The Doctor Is In: Leukocoria in Infants and Children

The Doctor Is In: Leukocoria in Infants and Children

Future Reflections Fall 1988, Vol. 7 No. 3
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THE DOCTOR IS IN:
LEUKOCORIA IN INFANTS AND
CHILDREN
by Dr. Steven Mattas, Ophthalmologist
Maxicare, Inc.
Editor's Note: The following is reprinted from the VIPS Parents Newsletter, Louisville, Kentucky.
There
are many causes for loss of vision in infancy
and childhood. Infections, tumors, and
developmental problems take a definite toll in
eyesight. Although quite dissimilar among themselves,
there are several eye problems of infancy
or childhood which present themselves with the
same sign -- leukocoria. Leukocoria means
"white pupil." Several eye problems of children
are first discovered because they cause a white or
opaque pupil. Congenital cataract, retinoblastoma,
retinopathy of prematurity, nematode endophthalmitis,
persistent hyperplastic primary
vitreous, and Coat's disease all may be first discovered
by observing that the child has a white or
opaque pupil.
Cataract might be our first thought when we see
leukocoria. Congenital cataract can appear
alone or associated with other eye or body system
problems. If examination determines that the eye
has potential for vision and the child's health permits,
congenital cataracts should be removed
soon after birth. An infant with cataracts can
develop a very profound amblyopia. This would
mean that even if successful surgery were performed
later in life, vision may not improve.
Once the cataracts are removed the infant must
use contact lenses or eyeglasses to properly focus
light on the retina. Often there are tactical difficulties
fitting an infant with contacts or glasses.
The doctor might then recommend
epikcratophakla. In this procedure a donor cornea
is ground to the power of a contact lens and
is sutured onto the child's cornea. In a way of
thinking the graft becomes a living contact lens.
A white pupil might also be caused by retinoblastoma.
Retinoblastoma is the most common eye
malignancy of childhood. The tumor arises from
the retina and appears in approximately 1 in
20,000 live births. About 6% of these tumors are
inherited. With the inherited form of the tumor
there is a 50/50 chance that each child of the affected
parent may develop the tumor. About 3
in 10 cases will affect both eyes. The average age
for diagnosis of retinoblastoma is 18 months, and
90% are discovered by age 3 years. As with any
malignancy, discovering the tumor when it is confined
to the retina is favorable. Today, about 90%
of patients who develop retinoblastoma survive
their disease. Removing the eye is recommended
in most cases of retinoblastoma. Radiation and
chemotherapy may also be used.
A relatively new cause of developing a white
pupil is retinopathy of prematurity (ROP). ROP
was first described in the 1940's and reached a
peak in the 1950's. The damage in ROP is caused
by oxygen toxicity to immature retinal blood vessels.
Naturally, a premature infant also has immature lungs and must receive oxygen therapy.
However, now the incidence of ROP has been
stabilized because pediatricians carefully
monitor the amount of oxygen in the premature
infant's blood. Oxygen toxicity to immature
retinal blood vessels can cause scar tissue to
develop within the eye. This scar tissue can apply
a constant traction to the retina and cause it to
detach. In the most severe cases the retina may
completely detach and form a whitish mass behind
the pupil. Retinal detachment surgery is a
benefit to some of these children.
Another disease of retinal blood vessels which
can cause leukocoria is Coat's disease. Coat's disease
usually affects one eye, usually involves
males and it is restricted to the eye with other
body systems unaffected. In Coat's disease
retinal blood vessels are abnormally leaky. Blood
plasma usually confined to the vessel permeates
through the wall of the abnormal vessel. This
leakage can progress to the point where fluid
detaches the retina. Doctors try to control these
abnormal vessels by photocoagulation with a
laser or freezing them with a cryoprobe. Retinal
detachment surgery may be necessary in severe
cases.
An infectious cause of leukocoria is nematode
endophthalmitis. This childhood eye disease is
caused by ingesting soil or perhaps vegetables
contaminated by the parasitic worm, Toxocara.
Toxocara can be found in the feces of puppies
and this is thought to be a main source of contamination.
Once the parasite is ingested it can
travel through the bloodstream to the retina. As
bodily defenses fight the infection, inflammatory
cells and debris can cloud the vitreous jelly of the
eye. Scarring and the development of traction
membranes might detach the retina. Once identified,
the inflammation Toxocara causes can be
combatted with cortecosteroid medication. The
condition usually affects just one eye.
A developmental problem secondary to
leukocoria is persistent hyperplastic primary
vitreous (PHPV). The vitreous is the clear jelly
which fills the back of the eye. Sometimes the
proper development of the vitreous is interrupted
and instead of a clear jelly an opaque
membrane develops behind the lens of the eye.
This membrane can cause a cataract and
glaucoma to develop. Cataract surgery can be
successful in these children if PHPV is the only
problem affecting the eye. The eye involved with
PHPV is usually smaller than the fellow eye, and
90% of the time only one eye is involved.
The variety and scope of these various eye
problems underscore the importance of discovering
a white pupil in an infant. In addition to
the problems described there are still other conditions
which may cause leukocoria. Once the
parent or doctor discovers a white pupil, a diagnostic
investigation is initiated as there are many
different conditions which may be responsible
and many different therapies which may follow.
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