To have a cataract describes a condition where the normally clear lens inside the eye is cloudy and obscures vision. Cataracts that develop at or soon after birth in both eyes are a major cause of childhood blindness in the world, especially in developing countries. Treatment is indicated if the cataract prevents normal vision. This can be assessed by measuring how much the child can see and looking into the eye at the cataract. The only way to correct the cataract is to surgically remove it. It is generally accepted that early surgery results in a greater chance of good vision. There are two main approaches to surgery: lensectomy and lens aspiration. Lensectomy removes the entire lens and some of the gel which fills the eye (anterior vitrectomy); lens aspiration removes the lens but leaves the posterior lens capsule intact. A significant complication from surgery is re-clouding of the central passage for vision (visual axis opacification (VAO)). All surgical procedures aim to reduce this and the need for further treatment. Removing the cataract leaves the eye without the ability to focus. This must be corrected as soon as possible after surgery using intraocular lenses (IOL), contact lenses or spectacles, or a combination. The aim of the review was to clarify which surgical approach resulted in the best visual improvement. We searched for studies where children with cataract at or soon after birth had been randomised to receive a type of surgical procedure. The primary outcome was the level of vision after surgery. In the four included randomised studies the type of surgical procedure made no real difference to the final vision but there were differences in the number of children who developed VAO. Procedures which appeared to reduce VAO were anterior vitrectomy (removing some of the gel which fills the eye) and optic capture (lodging the lens portion of the IOL into an opening created in the posterior capsule). Three of the four studies used IOLs to correct aphakia, an option increasingly popular but which may not be suitable in regions where careful follow up cannot be guaranteed. While there is evidence for successful surgical treatment of this type of potentially blinding cataract, there is a lack of good evidence regarding aspects of its delivery such as the best timing for surgery and the appropriate method for aftercare.
Evidence exists for the care of children with congenital or developmental bilateral cataracts to reduce the occurrence of visual axis opacification. Further randomised trials are required to inform modern practice about other concerns including the timing of surgery, age for implantation of an intraocular lens and development of long-term complications such as glaucoma and retinal detachment.
Congenital cataracts are opacities of the lens in one or both eyes of children that cause a reduction in vision severe enough to require surgery. Cataract is the largest treatable cause of visual loss in childhood. Paediatric cataracts provide different challenges to those in adults. Intense inflammation, amblyopia and posterior capsule opacification can affect results of treatment. Two treatments commonly considered for congenital cataract are lensectomy and lens aspiration.
The objective of this review was to assess the effects of surgical treatments for bilateral symmetrical congenital cataracts. Success was measured according to the vision attained and occurrence of adverse events.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochane Library, which contains the Cochrane Eyes and Vision Group Trials Register (2005, Issue 2), MEDLINE (1966 to June 2005), EMBASE (1980 to June 2005, week 27), LILACS (6 July 2005), the Science Citation Index and the reference list of the included studies. We also contacted trial investigators and experts in the field for details of further studies.
We included all prospective, randomised controlled trials that compared one type of cataract surgery to another, or to no surgery, in children with bilateral congenital cataracts aged 15 years or younger.
Two authors extracted data. No meta-analysis was performed.
Four trials met the inclusion criteria. All trials were concerned with reducing the development of visual axis opacification (VAO). This was achieved with techniques that included an anterior vitrectomy or optic capture. Posterior capsulotomy alone was inadequate except in older children.