Hi there!
Diabetes can affect the blood vessels that deliver oxygen to the eye, resulting in a lack of oxygen in the cells in the eye. When this happens, the eye responds by producing new blood vessels, with the hope of getting more oxygen delivered to its cells.
However, these new blood vessels grow hapzardly in different parts of the eye, including at the drainage angle, leading to obstruction of the drainage system that normally allows fluid (aqueous) to flow out of the eye.
As a result, aqueous fluid builds up in the eye, leading to (very) high eye pressures, damage of the optic nerve and loss of vision -- a condition known as neovascular ("new blood vessel") glaucoma, which is a serious form of secondary glaucoma, resulting from uncontrolled diabetes.
These abnormal new blood vessels are also very fragile and can easily bleed. The blood that is produced either in the front or back compartments of the eye can clog up the drainage system leading to high pressures, nerve damage and glaucoma.
These secondary forms of glaucoma can progress relatively quickly, leading to high pressures that are very difficult to treat, often requiring surgical or laser procedures in addition to eyedrops.
The good news is that this form of secondary glaucoma can be prevented if the blood glucose control is optimal. Furthermore, if detected early, the necessary laser procedures can be performed to prevent rise in pressure and blindness. However, as the condition can be relatively symptom-free until its late stages, do encourage your grandmother to keep to her eye reviews even though she may not have any eye symptoms.
Hope this helps!
Regards,
DQ
