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Archivos de La Sociedad Espanola de... Nov 2021The perform pre-clinical testing using optical design tools to simulate the optical quality of a smart artificial iris platform encapsulated in a scleral contact lens....
OBJECTIVE
The perform pre-clinical testing using optical design tools to simulate the optical quality of a smart artificial iris platform encapsulated in a scleral contact lens. These tools allow us to generate aniridia eye models and evaluate different metrics of visual quality and retinal illumination based on the aperture of the artificial iris based on liquid crystals.
METHOD
The OCT imaging technique was used to measure the geometry of the anterior segment in a patient with aniridia and, from these data, the eye model was generated with the Zemax optical design program and specific programs developed in Matlab. Ocular aberrations were calculated and the visual function of the anirida eye model was evaluated in three scenarios: (i) without optical correction, (ii) with correction with a commercial scleral contact lens, and (iii) with correction with an optical lens. Intelligent contact based on artificial iris.
RESULTS
Optical quality in patients with aniridia is limited by the magnitude of high-order aberrations. Conventional scleral contact lens design accurately corrects for blur but is unable to compensate for high-order ocular aberrations, especially spherical aberrations. The artificial iris-based smart contact lens design enables virtually all high-order aberrations to be compensated with active control of the pupillary diameter (activation of liquid crystal cells based on ambient lighting). In addition to minimizing high-order aberrations, reducing the pupil size would increase the depth of focus.
CONCLUSIONS
This article demonstrates by means of optical simulations the concept of an intelligent artificial iris platform encapsulated in a scleral contact lens and its possible application in patients with aniridia. Furthermore, it allows us to anticipate possible visual results in clinical trials with healthy patients (after application of mydriatic agents) and in patients with aniridia. The results demonstrate a better visual quality and a decrease in retinal illumination.
Topics: Aniridia; Contact Lenses; Humans; Iris; Lenses, Intraocular; Visual Acuity
PubMed: 34836591
DOI: 10.1016/j.oftale.2021.01.004 -
Graefe's Archive For Clinical and... Nov 2018Aniridia is a rare panocular disorder caused by mutations in the PAX6 gene and characterized mainly by iris hypoplasia. Here, we present six families with a history of...
PURPOSE
Aniridia is a rare panocular disorder caused by mutations in the PAX6 gene and characterized mainly by iris hypoplasia. Here, we present six families with a history of low vision/blindness with a previously undiagnosed mild aniridia phenotype with minimal iris changes.
METHODS
Retrospective case series of patients diagnosed with a subtle aniridia phenotype characterized by minimal iris abnormalities, foveal hypoplasia, and an identified mutation in PAX6. Data collection from patient's charts included ocular examination findings, visual acuity, refraction, and clinical pictures when available. Genetic analysis was performed by isolation of genomic DNA from peripheral blood. The main outcome was the identification of patients with mild aniridia harboring a PAX6 mutation.
RESULTS
In all six families, the phenotype included minimal corectopia and foveal hypoplasia; nystagmus was present in 10 out of 11 patients. A PAX6 mutation was identified in all six families; three of these mutations were identified previously, and three are novel mutations. All the mutations are located within the conventional 128-residue paired domain of PAX6.
CONCLUSIONS
A mild form of aniridia should be considered in the differential diagnosis of patients with low vision associated with mild iris abnormalities, nystagmus, and foveal hypoplasia. To ensure an accurate diagnosis of aniridia, minimal pupillary changes and/or incipient keratopathy should be examined. The broad phenotypic heterogeneity among aniridia leads to the fact that eye care clinicians must have a high index of suspicion for the disease when seeing undiagnosed low vision patients, because proper diagnosis can improve management as well as facilitate genetic testing and counselling.
Topics: Adult; Aged; Aniridia; Blindness; Child; Child, Preschool; Eye Diseases, Hereditary; Female; Humans; Male; Middle Aged; Mutation, Missense; PAX6 Transcription Factor; Pedigree; Phenotype; Refraction, Ocular; Retrospective Studies; Vision, Low; Visual Acuity; Young Adult
PubMed: 30167917
DOI: 10.1007/s00417-018-4119-1 -
Acta Ophthalmologica Nov 2008To investigate patients under the age of 20 with aniridia in Sweden and Norway in order to estimate the prevalence of aniridia, to describe clinical signs and identify...
PURPOSE
To investigate patients under the age of 20 with aniridia in Sweden and Norway in order to estimate the prevalence of aniridia, to describe clinical signs and identify complications in the young, which will help improve diagnostic tools and treatment.
METHODS
A thorough search for patients with aniridia (of all ages) was performed. Sixty-two of the 181 patients were under the age of 20. Fifty-two of them were examined and they constituted the study population. Patient history was obtained and all participants underwent clinical ophthalmologic examination, including photography. Blood samples were taken for mutation analysis.
RESULTS
Epidemiological data are only based on the results in Sweden. The age-specific prevalence in Sweden was 1:47,000, male/female ratio was 0.57, mean age 12 years and median age 14 years. The proportion of sporadic cases including WAGR (Wilms tumour, Aniridia, Genitourinary abnormalities, Mental Retardation) and Gillespie syndrome (aniridia, cerebellar ataxia and mental retardation) was 48%. In the entire study population (Sweden and Norway), the mean visual acuity (VA) was 0.2 (range 0.04-0.9). We found VA < 0.3 in 80% and <0.1 in 18% of the patients. Twenty-two patients (42%) had one or more of the sight threatening complications such as cataract/lens luxation, corneal clouding or glaucoma.
CONCLUSION
Descriptions of aniridia in the younger are rare. This study shows that aniridia seems to be more common than previously estimated and that some complications appear early in life. Watchfulness as regards these complications and regular examinations are essential even in the youngest.
Topics: Adolescent; Age Distribution; Aniridia; Cataract; Cerebellar Ataxia; Child; Child, Preschool; Corneal Opacity; Female; Glaucoma; Humans; Infant; Intellectual Disability; Lens Subluxation; Male; Norway; Prevalence; Sex Distribution; Sweden; Syndrome; Visual Acuity; WAGR Syndrome; Young Adult
PubMed: 18494744
DOI: 10.1111/j.1755-3768.2008.01310.x -
JCI Insight Jul 2021Aniridia is most commonly caused by haploinsufficiency of the PAX6 gene, characterized by variable iris and foveal hypoplasia, nystagmus, cataracts, glaucoma, and... (Observational Study)
Observational Study
Aniridia is most commonly caused by haploinsufficiency of the PAX6 gene, characterized by variable iris and foveal hypoplasia, nystagmus, cataracts, glaucoma, and aniridia-related keratopathy (ARK). Genotype-phenotype correlations have previously been described; however, detailed longitudinal studies of aniridia are less commonly reported. We identified 86 patients from 62 unrelated families with molecularly confirmed heterozygous PAX6 variants from a UK-based single-center ocular genetics service. They were categorized into mutation groups, and a retrospective review of clinical characteristics (ocular and systemic) from baseline to most recent was recorded. One hundred and seventy-two eyes were evaluated, with a mean follow-up period of 16.3 ± 12.7 years. Nystagmus was recorded in 87.2% of the eyes, and foveal hypoplasia was found in 75%. Cataracts were diagnosed in 70.3%, glaucoma in 20.6%, and ARK in 68.6% of eyes. Prevalence, age of diagnosis and surgical intervention, and need for surgical intervention varied among mutation groups. Overall, the missense mutation subgroup had the mildest phenotype, and surgically naive eyes maintained better visual acuity. Systemic evaluation identified type 2 diabetes in 12.8% of the study group, which is twice the UK prevalence. This is the largest longitudinal study of aniridia in the UK, and as such, it can provide insights into prognostic indicators for patients and guiding clinical management of both ocular and systemic features.
Topics: Adolescent; Adult; Aniridia; Cataract; Child; DNA Mutational Analysis; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Fovea Centralis; Genetic Association Studies; Glaucoma; Haploinsufficiency; Heterozygote; Humans; Longitudinal Studies; Male; Middle Aged; Nystagmus, Congenital; PAX6 Transcription Factor; Pedigree; Young Adult
PubMed: 34101622
DOI: 10.1172/jci.insight.148406 -
Vestnik Oftalmologii 2023Secondary glaucoma is one of the main problems of rehabilitation of patients with traumatic damage of the iris.
UNLABELLED
Secondary glaucoma is one of the main problems of rehabilitation of patients with traumatic damage of the iris.
PURPOSE
This study analyzes the long-term results of rehabilitation of patients with posttraumatic aniridia and glaucoma.
MATERIAL AND METHODS
The study included 310 patients (310 eyes) with posttraumatic aniridia who had artificial iris-lens diaphragm (ILD) MIOL-Raduzhka implanted in 2002-2022. Before ILD implantation, 61 patients (22.8%) had secondary glaucoma. Among them 35 patients (11.3%) underwent various modifications of glaucoma surgery. In 26 patients (8.6%), intraocular pressure (IOP) was compensated medically before ILD implantation.
RESULTS
Until the third month after ILD implantation, there was a trend for IOP increase in some patients. Decompensation was noted in 8 (22.9%) out of 35 patients who had underwent glaucoma surgery. IOP decompensation was observed in 21 (80.8%) of 26 cases in patients with glaucoma compensated by drugs before ILD implantation. After ILD implantation, glaucoma appeared for the first time in 21 patients (6.8%) out of 310. In order to compensate IOP after ILD implantation, Ahmed valve implantation was performed most often - in 35 cases (70%) out of 50, deep sclerectomy - in 5 cases (10%), non-penetrating deep sclerectomy - in 4 cases (8%), micropulse transscleral laser cyclophotocoagulation (MP-TSCPC) - in 5 cases (10%), endoscopic cyclophotocoagulation (ECP) - in 1 case (2%).
CONCLUSION
ILD implantation in patients with posttraumatic aniridia and secondary glaucoma should be performed with IOP compensated without hypotensive therapy and not earlier than 6-12 months after glaucoma surgery. The most optimal glaucoma surgery types in this group of patients are Ahmed valve implantation and MP-TSCPC.
Topics: Humans; Lens Implantation, Intraocular; Visual Acuity; Aniridia; Iris; Glaucoma; Intraocular Pressure; Retrospective Studies; Treatment Outcome; Laser Coagulation
PubMed: 38235632
DOI: 10.17116/oftalma202313906169 -
Experimental Eye Research Jan 2024Heterozygous mutation of PAX6 in humans leads to congenital aniridia (OMIM 106210) which is typified by congenital iris and foveal defects, and later onset glaucoma,...
Heterozygous mutation of PAX6 in humans leads to congenital aniridia (OMIM 106210) which is typified by congenital iris and foveal defects, and later onset glaucoma, aniridic keratopathy, and cataract. Mice heterozygous for Pax6 mutations phenocopy many aspects of aniridia including the iris defects, keratopathy and cataract, although Pax6 mutant mice have small lenses, a phenotype which is not typically reported in human aniridia, perhaps due to difficulties in measuring lens diameter during typical ophthalmic examinations as the lens periphery is shielded by the iris. In order to overcome this, records of patients diagnosed with congenital aniridia between April 2015 and May 2021 at the Necker-Enfants Malades Hospital, and genetically confirmed with a disease-causing PAX6 variant, were retrospectively reviewed for those with normal axial length whose iris defects allowed visualization of the lens margins and corneal diameter to allow calculation of a lens/corneal diameter ratio. This value was compared with values obtained from a cohort of patients with Sjödell grade IV oculocutaneous albinism type 1 (OCA1; OMIM 203100) which allowed visualization of the lens periphery via iris transillumination. This analysis revealed that patients with congenital aniridia had a significantly lower lens/corneal ratio when compared to those with albinism, suggesting that humans haploinsufficient for PAX6, like mice, rats, frogs, and zebrafish, exhibit reductions in lens size.
Topics: Humans; Mice; Rats; Animals; PAX6 Transcription Factor; Paired Box Transcription Factors; Retrospective Studies; Zebrafish; Aniridia; Mutation; Corneal Diseases; Cataract; Homeodomain Proteins; Eye Proteins
PubMed: 38056551
DOI: 10.1016/j.exer.2023.109746 -
Die Ophthalmologie Jul 2023
Topics: Humans; Iris; Aniridia; Cataract
PubMed: 35925348
DOI: 10.1007/s00347-022-01682-8 -
The British Journal of Ophthalmology May 2006
Review
Topics: Adult; Aniridia; Eye Proteins; Homeodomain Proteins; Humans; Iris; Male; PAX6 Transcription Factor; Paired Box Transcription Factors; Point Mutation; Repressor Proteins
PubMed: 16622108
DOI: 10.1136/bjo.2005.089698 -
Canadian Journal of Ophthalmology.... Jun 2009
Topics: Aged; Aniridia; Diagnosis, Differential; Eye Injuries; Female; Follow-Up Studies; Humans; Iris; Phacoemulsification; Time Factors; Wounds, Nonpenetrating
PubMed: 19491999
DOI: 10.3129/i09-022 -
Ophthalmology Jun 2000To use molecular genetic techniques to prenatally screen for aniridia.
OBJECTIVE
To use molecular genetic techniques to prenatally screen for aniridia.
DESIGN
Case report.
METHODS
DNA was extracted from cultured fibroblasts obtained through amniocentesis. Two mutation detection methods, Ava1 restriction digestion and single-strand conformational polymorphism electrophoresis, were used to screen the PAX6 gene.
MAIN OUTCOME MEASURES
The results from the amniocentesis sample were compared with DNA obtained from the affected father, firstborn infant, and unaffected mother to determine whether the fetus carried the PAX6 mutation.
RESULTS
DNA from the fetus demonstrated the same banding pattern as the affected father and firstborn infant.
CONCLUSIONS
The fetus carried the mutated PAX6 allele and was predicted to develop aniridia. This was later confirmed when the child was born. This case report illustrates an important use of genetic mutation screening in the clinical setting.
Topics: Adult; Amniocentesis; Aniridia; DNA Mutational Analysis; DNA Primers; DNA-Binding Proteins; Eye Proteins; Female; Fetal Diseases; Fibroblasts; Genetic Testing; Homeodomain Proteins; Humans; Infant; Male; PAX6 Transcription Factor; Paired Box Transcription Factors; Pedigree; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Pregnancy; Prenatal Diagnosis; Repressor Proteins
PubMed: 10857836
DOI: 10.1016/s0161-6420(00)00093-2