Eye Deceases

(B36.1) Keratomycosis

A Keratomycosis is an inflammation of the cornea of the eye which forms the anterior part of the eye covering the pupil. It occurs due to the infection of fungus. Keratomycosis is also called as mycotic keratitis. Infection of fungus is followed mostly by the painful implantation of spores. The fungal infection is difficult to treat and causes severe visual impairment if neglected.

ICD-10 B49., H19.2
eMedicine oph/99

Keratomycosis is found worldwide, but it is more prominent in tropics and subtropical areas.

Symptoms Observed in Keratomycosis

  1. Acute pain
  2. Ocular redness
  3. Photophobia
  4. Blurred vision
  5. Corneal ulcers
  6. Marked vision loss
  7. Corneal perforation
  8. Corneal scarring
  9. Anterior chamber infection

Investigations to know the type of species causing Keratomycosis can be done by:-

  1. Microscopy - Scrapping of the cornea when observed under the microscope can be useful to detect the type of species involved in the infection.
  2. Culture - Isolation of the fungi using the culture medium at 28 degrees for one or two weeks.

Treatment of Keratomycosis

Keratomycosis can be managed by removing the infected tissue, discontinuation of steroids and use of antifungal topical and oral drugs.

Treatment with topical solutions such as 5% natamycin, 0.15% amphotericin or 1%econazole or miconazole can be given. Dosage of topical solutions with hourly intervals should be continued for one or two days.

Oral treatment is essential for people with severe lesions. Fluconazole can be given orally for the infection of yeasts which is known for good corneal penetration. Itraconazole can be given orally for moulds and Voriconazole is active against moulds and yeast too.

Treatment should be monitored and controlled by drugs for a prolonged period of time. For Candida infections, treatment period should be almost six weeks and for 12 weeks for mould infections.

If the medical treatment is observed to fail, then surgical intervention can be done. Superficial debridement and superficial keratectomy can be performed according to the penetration level of fungal infections.

Corneal transplants can be performed repeatedly later on after several months of the declaration of infection.

Causes of Keratomycosis

The aetiological agents accused for the infection are found in the air present indoors and outdoors. They are also found in soil, dust and decomposite material of plants.

It is commonly found in men having outdoor occupations and in persons who use extended-wear contact lenses.

Keratomycosis or mycotic keratitis is observed to be caused by almost 70 species of fungi.

Group 1 - Moulds are the most common aetiological agents to cause Keratomycosis infection worldwide. The prevalence of disease in tropics and subtropical region is observed due to the infection of the fungi from the genera Fusarium and Aspergillus.

Group 2 - Hyaline moulds such as Acremonium species, Paecilomyces species, Penicillium species and Scedosporium species are also been reported as the cause of fungal infection in eye.

Group 3 - In India, 16% of the cases are caused due to the third group of aetiological agents called dematiaceous moulds from the genera Curvularia, Bipolaris and Exserohilum.

Group 4 - In US, predominantly, some species from Candida genus are found to infect the eye and cause Keratomycosis. C.albicans, C.guilliermondii and C.parapsilosis are observed to cause corneal infections.

Types of Keratomycosis

Keratomycosis can be classified into two types depending on the lesions involved as:-

  • All layer type- In this type of infection of cornea all the layers of cornea are involved.
  • Superficial type- only superficial layers of corneal epithelium are involved in this type of infection.