Corneal surgery is any medical operation carried out on the cornea, the clear jelly-like part at the front of the eye. The surgery can involve a portion of the cornea or the whole of it. It is a necessary therapy where other medical treatments have failed.
Corneal operations are common and can be performed on individuals of all ages. The aim of the surgical procedure depends on the problem presented. However, all surgeries are focused on enabling healthy vision.
Types of surgery
- Corneal transplantation
Replacing a damaged cornea portion with healthy donor tissues (transplantation) is a common surgical procedure. Transplantation can further be classified depending on the part that is taken out. Penetrating keratoplasty is one of the classifications. The operation involves replacing the entire cornea of the eye. It is indicated where several layers of the cornea are affected. Other types include the endothelial transplantation and the anterior lamellar keratoplasty. For the latter, transplantation is done on the anterior part, preserving the endothelium (innermost layer) and the Descemet’s membrane. Endothelial transplantation, on the other hand, involves replacing the endothelial when only the back part of the cornea is affected. The variations include the Descemet's stripping automated endothelial keratoplasty (DSAEK) and the Descemet's membrane endothelial keratoplasty (DMEK).
It involves replacing the cornea with an artificial one. It is an alternative approach in patients with severe ocular and corneal disease. Doctors perform the surgery where treatment and transplantation have failed.
- Intacs surgery
The surgeon makes a small incision and inserts two rings at the outer edge of the eye. The rings are meant to hold the cornea in place to focus light correctly on the retina. It is indicated for keratoconus where there’s corneal thinning.
- Corneal cross-linking
The surgery uses UV light to strengthen bonds in the cornea. It focuses on preventing a progressive irregular change in shape of the cornea (ectasia). It can be done on patients with keratoconus.
- Refractive corneal surgery
It is done to correct errors in vision. The operation involves adjusting the eye’s ability to focus by reshaping the cornea. The most common technique used is LASIK (Laser-assisted in situ keratomileusis).
- Phototherapeutic keratectomy (PTK)
This minor surgical procedure uses a laser to treat ocular diseases that affect the corneal surface. It involves removal of the outer layer of tissue from the cornea. It is indicated for corneal scarring and dystrophies.
- Ocular surface reconstruction
It is a surgery meant to reconstruct the cornea after an injury, thinning, scarring, or perforation.
Patients will require a corneal surgery for reasons such as:
- Correct vision – Most eye diseases threaten vision. They may cause blurred vision or loss of vision altogether. Corneal surgeries are aimed at restoring proper vision.
- Treatment of diseases – Eye diseases unresponsive to medications can be treated through the removal of part of or the whole cornea. The surgery may also reduce pain and other symptoms.
- Reconstruction – Where there’s scarring, perforation or thinning of the cornea, surgery is necessary to preserve the eye.
Preparation & expectation before Surgery
The patient should consult with the doctor on how to prepare for a corneal surgery. Some of the preparations may include:
- Undergoing a test – A comprehensive examination will tell whether the operation will be useful. Other eye problems can also be detected.
- Restrictions on what to eat and drink – Patients may need to fast hours prior to the surgery. Caffeinated beverages should also be avoided before the surgery.
- Restricted use of some medications – Can include blood thinners which may interfere with the surgery.
- Avoiding contact lenses and make-up
The procedure depends on the type of surgery. However, for all operations, the doctor will first issue an antibiotic eye drop to prevent infection. Sometimes, patients may also need sedatives to reduce anxiety. Local anesthesia is then issued to numb the pain.
The doctor will place a device to hold the eye open before performing the surgery. Most procedures, such as transplantation, will require an incision. The eye doctor may also need to use a microscope to operate on the eye properly.
After the operation, the eye may be stitched. An eye shield is also necessary and can be issued to protect the eye.
The patient should not drive him/herself after the surgery.
After care, recovery, results
Corneal surgeries are mostly successful. However, within the first few days, patients can expect a blurry vision. The eye then completely heals after a few months or so. Patients should avoid rubbing their eyes during the healing period. They can wear glasses or shields to protect their eyes.
Doctors will prescribe eye drops and pain medications to prevent infection and ease the pain. Follow up should be done afterward to monitor progress.
Risks & complications
In some instances, complications can arise after the surgery. They can include:
- Photophobia (light sensitivity)
- Clouding of the eye's lens (cataracts)
- Elevated pressure that may result in glaucoma
- Retinal detachment
- Rejection of donor tissue in transplant surgeries