ABSTRACT
According to the onset age, high myopia can be divided into late-onset high myopia (loHM) and early-onset high myopia (eoHM). Numerous genetic studies have shown that eoHM is different from loHM.EoHM, a special type of high myopia before school age (<7 years old), is more likely influenced by genetic factors with less contribution from environment.Therefore, individuals with eoHM are an available group for the research of pathogenesis of high myopia as a monogenic disease, and eoHM should be a unique resource in searching for genes responsible for high myopia.EoHM can be divided into nonsyndromic type which only presents with simple high myopia without any ocular or systemic abnormalities, and syndromic type that has other ocular or systemic disorders.More often, eoHM is the earliest sign of some inherited ocular diseases and the first reason for children seeking medical attention, which is an important clue for clinicians to detect underlying eye diseases.Therefore, in addition to further specific clinical examination of ocular structure and function, high attention should be paid to genetic screening of eoHM in order to promote early diagnosis and effective intervention, and long-term follow-up assessment.