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Clinical & Experimental Optometry Sep 2017Ocular pathology that manifests at an early age has the potential to alter the vision-dependent emmetropisation mechanism, which co-ordinates ocular growth throughout... (Review)
Review
Ocular pathology that manifests at an early age has the potential to alter the vision-dependent emmetropisation mechanism, which co-ordinates ocular growth throughout childhood. The disruption of this feedback mechanism in children with congenital or early-onset visual impairment often results in the development of significant ametropia, including high levels of spherical refractive error, astigmatism and anisometropia. This review examines the use of contact lenses as a refractive correction, low vision aid and therapeutic intervention in the rehabilitation of patients with bilateral, irreversible visual loss due to congenital ocular disease. The advantages and disadvantages of the use of contact lenses for increased magnification (telescopes and microscopes) or field expansion (reverse telescopes) are discussed, along with the benefits and practical considerations for the correction of pathological high myopia. The historical and present use of therapeutic tinted contact lenses to reduce photosensitivity and nystagmus in achromatopsia, albinism and aniridia are also presented, including clinical considerations for the contact lens practitioner. In addition to the known optical benefits in comparison to spectacles for high levels of ametropia (an improved field of view for myopes and fewer inherent oblique aberrations), contact lenses may be of significant psycho-social benefit for patients with low vision, due to enhanced cosmesis and reduced conspicuity and potential related effects of improved self-esteem and peer acceptance. The contact lens correction of patients with congenital vision impairment can be challenging for both practitioner and patient but should be considered as a potential optical or therapeutic solution in modern low vision rehabilitation.
Topics: Contact Lenses; Humans; Optics and Photonics; Refractive Errors; Vision, Low
PubMed: 28664572
DOI: 10.1111/cxo.12562 -
Indian Journal of Ophthalmology May 2023
Topics: Humans; Albinism, Ocular; Retina; Visual Acuity; Choroid
PubMed: 37203002
DOI: 10.4103/IJO.IJO_3182_22 -
European Journal of Ophthalmology May 2024The association between Autism spectrum disorders (ASD) and visual impairment has been mentioned in the literature. The aim of our study was to investigate the...
BACKGROUND
The association between Autism spectrum disorders (ASD) and visual impairment has been mentioned in the literature. The aim of our study was to investigate the prevalence of autism among children with albinism compared to the prevalence of ASD in children with visual impairment secondary to other causes.
METHODS
Retrospective study of children with albinism from January 2015 to December 2020. A control group was created with children with early onset visual impairment of similar visual range and age, secondary to diagnosis other than albinism. Patients with associated Autism were identified in both groups.
RESULTS
Seven hundred and eight children aged 1-18 years with visual impairment were included in the study. 401 children had a diagnosis of albinism, of whom 14 were also diagnosed with ASD. In the control group, composed of 307 patients, only 3 had ASD (p: 0·03).
CONCLUSIONS
The prevalence of ASD in patients with albinism was 1 in 28, while in children with visual impairment from other causes was 1 in 102. We aim to raise awareness of the higher prevalence of autism in children diagnosed with albinism in order to reach earlier diagnosis and support.
Topics: Humans; Retrospective Studies; Child; Prevalence; Male; Female; Child, Preschool; Adolescent; Infant; Visual Acuity; Albinism, Ocular; Autism Spectrum Disorder
PubMed: 37787167
DOI: 10.1177/11206721231206091 -
Investigative Ophthalmology & Visual... Mar 2020To test whether ganglion cell layer (GCL) and inner plexiform layer (IPL) topography is altered in albinism.
PURPOSE
To test whether ganglion cell layer (GCL) and inner plexiform layer (IPL) topography is altered in albinism.
METHODS
Optical coherence tomography scans were analyzed in 30 participants with albinism and 25 control participants. Horizontal and vertical line scans were acquired at the fovea, then strip registered and averaged. The Duke Optical Coherence Tomography Retinal Analysis Program was used to automatically segment the combined GCL and IPL and total retinal thickness, followed by program-assisted manual segmentation of the boundary between the GCL and IPL. Layer thickness and area under the curve (AUC) were calculated within 2.5 mm of the fovea. Nasal-temporal and superior-inferior asymmetry were calculated as an AUC ratio in each quadrant.
RESULTS
GCL and IPL topography varied between participants. The summed AUC in all quadrants was similar between groups for both the GCL (P = 0.84) and IPL (P = 0.08). Both groups showed nasal-temporal asymmetry in the GCL, but only participants with albinism had nasal-temporal asymmetry in the IPL. Nasal-temporal asymmetry was greater in albinism for both the GCL (P < 0.0001) and the IPL (P = 0.0006). The GCL usually comprised a greater percentage of the combined GCL and IPL in controls than in albinism.
CONCLUSIONS
The GCL and IPL have greater structural variability than previously reported. GCL and IPL topography are significantly altered in albinism, which suggests differences in the spatial distribution of retinal ganglion cells. This finding provides insight into foveal development and structure-function relationships in foveal hypoplasia.
Topics: Adolescent; Adult; Albinism, Ocular; Algorithms; Area Under Curve; Case-Control Studies; Child; Female; Humans; Image Processing, Computer-Assisted; Intraocular Pressure; Male; Nerve Fibers; Observer Variation; Retinal Ganglion Cells; Tomography, Optical Coherence; Visual Fields; Young Adult
PubMed: 32196097
DOI: 10.1167/iovs.61.3.36 -
Ophthalmology. Retina May 2024
PubMed: 38739070
DOI: 10.1016/j.oret.2024.04.011 -
Frontiers in Physiology 2019The ocular albinism type 1 (OA1), a pigment cell-specific integral membrane glycoprotein, is a member of the G-protein-coupled receptor (GPCR) superfamily that binds to...
The ocular albinism type 1 (OA1), a pigment cell-specific integral membrane glycoprotein, is a member of the G-protein-coupled receptor (GPCR) superfamily that binds to heterotrimeric G proteins in mammalian cells. We aimed to characterize the physiological functions an insect OA1 from () employs in the regulation of insecticide tolerance. In the present study, we investigated the roles of in response to deltamethrin exposure in both and . was expressed at the lowest level during the 4 instar stage, while was significantly upregulated in the 5 instar and male stages. Knockdown of by injecting dsRNA of into gypsy moth larvae caused a 4.80-fold higher mortality than in control larvae microinjected with dsRNA of under deltamethrin stress. Nine out of 11 genes were significantly downregulated under deltamethrin stress in silenced larvae as compared to control larvae. Moreover, the gene was successfully overexpressed in using transgenic technique. The deltamethrin contact assay showed that the overexpression in flies significantly enhanced the tolerance to deltamethrin compared to the control flies. Furthermore, the downstream CYP genes were upregulated in the overexpression flies, suggesting may play a master switch role in P450-mediated metabolic detoxification. This study is the first report of an insect OA1 gene regulating insecticide tolerance and potentially playing a role in the regulation of downstream cytochrome P450 expression. These results contribute to the future development of novel insecticides targeting insect GPCRs.
PubMed: 31275171
DOI: 10.3389/fphys.2019.00766 -
Presse Medicale (Paris, France : 1983) 2017Albinism is a genetic disease affecting 1/17,000 person worldwide. It constitutes the second cause of congenital loss of visual acuity after optic atrophy. Albinism is...
Albinism is a genetic disease affecting 1/17,000 person worldwide. It constitutes the second cause of congenital loss of visual acuity after optic atrophy. Albinism is heterogeneous both at the clinical and genetic levels. It is characterized by ocular development anomalies and by a variable degree of hypopigmentation. Clinically, three forms of the disease are described: oculocutaneous, ocular and syndromic (Hermansky-Pudlak syndrome, Chediak-Higashi syndrome). Nineteen genes involved in the different types of albinism have been described so far. The broad phenotypic variability between the different forms but also within a particular form renders the establishment of phenotype-genotype correlations impossible. A genetic test exploring all 19 genes is necessary to establish the diagnosis and to distinguish between syndromic and non-syndromic forms. We present the creation of an albinism-dedicated Day Hospital at the University Hospital of Bordeaux.
Topics: Albinism; Chediak-Higashi Syndrome; Genetic Testing; Humans; Mutation; Photophobia; Vision Disorders
PubMed: 28734636
DOI: 10.1016/j.lpm.2017.05.020 -
Scientific Reports Feb 2017X-linked ocular albinism (OA1) is an X-linked inherited disease characterized by hypopigmentation of the fundus and nystagmus. Our study performed mutation analysis of...
X-linked ocular albinism (OA1) is an X-linked inherited disease characterized by hypopigmentation of the fundus and nystagmus. Our study performed mutation analysis of the G protein-coupled receptor 143 gene (GPR143) and assessed the clinical characteristics of OA1 in three Chinese families. Three novel mutations, c.333_360+14del42insCTT, c.276G>A (p.W92X), and c.793C>T (p.R265X), were identified in GPR143 by PCR followed by Sanger sequencing in these families. All affected individuals presented with nystagmus, photophobia, poor visual acuity, foveal hypoplasia and varying degrees of hypopigmentation of the fundus. The fundus of female carriers showed pigmented streaks alternating with hypopigmented streaks. These results allowed us to expand the spectrum of mutations in GPR143 and phenotypes associated with ocular albinism.
Topics: Albinism, Ocular; Asian People; DNA Mutational Analysis; Eye Proteins; Family Health; Humans; Membrane Glycoproteins; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Sequence Analysis, DNA
PubMed: 28211458
DOI: 10.1038/srep33713 -
Retina (Philadelphia, Pa.) May 2018To investigate the clinical features in carriers of X-linked retinitis pigmentosa, X-linked ocular albinism, and choroideremia (CHM) using multimodal imaging and to... (Observational Study)
Observational Study
PURPOSE
To investigate the clinical features in carriers of X-linked retinitis pigmentosa, X-linked ocular albinism, and choroideremia (CHM) using multimodal imaging and to assess their diagnostic value in these three mosaic retinopathies.
METHODS
We prospectively examined 14 carriers of 3 X-linked recessive disorders (X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM). Details of abnormalities of retinal morphology were evaluated using fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain optical coherence tomography.
RESULTS
In six X-linked retinitis pigmentosa carriers, fundus appearance varied from unremarkable to the presence of tapetal-like reflex and pigmentary changes. On FAF imaging, all carriers exhibited a bright radial reflex against a dark background. By spectral domain optical coherence tomography, loss of the ellipsoid zone in the macula was observed in 3 carriers (50%). Regarding the retinal laminar architecture, 4 carriers (66.7%) showed thinning of the outer nuclear layer and a dentate appearance of the outer plexiform layer. All five X-linked ocular albinism carriers showed a characteristic mud-splatter patterned fundus, dark radial streaks against a bright background on FAF imaging, and a normal-appearing retinal structure by spectral domain optical coherence tomography imaging. Two of the 3 CHM carriers (66.7%) showed a diffuse moth-eaten appearance of the fundus, and all 3 showed irregular hyper-FAF and hypo-FAF spots throughout the affected area. In the CHM carriers, the structural changes observed by spectral domain optical coherence tomography imaging were variable.
CONCLUSION
Our findings in an Asian cohort suggest that FAF imaging is a practical diagnostic test for differentiating X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM carriers. Wide-field FAF is an easy and helpful adjunct to testing for the correct diagnosis and identification of lyonization in carriers of these three mosaic retinopathies.
Topics: Adult; Albinism, Ocular; Child; Child, Preschool; Choroideremia; Diagnostic Techniques, Ophthalmological; Female; Fluorescein Angiography; Genetic Carrier Screening; Genetic Diseases, X-Linked; Humans; Male; Middle Aged; Multimodal Imaging; Prospective Studies; Retinitis Pigmentosa; Tomography, Optical Coherence; Young Adult
PubMed: 28376043
DOI: 10.1097/IAE.0000000000001629 -
Documenta Ophthalmologica. Advances in... Aug 2019Albinism patients have poor visual acuity in addition to hypopigmentation. Their foveal anatomy is abnormal, but correlation with function is incompletely understood....
BACKGROUND
Albinism patients have poor visual acuity in addition to hypopigmentation. Their foveal anatomy is abnormal, but correlation with function is incompletely understood. This study correlates retinal electrophysiology, visual acuity and optical coherence tomography (OCT) anatomy in albinism patients and compares with age-similar controls.
METHODS
Institutional Review Board approval was obtained (IRB# 201408782). Patients were recruited from clinical practice. Inclusion criteria were at least three clinical features of albinism including iris transillumination, nystagmus, fundus hypopigmentation, or foveal hypoplasia on OCT and/or molecular genetic confirmation. Diagnosys (Lowell, Mass) full-field ERG (ffERG) and VERIS multifocal ERG (mfERG; Electro-Diagnostic Imaging, Milpitas, California) were obtained using standard International Society for Clinical Electrophysiology of Vision protocols. The mfERG protocol was a 4-min 103-hexagon protocol covering approximately 40° in diameter of central retina. Control subjects without albinism were recruited by in-hospital notices and invitations in clinic. OCT central thickness was recorded, and an OCT foveal score was calculated. Nonparametric permutation testing was utilized to determine the statistical significance.
RESULTS
A total of 16 albinism patients and 19 age-similar controls were recruited. Four of 16 albinism patients had no nystagmus. Seventeen non-albinism controls had no ocular disorder other than refractive error. Two controls had infantile nystagmus with normal maculas on OCT. There was no statistically significant difference in mfERG amplitude or latency between albinism patients with or without nystagmus (lowest p = 0.68; 0.54, respectively). mfERG: 12 of 16 (75%) albinism patients had average ring 1 amplitudes within one standard deviation of controls despite having abnormal foveal anatomy on OCT. Patients averaged shorter latencies in rings 1 and 2 than controls (p = 0.005, p = 0.02). Patients averaged higher amplitudes than controls in rings 4, 5 and 6 (p = 0.03, p = 0.006, p = 0.004). There was no significant correlation between visual acuity and mfERG amplitudes in any ring (smallest p = 0.15). ffERG: Patients averaged higher amplitudes on 30 Hz flicker (p = 0.008). In all conditions, albinism patients had higher amplitude a-waves (p ≤ 0.03). B-waves were higher amplitude than controls in light-adapted 3.0 (p = 0.03). There was no statistical correlation between ffERG amplitudes and visual acuity (smallest p = 0.45). OCT: In albinism patients, thicker central macula on OCT correlated with lower mfERG amplitudes in all rings except for ring 1 (p < 0.05) and lower ffERG a-wave amplitudes on dark-adapted 0.01 (p = 0.003). Macular thickness on OCT did not correlate with visual acuity (p = 0.51); OCT foveal score did (p = 0.0004).
CONCLUSIONS
Amplitude of mfERG does not correlate with visual acuity in any ring in patients with albinism. The slope of the change in amplitude from central to peripheral rings on the mferg is significantly different in albinism patients versus controls whether or not nystagmus is present. The decreased slope of change in amplitudes from center to periphery of the macula in albinism patients indicates changes in macular topography that are more important to visual deficits than the foveal depression.
Topics: Adolescent; Adult; Albinism, Oculocutaneous; Child; Electroretinography; Female; Fovea Centralis; Humans; Male; Middle Aged; Nystagmus, Pathologic; Retina; Retrospective Studies; Tomography, Optical Coherence; Visual Acuity; Young Adult
PubMed: 30927186
DOI: 10.1007/s10633-019-09692-9