What is Conjunctival Chalasis (CCH) and why should I care?
To understand conjunctival chalasis – which is a common disorder of the surface of the eye - it’s best to understand the surface of your eye and how it works.
- When you consider that a tear is the lifeblood of the surface of your eye, then the heartbeat is the blink - which moves that tear around. For this to work best, the surface of your eye must be smooth and even. There is a little gutter; think of a broad well - or a reservoir between our lower lid and the eyeball, housing the best tear that we have. This tear has yet to do any “work,” so that when you blink that tear can come up out of that little gutter with the force of your eyelids coming together and spreading that tear evenly around. This fresh tear needs to replace the old, dirty, used-up tear on the surface of your eye. That old tear gets washed away, ultimately going down into your nose by way of a tear duct. When you have good tears, with good oil, there is very little friction and very little drag over that surface - but if you lose oil, thereby losing tear lubrication, then every time you blink there’s increasing degrees of friction and drag. That friction and drag will, by degree, pull and then stretch the membrane over the surface of the white of your eye. This thin, clear membrane is called the conjunctiva and when it comes loose, we call that chalasis – hence the term conjunctival chalasis (also called conjunctivochalasis or CCH for short).
- Conjunctiva is commonly “shrink-wrapped” over that surface and reflects down into the gutter and then up over the inner surface of your lid - so that there is that nice smooth lining over the gutter housing a fresh healthy tear. With increasing friction comes inflammation or irritation which also weakens some of the support of that membrane to the underlying tissue. As the membrane comes loose from the friction pulling and stretching that membrane, then by degrees, the membrane starts to develop pleats, folds, and wrinkles. These wrinkles then disrupt and distract the tear from moving easily over the surface of your eye. Add poor tear volume to that disruption (the hallmark of Aqueous Tear Deficiency-related dry eye disease) and you end up with a tiny tear now being asked to crawl up a washboard of pleats, folds and wrinkles. This poor distribution means a smaller tear becomes an increasingly dysfunctional, deficient tear. When you blink, if you feel some degree of discomfort in the course of your blink - particularly during strong blinking - then it is possible that this feeling of “running in loose socks,” is an indication that you may have conjunctivochalasis, or CCH. As usual, I recommend seeing a dry eye specialist to sort out the full extent of your dry eye problems and to help you overcome them.
Next week, I’ll address what we can do about CCH