An update of the prevalence of myopia in an older Australian population

Abstract

Purpose : A worldwide myopia “epidemic” is being reported, but there have been no recent reports about myopia prevalence in older adults in Australia since the conclusion of the Blue Mountains Eye Study (BMES) and Melbourne Visual Impairment Project (MVIP) over 20 years ago. The purpose of this study is to report myopia prevalence in two contemporary cross-sectional studies in Western Australia: the coastal-rural Busselton Healthy Ageing Study (BHAS), and the metropolitan Generation 1 of the Raine study (G1RS) based in Perth, and compare to the older cohorts.

Methods : We obtained data for 15,821 participants from four Australian studies. Refractive error was measured by autorefraction or vertometry. Participants aged between 49 and 70 years of Northern European ancestry were included in this analysis, and they were excluded if there was self-reported/diagnosed cataract, corneal disease, refractive, or corneal surgery. Myopia and high myopia prevalence was evaluated using spherical equivalent cut-off points of ≤-0.50D and ≤-5.0D, respectively.

Results : Cleaned data included 2213, 1564, 3948 and 756 participants from BMES, MVIP, BHAS and G1RS, respectively. The mean age within cohorts ranged from 57.1 (SD 4.6) years in G1RS to 60.1 (SD 6.0) years in BMES, and 44 to 47% of participants were male. Crude myopia prevalence was higher in the more recent BHAS (35.6%[95%CI:34.1-37.1]) and GR1S (29.9% [95%CI:26.2-33.3) cohorts compared to adults of similar age in older studies (BMES: 21.2% [95%CI:19.5-23.0]; MVIP: 22.8%[95%CI:20.7-24.9]). The proportion of participants with high myopia was greatest in the urban G1RS (4.0% [95%CI:2.7-5.6]), but was lowest in coastal-rural BHAS (1.6%[95%CI:1.3-2.1]).

Conclusions : In agreement with the reported global trends, we report a significant increase in myopia prevalence in older adults in Australia born after World War ll compared to cohorts born before. Of particular note there seems to be a significantly more high myopia in modern urban populations. This rapid increase has important implications for public health, given the cost of optical correction, reduced vision-specific quality-of-life, and elevated risk of potentially blinding eye disease in myopia, particular high myopia.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.