Ocular synechia is an eye condition where the iris adheres to either the

cornea The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea ...

(i.e. ''anterior synechia'') or

lens A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements'') ...

(i.e. ''posterior synechia'').F. Salmon, J. (2019) Kanski’s Clinical Ophthalmology. 9th Edition, Elsevier. Synechiae can be caused by ocular trauma, iritis or iridocyclitis and may lead to certain types of

glaucoma Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of ...

. It is sometimes visible on careful examination but usually more easily through an

ophthalmoscope Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part ...

or slit-lamp. Anterior synechia causes closed angle glaucoma, which means that the iris closes the drainage way of aqueous humour which in turn raises the intraocular pressure. Posterior synechia can be observed in cases of anterior uveitis secondary to severe to moderate bacterial keratitis. Posterior synechia also cause glaucoma, but with a different mechanism. In posterior synechia, the iris adheres to the lens, blocking the flow of aqueous humor from the posterior chamber to the anterior chamber. This blocked drainage raises the intraocular pressure.

Management

Mydriatic or

cycloplegic Cycloplegia is paralysis of the ciliary muscle of the Human eye, eye, resulting in a loss of accommodation (eye), accommodation. Because of the paralysis of the ciliary muscle, the curvature of the lens can no longer be adjusted to focus on near ...

agents, such as topical

homatropine Homatropine (Equipin, Isopto Homatropine) is an anticholinergic medication that is an antagonist at muscarinic acetylcholine receptors and thus the parasympathetic nervous system. It is used in eye drops as a cycloplegic (to temporarily paral ...

, which is similar in action to

atropine Atropine is a tropane alkaloid and anticholinergic medication used to treat certain types of nerve agent and pesticide poisonings as well as some types of slow heart rate, and to decrease saliva production during surgery. It is typically give ...

, are useful in breaking and preventing the formation of posterior synechia by keeping the iris dilated and away from the crystalline lens. Dilation of the pupil in an eye with synechia can cause the pupil to take an irregular, non-circular shape (dyscoria) as shown in the photograph. If the pupil can be fully dilated during the treatment of iritis, the prognosis for recovery from synechia is good. This is a treatable status. To subdue inflammation, topical

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...

s can be used. A prostaglandin analogue, such as travoprost, may be used if the intra-ocular pressure is elevated.

References

External links

Disorders of iris and ciliary body Human pupil {{eye-stub