“The vision of world-renowned Prof. Isaac Caesar Michaelson, former Director of the Hadassah Medical Organization’s Department of Ophthalmology, of creating in 1973 The Jerusalem Institute for the Prevention of Blindness still amazes me,” says Dr. Claudia Yahalom, current head of the renamed Michaelson Institute for Rehabilitation of Vision at Hadassah Hospital Ein Kerem. It is the only multidisciplinary institute in Israel of its kind--a comprehensive facility that enables children as young as two months of age to capitalize on whatever vision they have.
The Institute’s multidisciplinary team includes an ophthalmologist, optometrist, genetic counselor, and social worker. “There are only a few centers like it in the world,” Dr. Yahalom reports.
When parents bring their children to the Institute, they receive a diagnosis, updated treatments when available, and visual rehabilitation, which helps children manage their daily tasks. As Dr. Yahalom explains, “We give parents the explanation they so desperately seek, we teach children how to live with their condition, and we give everyone hope and help.”
Because many of the low vision problems kids face are due to genetic conditions, the Institute offers genetic counseling and testing. “Gene therapy,” Dr. Yahalom notes, “is one of the biggest hopes in medicine nowadays.” However, she says, it is still in the research phase.
One of the most common pathologies seen among children with low vision is nystagmus, characterized by continuous, involuntary movement of the eyes, which induces poor vision. The condition is often a result of a genetic disease. There is no cure for nystagmus, but the symptoms can be improved with measures like eye muscle surgery (which dampens the nystagmus), contact lenses, and other visual aids.
Dr. Yahalom recalls one patient who had applied to serve in the army. When she fitted him with contact lenses, he was so happy because he was now able to see better and become a soldier. The lenses made a big difference, both in improving his vision and in reducing the effect of the nystagmus.
Another genetic eye disease often seen at the Institute is albinism, where a partial or complete absence of pigment in the eye results in poor development of the eye and poor vision. Ninety percent of kids with albinism also have nystagmus. “These children really suffer,” Dr. Yahalom relates. “Not only does the condition make it difficult to see, but the associated nystagmus also affects their self-esteem.” Often, the children say to her, “If you could just fix the nystagmus!”
While the technology to edit a defective gene or replace it with a healthy one has not yet been translated into an available treatment, Dr. Yahalom reports that intensive preclinical research is being done toward that goal. During a short sabbatical at Boston University, she was involved in preclinical research on albinism. She and her colleagues in Boston were performing gene editing in vitro. The technique, called CRISPR-CASP, involved correcting the gene at the mutation site, using stem cells.
Retinitis pigmentosa (RP), which compromises the retina’s ability to respond to light, is a group of inherited genetic eye disorders that are prevalent in Israel. Worldwide, RP affects 1 in 4,000 people. In Israel, it affects 1 in 1,500. Consequently, many families come to the Michaelson Institute for genetic counseling. Dr. Yahalom recalls the story of two individuals, both legally blind, who met in a center for the blind in Israel. They were married and wanted to know if they could have a child with normal vision. The young woman, 23 years old, was known to have albinism. “During our meticulous eye exam,” Dr. Yahalom relates, “we found she suffered in fact from two genetic eye conditions: albinism and aniridia. This latter condition was missed in two generations of her family. After checking the whole family, we saw that aniridia was present in her mom and two other siblings, all legally blind, but with no diagnosis of this disease because of their relatively mild form, which is difficult to recognize. Aniridia is usually associated with underdevelopment of the whole eye, leading to very poor vision or blindness in a high percentage of affected patients. The young woman’s husband also had a genetic eye condition, but, Dr. Yahalom explains, “we did not find the causing mutation for his disease.”
This scenario meant that their child would have between a 50 and 100 percent chance of having aniridia, and a 25 percent chance of having albinism. If the child was born with both albinism and aniridia, the child, like the mother, would be legally blind.
“The main benefit this family derived from their visit to the Michaelson Institute,” Dr. Yahalom explains, “was that we found a second dominant genetic condition, unknown to them until then, that is inherited in 50 percent of cases with each pregnancy.” By knowing about the aniridia, as well as the albinism, the couple could initiate in-vitro fertilization, using preimplantation genetic diagnosis (a technique to test the embryos for genetic or chromosomal disorders prior to transfer into the uterus) to ensure that the pregnancy began with a healthy embryo.
While the goal of identifying a mutation in many cases is to avoid having another child affected with the same blinding condition, Dr. Yahalom says, there are some diseases where gene therapy research is advanced, and gene therapy will probably be offered as treatment, hopefully, in the coming years.
In the meantime, the Michaelson Institute, also known as the Pediatric Low Vision Clinic, has many visual aids to help children see better, including magnifiers for near reading, which can be used from about the age of four or five; closed circuit TV (CCTV) to enlarge print for children at school; computer programs that enlarge the screen font; and telescopic glasses for distance, such as reading text on the board at school and watching television. For blind children, there are devices that read the text aloud.
One of the strengths of the Institute is the ability of its specialists to recognize eye disorders that ophthalmologists in general practice rarely see. Dr. Yahalom cites the case of a young girl who had been told by other professionals that everything was fine with her, despite her nystagmus. She was referred to Dr. Yahalom, who realized that something was wrong in the child’s brain, which was affecting her vision. The girl, in fact, had a brain tumor.
While the Institute is primarily focused on children, its staff members do see adults two days a week. Typically, they are individuals who have lost some of their vision more recently. They are fitted with vision aids so that they can continue working and living their normal lives.
“The Michaelson Institute, with its integrative approach,” Dr. Yahalom says, “provides children who were born with poor vision or blindness with tools to face life as strong as they can be, considering their handicap.” By the same token, Dr. Yahalom adds, “prevention of these diseases in other members of the family is a great help to many individuals.”