Well – they are spelt differently!
But seriously, if someone TOLD you that they had a disorder of the lower eyelid and that it was either an ectropion or entropion, you would be forgiven for not completely HEARING which one it was, remembering that you would probably never have come across the terms before and would ONLY HEAR ONE OF THEM PRONOUNCED!
Before looking at the difference, what is similar?
• Both terms are disorders of the eye, almost invariably the lower eyelid.
• Both involve movement of the eyelid to such an extent that the cornea of the eye can be susceptible to ulcers.
• Both are readily treated by minor surgery
So – what are the differences?
The main difference is provided by the Greek words used in the first part of each word:
• Ectropion – turning or rolling outwards (downwards)
• Entropion – turning or rolling within (inwards)
So then, ectropion involves the lower eyelid rolling outwards and downwards, exposing the eye ball, whereas entropion involves the lower eyelid turning inwards, which means the eyelashes turn upwards and inwards and rub against the eye.
In either of these circumstances the eye is not fully protected which can lead to unpleasant consequences.
Sagging of the lower eyelid means that lubrication of the lower part of the eye is ineffective – they eye dries out and allows infection to set in.
If the dryness extends over the cornea then serious problems can occur with corneal abrasions resulting from eyelids blinking over the dry corneal area.
The reasons why the lower eyelid sags can be due to either muscles and ligaments around the eyes becoming weaker, usually with age, or some kind of facial paralysis setting in.
After initial medication in the form of eye drops and steroid ointments to alleviate symptoms, some form of corrective surgery is required to bring the eyelid back to its normal position.
Turning in of the lower eyelid has a more sinister effect on the eye than does the turning out as in the case of ectropion. Eyelashes and hairs in general, although thought of as quite soft, can be very strong – for example ingrowing hairs on the body need surgery and hospitalisation to prevent blood poisoning and enable a full recovery.
It’s not surprising then that if eyelashes continually rub on the cornea they can do quite a bit of damage. Infections are liable to be contracted, and abrasion will almost certainly lead to corneal ulcers. If not treated correctly then there is the possibility of vision loss.
Initial treatments include eye drops to alleviate any pain and excessive tearing, but something physical and more permanent eventually becomes necessary.
Simple physical and temporary resolutions include suitably placed Botox injections, or tape to hold the eyelid away from the eye.
Surgical options are of course to be preferred. A few well placed stitches in a day surgery should do the trick, whereas some older patients with weak muscles may need a small excision to tighten up the skin.
How do you remember which is up and which is down?
You might be able to come up with a “tag” of some kind to remember which is which.
A simple memory jogger could be: – “n” for in (the eye) – entropion