Color Vision Screening Test Proven Fast and Accurate

Imagine being color blind in kindergarten where, before reading, virtually everything is color-coded. Worse, imagine overcoming that rough start and being colorblind at 18, with the lifelong dream and hard-won accomplishment of an appointment to a U.S. service academy -- only to lose it at the eye exam.

Now, there is a fast, accurate screening test that can save colorblind children, their teachers and parents a lot of grief from the start. The test was developed by a husband and wife research team from the Eye Institute of the Medical College of Wisconsin and Froedtert Hospital.

The efficiency and effectiveness of this simple screening tool were validated in a field study with the help of 5,058 children at 14 local elementary schools, and an unique genetic follow-up test, developed earlier by the same researchers. A grant from Ronald McDonald House Charities of Southeastern Wisconsin funded the field study.

The newly-patented Neitz Test of Color Vision is a pencil and paper test that a teacher with no special training can administer to an entire classroom, under ordinary lighting, in about ten minutes. Teachers can also see and score the results immediately, giving them a much clearer idea of how the vision of their colorblind students differs from their own. The test was developed by the MCW research team of Jay Neitz, Ph.D., associate professor of cell biology, neurobiology and anatomy, and ophthalmology; and Maureen E. Neitz, Ph.D., associate professor of ophthalmology, and cell biology, neurobiology and anatomy.

Current research reports that eight to ten percent of all boys and one in 230 girls is colorblind, and the screening test produced similar results. There are two major categories of colorblindness, and a wide range of severities for these congenital red-green color vision defects. For the genetic follow-up test, given to those whose screening tests suggested a color vision defect, a bit of DNA is obtained, via a soft swab rubbed inside the cheek, and analyzed. Genetic testing not only confirmed the presence of defects, but also revealed their type and severity with great accuracy. This provides students with much more-detailed information about how a specific defect might influence their life.

The genetic test represents years of color vision research by the Neitzes, who recently worked out the molecular genetic basis for why there are large individual differences inthe severity of color blindness among people with the defect. It is one of the first examples of a defect of the nervous system where examination of a person's DNA can predict not only the occurrence but also the severity of a defect.

This is an important breakthrough because as scientists strive to understand the genetic basis of human disease, it is often more important to forecast the severity of the impairment than to merely reveal the presence of a genetic defect.

While studying human color vision, the Neitzes have not only revolutionized the long-standing theory for its genetic basis, but also found unique opportunities to discover the causal chain from the gene, to protein function, to the neural signal. While they continue their study of color vision, they are also applying its lessons to other kinds of genetic defects that cause visual impairment. A long term goal is to extend their basic knowledge of the role that genes play in construction of the nervous system.

They also hope that some of their findings will lead directly to methods for early diagnosis of disorders of the retina, and ultimately, will contribute to the discovery of effective therapies for disorders of the visual system.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.