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... Show moreObjective: 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 signifi-cantly with BCVA (Spearman r = 0.744, P = 0.001, and r = 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 pres-ervation 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. Ophthalmology Retina 2022;6:711-722 (c) 2022 by the American Academy of Ophthalmology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). Show less
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... Show morePURPOSE: 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 pig mentosa (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. (Am J Ophthalmol 2021;234: 37-48. (C) 2021 The Authors. Published by Elsevier Inc. Show less
Koster, C.; Hurk, K.T. van den; Lewallen, C.F.; Talib, M.; Brink, J.B. ten; Boon, C.J.F.; Bergen, A.A. 2021
Purpose: We developed and phenotyped a pigmented knockout rat model for lecithin retinol acyltransferase (LRAT) using CRISPR/Cas9. The introduced mutation (c.12delA) is based on a patient group... Show morePurpose: We developed and phenotyped a pigmented knockout rat model for lecithin retinol acyltransferase (LRAT) using CRISPR/Cas9. The introduced mutation (c.12delA) is based on a patient group harboring a homologous homozygous frameshift mutation in the LRAT gene (c.12delC), causing a dysfunctional visual (retinoid) cycle. Methods: The introduced mutation was confirmed by DNA and RNA sequencing. The expression of Lrat was determined on both the RNA and protein level in wildtype and knockout animals using RT-PCR and immunohistochemistry. The retinal structure and function, as well as the visual behavior of the Lrat(-/-) and control rats, were characterized using scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), electroretinography (ERG) and vision-based behavioral assays. Results: Wildtype animals had high Lrat mRNA expression in multiple tissues, including the eye and liver. In contrast, hardly any expression was detected in Lrat(-/-) animals. LRAT protein was abundantly present in wildtype animals and absent in Lrat(-/-) animals. Lrat(-/-) animals showed progressively reduced ERG potentials compared to wildtype controls from two weeks of age onwards. Vison-based behavioral assays confirmed reduced vision. Structural abnormalities, such as overall retinal thinning, were observed in Lrat(-/-) animals. The retinal thickness in knockout rats was decreased to roughly 80% by four months of age. No functional or structural differences were observed between wildtype and heterozygote animals. Conclusions: Our Lrat(-/-) rat is a new animal model for retinal dystrophy, especially for the LRAT-subtype of early-onset retinal dystrophies. This model has advantages over the existing mouse models and the RCS rat strain and can be used for translational studies of retinal dystrophies. Show less
Purpose To investigate the retinal structure and function in patients with CRB1-associated retinal dystrophies (RD) and to explore potential clinical endpoints.Methods In this prospective cross... Show morePurpose To investigate the retinal structure and function in patients with CRB1-associated retinal dystrophies (RD) and to explore potential clinical endpoints.Methods In this prospective cross-sectional study, 22 patients with genetically confirmed CRB1-RD (aged 6-74 years), and who had a decimal best-corrected visual acuity (BCVA) >= 0.05 at the last visit, were studied clinically with ETDRS BCVA, corneal topography, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence, Goldmann visual field (VF), microperimetry, full-field electroretinography (ERG) and full-field stimulus testing (FST). Ten patients were from a genetic isolate (GI).Results Patients had retinitis pigmentosa (n = 19; GI and non-GI), cone-rod dystrophy (n = 2; GI) or macular dystrophy (n = 1; non-GI). Median age at first symptom onset was 3 years (range 0.8-49). Median decimal BCVA in the better and worse-seeing eye was 0.18 (range 0.05-0.83) and 0.08 (range light perception-0.72), respectively. Spectral-domain optical coherence tomography (SD-OCT) showed cystoid maculopathy in 8 subjects; inner retinal thickening (n = 20), a well-preserved (para)foveal outer retina (n = 7) or severe (para)foveal outer retinal atrophy (n = 14). All retinal layers were discernible in 13/21 patients (62%), with mild to moderate laminar disorganization in the others. Nanophthalmos was observed in 8 patients (36%). Full-field stimulus testing (FST) provided a subjective outcome measure for retinal sensitivity in eyes with (nearly) extinguished ERG amplitudes.Conclusions Despite the generally severe course of CRB1-RDs, symptom onset and central visual function are variable, even at advanced ages. Phenotypes may vary within the same family. Imaging and functional studies in a prospective longitudinal setting should clarify which endpoints may be most appropriate in a clinical trial. Show less
Nguyen, X.T.A.; Talib, M.; Cauwenbergh, C. van; Schooneveld, M.J. van; Fiocco, M.; Wijnholds, J.; ... ; Boon, C.J.F. 2021
Purpose: To investigate the natural history of RHO-associated retinitis pigmentosa (RP). Methods: A multicenter, medical chart review of 100 patients with autosomal dominant RHO-associated RP.... Show morePurpose: To investigate the natural history of RHO-associated retinitis pigmentosa (RP). Methods: A multicenter, medical chart review of 100 patients with autosomal dominant RHO-associated RP. Results: Based on visual fields, time-to-event analysis revealed median ages of 52 and 79 years to reach low vision (central visual field <20 degrees) and blindness (central visual field <10 degrees), respectively. For the best-corrected visual acuity (BCVA), the median age to reach mild impairment (20/67 <= BCVA < 20/40) was 72 years, whereas this could not be computed for lower acuities. Disease progression was significantly faster in patients with a generalized RP phenotype (n = 75; 75%) than that in patients with a sector RP phenotype (n = 25; 25%), in terms of decline rates of the BCVA (P < 0.001) and V4e retinal seeing areas (P < 0.005). The foveal thickness of the photoreceptor-retinal pigment epithelium (PR + RPE) complex correlated significantly with BCVA (Spearman's rho = 0.733; P < 0.001). Conclusion: Based on central visual fields, the optimal window of intervention for RHO-associated RP is before the 5th decade of life. Significant differences in disease progression are present between generalized and sector RP phenotypes. Our findings suggest that the PR + RPE complex is a potential surrogate endpoint for the BCVA in future studies. Show less
Talib, M.; Schooneveld, M.J. van; Duuren, R.J.G. van; Cauwenbergh, C. van; Brink, J.B. ten; Baere, E. de; ... ; Boon, C.J.F. 2019
