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Kruijt CC, de Wit GC, van Minderhout HM, Schalij-Delfos NE, van Genderen MM. Clinical and mutational characteristics of oculocutaneous albinism type 7. Sci Rep 2024; 14:7572. [PMID: 38555393 PMCID: PMC10981718 DOI: 10.1038/s41598-024-57969-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/23/2024] [Indexed: 04/02/2024] Open
Abstract
The purpose of this paper is to expand on the phenotype of oculocutaneous albinism type 7 (OCA7). We described three patients with OCA7: two from a consanguineous family of Kurdish origin and one patient of Dutch origin. We compared them with all patients described to date in the literature. All newly described patients had severely reduced visual acuity (VA), nystagmus, hypopigmentation of the fundus, severe foveal hypoplasia, and chiasmal misrouting. None had iris translucency. All patients had normal pigmentation of skin and hair. We found one novel mutation in the Dutch patient: c.565G > A; p.(Gly189Ser). We compared our patients to the 15 described in the literature to date. All 18 patients had substantially pigmented skin and hair, very poor VA (0.4-1.3 logMAR), nystagmus, (mild) ocular hypopigmentation, foveal hypoplasia, and misrouting. Although pigmentation levels were mildly affected in OCA7, patients had a severe ocular phenotype with VA at the poorer end of the albinism spectrum, severe foveal hypoplasia, and chiasmal misrouting. OCA7 patients had a phenotype restricted to the eyes, and similar to that of X-linked ocular albinism. We therefore propose to rename the disorder in ocular albinism type 2. Unfolding the role of LRMDA in OCA7, may bring us a step closer in identifying the responsible factors for the co-occurrence of foveal hypoplasia and misrouting.
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Affiliation(s)
- C C Kruijt
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.
- Department of Ophthalmology, Leiden University Medical Center, J3-S, Albinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - G C de Wit
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - H M van Minderhout
- Department of Ophthalmology, Medical Center Haaglanden, The Hague, The Netherlands
| | - N E Schalij-Delfos
- Department of Ophthalmology, Leiden University Medical Center, J3-S, Albinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - M M van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
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2
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Ren X, Huang L, Cheng S, Wang J, Li N. Novel pathogenic variants of SLC38A8 gene and literature review. Eur J Ophthalmol 2024:11206721241242155. [PMID: 38515398 DOI: 10.1177/11206721241242155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
PURPOSE This study aimed to analyze the clinical and genetic characteristics of 6 Chinese patients with foveal hypoplasia (FH) caused by the variants of solute carrier family 38 member 8 (SLC38A8), and to describe the genotype and phenotype of SLC38A8 variants from previous literature. METHODS All subjects underwent comprehensive ophthalmic examinations. Optical coherence tomography (OCT) was performed to evaluate the structural grade of FH. Pathogenic variants of SLC38A8 gene were identified using panel-based next-generation sequencing and direct Sanger sequencing techniques. Further, all previously reported cases of SLC38A8 variants were re-analyzed together with the novel ones identified in this study. RESULTS Nystagmus and FH were present in 6 patients with variants of SLC38A8 gene, accompanied by a normal anterior segment. Grade 4 FH was identified in 4 patients. A total of 12 variants of SLC38A8 gene were identified, including 9 novel variants. Systematical analysis revealed that half of the variants (30/60) were missense, the majority of which (23/30) were distributed in the transmembrane (TM) domains. Grade 4 FH was detected in the majority of patients (66%, 23/35). There was no statistical difference in the clinical features between the subgroups of patients with 0, 1 and 2 missense variants. CONCLUSION Severe arrest of foveal development was identified in patients with variants of SLC38A8. This study provides a brief summary of the clinical and genetic characteristics of the pathogenic SLC38A8 variants, which is helpful in the differentiation diagnosis of FH.
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Affiliation(s)
- Xiaofang Ren
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56 Nanlishi Road, Xicheng District, Beijing, 100040, China
| | - Lijuan Huang
- Department of Ophthalmology, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, 362000, China
| | - Shan Cheng
- Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Jing Wang
- Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Ningdong Li
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56 Nanlishi Road, Xicheng District, Beijing, 100040, China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, National Clinical Research Center for Eye Diseases, Shanghai, China
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Proudlock FA, McLean RJ, Sheth V, Ather S, Gottlob I. Phenotypic Features Determining Visual Acuity in Albinism and the Role of Amblyogenic Factors. Invest Ophthalmol Vis Sci 2024; 65:14. [PMID: 38319667 PMCID: PMC10854414 DOI: 10.1167/iovs.65.2.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/05/2024] [Indexed: 02/07/2024] Open
Abstract
Albinism is a spectrum disorder causing foveal hypoplasia, nystagmus, and hypopigmentation of the iris and fundus along with other visual deficits, which can all impact vision. Albinism is also associated with amblyogenic factors which could affect monocular visual acuity. The foveal appearance in albinism can range from mild foveal hypoplasia to that which is indistinguishable from the peripheral retina. The appearance can be quickly and easily graded using the Leicester Grading System in the clinic. However, interquartile ranges of 0.3 logMAR for the grades associated with albinism limit the accuracy of the grading system in predicting vision. Here, we discuss the potential role of nystagmus presenting evidence that it may not be a major source of variability in the prediction of visual acuity. We also show that interocular differences in visual acuity are low in albinism despite high levels of amblyogenic factors indicating that active suppression of vision in one eye in albinism is uncommon.
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Affiliation(s)
- Frank A Proudlock
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Rebecca J McLean
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Viral Sheth
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
- Health Sciences School, University of Sheffield, Sheffield, Yorkshire, United Kingdom
| | - Sarim Ather
- Oxford University Hospitals NHS Foundation Trust, Headley Way, Headington, Oxfordshire, United Kingdom
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
- Department of Neurology, Cooper University Health Care, Cooper Medical School of Rowan University, Camden, New Jersey, United States
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Shoji MK, Khodeiry MM, Sengillo JD, Mendoza C. Expanding the mutational spectrum of FHONDA syndrome. Ophthalmic Genet 2023; 44:602-605. [PMID: 36748941 DOI: 10.1080/13816810.2023.2175873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/09/2023] [Accepted: 01/29/2023] [Indexed: 02/08/2023]
Abstract
AIM The aim of the study is to present a rare case of Foveal Hypoplasia, Optic Nerve Decussation defects, and Anterior segment dysgenesis (FHONDA) confirmed by genetic testing with two separate pathogenic mutations in the SLC38A8 gene. MATERIALS AND METHODS This was a case report. RESULTS A 3-month-old female presented to a neuro-ophthalmology clinic with nystagmus. Her past medical and family history was unremarkable. Her examination demonstrated horizontal pendular nystagmus and small optic nerves with foveal hypoplasia bilaterally. Neuroimaging was unremarkable. She underwent an examination under anesthesia and electroretinogram (ERG). Her anterior segment examination was normal, and dilated fundus examination demonstrated foveal hypoplasia with diffuse pigment granularity. The ERG was normal. Genetic testing revealed two mutations in the SLC38A8 gene, p.Glu233Lys:c.697 G>A (pathogenic) and p.Asp283Ala:c.848A>C (likely pathogenic) with positive parental segregation analysis. Therefore, she was diagnosed with FHONDA. CONCLUSIONS To our knowledge, this is the first report of a patient with FHONDA who is compound heterozygous for these two SLC38A8 mutations, which represents an expansion of the known mutational spectrum associated with this syndrome. Moreover, it may provide guidance into genetic counseling for patients and parents with these mutations.
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Affiliation(s)
- Marissa K Shoji
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
| | | | - Jesse D Sengillo
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
| | - Carlos Mendoza
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA
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Guardia A, Fernández A, Seruggia D, Chotard V, Sánchez-Castillo C, Kutsyr O, Sánchez-Sáez X, Zurita E, Cantero M, Rebsam A, Cuenca N, Montoliu L. A Slc38a8 Mouse Model of FHONDA Syndrome Faithfully Recapitulates the Visual Deficits of Albinism Without Pigmentation Defects. Invest Ophthalmol Vis Sci 2023; 64:32. [PMID: 37862028 PMCID: PMC10599165 DOI: 10.1167/iovs.64.13.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/02/2023] [Indexed: 10/21/2023] Open
Abstract
Purpose We aimed to generate and phenotype a mouse model of foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA), a rare disease associated with mutations in Slc38a8 that causes severe visual alterations similar to albinism without affecting pigmentation. Methods The FHONDA mouse model was generated with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology using an RNA guide targeting the Scl38a8 murine locus. The resulting mice were backcrossed to C57BL/6J. Melanin content was measured using spectrophotometry. Retinal cell architecture was analyzed through light and electron microscopy. Retinal projections to the brain were evaluated with anterograde labelling in embryos and adults. Visual function was assessed by electroretinography (ERG) and the optomotor test (OT). Results From numerous Slc38a8 mouse mutant alleles generated, we selected one that encodes a truncated protein (p.196Pro*, equivalent to p.199Pro* in the human protein) closely resembling a mutant allele described in patients (p.200Gln*). Slc38a8 mutant mice exhibit wild-type eye and coat pigmentation with comparable melanin content. Subcellular abnormalities were observed in retinal pigment epithelium cells of Slc38a8 mutant mice. Anterograde labeling experiments of retinal projections in embryos and adults showed a reduction of ipsilateral fibers. Functional visual analyses revealed a decreased ERG response in scotopic conditions and a reduction of visual acuity in mutant mice measured by OT. Conclusions Slc38a8 mutant mice recapitulate the phenotype of patients with FHONDA concerning their normal pigmentation and their abnormal visual system, in the latter being a hallmark of all types of albinism. These mice will be helpful in better understanding the pathophysiology of this genetic condition.
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Affiliation(s)
- Ana Guardia
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Almudena Fernández
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Davide Seruggia
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Virginie Chotard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Carla Sánchez-Castillo
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Oksana Kutsyr
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Xavier Sánchez-Sáez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Esther Zurita
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Marta Cantero
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
| | - Alexandra Rebsam
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Lluís Montoliu
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER-ISCIII), Madrid, Spain
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Seguy PH, Korobelnik JF, Delyfer MN, Michaud V, Arveiler B, Lasseaux E, Gattoussi S, Rougier MB, Trin K, Morice-Picard F, Ghomashchi N, Coste V. Ophthalmologic Phenotype-Genotype Correlations in Patients With Oculocutaneous Albinism Followed in a Reference Center. Invest Ophthalmol Vis Sci 2023; 64:26. [PMID: 37707835 PMCID: PMC10506686 DOI: 10.1167/iovs.64.12.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/27/2023] [Indexed: 09/15/2023] Open
Abstract
Purpose Albinism is a group of genetic disorders that includes several conditions related to a defect in melanin production. There is a broad phenotypic and genotypic variability between the different forms. The aim of this study was to assess the ophthalmologic characteristics according to patients' genotypes in a cohort followed in the Reference Center for oculocutaneous albinism (OCA) of Bordeaux University Hospital, France. Methods A retrospective observational study was conducted in a cohort of patients with OCA seen in consultation in the ophthalmology department between 2017 and 2021 in whom a genetic analysis was performed. Results In total, 127 patients with OCA were included in this study and matched with the results of the genetic analysis. In the population aged over 6 years, there was no statistical difference in binocular visual acuity between the OCA1, OCA2, and OCA4 forms (P = 0.27). There was difference in ametropia between the three forms (P = 0.003). A two-by-two comparison using the Bonferroni correction showed a significant difference in ametropia between the OCA2 and OCA4 forms (P = 0.007) and between the OCA1 and OCA2 forms (P = 0.0075). Regardless of the form, most patients (75.4%) had grade 4 foveal hypoplasia. There was no association between the grade of foveal hypoplasia and the gene involved (P = 0.87). Conclusions We described a genotype-phenotype correlation for the three most represented forms of albinism in our cohort. This study allowed assessing the degree of visual deficiency in young children with OCA.
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Affiliation(s)
| | - Jean-François Korobelnik
- Ophthalmology Department, CHU Bordeaux, Bordeaux, France
- Inserm, Bordeaux Population Health Research Center, Team LEHA, Université de Bordeaux, Bordeaux, France
| | - Marie-Noëlle Delyfer
- Ophthalmology Department, CHU Bordeaux, Bordeaux, France
- Inserm, Bordeaux Population Health Research Center, Team LEHA, Université de Bordeaux, Bordeaux, France
| | - Vincent Michaud
- Medical Genetics Department, CHU Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, Université de Bordeaux, Bordeaux, France
| | - Benoit Arveiler
- Medical Genetics Department, CHU Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, Université de Bordeaux, Bordeaux, France
| | | | | | | | - Kilian Trin
- Department of Pharmacology Medical, Bordeaux Regional Pharmacovigilance, Bordeaux University Hospital, Bordeaux, France
| | - Fanny Morice-Picard
- Department of Dermatology and Pediatric Dermatology, National Reference Centre for Rare Disorders, Hôpital des Enfants Pellegrin, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
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7
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The retinal pigmentation pathway in human albinism: Not so black and white. Prog Retin Eye Res 2022; 91:101091. [PMID: 35729001 DOI: 10.1016/j.preteyeres.2022.101091] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 12/16/2022]
Abstract
Albinism is a pigment disorder affecting eye, skin and/or hair. Patients usually have decreased melanin in affected tissues and suffer from severe visual abnormalities, including foveal hypoplasia and chiasmal misrouting. Combining our data with those of the literature, we propose a single functional genetic retinal signalling pathway that includes all 22 currently known human albinism disease genes. We hypothesise that defects affecting the genesis or function of different intra-cellular organelles, including melanosomes, cause syndromic forms of albinism (Hermansky-Pudlak (HPS) and Chediak-Higashi syndrome (CHS)). We put forward that specific melanosome impairments cause different forms of oculocutaneous albinism (OCA1-8). Further, we incorporate GPR143 that has been implicated in ocular albinism (OA1), characterised by a phenotype limited to the eye. Finally, we include the SLC38A8-associated disorder FHONDA that causes an even more restricted "albinism-related" ocular phenotype with foveal hypoplasia and chiasmal misrouting but without pigmentation defects. We propose the following retinal pigmentation pathway, with increasingly specific genetic and cellular defects causing an increasingly specific ocular phenotype: (HPS1-11/CHS: syndromic forms of albinism)-(OCA1-8: OCA)-(GPR143: OA1)-(SLC38A8: FHONDA). Beyond disease genes involvement, we also evaluate a range of (candidate) regulatory and signalling mechanisms affecting the activity of the pathway in retinal development, retinal pigmentation and albinism. We further suggest that the proposed pigmentation pathway is also involved in other retinal disorders, such as age-related macular degeneration. The hypotheses put forward in this report provide a framework for further systematic studies in albinism and melanin pigmentation disorders.
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Neveu MM, Padhy SK, Ramamurthy S, Takkar B, Jalali S, Cp D, Padhi TR, Robson AG. Ophthalmological Manifestations of Oculocutaneous and Ocular Albinism: Current Perspectives. Clin Ophthalmol 2022; 16:1569-1587. [PMID: 35637898 PMCID: PMC9148211 DOI: 10.2147/opth.s329282] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/14/2022] [Indexed: 11/23/2022] Open
Abstract
Albinism describes a heterogeneous group of genetically determined disorders characterized by disrupted synthesis of melanin and a range of developmental ocular abnormalities. The main ocular features common to both oculocutaneous albinism (OCA), and ocular albinism (OA) include reduced visual acuity, refractive errors, foveal hypoplasia, congenital nystagmus, iris and fundus hypopigmentation and visual pathway misrouting, but clinical signs vary and there is phenotypic overlap with other pathologies. This study reviews the prevalence, genetics and ocular manifestations of OCA and OA, including abnormal development of the optic chiasm. The role of visual electrophysiology in the detection of chiasmal dysfunction and visual pathway misrouting is emphasized, highlighting how age-associated changes in visual evoked potential (VEP) test results must be considered to enable accurate diagnosis, and illustrated further by the inclusion of novel VEP data in genetically confirmed cases. Differential diagnosis is considered in the context of suspected retinal and other disorders, including rare syndromes that may masquerade as albinism.
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Affiliation(s)
- Magella M Neveu
- Department Electrophysiology, Moorfields Eye Hospital, London, EC1V 2PD, UK.,Institute of Ophthalmology, University College London, London, UK
| | | | | | - Brijesh Takkar
- Anant Bajaj Retina Institute, LV Prasad Eye Institute, Hyderabad, India
| | - Subhadra Jalali
- Anant Bajaj Retina Institute, LV Prasad Eye Institute, Hyderabad, India
| | - Deepika Cp
- Anant Bajaj Retina Institute, LV Prasad Eye Institute, Hyderabad, India
| | - Tapas Ranjan Padhi
- Anant Bajaj Retina Institute, LV Prasad Eye Institute, Bhubaneswar, India
| | - Anthony G Robson
- Department Electrophysiology, Moorfields Eye Hospital, London, EC1V 2PD, UK.,Institute of Ophthalmology, University College London, London, UK
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Toufeeq S, Gottlob I, Tu Z, Proudlock FA, Pilat A. Abnormal Retinal Vessel Architecture in Albinism and Idiopathic Infantile Nystagmus. Invest Ophthalmol Vis Sci 2022; 63:33. [PMID: 35616929 PMCID: PMC9150830 DOI: 10.1167/iovs.63.5.33] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Infantile nystagmus syndrome (INS) causes altered visual development and can be associated with abnormal retinal structure, to which vascular development of the retina is closely related. Abnormal retinal vasculature has previously been noted in albinism but not idiopathic infantile nystagmus. We compared the number and diameter of retinal vessels in participants with albinism (PWA) and idiopathic infantile nystagmus (PWIIN) with controls. Methods Fundus photography data from 24 PWA, 10 PWIIN, and 34 controls was analyzed using Automated Retinal Image Analyzer (ARIA) software on a field of analysis centered on the optic disc, the annulus of which extended between 4.2 mm and 8.4 mm in diameter. Results Compared with controls, the mean number of arterial branches was reduced by 24% in PWA (15.5 vs. 20.3, P < 0.001), and venous branches were reduced in both PWA (29%; 12.9 vs. 18.2, P < 0.001) and PWIIN (17%; 15.1 vs. 18.2, P = 0.024). PWA demonstrated 7% thinner "primary" (before branching) arteries (mean diameter: 75.39 µm vs. 80.88 µm, P = 0.043), and 13% thicker (after branching) "secondary" veins (66.72 µm vs. 59.01 µm in controls, P = 0.009). Conclusions PWA and PWIIN demonstrated reduced retinal vessel counts and arterial diameters compared with controls. These changes in the superficial retinal vascular network may be secondary to underdevelopment of the neuronal network, which guides vascular development and is also known to be disrupted in INS.
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Affiliation(s)
- Shafak Toufeeq
- Oxford Eye Hospital, Level LG1 John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, United Kingdom
| | - Irene Gottlob
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Zhanhan Tu
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Frank A. Proudlock
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Anastasia Pilat
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
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