[Characterization of the biometric eye profile of a high myopic population: does high myopia correspond to a homogenous phenotype?].

Purpose: High myopia is a public health problem because of its high prevalence and is a major cause of blindness. The physiopathology of myopia remains unknown and mechanisms causing the disease are most probably complex, combining acquired environmental and genetic factors. The most recent data suggest that genetic determinisms of high myopia could be highly dependent on subject phenotype. The aim of this study was to analyse the ocular components of a high myopic population to verify whether high myopia corresponds to a homogeneous phenotype.
Patients and Methods: We analysed the biometric characteristics of 718 myopic eyes with a spherical equivalent of less than -5 diopters. The biometric parameters (corneal radius, axial length, and intraocular pressure) were compared controlling for sex and the degree of myopia.
Results: We found a difference between the phenotype of males and females. For men, axial length was the only determinant of the myopic phenotype, whereas for women, the myopic phenotype was determined by axial length and corneal radius. This difference between the phenotypes was more evident for myopia with a spherical equivalent greater than -10 diopters (moderate myopia). This difference between males and females disappeared in myopia less than -15 diopters.
Conclusion: There are intersex differences considering the high myopia phenotype at a spherical equivalent less than -5 diopters. However, this difference disappears for extremely high myopia with a spherical equivalence of less than -15 diopters.
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