Introduction
Approximate 1.4 million children suffer from blindness around the world.1 Childhood preventable blindness has been identified as a priority of the Vision 2020: “The Right to Sight”2. Pediatric cataract is the leading cause of treatable childhood blindness and accounts for 5 - 20% of childhood blindness3-5. IOL implantation is the main option for optical rehabilitation in children after cataract surgery. There are two main surgical procedures for IOL implantation in cataract infants, i.e. primary IOL implantation and primary aphakia followed by secondary IOL implantation. Due to the risk of postoperative complications, such as inflammatory responses, VAO and secondary glaucoma, IOL implantation in cataract children older than 2 years has been a consensus among pediatric cataract surgeons around the world6-9. But in other cases, children with aphakic spectacles or contact lenses are susceptible to VA issues, corneal problems, compliance with lens-wearing and high cost.
Many studies had reported the clinical performance (including VA and postoperative complications) after congenital cataract surgery7,10-12. However, given the elongation of axial length, change of corneal curvature and high incidence of additional surgery, the benefits and risks of primary IOL implantation in cataract infants, especially in those younger than 2 years, still remains a controversial issue13-15. Surgeons need to weigh the visual benefits agains risk (such as inflammatory response, VAO and secondary glaucoma associated with the procedure) of surgery when they choose IOL implantation for a children younger than 2 years.
Glaucoma is the main complication of congenital cataract surgery and has been discussed in many studies16-18. However, there is no consistent conclusion on which type of surgery can decrease the incidence of glaucoma. Some studies suggested that primary IOL implantation was a protective factor of glaucoma after cataract surgery19,20. Whereas, other studies suggested that the incidences of glaucoma were comparable in primary IOL group and primary aphakia group 11,21,22. Similarly, previous studies didn’t reach consensus on which type of procedure would be better in terms of postoperative VA and complications23,24. Therefore, the present meta-analysis aims to compare the postoperative performance of primary IOL implantation and primary aphakia in cataract infants younger than 2 years, and provide solid evidence for better clinical practice.