Abstract
Purpose :
Studies have used choroidal vascularity index (CVI) to assess vascular status of the choroid in adults with high myopia. However, data in children with myopic eyes are lacking and, in this study, we examined the distribution and association of peripapillary CVI and ganglion cell inner plexiform layer (GCIPL) thickness in children with myopic refractive errors.
Methods :
Seventy seven myopic and nineteen emmetropic eyes with mean refractive error 4.29±2.30 D and 0.14±0.25 D, respectively, were recruited from the National University Hospital Eye Surgery outpatient clinic. All children underwent a detailed ocular examination, including refraction, and axial length (AL) measurement. Peripapillary choroid and GCIPL were imaged using spectral-domain optical coherence tomography (SD-OCT). Choroidal scans were segmented by a modified image binarization technique. Total peripapillary choroidal area (TCA) was segmented into luminal (LA) and stromal (SA) area and peripapillary CVI was calculated as the proportion of LA to TCA. Peripapillary CVI and GCIPL thickness were calculated in all children for the entire 360 degrees and four quadrants, respectively. Only scans with a signal strength of >6/10 were included. Correlation between peripapillary CVI and GC-IPL thickness was calculated using the Pearson correlation coefficient.
Results :
Of the 96 included eyes (77 myopic), the mean age, mean spherical equivalent refraction and mean AL was 8.84±3.10 years, -4.15±2.23 D and 24.39±1.72 mm, respectively. There was no significant difference in average CVI between myopic and emmetropic eyes (59.8±0.2% vs.60.4±0.4%, p=0.35). However, average GCIPL was significantly thinner in myopes than emmetropes (81.18±4.89 vs. 87.63±6.22, p<0.001). There were regional differences in the distribution of CVI and GCIPL thickness measurements in myopic eyes. Both CVI and GCIPL were thinnest at the inferior region. There was no correlation between peripapillary CVI and GCIPL thickness in myopic children
Conclusions :
Given both optic nerve head and peripapillary choroid shares the common source of blood supply, thinnest peripapillary CVI and GCIPL thickness in inferior quadrant may explain the susceptibility of the inferior optic nerve region to glaucoma in myopes. Future studies with a larger cohort are warranted to understand the role of the peripapillary choroid in myopia.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.