{"id":845,"date":"2019-04-12T15:49:04","date_gmt":"2019-04-12T19:49:04","guid":{"rendered":"http:\/\/localhost\/reviewmm\/?p=845"},"modified":"2020-09-18T15:27:41","modified_gmt":"2020-09-18T19:27:41","slug":"who-should-we-target-with-myopia-management-interventions","status":"publish","type":"post","link":"https:\/\/reviewofmm.com\/who-should-we-target-with-myopia-management-interventions\/","title":{"rendered":"Understanding the Characteristics of People at Greater Risk"},"content":{"rendered":"
April 12, 2019<\/strong><\/p>\n By Jennifer Sha, BOptom, BSc(Hons), Senior Research Optometrist<\/strong> By 2020 the global prevalences of myopia and high myopia are estimated to be 34% and 5.2%, respectively and are predicted to increase.1<\/sup> Due to the increased risk of developing associated complications such as retinal detachment, glaucoma, cataract, and myopic macular degeneration, as well as the burden to society, much effort has been made in recent decades to understand myopia progression and methods of slowing its progression.<\/p>\n Emmetropization is the process that occurs during childhood and adolescence whereby the axial length of the eye is regulated to closely match the refractive power.2<\/sup> Most infants are hyperopic, and while emmetropization reduces the refractive error, children typically converge to a low level of hyperopia by teen years.3<\/sup> However, emmetropization does not always proceed in this manner, and in children who become myopic, axial length is longer and refractive error is less hyperopic than normal for up to 3 years before even the onset of myopia.4<\/sup> With respect to the level of refractive error that is considered abnormal, the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) study demonstrated that 6 year old children with refraction \u2264+0.75D were at an increased risk of developing myopia, as well as 7-8 year old children with \u2264+0.50D, 9-10 year old children with \u2264+0.25D, and 11 year old children with \u22640.00D.5<\/sup><\/p>\n Research has uncovered some characteristics of people at greater risk of developing myopia. These include at least one parent with myopia,6, 7<\/sup> female gender,8-10<\/sup> very close reading distances and longer continuous\u00a0 reading time.11, 12<\/sup> Age is an interesting risk factor, as the prevalence of myopia is higher in older children,6<\/sup> while the progression rate is greater in younger children.13, 14<\/sup> Myopic children may also exhibit more esophoria,15<\/sup> more accommodative lag,16<\/sup> reduced accommodative facility,17<\/sup> and a greater AC\/A ratio,18<\/sup> however it is not clear whether these binocular vision features are a cause or an effect of the myopia.<\/p>\n In terms of ethnicity, myopia prevalence is significantly higher in East Asian children compared to Caucasian children even in the same geographic location.6, 8, 19<\/sup> Not only that; myopia progression is higher in Asian children compared to Caucasian children. A meta-analysis of studies reporting myopia progression in children wearing spectacles estimated that rates of progression were -0.55D per year for Caucasian children and -0.82D per year for Asian children with the same degree of myopia at 9 years of age.20<\/sup> Progression was faster for Asians compared to Caucasians at every time point over 3 years. However, it is not completely clear if these ethnicity differences are due to genetic factors, environmental factors, or both as East Asian children also spend less time outdoors on average than their Caucasian counterparts,6<\/sup> which is also a risk factor for developing myopia.21<\/sup><\/p>\n
\nBrien Holden Vision Institute
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