Corneal Edema Treatment

The endothelium cells of the cornea pump out fluid to keep vision clear. When these cells stop working, it creates water retention, which leads to swelling in the cornea. This condition is also known as corneal edema. 

Corneal edema is caused by disease of the inner cell layer, trauma to the eye, surgical trauma, certain types of glaucoma, or infections due to contact lens. 

The epithelial cells of the cornea are arranged in a single layer.

These cells rarely divide, therefore, when they are damaged they are not replaced. To mend the gap left by the damaged cells, the surviving cells change in size and shape to fill their places.

Also, fluids leak into the gaps left by the damaged cells.

The combination of the irregularly shaped epithelial cells and accumulated fluids interfere with the ability of the cornea to effectively focus light in the eyes. If left untreated, these factors can lead to blindness.

There are different types of treatment options that eye specialists can use to treat cornea edema. The specific treatment usually depends on the cause and the severity of the condition. Here are some popular treatment options to heal cornea edema. 

Hypertonic Solutions: 

These medicated solutions can be used to pull out the moisture from the cornea region to provide temporary relief. Over the counter medications such as Muro 128 ointment can also be used. 

These solutions are usually helpful in the early stages. After the underlying disease has progressed, this edema treatment option will not be as effective. 

Patients with mild corneal edema will find hypertonic solutions useful. These solutions can reduce the number of fluids seeping into the cornea and minimize the poor vision and pain associated with corneal edema.

The most popular hypertonic solutions and ointments used in treating corneal edema are made of sodium chloride. Both the 2% and 5% solutions and ointments are available.

When applied, hypertonic solutions create a tear film over the epithelial cells of the cornea. Because of the concentration gradient established, water is pulled out of the cornea into the hypertonic tear film by the osmotic pressure exerted across the epithelium. This helps keep the cornea dry.

Hypertonic solutions are, however, not as effective at night.

This is chiefly because evaporation of the water pulled out of cornea edema is restricted as a result of the eyes closing during sleep. Therefore, the symptoms of corneal edema are worse in the morning.

To help reduce the edema even at night, 5% sodium chloride ointment is recommended to be applied to the conjunctiva at night. Hypertonic solutions can also be applied in the morning to help remove the fluid built up in the cornea during the night.

Bandages Contact Lens: 

In some cases, the corneal epithelium may develop very painful blisters. This condition is known as bullous keratopathy. The eye doctor may use a soft bandage contact lens on the affected cornea to reduce discomfort. 

Wearing contact lenses for extended hours can increase the risk of corneal ulcers, so this should be taken into consideration when deciding to use a contact lens. 

The bandage contact lenses used in treating corneal edema are thin, high-water content contact lenses. These lenses are permeable to oxygen and so are well tolerated.

Bandage contact lenses are intended to help reduce the pain and discomfort of corneal edema. They may, however, worsen the corneal edema if they are too tight especially when worn at night.

Also, bandage contact lenses increase the likelihood of the cornea getting infected. Therefore, broad-spectrum antibiotics should be prescribed along with bandage contact lenses.

A common antibiotic used by corneal edema patients wearing these lenses is Polymyxin B. This antibiotic is available as eye drops and eye ointments.

Even then, long-term use of bandage contact lenses is not recommended since it can easily trap fluids in the cornea.

Temporary Surgical Procedures for Corneal Edema Treatment: 

There are certain surgical procedures that eye specialists may perform in patients with corneal edema, but this is only for individuals for whom corneal transplant is not an option. 

Various laser procedures can be used to improve the condition by reducing the formation of the blisters in bullous keratopathy. 

Another method of alleviating the symptoms of complex corneal edema is to embed tissue over the cornea. 

Yet another treatment option is Anterior Stroma Puncture. This technique is recommended for patients who are experiencing significant pain and impaired vision.

Anterior stromal puncture involves making some shallow punctures at or below the Bowman layer of the cornea with a 25-gauge needle.

This procedure is followed with the application of a bandage contact lens which is left in place for 7 – 14 days. This lens will help hold the healing epithelium in place long enough to grow back over the cornea.

Corneal Transplant: 

This is the most popular treatment for corneal edema. Penetrating keratoplasty is one form of corneal transplant in which a fragment in the center of the cornea is substituted with donor tissue. 

There is a certain risk of rejection with this treatment method, and the patient may need to use eye drops for some time during the healing period. 

Some doctors may replace just the endothelial layer of cells with donor cells. This is a recent procedure but can be quite useful in treating corneal edema. 

While Penetrating Keratoplasty (PK) is the longstanding procedure for doing corneal transplantation, there is a new technique called Descemet’s Stripping Endothelial Keratoplasty (DSEK).

While PK is useful for treating corneal scarring and other conditions involving extensive damage to the cornea, DSEK is used to treat corneal diseases limited to the innermost corneal endothelium layer.

DSEK produces a smaller surgical wound that heals faster. It also produces far fewer complications and can help restore vision with glasses instead of contact lenses.

In PK, the surgeon replaces the full-thickness of the central core of the cornea. It is done by making similar incisions in the recipient cornea and the donor cornea with a trephine or circular blade. After the transfer, the transplanted cornea is then sutured in place.

In DSEK, a small cut is made from the sclera of the eyes to the endothelium of the cornea. The two first layers (endothelium and Descemet’s membrane) of the cornea are then peeled away to be replaced by a similar partial graft from the donor cornea. The new transplant is held in place with a film of air instead of sutures.

Following a corneal transplant, corticosteroid eye drops are required to reduce the risk of the recipient’s immune system rejecting the donor corneal.

Antibiotic eye drops are also prescribed for a week after the transplant to fight any incidence of infection.

Treatment of Other Conditions: 

When corneal edema is caused by an underlying disease, treatment of that disease might improve or completely cure edema. 

Some types of infections such as herpes simplex stromal keratitis may cause corneal edema, and the use of corticosteroid eye drops can heal edema while treating the infection. 

Taking antibiotics to treat an infection may also resolve any corneal edema linked with the condition. If an individual has a cloudy cornea due to elevated eye pressure, then taking glaucoma medications can reduce the symptoms. 

Other drugs that might contribute indirectly to the resolution of corneal edema include alpha 2-adrenergic agonists and beta-adrenergic blockers.

These drugs lower intraocular pressure and reduce the production of aqueous humor or increase its outflow. By doing these, they remove the osmotic pressure generated in the eye which could contribute to the severity of corneal edema.

Brimonidine is an example of alpha 2-adrenergic agonists while Timolol eye drops are beta-adrenergic blockers.

To know more about edema treatment, read these articles: Edema Home Remedies, Drugs for Edema, and Edema Products.