The Cutting Edge

Jacqueline S. Homan

Myopia and hyperopia, two vision problems based on refractive errors in the eye, are primarily genetic, according to recent research led by Dr. Gu Zhu of the Genetic Epidemiology Unit, Queensland Institute of Medical Research, Brisbane, Australia. The probable location of the offending gene has been identified by Zhu and his team. He believes it lies on the long arm of chromosome 5, containing the genes that help determine axial length. Axial length, the measurement from the front to the back of the eye, is a key factor in these refractive errors. When the axial length is not normal, the eye cannot focus correctly without corrective lenses. Axial length is longer than normal in nearsighted people and shorter than normal in farsighted people.

Myopia is more commonly known as nearsightedness and hyperopia is farsightedness. Sufferers of myopia cannot see far away; those with hyperopia cannot see close up. Zhu’s research confirms the long-held view that both conditions are most likely inherited.

Vision experts have determined that myopia is on the rise both in the United States and globally, thus research efforts have intensified accordingly. Myopia is expensive to treat if it is severe, and costly to the patient’s quality of life. Dr. Zhu’s study focused on myopia, building on previous research on genetic aspects and environmental factors. He recruited 893 individuals from the Tasmania Twin Eye Study and the Brisbane Adolescent Twin Study (BATS) in Australia, obtaining axial length measurements. The team analyzed the proportional impacts of genetic and environmental factors on axial length values after adjusting for age and sex. His study breaks new ground in linking axial length to the heritability of refractive error.

By performing a genome scan on a subset of 318 individuals, the researchers found “strong evidence” for the role of chromosome 5 (specifically the 5q region) in the inheritance of axial length. Dr. Zhu’s team has launched a genomic analysis of a larger study group to confirm and refine this finding. Other studies have suggested that environmental factors such as regular periods of outdoor play during childhood as opposed to having children concentrate only on reading and other “near work” might help reduce the development of myopia, at least in those who are genetically susceptible. Identifying strong genetic markers could further this and other preventive efforts.

However, genetic research comes with a morally compelling caveat. Science has a history of being co-opted by elites who embraced American eugenics. Eugenics was a genocidal pseudoscience undertaken in 29th Century America determined to wipe out all individuals deemed “unfit.” A leading indicator of which families were entitled to live or die, in the eyes of the eugenists, was perfect vision. During the first decades of the 20th Century, the ophthalmology profession as a group, led by its most illustrious figures, began a crusade to identify, incarcerate and prohibit the reproduction of all individuals with even a slight eyesight problem, this in a misguided effort to eliminate vision problems in America.

Bestselling investigative author Edwin Black chronicled the dark history is his turning point book on the subject, War Against the Weak. Black devoted a special chapter entitled “Blinded” to the topic. American eugenics inspired Hitler to medicalize his war against the Jews and all mankind. Dr. Josef Mengele, a product of a Rockefeller Fund eugenics fund in Germany, based many of his gruesome and torturous eye color experiments on countless Jewish twin children, according to Black’s book. For this reason, cautionary critics of genetic research are always wary of forays into the realm of inherited vision problems.

Jacqueline S. Homan is an author and Cutting Edge News contributor.