Pulse
Eye for the Unusual
A University of Minnesota researcher has made the state a hub for the study of albinism and other genetic conditions that affect the eye.
Gail Summers will never forget the little boy on the tricycle. She was a transfer student to the University of Minnesota Medical School starting a pediatrics rotation when the boy came riding toward her. He wore big goggles to protect his eyes because they had no feeling and did not tear. More unsettling, he had no nose. He had picked at it until he’d removed it. Summers could see into his pharynx.
The boy had climbed onto a truck bed loaded with hollow cement pipes that rolled, crushing his head and damaging nerves to his eyes and nose. “It’s something I’ve never seen since,” says Summers, who eventually wrote a paper about him. Her job that day was to take the child to the eye clinic. She took an ophthalmology rotation soon after and knew the first day that she wanted to pursue the specialty. A former speech pathologist, Summers also knew she wanted to continue working with children and adolescents. What she didn’t yet know was that she’d build a career on unusual cases.
During her residency and fellowship at the University of Minnesota, Summers became intrigued by eye conditions that were genetic in origin. In 1984, during her fellowship year, she and retinologist William Knobloch, M.D., started the Genetics Eye Clinic, a multidisciplinary clinic with several geneticists on site that was unique at the time. “One of the first patients we saw,” Summers recalls, “was a woman who made some pigment, but not enough. She was in her 40s and had never been told she had albinism.” Work done in the clinic’s lab determined the exact gene defect causing her type of albinism.
Summers and geneticist Richard King, M.D., went on to establish the International Albinism Center at the university in 1989, which conducts research and tests patients for the specific gene mutations in various forms of albinism. Summers has since become known for her work in albinism. A PubMed search yields an impressive collection of published articles on the condition as well as strabismus, amblyopia, retinopathy of prematurity, and other genetic conditions with visual manifestations. And her many accomplishments include establishing a grading system for clinicians to better quantify the amount of pigment in the eye and to better relate the quantity of pigment with other features associated with albinism.
Albinism and the Eye
Derived from the Latin word albus, meaning white, albinism refers to a group of genetic disorders causing persons to make less melanin, sometimes with manifestations only in their eyes. The prevalence of albinism in the United States is one in 17,000.
Depending on the type of albinism a person has, he or she may or may not display white hair or pale skin (people with both ocular albinism and some forms of oculocutaneous albinism make pigment in the skin and hair). Most individuals with the condition are light-sensitive, needing filtered glasses, wide-brimmed hats, and sunscreen, and many have a high refractive error.
Albinism affects the eye in a number of ways: Diminished pigment in the iris increases light sensitivity. Lack of a central foveal pit, the location on the macula where vision is sharpest, can lead to blurred vision and poor stereopsis. A neural network abnormality in which the neurons from the optic nerve of each eye split off at the optic chiasm unequally rather than equally may contribute to an increased incidence of strabismus and poor stereopsis. And the presence of nystagmus (rapid eye movements) can reduce vision.
Summers explains that making a diagnosis of albinism can be difficult, as people with the condition can make varying degrees of pigment. In fact, most persons with albinism have blue or gray eyes. People with greater amounts of pigment have green or hazel eyes. An X-linked ocular form of albinism occurs in boys who otherwise have normal hair color and sun-tanning abilities.
“What’s nice about our clinic,” she says, “is that we have a higher level of awareness that a child with nystagmus may have albinism, and then we look carefully for those features.” Her staff then works with geneticists to further define the type of albinism the child has. Her message to primary care physicians is to forget cultural beliefs about albinism presenting with stereotypical white hair and pink eyes.
Summers says early diagnosis is important because even though children with albinism have a visual acuity typically quite below that of other children, they tend to develop better vision and better eye alignment when given glasses very early—even as early as 6 months of age—and for a mild refractive error not typically requiring correction.
In her joint appointment in the University of Minnesota’s departments of ophthalmology and pediatrics, and as director of the Genetics Eye Clinic, Summers sees two to four patients with albinism a week (general ophthalmologists may see only a few over the course of a career). Patients with albinism seek her out from as far away as Greece, Puerto Rico, Singapore, and South Africa. And through them, she has heard some shocking stories about how people with albinism are viewed in different cultures. For instance, she tells of the mother of one patient who fled Africa with her child when it became widely known that the baby had albinism, as folklore still holds that throwing an albino baby into a volcano will calm a threatened eruption. “Horrible things happen to people with albinism in parts of Africa including dismemberment, as body parts are thought to have magical powers, and the rape of girls with albinism, which is believed to cure AIDS in the rapist,” she says.
Questions Lead to Studies
One of the most rewarding aspects of Summers’s work is mentoring medical students, fellows, and residents. Together, they conduct clinical studies, write them up (she tells them to expect to do seven drafts), and present papers at national conferences.
Ideas for research projects often come from patient questions, including a recent study having to do with albinism and driving. Some persons with albinism are legally blind, but others can have their vision corrected well enough to drive. Summers says parents often ask if their child will be able to drive. “Over time I realized that what they really wanted to know was, ‘Will my child be able to drive as safely and as well as I want him to drive?’”
Summers and her students designed a study using a driving simulator. Twelve licensed drivers with albinism were matched by sex, age, and driving experience to 12 controls. They “drove” on pathways simulating rural and urban scenarios, in sunny and rainy conditions, and through speed-controlled areas and school zones. The only significant difference found was that drivers with albinism tended to follow a leading vehicle more closely under sunny conditions. Also, data from an accompanying questionnaire showed that the drivers with albinism had no history of significantly more serious or frequent accidents than the controls.
Many times over their 32-year marriage Summers has collaborated on studies with her husband, pediatric neurologist John MacDonald, M.D. “We continue to learn from each other,” she says. “There is overlap between the brain and the eye; we have conducted some very interesting studies together.”
Because parents often ask if their newly diagnosed child will be developmentally delayed, Summers and MacDonald recently looked at neurodevelopment in albinsim. “It had never been studied before,” she says. “We had them hopping, throwing a ball overhand,” she says of the tests they put participants through. They learned that neurodevelopment is completely normal in children with albinism and that families should expect to see the range of performance seen in the general population.
She and MacDonald also led a recent study investigating whether children with albinism have a higher incidence of ADHD (another question that came up too often to be ignored). Children attending a National Organization for Albinism and Hypopigmentation (NOAH) conference were examined by MacDonald, and their parents filled out questionnaires to determine whether the children are often inattentive because they don’t see well or because they have ADHD. They found that children with albinism do have a higher rate of ADHD.
The albinism community greatly appreciates these studies. “There is amazingly little research on albinism, let alone its effects on the quality of life of children,” says Michael McGowan, president of NOAH. Summers believes the International Albinism Center plays an important role in providing support to families. “I have a clinic in which I see a lot of families with albinism, but almost none of them have ever met another family with albinism,” she says. During a recent clinic, an African-American family told Summers they would like to meet another family raising an African-American child with blue eyes and blonde hair. She has since met such a family with twins who have albinism and introduced them to the other family.
Such introductions often take place right in the waiting room, and families have even moved to the Twin Cities to get care, resulting in local support groups and even playgroups for children with albinism.
Summers, who was recently elected president of the American Association for Pediatric Ophthalmology and Strabismus, hopes that one day treatments will become available to give individuals with albinism better vision. Toward that goal, she consults with researchers at other institutions. “They all want better vision,” Summers says of the parents of children who are seen in her clinic. “I have never had a parent not ask for their child to see better.”—Ann Treacy