Let us understand what a cornea is and its purpose. The cornea is a clear layer of tissue located in the front of the eye. It is like window through which the light enters the eye. Tears protect the cornea against viruses, fungi and bacteria.
Causes of corneal ulcer
There are several causes of corneal ulcers. The main reasons are:
- Bacterial infections
- Herpes simplex virus( causes cold sores) and varicella virus(chickenpox and shingles) are some of the viral infections causing corneal ulcer.
- Candida,Fusarium, Aspergillus, are some of the fungal infections that can occur due to an injury by a branch, twig or any other natural object. However, these infects are rare.
- Acanthamoeba, an amoeba found in fresh water and dirt is a type of Parasitic infection that can lead to corneal ulcer
- Cuts and scratches, abrasions in the corneal surface become infectious leading to corneal ulcer.
- Keratoconjunctivitis sicca or dry eyes syndrome is a condition characterized by zero germ-fighting protection of the tear film which can lead to corneal ulcer or aggravate it. This syndrome is rather common and affects younger age group also risking early visual loss.
- Bell's palsy causes paralysis of eyelid muscles that causes failure of full closure of eyelids or lashes growing inwards, and rubbing against the cornea. This exposure of cornea at night and the abrasions caused by rubbing of lashes can lead to ulceration.
- Any other condition leading to loss of sensation of the corneal surface
- Splashing of caustic solutions, chemical burns to the eyes can damage the cornea causing ulceration.
- Patients who wear contact lens can develop corneal ulcers, especially the long lasting type of contact lenses.
- Patients suffering from other autoimmune disorders like rheumatoid arthritis, lupus,with immune-mediated scleritis can develop corneal ulcers.
An ophthalmologist will check the eyes for corneal ulcer. The signs of corneal ulcer are
- Inflammation in the conjunctiva and in the anterior chamber of the eye with swelling of cornea/ conjunctiva
- Swollen eyelids with a gray or white round spot on the cornea maybe visible to the naked eye, if large in size.
- Location of the ulcer could be central or maybe located at the outer rim of the cornea.
- Scarring on account of earlier corneal ulcers
- Loss of sensation of cornea
- Indication of iritis, an inflammatory response within the anterior chamber which is also noticed in the hypopyon, the lower section of the anterior chamber, if the ulcer is severe
- Thinning of the cornea with inner layers of the cornea ballooning outwards
An ophthalmologist is qualified to conduct an examination for corneal ulcer using a slit lamp, special eye microscope. The corneal examination is done by placing a drop of dye fluorescein for better visibility of the ulcer.
If required, scrapings of the corneal ulcer are sent for further investigation to the laboratory. The investigation detects the presence of virus, fungi or bacteria and also the extent of infection in the cornea.
Surgery to prevent or healing the corneal ulcer
As a microsurgeon, Dr. Leena Jain, an experienced facial palsy surgeon in Borivali, Mumbai offers procedure to restore nerve supply of cornea and prevent ulceration through two surgical procedures -
- Salivary Gland Transplantation for Dry Eyes
- Corneal neurotization
Salivary Gland Transplantation
It is a major procedure that is performed to resolve dry eye issues. This surgery is recommended when the tear glands are secreting fewer or no tears, causing dryness of the eyes. Here, the microsurgeon removes the salivary gland (with its duct) from the neck and transplants it into the temple area of the forehead.
The duct is then tunneled into the eyes and fixed there. The blood vessels taken with the gland are joined with blood vessels in the temple area. Once the circulation of the gland is restored, it becomes functional and secretes saliva which moistens the eyes. Patients with cicatricial disorders wherein the mucous membranes are affected due to autoimmune conditions are suggested to undergo the Salivary Gland Transplantation procedure for dry eyes.
Surgery for insensate cornea or Corneal neurotization–
This procedure is performed to restore sensations to the cornea of a patient with an impending corneal ulcer or insensate cornea. The cornea is located centrally in the eye. The microsurgeon takes a small nerve graft from the lower limb and connects it to a nerve of the forehead which is then tunneled into the eye around the cornea.
The nerve regrowth is directed into the affected cornea to restore the eye's sensation. Through this procedure, the patient's tearing reflex, protective blink reflex, and normal wound healing pursues to help cure ulcers and provide a better result post corneal transplant.