Analysis Of The Morphological Characteristics Of Peripapillary Choroid Of Teenagers With Ametropia

Objective To study the morphological characteristics of peripapillary choroid of the teenagers aged 6 to 18 years old using spectral-domain optical coherence tomography(SD-OCT).The relationship of peripapillary choroidal thickness and the ocular or systemic parameters were analyzed.The emphasis was to observe the characteristic changes of the peripapillary choroidal thickness as the age grows and their thickness profiles under different refractive status.And we also aimed to establish a reference range of the peripapillary choroidal thickness of teenagers aged 6 to 18 years old by SD-OCT.Methods 834 teenagers aged 6 to 18 years old were randomly selected and measured the ocular parameters(Axial length,spherical equivalent,intraocular pressure,central corneal thickness,Corneal curvature,Radius of curvature of the cornea,anterior chamber depth,len thickness and so on)and systemic parameters(height,weight,body mass index(BMI),waist circumference,Systolic/diastolic blood pressure and so on)of them.To measure the peripapillary choroidal thickness with the optic disk centred the the scan diameter 3.4mm by OCT and the measurement parameters were as follows,eight locations(temporal,superotemporal,superior,supe-ronasal,nasal,inferonasal,inferior,and inferotemporal)each equidistant(45°)to the next location and we also divided the peripapillary region into six sectors and measured the PPCT in each of these sectors :the 360o circle PPCT,the temporal and nasal quadrants(90°)PPCT,the superiortemporal,inferiortemporal,superiornasal and inferiornasal sectors(45°)PPCT and then to analyse PPCT and its distribution under different refractive status(hyperopia,emmetropia,mild myopia,moderate myopia and high myopia)and analyse the related ocular parameters and systemic parameters.Results Mean PPCT of the right eye of all the participants was 138.27±34.58?m and the left eye was 138.23±35.19?m and there was no statistic difference between both eyes.The distribution of the PPCT under different refractive status is uneven.The mean PPCT,temporal PPCT,superior PPCT,nasal PPCT and inferior PPCT were 138.27±34.58?m,136.39±42.77?m,151.20±41.95?m,150.23±44.18?m,111.20±36.12?m respectively.The distributions of PPCT were different under different refractive status.The distribution the choroidal thickness of hypermetropia and emmetropia group was nasal PPCT >superior PPCT>temporal PPCT>inferior PPCT and was superior PPCT>nasal PPCT>temporal PPCT>inferior PPCT of mild myopia,moderate myopia and high myopia groups.Inferior PPCT was always the thinnest of all the PPCT under different refractive status.Mean PPCT was correlated with age,was not significantly associated with male,axial length and spherical equivalent.As myopia progressed,temporal and inferotemporal PPCT became thinner,superior PPCT became thicker and there is no change about the thickness of other places.The temporal and inferotemporal PPCT was not significantly associated with systemic parameters.Conclusion There is association between mean PPCT and age.Choroidal thickness increase with older age.The average peripapillary choroidal thickness of teenagers increases with age at age 6 to 8 years and 10 to 15 years,and decreases or tends to stabilize at the age of 8 to 10 years and 15 to 18 years.We speculate that the growth of the choroidal thickness of the adolescents is divided into two stages,early childhood and adolescence.With the increase of myopic degree,the temporal and inferotemporal PPCT by point measure and temporal PPCT by regional measure is gradually thinner and is not correlated with the body index.Therefore,the monitoring of the lower 1/2 region of the temporal may be of great significance for studying myopia and myopia complications in future.The distributions of PPCT were different under different refractive status,however,the inferior PPCT was always the thinnest.This discovery may play an important role in the monitoring and prevention of myopia glaucoma.