AB015.The relationship between copy number variations and high myopia in Chinese:a case-control study

As a complex disease,myopia is the most common eye disease worldwide.Many myopia susceptibility genes or variants have been successfully identified in the past years by genome-wide genetic association studies(GWAS),which focus mainly on the single-nucleotide polymorphisms.Little attention has been paid to examine the role of copy number variations(CNVs)in refractive error and myopia.This study adopted a systematic strategy to investigate the role of CNVs in high myopia.In the discovery phase,a pilot GWAS suggests putative CNVs for follow-up.Multiplex ligation-dependent probe amplification was then used to quantify the copy number of 89 CNV segments in 737 case-control samples in the second phase and then 24 top-ranking CNVs in a second group of 1,029 case-control samples in the final validation phase.This validation phase identified 22 significant CNVs.Further work is needed to examine the role of these few CNVs in myopia development.

Automatic quantification of superficial foveal avascular zone in optical coherence tomography angiography implemented with deep learning

An accurate segmentation and quantification of the superficial foveal avascular zone(sFAZ)is important to facilitate the diagnosis and treatment of many retinal diseases,such as diabetic retinopathy and retinal vein occlusion.We proposed a method based on deep learning for the automatic segmentation and quantification of the sFAZ in optical coherence tomography angiography(OCTA)images with robustness to brightness and contrast(B/C)variations.A dataset of 405 OCTA images from 45 participants was acquired with Zeiss Cirrus HD-OCT 5000 and the ground truth(GT)was manually segmented subsequently.A deep learning network with an encoder–decoder architecture was created to classify each pixel into an sFAZ or non-sFAZ class.Subsequently,we applied largestconnected-region extraction and hole-filling to fine-tune the automatic segmentation results.A maximum mean dice similarity coefficient(DSC)of 0.976±0.011 was obtained when the automatic segmentation results were compared against the GT.The correlation coefficient between the area calculated from the automatic segmentation results and that calculated from the GT was 0.997.In all nine parameter groups with various brightness/contrast,all the DSCs of the proposed method were higher than 0.96.The proposed method achieved better performance in the sFAZ segmentation and quantification compared to two previously reported methods.In conclusion,we proposed and successfully verified an automatic sFAZ segmentation and quantification method based on deep learning with robustness to B/C variations.For clinical applications,this is an important progress in creating an automated segmentation and quantification applicable to clinical analysis.

Short term effects of small incision lenticule extraction surgery on corneal endothelium

AIM： To assess the effects of small incision lenticule extraction（SMILE） surgery on the corneal endothelium at1 d to 1mo postoperatively.·METHODS： A retrospective, observational study was conducted on 47 patients（47 eyes） who received SMILE surgery. Patients were grouped according to contact lens wear condition. The corneal endothelium was examined preoperatively and at 1d, 1wk and 1mo postoperatively.The corneal endothelium was analyzed for endothelial cell density（ECD）, percentage of hexagonal cells, and coefficient of variation（CV） of cell size.·RESULTS： There were no significant decrease in the ECD, percentage of hexagonal cells or increase in CV at1 d, 1wk and 1mo postoperatively（P 〉0.05）. However,there was a small increase of ECD by 2.88% in contact lens wearers（78.26±113.62 cell/mm2, P 〈0.05）.· CONCLUSION： SMILE has no significant adverse effects on the corneal ECD and morphology during 1mo follow-up time.

This study was supported by the National Natural Science Foundation of China(Grant No.81800869 to Xiaoning Yu).

Purpose:To determine organisms present in the conjunctiva of children before and after orthokeratology lens wear,using MALDI-TOF mass spectrometry.Methods:Conjunctival samples were collected from children aged 8–12 years(inclusive)at baseline and on three occasions over the first six months of orthokeratology treatment.All lenses were disinfected using the povidone iodine-based solution every day after use.Specimens were cultured and all isolated colonies were identified using MALDI-TOF mass spectrometry.Numbers of organisms and diversity were compared over the study period and the presence of any ocular pathogens noted and participants informed,where appropriate,to enhance their compliance with lens care routine.Results:Organisms isolated from 76 children were generally similar to other studies employing culture methods.However,MALDI-TOF results yielded a wider range of species of micrococci and corynebacteria,as well as a few less frequently reported organisms.Only one culture yielded fungi.Ocular pathogens were only isolated from 9 subjects(4 before lens wear and 5 after lens wear),each on one occasion only.Diversity and numbers of organisms fell slowly over the period of the study,but the changes were not significant.Conclusions:Lens wear did not affect the overall content of the ocular microbiome,but the diversity was somewhat reduced.The incidence of ocular pathogens was low,suggesting that risk of ocular infection was not substantially increased by orthokeratology treatment using a povidone-iodine disinfecting solution.