“Synechia” is the medical term for adhesions or fibrous bands that bind two ocular structures that are meant to be separate. There are two different forms: anterior or posterior. Anterior synechia involves the bonding together of the iris and the cornea and posterior synechia is the fusing of the iris to the lens. Your iris is the coloured part of your eye that is suspended behind the cornea and immediately in front of the lens. It regulates the amount of light entering the eye by adjusting the size of the pupil. While it is a rather infrequent condition the anterior version tends to occur more often.
Anterior synechia can occur as a result of:
Posterior synechia can occur as a result of:
- inflammation (i.e. – iritis trauma)
Either type can be a serious trigger for angle-closure glaucoma. For example if a membrane forms between the trabecular meshwork (the area inside the front part of the eye through which the fluid leaves the eye) and the iris the angle of filtration will eventually close. Failure of this system leads to a rise in intraocular pressure which is the main cause of glaucoma. In addition to this posterior synechia can sometimes result in an irregularly shaped pupil.