Different Strategies Of Intraocular Lens Implantation In Children Aged 2 Years Or Younger With Bilateral Congenital Cataract

Objective: To evaluate the effect of different strategies of intraocular lens implantation(IOL)in children aged 2 years or younger with bilateral congenital cataract.Methods: This retrospective study included 40 patients(80 eyes)who were diagnosed as bilateral congenital cataract and operated between February 2011 and September 2017.The patients' age of accepting the first operation was 2years old or younger.And they were followed up for at least 12 months after surgery(including primary IOL implantation and cataract extraction/posterior capsulotomy/anterior vitrectomy or cataract extraction/posterior capsulotomy/anterior vitrectomy and secondary IOL implantation).Group A included 34 eyes of 17 patients who underwent primary IOL implantation at 2 years old or younger(?24 months).Group A was divided into two subgroups based on the first operation's age of eyes,the range of first operation's age for group A1(8eyes)was from 6 to 12 months and for group A2(26 eyes)was from 12 to 24 months.Group B included 22 eyes of 11 patients who underwent cataract extraction/posterior capsulotomy/anterior vitrectomy firstly and secondary IOL implantation at 2 years old or younger(?24 months).Group B was divided into two subgroups based on the age of cataract extraction of eyes,group B1(12eyes)was performed less than 6 months and group B2(10 eyes)between 6 and12 months.Group C included 24 eyes of 12 patients.The patients underwent cataract extraction/posterior capsulotomy/anterior vitrectomy at 2 years old or younger and secondary IOL implantation older than 2 years old((>24 months).Group C was divided into three subgroups based on the age of cataract extraction of eyes.group C1(11 eyes)was performed less than 6 months,group C2(9 eyes)was performed between 6 and 12 months and group C3(2 eyes)between 12 and 24 months.In group C,age data of cataract extraction was not clear in 2 eyes,and the data of 2 eyes only participated in comparisons among group A ?B and C.Comparisons were made among group A ?B and C,group B1 and C1,group A1?B2 and C2,group A1?B1 and C1,respectively.The comparison indexes included best corrected distance visual acuity(BCDVA),spherical equivalent(SE),anisometropia,the incidence of adverse events(visual axis opacity(VAO),glaucoma,suspected glaucoma,glaucoma-related adverse events,pupil deformation,endophthalmitis,posterior synechia)and total adverse events and number of operations.Spherical equivalent refraction(SE)was calculated as spherical diopters(D)plus one-half cylindrical diopters using data.The definition of anisometropia was the bilateral difference of refractive error in SE ?1.0D,interocular SE difference ?2.50 D was classified into the severe anisometropia,interocular SE difference ?1.00 D and <2.50 D was classified into the mild anisometropia.Statistical analysis was performed using SPSS 22.0Statistics.Results:(1)Comparisons among group A?B and C:There was no significant difference in the BCDVA among the three groups,but the percentage of better visual acuity(? 0.5 LogMar)in group A was significantly higher than that in group B and C(56% VS 30% VS 17%).There was no significant difference in the average SE at the last follow-up compared with the normal children of the same age for group A,group B and group C,respectively(p > 0.05),there was no significant difference in the proportion of low,high,non-anisometropia among the three groups at the last follow-up.There was no significant difference in the incidence of adverse events and the total incidence of adverse events among the three groups.The number of operations in group A was significantly lower than that in group B and C(median: 1 VS 2 VS 2).(2)Comparisons between group B1 and C1: There were no significant difference in the BCDVA,the percentage of better visual acuity(? 0.5 LogMar),the proportion of low,high,non-anisometropia in the last follow-up,the incidence of adverse events and the number of operations between the two groups.(3)Comparisons among group A1?B2 and C2:There was no significant difference in the BCDVA,the percentage of better visual acuity(? 0.5 LogMar),the proportion of low,high,non-anisometropia in the last follow-up,the incidence of adverse events and the overall incidence of adverse events among the three groups.The number of operations in group A1 was significantly lower than that in group B2 and C2(median: 1 VS 2 VS 2).(4)Comparisons among group A1?B1and C1: There were no significant differences in the BCDVA,the percentage of better visual(? 0.5 LogMar),the proportion of low,high,non-anisometropia in the last follow-up,the incidence of adverse events and the overall incidence of adverse events among the three groups.The number of operations in group A1 was significantly lower than that in group B1 and C1(median: 1 VS 2 VS 2).Conclusions:(1)Primary IOL implantation is safety and also bring good clinical effect for children with bilateral congenital cataract whose first visit time is between 6 and 24 months,including better visual acuity,better refractive control,less number of operations and does not increase the incidence of adverse events.(2)Advancing the time of secondary IOL implantation(12-24 months)can not increase the benefit for children who undergoing cataract extraction less than 6months with bilateral congenital cataract.