corneal ulcer Complications

 Complications of corneal ulcer

1. Toxic iridocyclitis. It is usually associated with cases of purulent corneal ulcer due to absorption of toxins in the anterior chamber.

2. Secondary glaucoma. It occurs due to fibrinous exudates blocking the angle of anterior chamber (inflammatory glaucoma).

3. Descemetocele. Some ulcers caused by virulent organisms extend rapidly up to Descemet's membrane, which gives a
great resistance, but due to the effect
of intraocular pressure it herniates as a transparent vesicle called the descemetocele or keratocele (Fig.1). This is a sign of impending perforation and is usually associated with severe pain.

fig 1 Descemetocele : A, Diagrammatic depiction;
B.Clinical photographs.

4. Perforation of corneal ulcer. Sudden strain due to cough, sneeze or spasm of orbicularis muscle may convert impending perforation into actual perforation
(Fig. 2). Following perforation, immediately pain is decreased and the patient feels some hot fluid (aqueous) coming out of eyes.

fig 2 Perforated corneal ulcer with prolapse of iris:
A, diagrammatic depiction; B, clinical photograph.

Sequelae of corneal perforation include :

i. Prolapse of iris. It occurs immediately following perforation in a bid to plug it.

ii. Subluxation or anterior dislocation of lens may occur due to sudden stretching and rupture of zonules.

iii. Anterior capsular cataract. It is formed when the lens comes in contact with the ulcer following a perforation in the pupillary area.

iv. Corneal fistula. It is formed when the perforation in the pupillary area is not plugged by iris and is lined by epithelium which gives way
repeatedly. There occurs continuous leak of aqueous through the fistula.
v. Purulent uveitis, endophthalmitis or even panophthalmitis may develop due to spread of intraocular infection.

vi. Intraocular haemorrhage in the form of either vitreous haemorrhage or expulsive choroidal haemorrhage may occur in some patients due to sudden lowering of intraocular pressure.

5. Corneal scarring. It is the usual end result of healed corneal ulcer. Corneal scarring leads to permanent visual impairment ranging from slight blurring to total blindness. Depending upon the clinical course of ulcer, corneal scar noted may be nebula, macula, leucoma, ectatic cicatrix or kerectasia, adherent leucoma or anterior staphyloma