Early-age surgery presents challenges, benefits
David Hunter, MD, PhD
Brennan Hughes-Shiverick was diagnosed with pediatric
cataracts at 1 year old. He needed surgical removal of the cataracts,
but with traditional methods, even after the procedure his parents
would have needed to fit his tiny eyes with contact lenses for
his vision to develop correctly.
Although mild cataracts in older children can sometimes
be treated by patching the eye, using dilating eyedrops or prescription
glasses, most pediatric cataracts require removal by surgery.
Pediatric cataracts are uniquely challenging to ophthalmologists
and are not like the cataracts that occur in adults. The eyes
are too small for some of the standard cataract instruments. The
lens itself can be extremely soft, rock hard or membrane-like,
with increased risk of bleeding. The inflammatory response of
the eye can be tremendous, requiring removal of the vitreous and
intense steroid therapy after surgery. And after surgery, the
child must be treated with amblyopia therapy, or the vision will
not recover despite a good technical result.
Brennan's problem was not the removal of the
cataracts, but retraining his eyes to focus after the procedure.
The options available to children his age are problematic. Contact
lenses and prescription eyeglasses are an option, but pose serious
compliance issues, especially in younger children. If a child
fails to wear lenses regularly after the procedure, long-term
outcomes will be affected.
The alternative is surgical implantation of intraocular
lenses, but this has traditionally been avoided in children under
6 years because of their intense inflammatory response and high
rate of implant rejection. However, under the leadership of David
Hunter, MD, PhD, chair of Ophthalmology
at Children's Hospital Boston, intraocular lenses are successfully
being placed in younger and younger patients. Dr. Deborah
VanderVeen [assistant in Ophthalmology] and I have been
successfully doing this procedure on children from 1 to 5 years
old for long enough that it is now fairly routine for us, although
it is never easy, says Dr. Hunter. In some cases the
procedure is appropriate for children as young as 6 months.
Surgical implantation of an intraocular
lens. The folded lens is inserted through a 3 mm incision
and unfolded to its full 13 mm size.
When Dr. Hunter met Brennan, he was certain surgery would be appropriate.
He not only performed the procedure, but invited the child's
ophthalmologist to participate. Dr. Hunter used a 3-mm knife to
enter the anterior chamber of the eye. He aspirated the cloudy lens,
then injected an acrylic lens into the existing lens capsule, where
it unfolded to its full, 13-mm size. He removed the posterior capsule
behind the implant to prevent clouding, as well as part of the vitreous
to prevent formation of cloudy scar tissue. He closed the tiny incisions
with ultra-fine, absorbable sutures.
Choosing the lens power is a very complex
process, since the eye is still growing, says Dr. Hunter.
We use special software in the operating room to predict
the patients' eye growth in future years so that we can choose
the best possible lens. Ideally, we will never have to replace
the implant even though we know that the eye will grow.
The success of cases such as Brennan's owes
both to the technology employed and the experience of Children's
doctors, who see relatively high
volume for a disease that affects just one in 2,000 children.