Lund University researchers in Sweden have shown that chemicals commonly used in chemotherapy treatments negatively affect the eyesight in children being treated for cancer. The chemicals impair their vision indirectly by having an impact on the child's central nervous system.
Modern medicine has saved the lives of countless childhood cancer patients, but the methods used to destroy cancer often comes at a cost, one above and beyond the actual price tag for the procedures. A measurable number of patients treated for cancer with chemotherapy suffer from long-term injuries due to the toxins used in the process.
The study details the effects these toxins had on the children's vision, which didn't impair their visual acuity, but rather the muscles around the eyes, limiting their ability to track and follow moving objects.
Per-Anders Fransson, Otorhinolaryngologist and researcher at Lund University, states "We observed that most of these patients were not able to move their eyes smoothly and steadily, but 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.”
The 23 participants in the study, currently aged between 20 and 30, were all childhood cancer survivors who had undergone chemotherapy treatments. Their test results were compared against those of 25 healthy people within the same age range. Of the cancer survivors group, only a small minority did not presents symptoms of the disorder, including headaches and dizziness. There appears to be a correlation between the degree to which the motors skill of the eye were affected, and the degree of symptoms experienced, suggesting damage to the central nervous system caused by chemotherapy.
It has been known for some time that the three forms of chemo tested in the study, cisplatin, methotrexate, and ifosfamide, are capable of passing through the blood-brain barrier and affecting the nervous system. What has not been known is to what degree did these drugs have on eye motor skills and vision, specifically in children.
For the 23 cancer surviving participants, an average of 15 years had passed since their chemotherapy treatments. Too much time had passed for any information to be gathered on short term side effects, but the data collected indicated that their age at the time of treatment played a large role in the severity of the effect. Those who underwent chemotherapy at a younger age were more affected than those that were treated later in life.
Consulting Pediatric Oncologist Thomas Weibe said "A child's brain has not completely developed, which makes it more susceptible to the influence of foreign substances." However, he argues that, until further advancement are made in medicine, we must continue to use the methods we have available to us today. Ultimately, saving someone's life is a much greater concern than some of the possible side affects that have been observed. That's not to undermine the importance of further research, and developing new and better treatments.