The Study Of Lens Parameters On Myopic Children With A History Of Retinopathy Of Prematurity

Objective: To investigate the change characteristics of biometrical optical components and lens parameters in myopic children with a history of retinopathy of prematurity(ROP)at 1 to 6 years of age and to explore the mechanism of myopia of retinopathy of prematurity(MOR).Methods: From January 2015 to December 2016,preschool children with a history of retinopathy of prematurity who were followed-up at the department of ophthalmology enrolled in our study.They were divided into two groups according to the presence of myopia :Myopic children with a history of retinopathy of prematurity(MOR group),non-myopic children with a history of retinopathy of prematurity(Non-MOR group),age-matched preterm children with normal refractive status were recruited as control group.For all subjects of each group,Corneal Curvature(CR)were measured by Auto-refractomer.Refraction was measured by retinal retinoscopy under small pupil.Anterior chamber depth(ACD),Lens thickness(LT),Vitreous depth(VITR),and axial length(AL)were measured by A-scan ultrasonography.cycloplegic streak retinoscopy and A-scan were performed after 1% atropine ophthalmic gel applied for three days and recorded as spherical equivalent(SE)and lens thickness after the mydriasis.The optical components of MOR were analyzed by comparing the differences of optical components in each group.The relationship between MOR and lens accommodation parameters was investigated by comparing the diopter before and after dilation and the change of lens thickness before and after mydriasis.Results:1.The study included 156 cases and 305 eyes,MOR group of 52 cases(100 eyes),Non-MOR group of 51 cases(99 eyes),Control group of 53 patients(106 eyes).There was no significant difference in age,gender distribution,gestational age and birth weight among the three groups(P> 0.05).2.Compared with Non-MOR group and the control group,MOR group was characterized by shallower ACD and thicker LT,the difference was statistically significant(P <0.01),and the CR,VITR and AL among the three groups were not statistically significant(P> 0.05).3.Compared with Non-MOR group and the control group,MOR group aged 1 to 3 years of age had relatively steeper CR,shallower ACD and thicker LT,there were significantly statistically significant among the three groups(P <0.01),the CR,ACD,VITR and AL values among the three groups were not statistically significant(P> 0.05);MOR group aged 4 to 6 years of age had thicker LT,there were significantly statistically significant among the three groups(P=0.006),while the diffrence in CR,VITR,VITR and AL were not statistically significant among the three groups(P> 0.05).4.Compared with Non-MOR group and control group,the difference of lens thickness before and after mydriasis(?LT)in MOR group was smaller(P<0.001),there were significantly statistically significant among the three groups(P<0.01).5.Compared with Non-MOR group and control group,the difference of rafractive diopter before and after mydriasis(?SE)in MOR group was smaller(P=0.009),the difference was significantly statistically significant among the three groups(P<0.01).Conclusions: 1.MOR children were characterized by thicker lens and shallower anterior chamber,but there were no significant abnormalities in corneal curvature,vitreous cavity depth and axial length compare to preterm children with normal refractive status.2.The occurrence of MOR at 4 to 6 years may be related to the changes of lens parameter,While the occurrence of MOR at 1 to 3 years may be also related to steeper corneal curvature.3.The changes of lens parameters in children with a history of ROP may be one of the main mechanisms for the development of MOR.