PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 3934105

Amblyopia: a multidisciplinary approach. Proctor lecture.

G K von Noorden
View original source ↗Export metadata ↓

Abstract

Clinically different forms of amblyopia share as common denominators an inability to form well-defined and focused images in one or both eyes and, in the case of unilateral amblyopia, unequal visual input to the brain. This suggests two amblyopiogenic mechanisms which are effective, individually or in unison, in the various forms of amblyopia. The first is lack of adequate visual stimulation during infancy, causing visual deprivation. The second mechanism is based on abnormal binocular interaction. The clinical evidence and data from the animal laboratory will be reviewed in support of this dual etiological concept of amblyopia. An etiological classification of amblyopia suggested in 1972 on hypothetical grounds can be upheld on the basis of information that has accumulated since that time. Amblyopia is not a static condition but has a strong dynamic component since its severity can be modified by the type of stimulation received by the sound eye. Special emphases is placed in this lecture on this unique feature which is based on binocular interaction and is similar to the inhibition of afferent visual stimulation during suppression.

Explore related subjects

AmblyopiaAnimalsCatsChildChild, PreschoolEyeFemaleHaplorhiniHumansHyperopiaMalePhotic StimulationSensory DeprivationVision, OcularVisual CortexVisual PathwaysCase ReportsJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G K von Noorden. 1985. Amblyopia: a multidisciplinary approach. Proctor lecture.. https://pubmed.ncbi.nlm.nih.gov/3934105/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Genome-Wide and Rare Variant Association Studies of Amblyopia in Admixed American and African Ancestry Groups.

OBJECTIVE: To identify genetic variants associated with amblyopia in African (AFR) and Admixed American (AMR) ancestry groups, expanding on previous studies conducted in European ancestry. DESIGN: Retrospective ancestry-stratified genome-wide association study (GWAS) and gene-level rare variant association study (RVAS). PARTICIPANTS: Participants in the All of Us Research Program from AFR and AMR ancestry groups who had whole-genome sequencing available. Cases and controls were distinguished based on the presence of International Classification of Diseases 9/10/SNOMED diagnosis codes for amblyopia in electronic health records. This yielded ancestry-stratified subsets of 269 cases and 71 585 controls of AMR ancestry and 366 cases and 79 460 controls of AFR ancestry. METHODS: Stratified logistic regression models were adjusted for age, biological sex, and the top 10 principal components of genomic ancestry. GWAS was limited to common variants (minor allele frequency &#x2265;1%), and RVAS was limited to rare variants with coding sequence-altering effects (minor allele frequency >1%, exonic only, excluding synonymous variants) aggregated at the gene level using the SKAT algorithm. Downstream analyses of the significant variants were performed using KEGG and GO pathway analysis and STRING database queries for protein-protein interactions and gene-gene interactions. MAIN OUTCOME MEASURES: Single-nucleotide polymorphisms were determined to have genome-wide significance if P < 5e-8 in the GWAS, and genes were determined to have significant association with amblyopia in the RVAS if P < 8.0 &#xd7; 10-4. RESULTS: In the AMR GWAS, 245 unique single-nucleotide polymorphisms mapping to 97 distinct loci were identified, notably within neurodevelopmental and axonal guidance genes, including ROBO1, SEMA4B, PTPRD, NRXN1, and CAMK2D. The AFR GWAS identified 11 significant variants corresponding to 6 loci mapping primarily to long noncoding RNAs and pseudogenes. The AMR RVAS identified 15 genes, including axonal transport genes (KIF1B and KIF7) and growth factor signaling genes (EGF, ERBIN, and AKAP17A). The AFR RVAS identified a single gene, DLG2, which encodes the postsynaptic protein PSD-93, which promotes the closure of the sensitive period of neuroplasticity for vision in early childhood. CONCLUSIONS: Genetic risk architectures for amblyopia differ across ancestries but fundamentally converge on neurodevelopmental signaling, cortical synapse assembly, and sensitive period plasticity rather than ocular structural dynamics. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Amblyopia↗
PubMed2006

Detection of abnormal visual cortex in children with amblyopia by voxel-based morphometry.

PURPOSE: To detect the abnormalities of gray matter in children with amblyopia by voxel-based morphometry (VBM). DESIGN: Prospective, nonrandomized clinical trial. METHODS: Thirteen children with amblyopia and 14 normally sighted children underwent magnetic resonance (MR) examination. The two groups were age-matched with a mean age of 5.8 years. In the amblyopia group, five children had strabismus amblyopia, and eight had anisometropic amblyopia. We analyzed the original 3-dimensional T1 brain images using the VBM module within the widely used analysis software package SPM2 (Welcome Department of Cognitive Neurology, London, United Kingdom). After normalization, segmentation, and smoothing of the images, comparison between amblyopic and control groups was derived for the gray matter of the entire brain using parametric statistics. RESULTS: The results of VBM analysis indicated that the amblyopic group had decreased gray matter density in the middle frontal gyrus, parahippocampal gyrus, fusiform gyrus, inferior temporal gyrus of the left hemisphere, and the bilateral calcarine cortices. The radii of these regions ranged from 12 to 36 voxels. These abnormalities were consistent with morphologic changes in brain regions related to visual function. CONCLUSIONS: Using MR and VBM analysis, we detected morphologic changes in the visual cortex of children with amblyopia, which may indicate developmental abnormalities of visual cortex during the critical growth period.

Amblyopia↗