ABSTRACT
Background: High myopia is one of the main causes of visual impairment worldwide. About 1% of the population has high myopia. There is significant evidence from research with animal models and humans that the development of refractive errors is associated with changes in the structural characteristics of the choroid. Studies from a range of different animal species, including chicks, macaque monkeys, indicate that alterations in choroidal thickness [CT] can precede and accompany the development of myopic refractive errors
Aim of the Work: The aim of this study was to evaluate the choroid by Enhanced Depth Imaging OCT, as regards to its morphology and thickness in high axial myopic patients
Patients and Methods: The controlled cross sectional study that was conducted on a consecutive series of subjects attending outpatient clinic of Ophthalmology Department, Ain Shams University. The patients were divided into two groups: Study group [group I]: includes 100 high axial myopic eyes [more than -6.00 diopters] and Control group [group II]: includes 100 emmetropic eyes
Results: According to ANOVA test and Tukey HSD post ANOVA test], choroidal thickness changed significantly with different measurement location, with the thinnest choroid observed in the 3 mm nasal and the thickest choroid in the 3 mm upper. CT varied significantly across the myopic subgroups and the emmetropic control group at all the locations [
Conclusion: Our study along with the comprehensive meta-analysis showed that the choroidal thickness is significantly lower in high myopic eyes than control emmetropic eyes. UCVA, AL and the presence of posterior staphyloma are the significant predictors of CT in high myopia and must be taken into account when interpreting the data on CT. Given the large number of people with myopia in the world, these findings seem to have widespread implications