Aging and longer axial length are independent and significant risk factors for myopic maculopathy, according to a study published in JAMA Ophthalmology. The study also found the condition, which is the leading cause of irreversible visual impairment and blindness for middle-aged and older individuals, has a much higher prevalence rate in Japan compared with other Asian countries.
Aging and longer axial length are independent and significant risk factors for myopic maculopathy, according to a study published in JAMA Ophthalmology.
The study also found the condition, which is the leading cause of irreversible visual impairment and blindness for middle-aged and older individuals, has a much higher prevalence rate in Japan compared with other Asian countries.
“Population-based data from several countries have estimated myopic maculopathy as the first or second most frequent cause of blindness in the Asian population and the second to fourth most common cause of low vision/blindness in the European population and Latino population,” the study authors wrote.
In a longitudinal, population-based study, researchers investigated the 5-year incidence of myopic maculopathy and identified risk factors in a population residing in the southwest of Japan. A total of 2164 residents 40 years and older were included in the prospective cohort study, which was part of the ongoing Hisayama Study. The Hisayama Study began in 1998 and is designed to assess cardiovascular disease and its risk factors in the town of Hisayama, Japan.
A total of 920 men and 1244 women completed a baseline eye examination in 2012 and a follow-up exam in 2017. At each exam, ophthalmologists measured objective refraction and axial lengths, while noncontact tonometry and color fundus photography were performed on both eyes. No study participants had myopic maculopathy at baseline.
Incidence of myopic maculopathy was divided into 3 categories: diffuse chorioretinal atrophy (category 2), patchy chorioretinal atrophy (category 3), and macular atrophy (category 4). Additional features, including lacquer cracks, myopic choroidal neovascularization, and Fuchs spot, were classified as “plus lesion.” Specifically, “myopic maculopathy was diagnosed as the presence of any lesions of category 2, 3, 4, or any plus lesion in either eye based on the grading of the color fundus photographs,” researchers explain.
The study yielded the following results:
After adjusting for age and sex, researchers found “the odds ratios (ORs) for the development of myopic maculopathy increased with longer axial length (per 1 mm: OR, 2.94; 95% CI, 2.19-3.95; P < .001) and spherical equivalent (SE) refraction (per —1 diopter: OR, 1.53; 95% CI, 1.01-2.32; P = .046).” A further multivariable-adjusted analysis found older age (per 1 year: OR, 1.06; 95% CI, 1.01-1.11; P = .01) and longer axial length (per 1 mm: OR, 2.94; 95% CI, 2.19-3.95; P < .001) were associated with the condition’s development.
Compared with other Asian populations, the findings show an increased prevalence in the Japanese population. Two studies assessing incidence of myopic maculopathy, the Handan Eye Study and Beijing Eye Study, estimated the 5-year incidences of the condition to be 0.08% and 0.12%, respectively. Researchers hypothesize that the differences may be due to myopic refractive error, varied definition of chorioretinal atrophy, or use of different measurement tools.
“Because the prevalence of myopic maculopathy has been expected to increase owing to the rising prevalence of myopia globally, the research in not only the Japanese population but also various populations may be needed to identify health services planning in the world,” authors concluded.
Ueda E, Yasuda M, Fujiwara K, et al. Five-year incidence of myopic maculopathy in a general Japanese population: The Hisayama study. JAMA Ophthalmol. Published online June 25, 2020. doi:10.1001/jamaophthalmol.2020.2211