations with disease duration (r = 0.87 for blue, r = 0.65 for red, r = 0.8 for blue–red difference). The maximal relative pupil constriction amplitude (MRA) showed low or no correlations with disease duration (r = −0.55 for blue, r = −0.3 for red light); the blue–red difference in the post-illumination pupil responses (PIPR) showed no correlation with disease duration (r = −0.05). Compared to healthy eyes, the MRA to red and blue light was significantly decreased (P < 0.001) and the blue–red PIPR difference was significantly increased (P = 0.003). Conclusions FST features a valid clinical marker in late-stage early-onset retinitis pigmentosa caused by CRB1 mutations correlating with disease duration. This indicates the potential as a progression marker of disease. The pupil responses to full-field chromatic stimuli show significant differences from the normal population: the remaining responses, although reduced, indicate a partially preserved inner retinal function despite severe photoreceptor dysfunction. Translational Relevance The functional measurements presented in this study present a valid clinical progression marker in late-stage early onset retinitis pigmentosa caused by biallelic CRB1 mutations. Additionally, they can be used as outcome measures for safety and efficacy in clinical therapy trials.
Collapse
|
67
|
Kelbsch C, Stingl K, Kempf M, Strasser T, Jung R, Kuehlewein L, Wilhelm H, Peters T, Wilhelm B, Stingl K. Objective Measurement of Local Rod and Cone Function Using Gaze-Controlled Chromatic Pupil Campimetry in Healthy Subjects. Transl Vis Sci Technol 2019; 8:19. [PMID: 31788348 PMCID: PMC6871544 DOI: 10.1167/tvst.8.6.19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/02/2019] [Indexed: 02/06/2023] Open
Abstract
Purpose We introduce a new approach for functional mapping of rod and cone activity by measuring pupillary responses to local stimulation via gaze-controlled chromatic pupil campimetry (CPC). Methods Pupillary constriction amplitude and latency to constriction onset to local photopic and scotopic light stimuli at different locations within the 30° central visual field were analyzed in 14 healthy subjects (4 males, 34 ± 11 years, mean ± standard deviation [SD]). All subjects were measured twice for evaluating the test–retest variability and reproducibility of the method. Results For the cone-favoring protocol (ConeProt), the relative maximal constriction amplitude was most pronounced in the center (26.8% ± 6.3%) with a hill-shaped decrease from the fovea to the periphery. For the rod-favoring protocol (RodProt), it was smaller (center, 13.5% ± 4.5%) with a profile lacking the central peak. Mean latency to constriction onset was faster for cones (277 ± 25 ms) than for rods (372 ± 13 ms). Mean intraclass correlation at the different stimulus locations was 0.84 ± 0.08 for RodProt and 0.75 ± 0.11 for ConeProt; mean coefficients of repeatability value of all stimulus locations was 5.9% ± 1.2% and 8.6% ± 1.7%, respectively. Conclusions CPC provides an objective evaluation of local rod and cone function within the central 30° visual field. It shows a photoreceptor-specific profile in healthy subjects. Due to its easy, noncontact, gaze-controlled character, it is a clinically applicable method and may fill the gap of functional diagnostics of rods and cones of the human retina. Translational Relevance Chromatic pupil campimetry provides information about the local rod and cone function of the human retina with distinct pattern of distributions in an objective manner.
Collapse
|
68
|
Weisschuh N, Sturm M, Baumann B, Audo I, Ayuso C, Bocquet B, Branham K, Brooks BP, Catalá-Mora J, Giorda R, Heckenlively JR, Hufnagel RB, Jacobson SG, Kellner U, Kitsiou-Tzeli S, Matet A, Martorell Sampol L, Meunier I, Rudolph G, Sharon D, Stingl K, Streubel B, Varsányi B, Wissinger B, Kohl S. Deep-intronic variants in CNGB3 cause achromatopsia by pseudoexon activation. Hum Mutat 2019; 41:255-264. [PMID: 31544997 DOI: 10.1002/humu.23920] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/20/2019] [Accepted: 09/16/2019] [Indexed: 01/18/2023]
Abstract
Our comprehensive cohort of 1100 unrelated achromatopsia (ACHM) patients comprises a considerable number of cases (~5%) harboring only a single pathogenic variant in the major ACHM gene CNGB3. We sequenced the entire CNGB3 locus in 33 of these patients to find a second variant which eventually explained the patients' phenotype. Forty-seven intronic CNGB3 variants were identified in 28 subjects after a filtering step based on frequency and the exclusion of variants found in cis with pathogenic alleles. In a second step, in silico prediction tools were used to filter out those variants with little odds of being deleterious. This left three variants that were analyzed using heterologous splicing assays. Variant c.1663-1205G>A, found in 14 subjects, and variant c.1663-2137C>T, found in two subjects, were indeed shown to exert a splicing defect by causing pseudoexon insertion into the transcript. Subsequent screening of further unsolved CNGB3 subjects identified four additional cases harboring the c.1663-1205G>A variant which makes it the eighth most frequent CNGB3 variant in our cohort. Compound heterozygosity could be validated in ten cases. Our study demonstrates that whole gene sequencing can be a powerful approach to identify the second pathogenic allele in patients apparently harboring only one disease-causing variant.
Collapse
|
69
|
Kuehlewein L, Troelenberg N, Stingl K, Schleehauf S, Kusnyerik A, Jackson TL, MacLaren RE, Chee C, Roider J, Wilhelm B, Gekeler F, Bartz‐Schmidt KU, Zrenner E, Stingl K. Changes in microchip position after implantation of a subretinal vision prosthesis in humans. Acta Ophthalmol 2019; 97:e871-e876. [PMID: 30816625 DOI: 10.1111/aos.14077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 02/02/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE Retinal prosthetic devices have been developed to partially restore very low vision in legally blind patients with end-stage hereditary retinal dystrophies. Subretinal implants, unlike epiretinal implants, are not fixated by a tack. The aim of this study was to assess and analyse possible changes over time in the subretinal position of the RETINA IMPLANT Alpha IMS and Alpha AMS (ClinicalTrials.gov NCT01024803). METHODS Imaging studies were performed on fundus photographs using GIMP (Version 2.8.14). Postoperative photographs of the implanted eye were scaled and aligned. Landmarks were chosen and distances between landmarks were measured to then calculate the displacement of the microchip using a transformation matrix for rotational and translational movements. Analyses were performed using MATLAB 8.6 (The MathWorks Inc., Natick, MA). RESULTS Of the 27 datasets with the Alpha IMS device, 12 (44%) remained stable without displacement of the microchip relative to the optic disc and the major blood vessels, whereas in 15 (56%), displacement occurred. The mean ± SD displacement in those 15 eyes was 0.66 ± 0.35 mm (range, 0.24-1.67 mm). Of the eight datasets with the Alpha AMS device, 1 (13%) remained stable without displacement of the microchip relative to the optic disc and the major blood vessels, whereas in 7 (87%), displacement occurred. The mean ± SD displacement in those seven eyes was 0.66 ± 0.26 mm (range, 0.32-0.97 mm). Calculated from all eyes (including those in which no displacement occurred), the mean displacement was 0.36 mm in the IMS cohort, and 0.58 mm in the AMS cohort, however, the difference was not statistically significant (p = 0.17). CONCLUSIONS We have shown that the position of the subretinal implant changes in the majority of the cases after implantation. While the overall mean displacement of the chip was not significantly different in either of the cohorts, the maximum displacement was smaller in the Alpha AMS cohort.
Collapse
|
70
|
Stingl K, Kurtenbach A, Hahn G, Kernstock C, Hipp S, Zobor D, Kohl S, Bonnet C, Mohand-Saïd S, Audo I, Fakin A, Hawlina M, Testa F, Simonelli F, Petit C, Sahel JA, Zrenner E. Full-field electroretinography, visual acuity and visual fields in Usher syndrome: a multicentre European study. Doc Ophthalmol 2019; 139:151-160. [PMID: 31267413 DOI: 10.1007/s10633-019-09704-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/19/2019] [Indexed: 01/30/2023]
Abstract
PURPOSE Usher syndrome (USH) is a multisensory deficiency involving vision, hearing and the vestibular system. The purpose of this study is to report on the functional data (i.e. electroretinography, visual fields, visual acuity) of patients with retinitis pigmentosa (RP) due to Usher syndrome that were collected in a multicentre European study (TREATRUSH). METHODS A total of 268 genetically confirmed USH patients underwent electrophysiological examinations in the context of multimodal ophthalmological examination in the study (75 USH1, 189 USH2 and four USH3). Full-field electroretinography (ERG) was performed according to ISCEV standards, visual field determination was carried out with either the Octopus or Goldmann perimeters and visual acuity was examined with either ETDRS or Snellen charts. The data were compared between USH subtypes (USH1/USH2/USH3) and correlated with age. RESULTS Visual acuity decreases significantly with age for both USH1 and USH2 (p < 0.001), without a difference between the two cohorts. When corrected for age, the preserved kinetic visual field was significantly larger in USH2 than in USH1 (p = 0.04). Furthermore, the preserved kinetic visual field area showed a significant decrease with age (based on an exponential fit) in both USH1 and USH2 (p < 0.001). In USH1 patients, however, the visual field was already vastly reduced at an early age. The ERG results were abnormal in all patients. Detectable data for scotopic ERG were obtained from nine patients, and data of photopic ERG were obtained from 24 patients, without a difference between USH1 and USH2 subtypes. CONCLUSIONS There are differences in the phenotypes of RP in USH subtypes, most visible in the progression of visual fields between USH1 and USH2. The perimetric reduction occurs earlier in USH1 than in USH2. In both subtypes, visual acuity decreases significantly with age and the ERG is not detectable already at early ages.
Collapse
|
71
|
Felden J, Baumann B, Ali M, Audo I, Ayuso C, Bocquet B, Casteels I, Garcia-Sandoval B, Jacobson SG, Jurklies B, Kellner U, Kessel L, Lorenz B, McKibbin M, Meunier I, de Ravel T, Rosenberg T, Rüther K, Vadala M, Wissinger B, Stingl K, Kohl S. Mutation spectrum and clinical investigation of achromatopsia patients with mutations in the GNAT2 gene. Hum Mutat 2019; 40:1145-1155. [PMID: 31058429 DOI: 10.1002/humu.23768] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/03/2019] [Accepted: 04/18/2019] [Indexed: 02/04/2023]
Abstract
Achromatopsia (ACHM) is a hereditary cone photoreceptor disorder characterized by the inability to discriminate colors, nystagmus, photophobia, and low-visual acuity. Six genes have been associated with this rare autosomal recessively inherited disease, including the GNAT2 gene encoding the catalytic α-subunit of the G-protein transducin which is expressed in the cone photoreceptor outer segment. Out of a cohort of 1,116 independent families diagnosed with a primary clinical diagnosis of ACHM, we identified 23 patients with ACHM from 19 independent families with likely causative mutations in GNAT2, representing 1.7% of our large ACHM cohort. In total 22 different potentially disease-causing variants, of which 12 are novel, were identified. The mutation spectrum also includes a novel copy number variation, a heterozygous duplication of exon 4, of which the breakpoint matches exactly that of the previously reported exon 4 deletion. Two patients carry just a single heterozygous variant. In addition to our previous study on GNAT2-ACHM, we also present detailed clinical data of these patients.
Collapse
|
72
|
Nasser F, Kurtenbach A, Kohl S, Obermaier C, Stingl K, Zrenner E. Retinal dystrophies with bull's-eye maculopathy along with negative ERGs. Doc Ophthalmol 2019; 139:45-57. [PMID: 30945053 DOI: 10.1007/s10633-019-09694-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/28/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE The aim of this study was to examine the ophthalmological characteristics and genotypes of patients with congenital retinal pathologies, who display a bull's-eye maculopathy in the fundus, along with a negative scotopic electroretinogram. METHODS We analysed the results of five patients showing both a bull's-eye maculopathy, as well as a negative scotopic ERG evoked by a bright flash. Their median age was 39 years (range 11-63 years): three males and two females. All underwent a comprehensive examination with determination of distant visual acuity (ETDRS) and recording of the full-field ERG (scotopic and photopic). Fundus, OCT, and FAF images were obtained, the kinetic visual field was determined, and colour vision (D-15) was tested in most patients. Targeted gene panel sequencing was performed on peripheral blood. RESULTS One patient carried a homozygous ABCA4 mutation and an additional heterozygous variant in CRX. Two of the five patients were shown to have a heterozygous mutation in the CRX gene, one of whom had an additional heterozygous ABCA4 mutation. Two patients had the common heterozygous mutation c.2413G>A;p.Arg838His in GUCY2D. In all of the patients, there was a reduction in the amplitude of the b-wave with a regular a-wave amplitude in the scotopic bright-flash ERG. CONCLUSIONS The five patients with bull's-eye maculopathy along with a negative ERG had differing genotypes. Mutations were found in the CRX gene (2 patients), the ABCA4 gene (1 patient), and the GUCY2D gene (2 patients).
Collapse
|
73
|
Palmowski-Wolfe A, Stingl K, Habibi I, Schorderet D, Tran HV. Correction: Novel PDE6B Mutation Presenting with Retinitis Pigmentosa - A Case Series of Three Patients. Klin Monbl Augenheilkd 2019; 236:e37-e37. [PMID: 30769346 DOI: 10.1055/a-0853-8855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
74
|
Nasser F, Mulahasanovic L, Alkhateeb M, Biskup S, Stingl K, Zrenner E. Hypotrichosis with cone-rod dystrophy in a patient with cadherin 3 (CDH3) mutation. Doc Ophthalmol 2019; 138:153-160. [PMID: 30710256 DOI: 10.1007/s10633-019-09675-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/26/2019] [Indexed: 12/11/2022]
Abstract
PURPOSE To investigate a very rare case of hypotrichosis with cone-rod dystrophy caused by a P-cadherin CDH3 mutation. METHODS A 16-year-old Syrian girl was examined at age 9 and 14 years with an ophthalmological examination, fundus imaging, OCT and electrophysiological recordings (ERG and PERG). A disease-targeted gene panel sequencing was performed. RESULTS Fundus images showed pigmentations at the posterior eye pole to the mid periphery, as well as vessel tortuosity. OCT images revealed a loss of the outer retinal segments and IS/OS in the central macula. The scotopic and photopic ERGs showed moderately reduced amplitudes at age 9 years that became severely reduced at age of 14 years. The PERG was undetectable at age 9 years. In color vision testing, protan-deutan confusion errors occurred. Gene panel analysis revealed one homozygous mutation in CDH3 (c.1508G>A; p.Arg503His). CONCLUSION This case shows that a CDH3 mutation besides macula dystrophy can cause widespread cone-rod dystrophy with hypotrichosis without any other pathology besides hypoplastic nails. This points to a common pathway of hair growth and photoreceptor development that can be disturbed by a CDH3 mutation (c.1508G>A; p.Arg503His) located in the EC4 repeat region of the gene.
Collapse
|
75
|
Palmowski-Wolfe A, Stingl K, Habibi I, Schorderet D, Tran HV. Novel PDE6B Mutation Presenting with Retinitis Pigmentosa - A Case Series of Three Patients. Klin Monbl Augenheilkd 2019; 236:562-567. [PMID: 30646425 DOI: 10.1055/a-0811-5480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Retinitis pigmentosa (RP) affects 2.5 million people worldwide. Increased identification of causative gene defects and the increasing possibility of treatment necessitates better knowledge of phenotype-genotype correlations to help identify patients who would benefit from targeted gene therapy and improve patients' care. Here, we report on three RP patients with mutations in the PDE6Β Gene that have not been described previously. HISTORY AND SIGNS Three patients with a PDE6Β mutation were identified: 1. A 30-year-old male with a homozygotous mutation (c.[2351dupA],[2351dupA], p.[Q785Gfs*20],[Q785Gfs*20]) who was followed for 8 years. 2. A 54-year-old Caucasian woman with a heterozygous mutation [p.(K611Nfs*6), p.(Q567*)] who was followed for 40 years. 3. A 46-year-old Caucasian male [p.(E271K), p.(R627_E631del)]. All had noted an onset in childhood and complained of night blindness and photophobia. Typical bone spiculae were seen, and peripheral visual fields were progressively affected in all patients. Ganzfeld-ERG showed typical signs of rod-cone dystrophy. Patients 1 and 2 underwent cataract surgery at ages 27 and 36 years with an improvement in vision, while patient 3 had not developed a cataract at age 54. CONCLUSIONS In children complaining of night blindness, a PDE6Β-associated RP needs to be taken into consideration. Apart from helping patients with optical aids, such as polarizing filters or magnification, a specific diagnosis is especially important in view of emerging genetic treatment options. In particular, in RP patients with a PDE6Β mutation, a phase I/II study is currently ongoing (https://clinicaltrials.gov/ct2/show/NCT03328130).
Collapse
|