The topic of cataracts in children is surprisingly complex and it is a rare topic that is seen on the preadoption referral information. Cataracts in children have significantly different causes and outcomes than the kind that usually develop in adults. Since most children are young at the time of referral and the timing of the cataract development may not be known, we have to consider most cataracts to be congenital cataracts unless other specific information exists.

The lens of the eye is a clear structure that allows light to pass through and then focuses light on the back of the eye. A cataract is when the lens loses its clarity and develops an area that is cloudy or opaque (opacification). Depending on the location it forms on the lens, a cataract may or may not obstruct the light or vision in the affected eye.

A congenital cataract, by definition, is one that appears within the first year of life. The incidence in the general U.S. population is 4 per 1,000 births.¹ Worldwide, it is estimated that approximately 200,000 children are blind in both eyes as a result of cataracts and that 20,000-40,0000 children are born with cataracts each year.² Congenital cataracts are responsible for 10% of all vision loss in children worldwide.³The high incidence may be due to lower rates of vaccinations (some are caused by infections) and the fact that prenatal care is less widely available in developing countries.^4,5

Cataracts can be unilateral (affecting one eye) or bilateral (affecting both eyes). Some cataracts are stable and do not progress. Others can grow larger over time, which can make it difficult to tell how accurate the diagnosis is with the resources that are available in some referring countries. A unilateral cataract is slightly less likely than a bilateral to be part of another systemic disorder (a disease that affects the whole body), but a unilateral cataract is also more associated with problems in that affected eye.⁶

Cataracts can usually be physically removed through surgery, and lens implantation is now also available for children. However, the younger the child at time of cataract removal, the better the chance they will be able to attain full vision in the affected eye(s). The younger the child with cataract, the greater the urgency to remove it due to the risk of amblyopia or “lazy eye” where the brain does not associate clear vision with the affected eye and turns off signals from that eye. This is especially important in children with significant cataracts in both eyes as they are in danger of blindness or visual disability due to the cataracts. Studies have shown that if the surgery happens at less than six months old, there is a better chance for the development of sight if the cataract obstructs vision. We don’t have studies on the visual potential of children who have their cataracts removed later in life so there is the chance for visual impairment if the child comes home at an older age and has not had their cataract removed. Thus, the earlier the child can have the cataract removed, the better potential there is for the development of their vison.5

However, the main reason that I am cautious about a history of congenital cataract is that 62% (approximately 2/3) of bilateral cataracts are associated with syndromes, prenatal infections, metabolic diseases or other genetic diseases.⁷ All of these can have long lasting brain and other organ effects. Causes include Lowe syndrome, chromosomal defects (genetic), galactosemia (metabolic disease) and TORCH infections (an acronym for a group of diseases/viruses that the pregnant mother can pass to the fetus: toxoplasmosis, “other”agents, rubella, cytomegalovirus, herpes simplex). Most metabolic diseases are lifelong and some have treatments and others are able to be supported but can have consequences for the child’s internal organs including brain. Likewise, TORCH infections are prenatal (before birth) infections that occurred in the birthmother and can infect the developing fetus and can have an impact on the child in terms of vision, hearing, organ systems and brain as well. No matter the type of cataract, it is very important to identify their cause, because cataracts in children often do not occur in isolation. The child should undergo a thorough pediatric ophthalmologic exam and full medical workup, including genetics and metabolic testing and this is not likely to be done in the country of origin so will usually need to be done after the child comes to join your family. The cataract’s exact location on the lens can sometimes also lend clues to what caused it, but this information is not often specified in the preadoption referral.

If there is a history of cataract in the preadoption information, then careful consideration should be given to other physical exam findings, development and screening should be done with an experienced medical provider but the final diagnosis will likely require a leap of faith until the child can come for a full, in-person workup. Because of the statistical odds that the child could have other brain or medical issues besides the cataract, this should be considered with the family in deciding whether they have the resources to workup and support a child should other issues be found after they come to their home.

Summary:

• Cataracts, congenital: The child's vision should be tested by a pediatric ophthalmologist when they arrive in their adoptive home.
• 2/3 of congenital cataracts have causes that may affect learning, brain, and other organs so will need comprehensive testing for metabolic diseases, prenatal infections, syndromes, etc. but likely cannot be done until after adoption.
• The pre-adoptive parent(s) should give consideration to the particular challenges of parenting a child who may have limited or no vision if both eyes are affected and the child is visually impaired/blind.

References

1. Morselli S, Bellucci R. Updated Management of Congenital. Recent Trends in Cataract Management. 2013;2:67.

2. Lim, A., Rubab, S., Chan, Y., Levin, A., "Pediatric Cataract: The Toronto Experience - Etiology" Am J Ophthalmol, 2010; 149:887-892.

3. Plager, D. and Carter, B. "Pediatric Cataracts" Focal Points, AAO, March 2011, Vol. XXIX, No. 2.

4. Bashour M, Menassa J, Gerontis C. Cataract, Congenital. Retrieved January. 2008;23:2009.

5. Foster A, Gilbert C, Rahi J. Epidemiology of cataract in childhood: a global perspective. J Cataract Refract Surg. 1997;23 Suppl 1:601-604.

6. Birch EE, Cheng C, Stager DR. Visual acuity development after the implantation of unilateral intraocular lenses in infants and young children. Journal of American Association for Pediatric Ophthalmology and Strabismus. 2005;9(6):527-532.

7. Rahi JS, Dezateux C. Congenital and infantile cataract in the United Kingdom: underlying or associated factors. Invest Ophthalmol Vis Sci. 2000;41(8):2108.

This article was generously shared by Dr. Judith Eckerle of the University of Minnesota, Adoption Medicine Clinic. Child referrals are becoming increasingly complex, and adoption medicine professionals are identifying many more children with special needs from all countries that participate in intercountry adoption, as well as from the United States. To help families prepare for these changes, Dr. Eckerle and other medical specialists are writing a book: Health Topics For Preadoptive Families.