Nationwide Prevalence of Inherited Retinal Diseases in the Israeli Population

Importance

Data regarding the prevalence of various inherited retinal diseases (IRDs) are limited and vary across populations; moreover, nationwide prevalence studies may be limited to a specific IRD phenotype, potentially leading to inaccurate prevalence estimations. Therefore, nationwide prevalence data are needed.

Objective

To determine the prevalence of 67 IRD phenotypes in the Israeli population.

Design, Setting, and Participants

This cohort study collected nationwide data regarding the number of individuals affected with IRD phenotypes assessed in 10 clinical and academic centers in Israel as part of the research activity of the Israeli inherited retinal disease consortium. Data were collected in May 2023 on 9396 individuals residing in Israel who were diagnosed by an ophthalmologist with an IRD using either electroretinography or retinal imaging where included. Individuals with retinal diseases known to have a nonmendelian basis or without a clear genetic basis and those who were reported as deceased at the time of data collection were excluded from this study.

Main Outcomes and Measures

Prevalence of 67 IRD phenotypes.

Results

Among the 9396 participants in our cohort, the most common IRD in Israel was retinitis pigmentosa with a disease prevalence of approximately 1:2400 individuals, followed by cone-rod dystrophy (approximately 1:14 000), Stargardt disease (approximately 1:16 000), Usher syndrome (approximately 1:16,000), and congenital stationary night blindness (approximately 1:18 000). The prevalence of all IRDs combined was 1:1043 individuals.

Conclusions and Relevance

The current study provides large prevalence dataset of 67 IRD phenotypes, some of which are extremely rare, with only a single identified case. This analysis highlights the potential importance of performing additional nationwide prevalence studies to potentially assist with determining the prevalence of IRDs worldwide.

Elastic Deformation of Optical Coherence Tomography Images of Diabetic Macular Edema for Deep-Learning Models Training: How Far to Go?

- Objective: To explore the clinical validity of elastic deformation of optical coherence tomography (OCT) images for data augmentation in the development of deep-learning model for detection of diabetic macular edema (DME).

METHODS

Prospective evaluation of OCT images of DME (n = 320) subject to elastic transformation, with the deformation intensity represented by ([Formula: see text]). Three sets of images, each comprising 100 pairs of scans (100 original & 100 modified), were grouped according to the range of ([Formula: see text]), including low-, medium- and high-degree of augmentation; ([Formula: see text] = 1-6), ([Formula: see text] = 7-12), and ([Formula: see text] = 13-18), respectively. Three retina specialists evaluated all datasets in a blinded manner and designated each image as 'original' versus 'modified'. The rate of assignment of 'original' value to modified images (false-negative) was determined for each grader in each dataset.

RESULTS

The false-negative rates ranged between 71-77% for the low-, 63-76% for the medium-, and 50-75% for the high-augmentation categories. The corresponding rates of correct identification of original images ranged between 75-85% ([Formula: see text]0.05) in the low-, 73-85% ([Formula: see text]0.05 for graders 1 & 2, p = 0.01 for grader 3) in the medium-, and 81-91% ([Formula: see text]) in the high-augmentation categories. In the subcategory ([Formula: see text] = 7-9) the false-negative rates were 93-83%, whereas the rates of correctly identifying original images ranged between 89-99% ([Formula: see text]0.05 for all graders).

CONCLUSIONS

Deformation of low-medium intensity ([Formula: see text] = 1-9) may be applied without compromising OCT image representativeness in DME. Clinical and Translational Impact Statement-Elastic deformation may efficiently augment the size, robustness, and diversity of training datasets without altering their clinical value, enhancing the development of high-accuracy algorithms for automated interpretation of OCT images.

A nationwide genetic analysis of inherited retinal diseases in Israel as assessed by the Israeli inherited retinal disease consortium (IIRDC)

Inherited retinal diseases (IRDs) cause visual loss due to dysfunction or progressive degeneration of photoreceptors. These diseases show marked phenotypic and genetic heterogeneity. The Israeli IRD consortium (IIRDC) was established in 2013 with the goal of performing clinical and genetic mapping of the majority of Israeli IRD patients. To date, we recruited 2,420 families including 3,413 individuals with IRDs. On the basis of our estimation, these patients represent approximately 40% of Israeli IRD patients. To the best of our knowledge, this is, by far, the largest reported IRD cohort, and one of the first studies addressing the genetic analysis of IRD patients on a nationwide scale. The most common inheritance pattern in our cohort is autosomal recessive (60% of families). The most common retinal phenotype is retinitis pigmentosa (43%), followed by Stargardt disease and cone/cone-rod dystrophy. We identified the cause of disease in 56% of the families. Overall, 605 distinct mutations were identified, of which 12% represent prevalent founder mutations. The most frequently mutated genes were ABCA4, USH2A, FAM161A, CNGA3, and EYS. The results of this study have important implications for molecular diagnosis, genetic screening, and counseling, as well as for the development of new therapeutic strategies for retinal diseases.

[THE ISRAELI INHERITED RETINAL DISEASES CONSORTIUM (IIRDC)- CLINICAL-GENETIC MAPPING AND FUTURE PERSPECTIVES]

INTRODUCTION

The sense of vision is highly important for humans and its loss markedly affects function and quality of life. Many inherited retinal diseases (IRDs) cause visual loss due to dysfunction or progressive degeneration of photoreceptor cells. These diseases show clinical and genetic heterogeneity.

AIMS

The Israeli IRD consortium (IIRDC) was established with the goal of performing clinical and genetic mapping of IRDs in the Israeli population.

METHODS

Clinical evaluation is carried out at electroretinography (ERG) centers and ophthalmology departments, where the patients undergo a comprehensive eye exam, including testing of visual acuity, refractive error, imaging techniques and ERG tests. Genetic analysis is performed using Sanger sequencing, analysis of founder mutations, and whole exome sequencing.

RESULTS

We recruited over 2,000 families including more than 3,000 individuals with IRDs. The most common inheritance pattern is autosomal recessive (65% of families). The most common retinal phenotype is retinitis pigmentosa (RP- 45% of families), followed by cone/cone-rod dystrophy, Stargardt Disease and Usher syndrome. We identified the cause of disease in 51% of families, mainly due to mutations in ABCA4, USH2A, FAM161A, CNGA3, and EYS. IIRDC researchers were involved in the identification of 16 novel IRD genes. In parallel, IIRDC members are involved in the development of therapeutic modalities for these currently incurable diseases.

CONCLUSIONS

IIRDC works in close collaborative efforts aiming to continue and recruit for the genotype - phenotype study from the vast majority of Israeli IRD families, to identify all disease-causing mutations, and to tailor therapeutic interventions to each IRD patient.

Ocular Phenotype of a Family with FAM161A-associated Retinal Degeneration

BACKGROUND

Characterization of retinal degeneration (RD) using high-resolution retinal imaging and exome sequencing may identify phenotypic features that correspond with specific genetic defects.

MATERIALS AND METHODS

Six members from a non-consanguineous Indian family (three affected siblings, their asymptomatic parents and an asymptomatic child) were characterized clinically, using visual acuity, perimetry, full-field electroretinography (ERG), optical coherence tomography and cone structure as outcome measures. Cone photoreceptors were imaged in the proband using adaptive optics scanning laser ophthalmoscopy. The exome was captured using Nimblegen SeqCap EZ V3.0 probes and sequenced using lllumina HiSeq. Reads were mapped to reference hg19. Confirmation of variants and segregation analysis was performed using dideoxy sequencing.

RESULTS

Analysis of exome variants using exomeSuite identified five homozygous variants in four genes known to be associated with RD. Further analysis revealed a homozygous nonsense mutation, c.1105 C > T, p.Arg335Ter, in the FAM161A gene segregating with RD. Three additional variants were found to occur at high frequency. Affected members showed a range of disease severity beginning at different ages, but all developed severe visual field and outer retinal loss.

CONCLUSIONS

Exome analysis revealed a nonsense homozygous mutation in FAM161A segregating with RD with severe vision loss and a range of disease onset and progression. Loss of outer retinal structures demonstrated with high-resolution retinal imaging suggests FAM161A is important for normal photoreceptor structure and survival. Exome sequencing may identify causative genetic variants in autosomal recessive RD families when other genetic test strategies fail to identify a mutation.

Identification of a novel mutation in the CDHR1 gene in a family with recessive retinal degeneration

OBJECTIVES

To describe the clinical phenotype and identify the molecular basis of disease in a consanguineous family of Palestinian origin with autosomal recessive retinal degeneration.

METHODS

Eight family members were evaluated with visual acuity and perimetry tests, color fundus photographs, full-field electroretinography, and optical coherence tomography. Cone photoreceptors surrounding the fovea were imaged in 2 members, using adaptive optics scanning laser ophthalmoscopy. Exome was captured using probes and sequenced. Readings were mapped to reference hg19. Variant calls and annotations were performed, using published protocols. Confirmation of variants and segregation analysis was performed using dideoxy sequencing.

RESULTS

Analysis detected 24 037 single-nucleotide variants in one affected family member, of which 3622 were rare and potentially damaging to encoded proteins. Further analysis revealed a novel homozygous nonsense change, c.1381 C>T, p.Gln461X in exon 13 of the CDHR1 gene, which segregated with retinal degeneration in this family. Affected members had night blindness beginning during adolescence with progressive visual acuity and field loss and unmeasurable electroretinographic responses, as well as macular outer retinal loss, although residual cones with increased cone spacing were observed in the youngest individual.

CONCLUSIONS

Exome analysis revealed a novel CDHR1 nonsense mutation segregating with progressive retinal degeneration causing severe central vision loss by the fourth decade of life. High-resolution retinal imaging revealed outer retinal changes suggesting that CDHR1 is important for normal photoreceptor structure and survival.

CLINICAL RELEVANCE

Exome sequencing is a powerful technique that may identify causative genetic variants in families with autosomal recessive retinal degeneration.

Repeated noninfectious endophthalmitis after intravitreal administration of bevacizumab: a report of two cases

PURPOSE

To report on two patients with sterile endophthalmitis recurring twice after intravitreal bevacizumab injection.

METHODS

Two cases of sterile intraocular inflammation recurring after repeated intravitreal injections of bevacizumab are described, followed by a review of the literature.

RESULTS

Two patients presented with painful eyes and decreased vision associated with endophthalmitis several days after intravitreal bevacizumab injection. In both patients, vitreous specimens were sterile. The intraocular inflammation recurred after additional intravitreal injection of bevacizumab that was performed during subsequent follow-up.

CONCLUSION

This is the first report of sterile intraocular inflammation recurring after repeated intravitreal injections of bevacizumab. Awareness of the possible association between bevacizumab administration and sterile endophthalmitis may be warranted.