FUNGAL KERATITIS

Clinical features:

Ø  Common organisms are aspergillus, penicillium, fusarium and candida.

Ø  Risk factors are leukemia and diabetes, pre existing corneal disease like dry eye, vegetative injury and long term treatment with antibiotic and steroids.

Ø  On examination, definite white ring in the mid periphery of the cornea with healthy cornea between the ring and ulcer margin is seen (Immune ring- diagnostic of fungal infection).

Ø  Presence of hypopyon is the rule. Higher the hypopyon more ominous the sign and chances of perforation.

Non -pharmacological treatment:

l  Use dark goggles and avoid close contact with other persons for two weeks.

l  Restrict work and school for patients with significant exposure to others.

l  Frequent handwashing.

Pharmacological treatment:

1.       Treatment should be instituted promptly with topical antifungal drops, initially every hour during the day tapered to 4 hrly interval for 3-4 days, then reduced to 4 times a day for at least 14-21 days or till there is resolution of active stage.

2.       Subconjunctival injections also may be used in cases of severe keratitis, or when poor compliance exists.

3.       An oral antifungal (eg, ketoconazole, fluconazole 100mg) should be considered for cases of deep stromal infection.

4.       Fluconazole has been shown to penetrate better into the cornea after systemic administration compared to other azoles and is associated with fewer adverse effects.

5.       Intra-cameral: Inj. amphotericin-B (5 - 7.5% µg in 0.1ml in 5% dextrose).

6.         Intracorneal:

Inj. amphotericin-B (5µg in 0.1ml) four to five places around the lesion intrastromaly, not in thin area.

Inj. voriconazole (50 µg in 0.1% in RL solution).

Systemic antifungal:

1.       Oral fluconazole and ketoconazole are absorbed systemically with good levels in the anterior chamber and cornea - therefore they should be considered in the management of deep fungal keratitis fungal abscess, endothelial plaque.

2.       Cycloplegics are mandatory and antiglaucoma drugs may be added to the treatment depending on the intraocular pressure etc.

3.       Frequent corneal debridement with a spatula is helpful. It debulks fungal organisms and epithelium, and enhances penetration of the topical antifungal agent.

4.       Surgery is considered in those patients who fail to respond to medical treatment and may result in corneal perforation.

5.       The treatment of choice is therapeutic penetrating keratoplasty.