Surgical Outcomes Of Congenital Cataract In Eyes With Microcornea

Objective: To investigate the intraoperative and postoperative outcomes of congenital cataract surgery in eyes with microcornea.Methods: We retrospectively reviewed the records of 36 eyes of 20 patients who were diagnosed as microcornea and congenital cataract,and accepted the operation between June 2009 and September 2019 with a minimum follow-up period of 3 months.Corneal diameter was less than 10 mm in all patients.All children underwent Cataract surgery,with or without intraocular lens(IOL)implantation.Patients with a history of ocular trauma or existing eye disease such as glaucoma or retinal detachment were excluded from the study.The age at surgery was collected before surgery.Preoperative examinations included corneal diameter,axial length,and eye and systemic abnormalities.Intraoperative observations included pupillary dilatation,the size of anterior and posterior capsulotomy.Postoperative observations included visual outcome,intraocular pressure,visual axis obscuration(VAO),glaucoma and unplanned secondary surgery rate.Statistical analysis was performed using SPSS 22.0Statistics.Results:(1)Basic information : This retrospective study included 36 eyes of 20patients(twelve boys and eight girls).Preoperative diagnosis was bilateral microcornea and bilateral congenital cataract in 16 cases.4 cases of unilateral microcornea and bilateral congenital cataract were diagnosed.The corneal diameter was more than 10 mm in all 4 children with monocular microcornea.Among the 20 patients,family history of cataract in 1 case and cerebral palsy in1 case.(2)Preoperative ocular condition : The corneal diameters at the time of surgery was 8.33±0.25mm(6.8 to 9.54mm),including 1 eye with corneal diameter less than 7.0 mm,3 eyes with 7.00～8.00 mm,29 eyes with 8.01～9.00 mm,and 3 eyes with 9.01～9.54 mm.Of the 36 eyes,23(63.9 %)had nuclear cataract,13(36.1 %)had total cataract.The mean axial length was 17.76±0.56mm(range 13.37 to 23.59 mm)and the mean preoperative average intraocular pressure was 12.56±2.97 mm Hg.(3)Operation condition: The mean age at initial surgery was 9.01 ± 3.97months(range,3 to 72 months).There were 12 eyes in 6 patients aged less than6 months at the time of initial surgery,and the surgical approach was cataract extraction + posterior capsulotomy + anterior vitrectomy,of which 8 eyes in 4patients were combined with prophylactic peripheral iridectomy during surgery,and none of the 12 eyes underwent IOL implantation at the time of the first surgery.The age of operation ranged from 6 to 12 months,18 eyes of 11 patients underwent cataract extraction + posterior capsulotomy + anterior vitrectomy,of which 3 eyes of 2 patients received primary IOL implantation and 1 eye received intraoperative combined preventive peripheral iridectomy.There were 4 eyes of2 patients aged 2 ～ 5 years,of which 3 eyes of 2 patients received primary IOL implantation,and the other eye did not undergo primary IOL implantation because the corneal diameter was less than 8.5 mm.There were 2 eyes in 1 case over 6 years old,2 eyes with cataract extraction + IOL implantation + posterior capsulotomy + anterior vitrectomy.Intraoperatively,8 eyes showed poor pupillary dilatation,and iris hooks was used in all 8eyes to stretch the pupil and increase the surgical field of vision.According to the corneal diameter and axial length,a total of 14 eyes of 8patients underwent IOL implantation in this study,of which 8 eyes of 5 patients were underwent primary IOL implantation,the corneal diameter ranged from8.54 ～ 9.00 mm in 4 eyes,the corneal diameter ranged from 9.01 ～ 9.54 mm in 3eyes,and the corneal diameter was 8.54 mm in 1 eye,and the IOL loops were subtracted and implanted during surgery;6 eyes of 3 patients were underwent secondary IOL implantation,the corneal diameter ranged from 8.14 ～ 9.00 mm in 3 eyes,and the corneal diameter ranged from 9.01 ～ 9.50 mm in 4 eyes.Among the children with secondary IOL implantation,the corneal diameter of 1eye was 8.14 mm,the preoperative pupil could not be dilated,the residual capsule could not be assessed,and the residual capsule was found to be unable to support the IOL during surgery,so IOL ciliary sulcus suture fixation was performed,and the IOL was removed due to uncontrolled intraocular pressure 1year after surgery due to secondary glaucoma caused by trauma.(4)Postoperative condition: The median follow-up period was 24 months(range: 5 to 86 months).Postoperatively,the most common early complication was transient corneal edema observed in 9 eyes(25.0%).Late complications included visual axis opacification in 2 eyes(5.5%),secondary glaucoma in 3eyes(8.3%)and ocular atrophy in 1 eye(2.8%).Of the 3 eyes with secondary glaucoma,1 eye had a corneal diameter of 8.14 mm,the age of initial surgery was 12 months,and phase II IOL ciliary sulcus suture suspension was performed at 24 months.One year after the second surgery,the secondary glaucoma was caused by trauma,and the glaucoma could not be controlled by triple ocular hypotensive drugs(timolol maleate eye drops + brinzolamide eye drops +travoprost eye drops),while IOL removal was performed to remove the IOL,and the postoperative intraocular pressure was controlled steadily(12 ～ 18 mm Hg);2 eyes had a corneal diameter of 9.00 mm,the age of initial surgery was 6 months,and no second surgery was performed.At 90 months after the initial surgery,the secondary glaucoma occurred,and the intraocular pressure was still poorly controlled(intraocular pressure 17 ～ 36 mm Hg)after the use of triple ocular hypotensive drugs(timolol maleate eye drops + brinzolamide eye drops + travoprost eye drops).There were 3 eyes with unplanned second surgery,2 eyes had optic axis opacification 1 year after the initial surgery,and 2 eyes had posterior cataract resection.One eye underwent IOL ciliary sulcus suspension at stage II,and 1 year after surgery,IOL removal was performed due to secondary glaucoma caused by traumatic impingement of the eye,which could not be controlled by intraocular pressure.The Best corrected visual acuities in 15 eyes in children capable of the vision test at the last follow-up were 0.3 or better in 8 eyes,0.15 to 0.25 in 6eyes,and 0.1 or worse in 1 eye.Refractive status was followed up in 13 eyes with IOL,emmetropia(-0.5 ～ + 0.5)in 4 eyes;hyperopia in 6 eyes,all with mild hyperopia(+ 0.5 ～ + 3.0);and myopia in 3 eyes,all with mild myopia(-0.5 ～-3.0).Conclusions : Surgical intervention for congenital cataract in eyes with microcornea can result in favorable outcomes with an acceptable rate of postoperative complications.