Refractive error in Nigerian adults: prevalence, type, and spectacle coverage

Christian Ezelum, Hessom Razavi, Selvaraj Sivasubramaniam, Clare E Gilbert, Gudlavalleti V S Murthy, Gabriel Entekume, Tafida Abubakar, Nigeria National Blindness and Visual Impairment study group

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Purpose. To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles.

Methods. Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause.

Results. Included in the survey were 13,599 (89.9%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9% of mild visual impairment (<6/12–6/18), 57.1% of moderate visual impairment (<6/18–6/60), 11.3% of severe visual impairment (<6/60–3/60), and 1.4% of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2% and 2.1%, respectively. Spectacles could improve the vision of 1279 (9.4%) and 882 (6.5%) participants at the 6/12 and 6/18 level, respectively, but only 3.4% and 4.4% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles.

Conclusions. Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.
Original languageEnglish
Pages (from-to)5449-5456
Number of pages8
JournalInvestigative Ophthalmology & Visual Science
Volume52
Issue number8
Early online date17 Feb 2011
DOIs
Publication statusPublished - 22 Jul 2011

Fingerprint

Refractive Errors
Vision Disorders
Nigeria
Myopia
Blindness
Costs and Cost Analysis

Keywords

  • adult
  • age distribution
  • aged
  • aged, 80 and over
  • astigmatism
  • eyeglasses
  • female
  • health services needs and demand
  • health surveys
  • humans
  • hyperopia
  • male
  • middle aged
  • myopia
  • Nigeria
  • prevalence
  • refraction, ocular
  • sex distribution
  • visual acuity
  • visually impaired persons

Cite this

Ezelum, C., Razavi, H., Sivasubramaniam, S., Gilbert, C. E., Murthy, G. V. S., Entekume, G., ... Nigeria National Blindness and Visual Impairment study group (2011). Refractive error in Nigerian adults: prevalence, type, and spectacle coverage. Investigative Ophthalmology & Visual Science, 52(8), 5449-5456. https://doi.org/10.1167/iovs.10-6770

Refractive error in Nigerian adults : prevalence, type, and spectacle coverage. / Ezelum, Christian; Razavi, Hessom; Sivasubramaniam, Selvaraj; Gilbert, Clare E; Murthy, Gudlavalleti V S; Entekume, Gabriel; Abubakar, Tafida; Nigeria National Blindness and Visual Impairment study group.

In: Investigative Ophthalmology & Visual Science, Vol. 52, No. 8, 22.07.2011, p. 5449-5456.

Research output: Contribution to journalArticle

Ezelum, C, Razavi, H, Sivasubramaniam, S, Gilbert, CE, Murthy, GVS, Entekume, G, Abubakar, T & Nigeria National Blindness and Visual Impairment study group 2011, 'Refractive error in Nigerian adults: prevalence, type, and spectacle coverage', Investigative Ophthalmology & Visual Science, vol. 52, no. 8, pp. 5449-5456. https://doi.org/10.1167/iovs.10-6770
Ezelum C, Razavi H, Sivasubramaniam S, Gilbert CE, Murthy GVS, Entekume G et al. Refractive error in Nigerian adults: prevalence, type, and spectacle coverage. Investigative Ophthalmology & Visual Science. 2011 Jul 22;52(8):5449-5456. https://doi.org/10.1167/iovs.10-6770
Ezelum, Christian ; Razavi, Hessom ; Sivasubramaniam, Selvaraj ; Gilbert, Clare E ; Murthy, Gudlavalleti V S ; Entekume, Gabriel ; Abubakar, Tafida ; Nigeria National Blindness and Visual Impairment study group. / Refractive error in Nigerian adults : prevalence, type, and spectacle coverage. In: Investigative Ophthalmology & Visual Science. 2011 ; Vol. 52, No. 8. pp. 5449-5456.
@article{37d53b7ba17642ec8f02c707ddec8099,
title = "Refractive error in Nigerian adults: prevalence, type, and spectacle coverage",
abstract = "Purpose. To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles.Methods. Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause.Results. Included in the survey were 13,599 (89.9{\%}) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9{\%} of mild visual impairment (<6/12–6/18), 57.1{\%} of moderate visual impairment (<6/18–6/60), 11.3{\%} of severe visual impairment (<6/60–3/60), and 1.4{\%} of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2{\%} and 2.1{\%}, respectively. Spectacles could improve the vision of 1279 (9.4{\%}) and 882 (6.5{\%}) participants at the 6/12 and 6/18 level, respectively, but only 3.4{\%} and 4.4{\%} of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles.Conclusions. Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.",
keywords = "adult, age distribution, aged, aged, 80 and over, astigmatism, eyeglasses, female, health services needs and demand, health surveys, humans, hyperopia, male, middle aged, myopia, Nigeria, prevalence, refraction, ocular, sex distribution, visual acuity, visually impaired persons",
author = "Christian Ezelum and Hessom Razavi and Selvaraj Sivasubramaniam and Gilbert, {Clare E} and Murthy, {Gudlavalleti V S} and Gabriel Entekume and Tafida Abubakar and {Nigeria National Blindness and Visual Impairment study group}",
year = "2011",
month = "7",
day = "22",
doi = "10.1167/iovs.10-6770",
language = "English",
volume = "52",
pages = "5449--5456",
journal = "Investigative Ophthalmology & Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "8",

}

TY - JOUR

T1 - Refractive error in Nigerian adults

T2 - prevalence, type, and spectacle coverage

AU - Ezelum, Christian

AU - Razavi, Hessom

AU - Sivasubramaniam, Selvaraj

AU - Gilbert, Clare E

AU - Murthy, Gudlavalleti V S

AU - Entekume, Gabriel

AU - Abubakar, Tafida

AU - Nigeria National Blindness and Visual Impairment study group

PY - 2011/7/22

Y1 - 2011/7/22

N2 - Purpose. To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles.Methods. Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause.Results. Included in the survey were 13,599 (89.9%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9% of mild visual impairment (<6/12–6/18), 57.1% of moderate visual impairment (<6/18–6/60), 11.3% of severe visual impairment (<6/60–3/60), and 1.4% of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2% and 2.1%, respectively. Spectacles could improve the vision of 1279 (9.4%) and 882 (6.5%) participants at the 6/12 and 6/18 level, respectively, but only 3.4% and 4.4% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles.Conclusions. Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.

AB - Purpose. To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles.Methods. Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause.Results. Included in the survey were 13,599 (89.9%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9% of mild visual impairment (<6/12–6/18), 57.1% of moderate visual impairment (<6/18–6/60), 11.3% of severe visual impairment (<6/60–3/60), and 1.4% of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2% and 2.1%, respectively. Spectacles could improve the vision of 1279 (9.4%) and 882 (6.5%) participants at the 6/12 and 6/18 level, respectively, but only 3.4% and 4.4% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles.Conclusions. Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.

KW - adult

KW - age distribution

KW - aged

KW - aged, 80 and over

KW - astigmatism

KW - eyeglasses

KW - female

KW - health services needs and demand

KW - health surveys

KW - humans

KW - hyperopia

KW - male

KW - middle aged

KW - myopia

KW - Nigeria

KW - prevalence

KW - refraction, ocular

KW - sex distribution

KW - visual acuity

KW - visually impaired persons

U2 - 10.1167/iovs.10-6770

DO - 10.1167/iovs.10-6770

M3 - Article

C2 - 21330658

VL - 52

SP - 5449

EP - 5456

JO - Investigative Ophthalmology & Visual Science

JF - Investigative Ophthalmology & Visual Science

SN - 0146-0404

IS - 8

ER -