Genetic Research on High Myopic Individuals in Northern China
Condition: High Myopia
MeSH terms: Myopia
Study type: Observational

Summary: 
      HM, which can dramatically cripple the eyesight of those affected, is a rampant ophthalmic
      disorder around the globe. It is in recent years that substantial studies covering the
      relationship between distinct variations and HM susceptibility sprang expeditiously. However,
      these studies have not yielded sufficiently credible and universally significant conclusions.
      Consequently, the study is conducted by including HM subjects residing in Northern China to
      explicitly illustrate this issue.
    

Detailed description: 
      As a serious pattern of myopia, high myopia (HM) generally refers to a condition where the
      spherical equivalent (SE) refraction exceeds -6.00 diopters (D) or the axial length (AL) is
      longer than 26.00 mm. Abundant studies have indicated the strong correlation of HM with
      multiple vision-threatening ophthalmic diseases, including rhegmatogenous retinal detachment,
      retinoschisis, retinochoroid atrophy and open-angle glaucoma. It is reported that the
      worldwide prevalence of HM has surpassed over 2.9% in recent years. And a study on subjects
      living in Minnesota from the 1960s to the 2010s demonstrates that the data has progressively
      increasing from 2.8% to 8.3%, which is not related with gender or race, although no evident
      significance has yet been proved in some groups. What's worse, it is speculated that HM
      patients are expected to account for 9.8% of the global population by 2050, which will
      gravely hinder the progress of social development. As a result, it is of profound
      implications to explore the pathogenesis of HM and the prospective therapeutic or remedial
      strategies.

      What has been universally acknowledged is that both environmental and genetic factors matter
      much in the onset and exacerbation of myopia, with the latter particularly predominating in
      the etiology of HM. Accordingly, discussing the causation of HM from heredity version is
      likely to be the most promising research field, which is just the researchers' interest at
      the present.
    

Intervention name(s): ophthalmologic examinations
Intervention type(s): Diagnostic Test
Intervention description(s): All the included personnel underwent routine ophthalmologic examinations on binoculus, including slit lamp microscope observation, intraocular pressure, diopters of refractive error, best corrected visual acuity, AL measurement, fundus photography and optical coherence tomography, adhering to the established and normalized principles.
Observational model: Case-Control
Time perspective: Retrospective
Sampling method: Probability Sample
Study population: 
        We enrolled HM participants characterized by AL ≥ 26.00 mm or SE ≤ -6.00 D in at least one
        eye at the Department of Ophthalmology of the First Affiliated Hospital of Zhengzhou
        University (Zhengzhou, Henan Province, China) from May 2022 to April 2023 as cases and
        unrelated normal volunteers with SE ranging from -0.50 D to +0.50 D as controls.
      
Biospecimen description: 
      Blood DNA were isolated utilizing the QIAamp DNA Blood Mini Kit (Qiagen, Hilden, North
      Rhine-Westphalia, Germany). And subsequently, the purity and concentration of obtained DNA
      were surveyed by the Nanodrop 2000 spectrophotometer (Thermo Fisher Scientific, Wilmington,
      Delaware, the United States of America), after which the normalization of qualified DNA
      samples followed. Finally, standardized DNA specimens were hold at -80 ℃ for future use.