Secondary Intraocular Lens Implantation in Pediatric Patients

Pediatric patients received minimal invasive surgery and traditional lens removal surgery (anterior capsulorhexis and irrigation/aspiration and posterior capsulorhexis and anterior vitrectomy) are enrolled. The patients are assigned to two groups according to the strategy of primary surgery: Group I: the participants received minimal invasive surgery, while in Group II, the participants received a traditional cataract surgery. Investigators perform a secondary intraocular lens implantation for the patients. Investigators compare the visual acuity, incidence of high intraocular pressure, incidence of visual axis opacification, uveitis and iris/pupil abnormality between two groups after the first and the second surgery, aiming at comparing the prognosis of minimal invasive lens surgery and traditional cataract surgery for treating congenital cataracts.

• minimal invasive surgery and secondary IOL implantation (Procedure): We decreased the size of the capsulorhexis opening to 1.0-1.5 mm in diameter and moved the location of the capsulorhexis to the peripheral area of the lens instead of the central area. A 0.9 mm phacoemulsification probe was used to remove the lens contents and/or cortical opacities. Secondary IOL implantation: implant the IOL either into the capsule bag or fix at the ciliary sulcus.
• traditional cataract surgery and secondary IOL implantation (Procedure): traditional cataract surgery: anterior continuous capsulorhexis + irrigation/aspiration + posterior capsulorhexis + anterior vitrectomy (ACCC+ I/A + PCCC + Anti-vit). Secondary IOL implantation: implant the IOL either into the capsule bag or fix at the ciliary sulcus.

Primary outcomes

• Best corrected visual acuity [recorded at each follow-up (one week, one month, three months, six months after surgery, and every six months thereafter)]: measured using the Teller's acuity card, the Lea symbol visual acuity chart or the ETDRS chart according to the patient's age.

Secondary outcomes

• Visual axis opacification [recorded at each follow-up (one week, one month, three months, six months after surgery, and every six months thereafter)]: Visual axis opacification was recorded by standardized slit lamp retroillumination.
• High intraocular pressure [recorded at each follow-up (one week, one month, three months, six months after surgery, and every six months thereafter)]: measured with Tono-pen tonometer
• Bi-ocular visual function [The examination is performed when the patient is four years old and older, once a year.]: determined with synoptophore

Sex: All, ages: 24 Months to 72 Months

Inclusion Criteria:

Age between 24 months and 72 months Uncomplicated congenital cataract and underwent cataract removal Informed consent signed by a parent or legal guardian

Exclusion Criteria:

* Intraocular pressure >21 mmHg at enrollment Preterm birth (<28 weeks) Presence of other ocular diseases (keratitis, keratoleukoma, aniridia, glaucoma) or systemic disease (congenital heart disease, ischemic encephalopathy) History of ocular diseases (any congenital eye diseases, such as, congenital cataract, congenital glaucoma, congenital aniridia) in the family History of ocular trauma Microcornea Persistent hyperplastic primary vitreous Rubella Lowe syndrome

• Haotian Lin, M.D,Ph.D, Principal investigator, Zhongshan Ophthalmic Center, Sun Yat-sen University