Purchase this article with an account.
JE Farbrother, E Farrow, R Black, H Fletcher, JA Guggenheim; Genetic Epidemiology of High Myopia: Prevalence of Myopia in Siblings and Parents of High Myopes . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1847.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To estimate the prevalence of myopia in relatives of high myopes in a UK cohort, to calculate relative risk to siblings and to establish whether there is consistency with the dominant highly penetrant model for which putative high myopia loci have been identified. Methods: Of 218,410 patients attending optometric practices in the north of England, 2112 (1%) met our criteria for high myopia [refractive error in least minus meridian (LMMRx) of each eye ≥-6.00DS]. For a random group of these probands, we obtained data about the spectacle wearing status of their relatives by postal (n=159, 44% response) and telephone (n=135, 81% response) questionnaires. Age, sex and refractive status were the same for the respondent and non-respondent probands (Age p=0.15, Rx p=0.84). Age of onset of spectacle wear (AOSW) was used as a surrogate for degree of myopia in siblings of these highly myopic probands. Regression analysis of right eye LMMRx on loge AOSW for a cohort of myopic families participating in a separate genetic study at our lab (n=264, LMMRx -0.50DS to -20.75DS) indicated that an AOSW ≤ 9.4 ± 0.8 years would correspond to a LMMRx ≥ -6.00DS. Results: Prevalence of myopia (full time spectacle wear for myopia, FTSW) and a high myopia surrogate (AOSW ≤ 9.4 ± 0.8 years) in siblings of the highly myopic probands were markedly higher than population prevalence. Data shown in the table includes 95% confidence limits incorporating standard errors for the regression analysis and proportion estimates. View OriginalDownload SlideView OriginalDownload Slide The relative risk to siblings of high myopes was increased if one parent was a full time distance spectacle wearer (F=3.95, p=0.01), but no additional risk was conferred if this was true of both parents (F=0.09, p=0.92). Cases with no myopic parents were common (43.0%) and had a low (∼4%) sibling prevalence of our high myopia surrogate. Conclusion: High penetrance monogenic inheritance of high myopia as a discrete phenotype would predict a higher relative risk to siblings (λs) than our estimate. Observations in our cohort are more easily explained by the presence of phenocopies and/or additive polygenes along with heterogeneity.
This PDF is available to Subscribers Only