A red eye is the rush of blood through the vessels of the soft tissues of the eye (conjunctiva, sclera, episclera). It is a symptom caused by a lot of etiologies that can be benign or very dangerous. Consequently, some need treatment and are considered as medical emergencies and other not. How to differentiate between these two conditions? What to do about the dangerous ones?
What symptoms should indicate that the underlying cause is serious?
If you have a red eye you should pay attention to the presence of at least one of these 3 symptoms:
- Visual loss (or colored halos);
- Painful eye;
- Photophobia (discomfort in the light).
If any of these three is present it could be one of these 4 main etiologies: acute glaucoma, keratitis, scleritis or iridocyclitis.
I-Acute glaucoma
An acute glaucoma is the result of a high pressure in the eye. This pressure is due to a tight angle (this why it is also called "closed angle glaucoma") between the iris and the cornea, that prevents the reabsorption of the eye liquid (vitreous humor) causing the internal pressure of the eye to increase.
The pain is unbearable. This is why most cases consult immidiately. The treatment of such cases is urgent due to a potential permanent lost in vision and consists of medications to lower the intra-ocular pressure and a laser iridectomy.
II- Keratitis
It is an inflammation of the cornea caused by a virus (herpes, zona …), a bacteria, an allergy (e.g.: to lenses),a trauma or a neurological defect (inability to close the eye). If not treated, it may evolve into an ulcer that may permanently deform the cornea. The treatment consists of an application of local antibiotics and not of cortisone that is contraindicated in such cases.
III- scleritis
It is an inflammation of the white outer coating of the eye. Scleritis is a connective tissue disease that may be accompanied by other systemic manifestations. It is caused by a modification of the caliber of the vessels, and this is why the treatment consists of nonsteroidal anti-inflammatory drugs (NSAID) to reduce the vessels caliber and in some serious cases surgery must be performed to repair the damaged corneal tissue.
IV- iridocyclitis
It is an inflammation of the iris due to an infection or another systemic or local disease. If not treated it may cause glaucoma and cataract. The treatment is etiological if the cause is known. Usually it consists of anti-inflammatory drugs (as cortical steroids) and atropine (to immobilize the iris and decrease pain).
Take home message:
If you have a red eye with any of these three symptoms:
- Visual loss
- Painful eye
- Photophobia
Do not try a corticoid based drops because it can aggravate a bacterial keratitis just consult your ophthalmologist urgently.
Author : Samer JABBOUR
