Unknown to most, smoking can lead to blindness and severe vision loss. Smoking is usually tied to causing heart attacks, cancer, and pregnancy complications, but it can also be tied to glaucomas and cataracts. We tend to focus more on the inhalation of cigarette smoke rather than its effect on the surface of the eyes. These surface eye effects occur in inner regions of the eye: the retina, optic nerve, and lens, respectively. Scientists have now discovered that smoke and aerosols from heated tobacco devices also kill cells in the outmost layer of the eye: the cornea. A biomedical researcher from Gifu Pharmaceutical University in Japan named Wataru Otsu said “This is the outermost surface of the eye that is exposed to environmental factors like chemicals, light, and infection,” found in the research article on Scientific American.
Otsu and his colleges performed experiments on corneal cells by exposing them to the smoke of tobacco products for 24-hours. They found that the cells exposed to tobacco smoke died more often than cells that had no exposure. A closer look into the experiment revealed that the cell membrane was damaged due to clumps of iron and an abundance of damaged ferritin: a protein that stores iron needed for DNA synthesis and division. Ferritin is the level of iron in the blood that allows doctors to see whether you have a high or low level of iron. When the cells were exposed to tobacco in high amounts, the signs of damage caused the cell to a programmed cell death driven by iron called ferroptosis.
The effect of tobacco products on the corneal cells leads to ferritin inside the cell starting to break down. When this occurs stored iron begins to be released. The iron will then bunch together and start to react with naturally occurring hydrogen peroxide. Normally the cells’ repair system can cope, but when too many are formed at the same time, they damage the fat in is the phospholipid bilayer, it triggering the lysosomes to explode and causing the cell to die. The breakage of the lipid cell membrane causes the nucleus of the cell to send signals to the lysosomes to start the break down the cell. Eventually, a mass amount of cells in the cornea will break down and begin to make the person go blind.
Though the study proved that smoke from tobacco products is harmful to the corneal cells it cannot be determined how fast the effects can take place. Since the study was on corneal cells rather than a live eye, scientists are unable to predict how fast these cells will self-destruct in a human eye. The next step for this is to conduct experiments on animals involving vaping and the harmful effects it may have. Do you think it will have the same effects?