Surgical affections of Uvea
Surgical affections of Uvea are Periodic Ophthalmia, Coloboma, Aniridia, Iritis, Cyclitis, Iridocyclitis, Choroiditis, Uveitis, Hyalitis, Retinitis, synechia etc.
Uvea is the pigmented layer of the eye, lying beneath the sclera and cornea, and comprising the iris, choroid, and ciliary body.
Surgical affections of Uvea in animals are-
- Coloboma
- Aniridia
- Iritis
- Cyclitis
- Iridocyclitis
- Choroiditis
- Uveitis
- Hyalitis
- Retinitis
- Synechia
- Periodic Ophthalmia
Coloboma
Coloboma is a congenital condition in which the pupil will be irregular in shape due to absence of a portion of the iris.
More than one pupil may become apparent, when coloboma is situated away from the pupillary margin.
Aniridia
Aniridia is a condition in which iris is completely absent.
Iritis
Iritis is the Inflammation of the iris.
Cyclitis
Cyclitis is the Inflammation of the ciliary body.
Iridocyclitis
Iridocyclitis is inflammation of the iris and the ciliary body. A very characteristic symptom of this condition is engorgement of vessels at the limbus .
Choroiditis
Choroiditis is the inflammation of the choroids
Uveitis
Uveitis is the inflammation of the iris, ciliary body and choroids.
Hyalitis
Hyalitis is the inflammation of the vitreous body (vitreous humour).
Retinitis
Retinitis is the inflammation of retina.
Synechia
Anterior synechia
Attachment of the iris to the cornea is called anterior synechia. This is sometimes seen as a sequela of staphyloma.
Posterior synechia
Attachment of the iris to the lens is called posterior synechia. Sometimes seen as a sequela of periodic ophthalmia in the horse.
Periodic Ophthalmia
Periodic ophthalamia of horses is characterized initially by repeated attacks of iridocyclitis. After repeated attacks of the disease there is atrophy of the eyeball and it sinks into the orbit.
The eyelids become greatly wrinkled and shrunken.
Etiology
The cause of the disease is not definitely known.
The disease appears to be contagious but attempts to transmit the disease artificially have not been successful.
The disease occurs in places where a number of horses are housed together, as in the army.
Symptoms
The disease usually starts unilaterally with photophobia, blepharospasm and lacrimation – acute uveitis
The tears are sticky and become adherent to the eyelids and cheek. Conjunctivitis and engorgement of blood vessels around the sclero – corneal junction are seen.
The consistency of the aqueous humour is altered, there is accumulation of whitish or yellowish precipitates in the anterior chamber (hypopyon) and due to this the cornea may appear completely opaque. Pupil is constrited. Recovery takes place in about 3 weeks, the precipitates get absorbed and the pupil dilates to the normal size.
After seven to ten days the symptoms recur either in the same eye or in the other eye. During this second attack symptoms are more severe. Thus the same eye may become affected repeatedly. Due to these recurrent attacks the eye is permanently damaged.
The cornea and the lens show opacity; posterior synechia is a constant sequela of the disease: the retina atrophies; and the vitreous humour undergoes liquefaction.
The vitreous humour when examined through an ophthalmoscope presents a characteristic appearance with star – like floating bodies described as synchysis scintillans. – posterior uveitis
The aqueous humour gets partially absorbed and the eyeball shrinks. The fat in the orbit gets absorbed, the eyeball sinks into the orbit and the eyelids get wrinkled resulting in permanent blindness.
In kerato uveitis a fleshy corneal infiltrate and pannus are identified on ocular exam.
Diagnosis
The disease is characterized by its sudden onset without any apparent cause. The pupil is constricted and fails to dilate. Pressure on the supraorbital fossa evinces pain. Posterior synechia may be noticed.
Treatment
- Symptomatic treatment for uveitis and presence of systemic infection should be ruled out.
- Agressive therapy should be intiated first. It consists of topical , subconjunctival or systemic use of corticosteroids
- NSAIDS – flunixine meglumine, asprin are also effective.
- A cycloplegic atropine can also be used.