Advertisement

Visual Acuity and the Causes of Visual Loss in a Population-Based Sample of 6-Year-Old Australian Children

      Purpose

      To describe the distribution of visual acuity and causes of visual loss in a representative sample of Australian schoolchildren.

      Design

      Population-based cross-sectional study.

      Participants

      One thousand seven hundred thirty-eight predominantly 6-year old children examined during 2003 to 2004.

      Methods

      Logarithm of the minimum angle of resolution (logMAR) visual acuity was measured in both eyes before and after pinhole correction and with spectacles if worn. Cycloplegic autorefraction (cyclopentolate) and detailed dilated fundus examination were performed.

      Main Outcome Measures

      Visual impairment was defined as any (visual acuity <20/40; <40 letters) or severe (visual acuity ≤20/200; 0–5 letters) for both better and worse eyes. Myopia was defined as spherical equivalent (SE) refraction ≤−0.50 diopters (D), and hyperopia as SE refraction ≥+2.0 D, deemed significant when ≥+3.0 D. Astigmatism was defined as cylinder ≥1.0 D and anisometropia as SE refraction difference between eyes at least 1.0 D. Amblyopia was defined as corrected visual acuity <0.3 logMAR units (<20/40; <40 letters) in the affected eye not attributable to any underlying structural abnormality of the eye or visual pathway, together with a 2-logMAR line difference between the eyes and presence of an amblyogenic risk factor.

      Results

      The mean visual acuity of this sample was 20/25 (49.3 letters). Uncorrected visual impairment was found in the better eye of 23 children (1.3%) and in the worse eye of 71 children (4.1%). The prevalence was higher in girls than boys and among children of lower socioeconomic status. Refractive error was the most frequent cause, accounting for 69.0%, followed by amblyopia (22.5%). Astigmatism was the principle refractive error causing visual impairment and was frequently uncorrected. Presenting visual impairment (using current glasses if worn) was found in the better and worse eyes of 15 children (0.9%) and 54 children (2.8%), respectively. This was mainly due to under corrected or uncorrected refractive error.

      Conclusions

      This study has documented a relatively low prevalence of visual impairment in a population of Australian children. Uncorrected astigmatism and amblyopia were the most frequent causes.
      To read this article in full you will need to make a payment

      Subscribe:

      Subscribe to Ophthalmology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Gilbert C.
        • Foster A.
        Childhood blindness in the context of VISION 2020—the right to sight.
        Bull World Health Organ. 2001; 79: 227-232
        • Simons K.
        Visual acuity norms in young children.
        Surv Ophthalmol. 1983; 28: 84-92
        • Zhao J.
        • Pan X.
        • Sui R.
        • et al.
        Refractive Error Study in Children.
        Am J Ophthalmol. 2000; 129: 427-435
        • He M.
        • Zeng J.
        • Liu Y.
        • et al.
        Refractive error and visual impairment in urban children in southern china.
        Invest Ophthalmol Vis Sci. 2004; 45: 793-799
        • Dandona R.
        • Dandona L.
        • Srinivas M.
        • et al.
        Refractive error in children in a rural population in India.
        Invest Ophthalmol Vis Sci. 2002; 43: 615-622
        • Murthy G.V.
        • Gupta S.K.
        • Ellwein L.B.
        • et al.
        Refractive error in children in an urban population in New Delhi.
        Invest Ophthalmol Vis Sci. 2002; 43: 623-631
        • Pokharel G.P.
        • Negrel A.D.
        • Munoz S.R.
        • Ellwein L.B.
        Refractive Error Study in Children.
        Am J Ophthalmol. 2000; 129: 436-444
        • Naidoo K.S.
        • Raghunandan A.
        • Mashige K.P.
        • et al.
        Refractive error and visual impairment in African children in South Africa.
        Invest Ophthalmol Vis Sci. 2003; 44: 3764-3770
        • Maul E.
        • Barroso S.
        • Munoz S.R.
        • et al.
        Refractive Error Study in Children.
        Am J Ophthalmol. 2000; 129: 445-454
        • Ojaimi E.
        • Rose K.A.
        • Smith W.
        • et al.
        Methods for a population-based study of myopia and other eye conditions in school-children.
        Ophthalmic Epidemiol. 2005; 12: 59-69
      1. SAS [computer program]. Version 8.2. Cary, NC: SAS Institute; 2001.

        • Fern K.D.
        • Manny R.E.
        Visual acuity of the preschool child.
        Am J Optom Physiol Opt. 1986; 63: 319-345
        • Tong L.
        • Saw S.M.
        • Tan D.
        • et al.
        Sensitivity and specificity of visual acuity screening for refractive errors in school children.
        Optom Vis Sci. 2002; 79: 650-657
        • Pott J.W.
        • van Hof-van Duin J.
        The Rotterdam C-chart.
        Behav Brain Res. 1992; 49: 141-147
        • Merritt J.C.
        • Game S.
        • Williams O.D.
        • Blake D.
        Visual acuity in preschool children.
        J Natl Med Assoc. 1996; 88: 709-712
        • Lippmann O.
        Vision of young children.
        Arch Ophthalmol. 1969; 81: 763-775
        • Tibbenham A.D.
        • Peckham C.S.
        • Gardiner P.A.
        Vision screening in children tested at 7, 11, and 16 years.
        Br Med J. 1978; 1: 1312-1314
        • Slataper F.J.
        Age norms of refraction and vision.
        Arch Ophthalmol. 1950; 43: 466-481
        • Klein R.
        • Klein B.E.
        • Linton K.L.
        • De Mets D.L.
        The Beaver Dam Eye Study.
        Ophthalmology. 1991; 98: 1310-1315
        • Taylor H.R.
        • Livingston P.M.
        • Stanislavsky Y.L.
        • McCarty C.A.
        Visual impairment in Australia.
        Am J Ophthalmol. 1997; 123: 328-337
        • Attebo K.
        • Mitchell P.
        • Smith W.
        Visual acuity and the causes of visual loss in Australia. The Blue Mountains Eye Study.
        Ophthalmology. 1996; 103: 357-364
        • Manny R.E.
        • Hussein M.
        • Gwiazda J.
        • Marsh-Tootle W.
        • COMET Study Group
        Repeatability of ETDRS visual acuity in children.
        Invest Ophthalmol Vis Sci. 2003; 44: 3294-3300
        • Leibowitz H.M.
        • Krueger D.E.
        • Maunder L.R.
        • et al.
        The Framingham Eye Study monograph.
        Surv Ophthalmol. 1980; 24: 335-610
        • Roberts J.
        • Ludford J.
        Monocular visual acuity of persons 4-74 years, United States, 1971-1972.
        Vital Health Stat 11. 1977; 201 (1–67): iii-iv
        • Rosenberg T.
        • Flage T.
        • Hansen E.
        • et al.
        Incidence of registered visual impairment in the Nordic child population.
        Br J Ophthalmol. 1996; 80: 49-53
        • Negrel A.D.
        • Maul E.
        • Pokharel G.P.
        • et al.
        Refractive Error Study in Children.
        Am J Ophthalmol. 2000; 129: 421-426
        • Bremner M.H.
        Visual acuity in the primary school child aged four to twelve years.
        Aust J Ophthalmol. 1984; 12: 295-299
        • Macfarlane D.J.
        • Fitzgerald W.J.
        • Stark D.J.
        The prevalence of ocular disorders in 1000 Queensland primary schoolchildren.
        Aust N Z J Ophthalmol. 1987; 15: 161-174
        • Junghans B.
        • Kiely P.M.
        • Crewther D.P.
        • Crewther S.G.
        Referral rates for a functional vision screening among a large cosmopolitan sample of Australian children.
        Ophthalmic Physiol Opt. 2002; 22: 10-25
        • Donahue S.P.
        How often are spectacles prescribed to “normal” preschool children?.
        J AAPOS. 2004; 8: 224-229
        • Preslan M.W.
        • Novak A.
        Baltimore Vision Screening Project. Phase 2.
        Ophthalmology. 1998; 105: 150-153
        • Matsumura H.
        • Hirai H.
        Prevalence of myopia and refractive changes in students from 3 to 17 years of age.
        Surv Ophthalmol. 1999; 44: S109-S115
        • Seet B.
        • Wong T.Y.
        • Tan D.T.
        • et al.
        Myopia in Singapore.
        Br J Ophthalmol. 2001; 85: 521-526
        • Lin L.L.
        • Shih Y.F.
        • Tsai C.B.
        • et al.
        Epidemiologic study of ocular refraction among schoolchildren in Taiwan in 1995.
        Optom Vis Sci. 1999; 76: 275-281
        • Attebo K.
        • Ivers R.Q.
        • Mitchell P.
        Refractive errors in an older population.
        Ophthalmology. 1999; 106: 1066-1072
        • Eye Diseases Prevalence Research Group
        The prevalence of refractive errors among adults in the United States, Western Europe, and Australia.
        Arch Ophthalmol. 2004; 122: 495-505