IOL implantation promising for pediatric traumatic cataract

A study finds good visual recovery, yet PCO is still a factor.

Issue: August 1, 2003

ByBob Kronemyer

SAN FRANCISCO – Replacing a pediatric traumatic cataract with an IOL will likely result in favorable visual outcomes in the absence of central corneal or macular scarring, according to one surgeon.

“Trauma is a leading cause of unilateral blindness in children. But I would rather defer cataract surgery until the eye is stabilized from the trauma and after any initial repairs,” said M. Edward Wilson, MD, professor and chair of the department of ophthalmology, Storm Eye Institute.

At the American Society of Cataract and Refractive Surgery meeting, Dr. Wilson presented a review of 40 consecutive cases he operated on for traumatic cataracts. The age at surgery ranged from 1.4 to 13.9 years.

“These patients were evenly split between blunt and penetrating trauma cases. The objects responsible for injury varied from BB gun, knife and toy to automobile airbag,” he said.

Complications

Pediatric traumatic cataracts are often complicated by iris damage and lens rupture as shown here.

After removal of a complete traumatic cataract and repair of an iridodialysis, this child’s pupil is reasonably functional. The vision is 20/25.
Photos courtesy of M. Edward Wilson, MD.

Cataract surgery was performed an average of 6 weeks after initial repairs (1 day to 84 months).

“Most of the cataracts were total, white and complete,” Dr. Wilson said.

The median preoperative best corrected visual acuity was hand movements. Preop complications in the group were very common (lens rupture in 19 patients, marked hyphema in 12, corneal scars in or near the visual axis in 11, iris sphincter damage in nine, iridodialysis in eight, significant zonular loss in five, vitreous hemorrhage in four, retinal detachment in three).

Most patients received IOLs in the capsular bag.

“Sometimes we used foldable acrylic lenses and other times PMMA lenses, depending on the shape of the capsular bag,” Dr. Wilson said.

Ciliary sulcus fixation was required in 12 patients, and one patient had an anterior chamber lens.

Pupillary capture was an IOL-related complication in four patients, based on existing iris damage and the re-formation of posterior synechiae. Other postop complications included macular scarring in four patients and posterior capsular opacification (PCO) in 10 of 11 patients where the capsule was left intact.

“My bias has been to take posterior capsules in children,” Dr. Wilson said.

Overall, 29 of the 40 patients had a primary posterior capsulorrhexis because of patient age, a posterior plaque or traumatic existing posterior rupture.

Visual outcomes

BCVA for the total group was a median of 20/30, with blunt and penetrating trauma having equal visual acuity medians.

“When central corneal scarring and retinal macular scarring were avoided, 89% (24 of 27) achieved 20/40 or better,” Dr. Wilson said.

The remaining three patients had deprivation amblyopia from long delays between injury and presentation.

All 20 penetrating trauma patients developed corneal scars, with five scars in the visual axis. One blunt trauma patient also had a traumatic optic neuropathy with a relative afferent pupillary defect. Four blunt trauma patients acquired central retinal scars.

Inflammatory response can be severe when there is no compliance with postop medications, Dr. Wilson said. The instillation of steroids orally can greatly help restore good vision. Surgeons should also consider a scleral tunnel as opposed to a corneal tunnel.

IOP spikes

Surgeons should be alert for postop IOL pressure spikes in patients who have spiked preoperatively.

“Often I find this out after the fact. Therefore, it is important to ask the right questions of the referring surgeon who sewed the cornea. Was there a pressure rise he had trouble controlling?” said M. Edward Wilson, MD.

Patients with traumatic cataract appear to have a temporary pressure spike after cataract surgery, even with uncomplicated surgery, he said.

“A scleral wound is easier to enlarge when you realize the capsule is in poorer shape than you had hoped,” he said.

Other surgical options

Alternative capsulotomy options should also be considered. For example, many children with trauma have fibrosed capsular bags.

“Using diathermy, the Fugo blade or a vitrector may be useful, but avoid aggressive hydrodissection. In many of these cases, you really don’t know whether the posterior capsule was truly intact or not,” Dr. Wilson said.

A vitrector handpiece can be helpful for lens aspiration.

“Previously, I would often find myself engaging vitreous as well as cortex. By aspirating with a vitrector, I can turn on the cutter and minimize the problem from an admixture of cortex and vitreous,” he said.

When the iris is damaged, an anterior capture of the optic through the capsulorrhexis may be advantageous for sulcus IOLs, even when the posterior synechiae re-form. This helps prevent pupillary capture of the IOL. Surgeons should also consider primary posterior capsulotomy and anterior vitrectomy, even in older children.

“I find that PCO is much more common in these patients overall,” Dr. Wilson said. In children where zonular support is in doubt, transscleral suturing is an option. “Only a few clock hours of zonular dialysis and a good bag-fixated lens may warrant suturing that part of the bag through the bag and the IOL,” he said.

Oral steroids may also be appropriate in children implanted with an IOL after removal of a traumatic cataract, “especially if you think that compliance with steroid drops after surgery will be poor,” Dr. Wilson said.

For Your Information:

M. Edward Wilson, MD, can be reached at the N. Edgar Miles Center for Pediatric Ophthalmology, Storm Eye Institute, Medical University of South Carolina, 167 Ashley Avenue, Charleston, SC 29425; (843) 792-7622; fax: (843) 792-1166; e-mail: wilsonme@musc.edu.