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Survey of Ophthalmology 2023Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive... (Review)
Review
Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive loss of corneal transparency and thereby loss of vision. Currently, there is no approved therapy to delay or prevent its progression, and clinical management is challenging because of phenotypic variability and high risk of complications after interventions; however, new insights into the molecular pathogenesis of AAK may help improve its management. Here, we review the current understanding about the pathogenesis and management of AAK. We highlight the biological mechanisms involved in AAK development with the aim to develop future treatment options, including surgical, pharmacological, cell therapies, and gene therapies.
Topics: Humans; Corneal Diseases; Aniridia; Cornea; Vision Disorders; Forecasting
PubMed: 37146692
DOI: 10.1016/j.survophthal.2023.04.003 -
Progress in Retinal and Eye Research Jul 2023Wnt signaling comprises a group of complex signal transduction pathways that play critical roles in cell proliferation, differentiation, and apoptosis during... (Review)
Review
Wnt signaling comprises a group of complex signal transduction pathways that play critical roles in cell proliferation, differentiation, and apoptosis during development, as well as in stem cell maintenance and adult tissue homeostasis. Wnt pathways are classified into two major groups, canonical (β-catenin-dependent) or non-canonical (β-catenin-independent). Most previous studies in the eye have focused on canonical Wnt signaling, and the role of non-canonical signaling remains poorly understood. Additionally, the crosstalk between canonical and non-canonical Wnt signaling in the eye has hardly been explored. In this review, we present an overview of available data on ocular non-canonical Wnt signaling, including developmental and functional aspects in different eye compartments. We also discuss important changes of this signaling in various ocular conditions, such as keratoconus, aniridia-related keratopathy, diabetes, age-related macular degeneration, optic nerve damage, pathological angiogenesis, and abnormalities in the trabecular meshwork and conjunctival cells, and limbal stem cell deficiency.
Topics: Humans; Wnt Signaling Pathway; beta Catenin; Conjunctiva; Cell Differentiation; Trabecular Meshwork
PubMed: 36443219
DOI: 10.1016/j.preteyeres.2022.101149 -
Taiwan Journal of Ophthalmology 2023The anterior segment dysgeneses are a broad group of heterogeneous disorders characterized by developmental abnormalities of the anterior segment of the eye, including... (Review)
Review
The anterior segment dysgeneses are a broad group of heterogeneous disorders characterized by developmental abnormalities of the anterior segment of the eye, including primary congenital aphakia, Peters sequence, aniridia, and Axenfeld-Rieger spectrum. These conditions can have overlapping phenotypes and both genotypic and phenotypic heterogeneity. This article provides a strategy for both phenotyping and then genotyping using a targeted stepwise approach.
PubMed: 38249510
DOI: 10.4103/tjo.TJO-D-23-00062 -
Orvosi Hetilap Jul 2023Congenital aniridia is a rare panocular disease that affects almost all eye structures leading in most patients to reduced visual acuity. Ophthalmological signs include...
INTRODUCTION
Congenital aniridia is a rare panocular disease that affects almost all eye structures leading in most patients to reduced visual acuity. Ophthalmological signs include aniridia-associated keratopathy, secondary glaucoma, cataract, macular and optic nerve head hypoplasia, nystagmus. Although the term aniridia-associated keratopathy has long been used in the literature, various staging proposals have been described.
OBJECTIVE
To analyze aniridia-associated keratopathy stages, using available literature classifications, in patients with aniridia in Hungary.
PATIENTS AND METHODS
We examined 65 eyes of 33 patients with congenital aniridia (age: 25.69 ± 17.49 [5-59] years, 17 females [51.51%]). We recorded the corneal status by slit-lamp examination and classified the corneal abnormalities according to the Mackman, Mayer, López-García and Lagali staging.
RESULTS
According to Mackman's classification, 8 eyes (12.3%) were in stage 0, 0 eye in stage 1A, 38 eyes (58.46%) in stage 1B and 19 eyes (29.23%) in stage 2. According to Mayer, stage I included 8 eyes (12.3%), stage II 38 eyes (58.46%), stage III 5 eyes (7.7%), stage IV 7 eyes (10.77%) and stage V 7 eyes (10.77%). In López-García's classification, 8 eyes (12.3%) could not be grouped, 20 eyes (30.77%) were in stage 1, 18 eyes (27.7%) in stage 2 and 19 eyes (29.3%) in stage 3. Lagali's classification included 8 eyes (12.3%) in stage 0, 20 eyes (30.77%) in stage 1, 18 eyes (27.7%) in stage 2, 5 eyes (7.7%) in stage 3 and 14 eyes (21.54%) in stage 4.
CONCLUSION
We recommend using Lagali's staging scheme for aniridia-associated keratoptahy due to its ease of use, detailed progression assessment, and treatment planning. In stage 1 according to Lagali, blood vessels cross the limbus by up to 1 mm, in stage 2 the central 2-3 mm of the corneal area is spared of blood vessels. When the blood vessels reach the center of the cornea, it is stage 3, followed by opaque, uneven corneal pannus in stage 4. Orv Hetil. 2023; 164(27): 1063-1069.
Topics: Female; Humans; Child; Adolescent; Young Adult; Adult; Corneal Diseases; Aniridia; Cornea; Vision Disorders; Cataract
PubMed: 37422887
DOI: 10.1556/650.2023.32803 -
Progress in Retinal and Eye Research Jul 2023Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities... (Review)
Review
Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities and systemic features making congenital aniridia a complex syndromic disorder rather than a simple isolated disease of the iris. Moreover, foveal hypoplasia is now recognized as a more frequent feature than complete iris hypoplasia and a major visual prognosis determinant, reversing the classical clinical picture of this disease. Conversely, iris malformation is also a feature of various anterior segment dysgenesis disorders caused by PAX6-related developmental genes, adding a level of genetic complexity for accurate molecular diagnosis of aniridia. Therefore, the clinical recognition and differential genetic diagnosis of PAX6-related aniridia has been revealed to be much more challenging than initially thought, and still remains under-investigated. Here, we update specific clinical features of aniridia, with emphasis on their genotype correlations, as well as provide new knowledge regarding the PAX6 gene and its mutational spectrum, and highlight the beneficial utility of clinically implementing targeted Next-Generation Sequencing combined with Whole-Genome Sequencing to increase the genetic diagnostic yield of aniridia. We also present new molecular mechanisms underlying aniridia and aniridia-like phenotypes. Finally, we discuss the appropriate medical and surgical management of aniridic eyes, as well as innovative therapeutic options. Altogether, these combined clinical-genetic approaches will help to accelerate time to diagnosis, provide better determination of the disease prognosis and management, and confirm eligibility for future clinical trials or genetic-specific therapies.
Topics: Humans; PAX6 Transcription Factor; Aniridia; Eye Abnormalities; Mutation; Phenotype; Eye Proteins
PubMed: 36280537
DOI: 10.1016/j.preteyeres.2022.101133