Comparison of choroid thickness difference between myopia children corrected by spectacles and orthokeratology / 眼科新进展

ABSTRACT

Objective To investigate choroid thickness at horizontal meridian with optical coherence tomography (OCT) and compare the choroid thickness difference between first visit myopia children with those children who wear orthokeratology lens for more than 1 year.Methods This retrospective study enrolled 68 myopia children with low to moderate myopia (-1.00--6.00 D) who visited our hospital and took choroid images by OCT.The total subjects were divided into 2 groups.The subjects of 34 children in group 1 visited for myopia initially and wear spectacles.The other one group wear orthokeratology lens more than 1 year.Only the data of right eye were analyzed.Scans through the fovea at horizontal meridian were acquired with OCT.Choroid images were detected by custom software with 500 μm intervals up to 3.5 mm around fovea.Choroid thickness (CT) was calc~ated based on the average of the 7 zones.Statistical analysis was performed to evaluate choroid thickness at each zone.ANOVA was used to compare choroid thickness differences between various zones in each group.Paired t test was used to compare choroid thickness difference at the same zone between two groups.Results The mean age of OK lens group was (12.3 ± 1.8) years old,and the spectacles group was (11.8 ± 1.4) years old,there was no statistical difference.From temple to nasal choroid,the mean CT of the orthokeratology lens group were (296.7 ± 61.8) μm (T3),(290.7 ± 58.9) μm (T2),(285.7 ± 57.4) μm (T1),(278.5 ±57.7) μm (M),(262.2 ±57.9) μm (N1),(239.8 ±59.7) μm (N2),(214.7 ±59.0) μm (N3);And the mean CT of the spectacles group were (294.2 ± 45.4) μm (T3),(292.0±44.0) μm (T2),(283.6 ±45.5) μm (T1),(272.0 ±51.6) μm (M),(255.2 ± 56.3) μm (N1),(236.5 ±58.1)μm (N2),(212.8 ±57.7) μm (N3),respectively.The thicknesses were significantly thicker in temple zones than that in nasal zones in each group (all P ＜ 0.05),but the CT was not significantly different between the two groups in each zone (all P ＞ 0.05).Conclusion The choroid thickness has regional deference in myopia children,the thickest is in the temple and the thinnest in the nasal region.There is no significant difference between the children who initially corrected by spectacles and those who wear OK lens more than 1 year.