Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 7704921

Global data on blindness.

B Thylefors·A D Négrel·R Pararajasegaram·K Y Dadzie
View original source ↗Export metadata ↓

Abstract

Globally, it is estimated that there are 38 million persons who are blind. Moreover, a further 110 million people have low vision and are at great risk of becoming blind. The main causes of blindness and low vision are cataract, trachoma, glaucoma, onchocerciasis, and xerophthalmia; however, insufficient data on blindness from causes such as diabetic retinopathy and age-related macular degeneration preclude specific estimations of their global prevalence. The age-specific prevalences of the major causes of blindness that are related to age indicate that the trend will be for an increase in such blindness over the decades to come, unless energetic efforts are made to tackle these problems. More data collected through standardized methodologies, using internationally accepted (ICD-10) definitions, are needed. Data on the incidence of blindness due to common causes would be useful for calculating future trends more precisely.

Explore related subjects

BlindnessCataractGlaucomaHumansTrachomaJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B Thylefors, A D Négrel, R Pararajasegaram, K Y Dadzie. 1995. Global data on blindness.. https://pubmed.ncbi.nlm.nih.gov/7704921/

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

KEEP EXPLORING

Related citations

PubMed1996

Activation of the primary visual cortex by Braille reading in blind subjects.

Primary visual cortex receives visual input from the eyes through the lateral geniculate nuclei, but is not known to receive input from other sensory modalities. Its level of activity, both at rest and during auditory or tactile tasks, is higher in blind subjects than in normal controls, suggesting that it can subserve nonvisual functions; however, a direct effect of non-visual tasks on activation has not been demonstrated. To determine whether the visual cortex receives input from the somatosensory system we used positron emission tomography (PET) to measure activation during tactile discrimination tasks in normal subjects and in Braille readers blinded in early life. Blind subjects showed activation of primary and secondary visual cortical areas during tactile tasks, whereas normal controls showed deactivation. A simple tactile stimulus that did not require discrimination produced no activation of visual areas in either group. Thus in blind subjects, cortical areas normally reserved for vision may be activated by other sensory modalities.

Blindness↗
PubMed1996

Dr C. Miller Fisher and the history of carotid artery disease.

BACKGROUND AND PURPOSE: Our aim was to analyze the role that C. Miller Fisher (C.M.F.) had in promoting an understanding of carotid artery disease (CAD). Although Chiari in 1905 and later Hunt, Moniz, and Hultquist, among others, described the association of CAD and stroke, this received little attention until C.M.F. published his clinicoanatomic correlations in "Occlusion of the Carotid Arteries." Until then, some 55% of strokes were attributed to "vasospasm." METHODS: We analyzed articles ("Occlusion of the Internal Carotid Artery," 1951; "Occlusion of the Carotid Arteries," 1954; "Transient Monocular Blindness Associated with Hemiplegia," 1952; "The Microembolic Theory of Transient Ischemic Attacks," 1976; "A Clinico-pathologic Study of Carotid Endarterectomy Plaques," 1986) and conducted personal interviews with C.M.F. RESULTS: During the 1950s, C.M.F. described the clinical implications of transient ischemic attacks and their relationship to CAD and stroke. The last sentence in the 1951 article read: "Unexplained cerebral embolism may arise from thrombotic material lying in the carotid sinus." In the same article he also wrote that "it is even conceivable that some day vascular surgery will find a way to by-pass the occluded portion of the artery during the period of ominous fleeting symptoms," heralding the future surgical treatment of carotid artery disease. C.M.F. called attention to the commonness of carotid disease, described transient monocular blindness, and studied the relationship between plaque pathology and clinical findings. CONCLUSIONS: C.M.F.'s clinicopathologic observations were a major factor in promoting recognition of the clinical features, stroke risk, and treatment of CAD.

Blindness↗