Eye Movement Affected in Some Former Childhood Cancer Patients
A study from Lund University in Sweden has shown that commonly used chemotherapy toxins impair the eyesight in childhood cancer survivors in a way that indicates an impact on the central nervous system. The results were published by Einarsson et al in PLOS One.
It was not the former patients' visual acuity that had been damaged, but rather, their eye motor skills—the eye’s ability to follow moving objects.
“We observed that most of these patients were not able to move their eyes smoothly and steadily, but [instead moved their eyes] jerkily and fitfully. Eye movement like that makes it harder to focus on moving objects in traffic, for instance. It can also cause headaches and dizziness,” said corresponding author Per-Anders Fransson, PhD, Reader in Otorhinolaryngology at Lund University.
Study Details
The study included 23 childhood cancer survivors, now aged 20 to 30, and compared them to 25 healthy people of the same age. An average of 15 years had passed since the patients underwent cancer treatment. Only a few of those who had survived cancer experienced no visual disorders, headaches, and dizziness.
The degree of the problem appeared to be related to the degree to which the eye motor skills had been affected, which suggests damage to the central nervous system from the chemotherapy. It has been previously known that cisplatin, methotrexate, and ifosfamide can penetrate the blood-brain barrier, and thereby can damage the nervous system.
The study could not determine whether any of them had experienced side effects that by now had worn off, but it is clear that the majority of them are still suffering the effects of their treatment. Age at the time of treatment appears to play an important role: Those who were youngest at the time of treatment were the most affected.
The study reinforces the importance of coming up with new and better treatments. In the future, the new knowledge, and the diagnostic method described in the study will enable oncologists to pay closer attention to any side effects, in which case it may be possible to reduce the dosage or change medications. Survivors of childhood cancer may experience problems not only with their balance and vision, but also with cardiovascular diseases, fertility, growth, and cognition.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
