With irreversible damage to the cornea, and subsequent vision loss, experts like Best Eye Specialist in Karachi recommend corneal transplantation to restore the vision. But what exactly is cornea, and why does it need transplantation, read on to find out:
What is cornea?
Cornea is the outer transparent layer of the eye overlying the iris which protects the eye from foreign bodies and plays a key role in vision. Along with the other layers of the eye, cornea allows light rays to enter, and then bends these rays to focus on the retina. Damage to the cornea due to any cause can interfere with vision by blocking or distorting the entry of light into the eye.
There are three main layers of the cornea:
- Epithelium: this is the outermost layer of the cornea and allows oxygen and nutrients to enter the cornea from the air and the tear film.
- Stroma: this is the middle layer, made mostly of protein and water.
- Endothelium: this is a single layer located at the back of the stroma to maintain the transparency of the cornea, by working like a pump. If the endothelium is distorted, the cornea can become opaque and cause disruption in vision.
What are the symptoms of corneal disease?
Cornea can heal itself after minor injuries. However, in case this healing is delayed, or prolonged, there are symptoms like:
- Redness
- Pain
- Blurring of vision
- Tearing of the eye
- Extreme sensitivity to light
When is corneal transplant performed?
Corneal transplant is performed when the vision of the patient is compromised due to reduction in corneal clarity. This can be due to direct damage to the cornea or any underlying condition. Example of these conditions include:
- Corneal scarring
- Corneal dystrophy
- Complications from cataract surgery
- Infection of the cornea called keratitis, causing permanent damage to the cornea
- Bullous keratopathy with blister-like swelling of the cornea
- Previous eye surgery that can damage the cornea
- Traumatic injury to the cornea
- Keratoconus i.e. change in the shape of the cornea
What are the risks of corneal transplant?
Even though corneal transplant is one of the safest surgeries performed, it has certain risks. These include:
- New onset glaucoma
- Worsening of already present glaucoma
- Bleeding inside the eye
- Retinal detachment
- Cataract formation
- Inflammation of the eye
- Infection of the eye (endophthalmitis)
- Corneal ulcer formation
- Refractive errors requiring correction with glasses
What happens if the cornea is rejected?
As with any transplant, the body can recognize the tissue as ‘foreign’ and the body’s immune system can attack it. In such cases, the symptoms of rejection include:
- Sensitivity to light after the surgery
- Loss of vision
- Red eye
- Pain in the eye
About 10 percent of all corneal transplants face rejection.
How to prepare for surgery?
As part of the preparation procedure of surgery, there is:
- Complete history: in the preparatory phase, a thorough history is taken from the patient by the healthcare provider.
- Physical examination of the eye: the history is followed by complete physical examination of the eye, on a slit lamp or microscope that enlarges the structures of the eye to identify any pathology.
- Measurement of the eye: to determine what dimensions of the donor cornea is needed, the healthcare provider measures the size of the eye.
- Treatment of underlying medical conditions: to decrease the chances of corneal rejection and other complications, underlying eye conditions or other unrelated eye conditions are treated. These may include infections etc.
- Review of medication: certain medication must be stopped before the procedure can be performed. Therefore, the healthcare provider will review all the oral and topical medications the patient is taking.
What to expect after corneal transplant?
Following the surgery, there is expected redness, irritation and sensitivity to light. This is managed by prescription medication recommended by the Eye Specialist in Rawalpindi. After 24-48 hours there is a follow-up by the surgeon to check healing of eye. Protective eye gear use is recommended for some time to protect the eye.
