How can you tell that this contact lens wearer is not getting enough oxygen to their cornea?
Answer: The above eye looks slightly red and irritated, but that can be just as much from an irritating environment as it is from the contacts. To find out if enough oxygen is getting to the cornea, we need to look at this eye under a bit more magnification. Pictured below is the same eye as above in a magnified view and with a narrow light beam to show the corneal neovascularization. The slit lamp biomicroscope picture (below) shows blood vessels moving (right to left) from the white conjunctiva into the clear cornea (the clear cornea is in front of the aqua colored iris). This cornea is starving for oxygen so much that it is recruiting new ("neo") blood vessels ("vascular") from the white conjunctiva because not enough oxygen is getting through the contact lens that this patient has been wearing.
The healthy cornea is clear because of numerous reasons and one reason is that it is an avascular tissue, meaning that in it's normal state it does not have blood vessels going through it so the cornea does not have a direct oxygen supply from the body in its normal state. To acquire oxygen, the cornea relies on receiving oxygen from the environment and when we sleep, the eyelid does a good enough job limiting the amount of oxygen to the cornea. That is why it is extremely important for contact lens wearers to get as much oxygen to their corneas during their time wearing contacts.
Check out one of my next posts that will talk about how contact lens wearers can reduce their risk
for developing corneal neovascularization.
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