These are common in contact lens wearers, especially in people using extended-wear lenses.

The virus that causes cold sores (the herpes simplex virus) may cause recurring attacks. These attacks are triggered by stress, an impaired immune system, or exposure to sunlight. Also, the virus that causes chicken pox and shingles (the varicella virus) can cause corneal ulcers.

Improper use of contact lenses or steroid eye drops can lead to fungal infections, which in turn can cause corneal ulcers. Also, a corneal injury that results in plant material getting into the eye can lead to fungal keratitis.

Acanthamoeba are microscopic, single-celled amoeba that can cause human infection. They are the most common amoebae in fresh water and soil. When Acanthamoeba enters the eye it can cause a bad infection, particularly for contact lens users.
Other causes of corneal ulcers include:
Abrasions or burns to the cornea caused by injury to the eye. Scratches, scrapes and cuts can become infected by bacteria and lead to corneal ulcers. These injuries can happen from fingernail scratches, paper cuts, makeup brushes and tree branches. Burns caused by corrosive chemicals found in the workplace and at home can cause corneal ulcers.
Dry eye syndrome.
Bell’s palsy and other eyelid disorders that prevent proper eyelid function. If the eyelid does not function properly, the cornea can dry out, and an ulcer can develop.

Your ophthalmologist will use a special dye called fluorescein (pronounced FLOR-uh-seen) to light up any damage to your cornea. They will then examine your cornea using a special microscope called a slit lamp. The slit-lamp exam will allow your ophthalmologist to see the damage to your cornea and determine if you have a corneal ulcer.
If your ophthalmologist thinks that an infection has caused your corneal ulcer, they may take a tiny tissue sample. Examination of this sample helps identify and properly treat the infection

Antibiotic, antifungal or antiviral eye drops are the treatments of choice. Sometimes your ophthalmologist will prescribe antifungal tablets. In other cases, they will treat you with an injection of medication near the eye.
Your ophthalmologist may prescribe steroid or anti-inflammatory eye drops after your infection has improved or is gone. This should reduce swelling and help prevent scarring. Steroid eye drop use is controversial for corneal ulcer. You should only use them under close supervision by your ophthalmologist. It is possible that steroid eye drops may worsen an infection.
Your ophthalmologist may prescribe pain medication to take by mouth to reduce pain.
If your symptoms suddenly change or get worse during treatment, then let your ophthalmologist know right away.
Symptoms to look for include:
• pain and redness of the eye
• tearing and discharge from the eye
• blurry vision

A corneal transplant can replace your damaged cornea with a healthy donor cornea to restore vision. When the infection is gone and the ulcer is healed after treatment with medication, sometimes a significant scar remains. In this case, a transplant may be done to improve vision. And if corneal ulcers cannot be treated with medication, you may also need corneal transplant surgery to keep your vision.

Pinguecula and pterygium are growths on your eye’s conjunctiva, the clear covering over the white part of the eye.

is a yellowish, raised growth on the conjunctiva. It’s usually on the side of the eye near your nose, but can happen on the other side too. A pinguecula is a deposit of protein, fat, or calcium.

Eye banks are the institutions responsible for collecting (harvesting) and processing donor corneas, and for distributing them to trained corneal graft surgeons.1 Eye banks are regulated and part of the local health system; they may be attached to a hospital or housed in a separate building.
Cornea harvesting is the surgical removal from a deceased person of either the whole eye (enucleation) or the cornea (in situ corneal excision). This can be done by appropriately trained eye care personnel (eye bank technicians, ophthalmology residents, ophthalmologists, or general practitioners) in a variety of settings, including hospitals, homes, and funeral grounds.

Corneas can be harvested up to twelve hours after death, but ideally within six hours. The person who will harvest the cornea must first do the following:
• Obtain written consent from the senior next of kin of the deceased.
• Verify the death certificate and ensure there is a stated cause of death.
• Review the donor’s medical and social history to ensure they have no contraindications to donation. (This is done by studying medical records, interviewing the physician under whose care the donor was, and interviewing close family members. Each eye bank must have a list of such contraindications, which are available from other well-established eye banks.)
• Obtain information about any blood loss occurred prior to and at time of death, and whether the donor received infusion/transfusion of crystalloids, colloids, and blood; these are used to calculate plasma dilution.

Aseptic methods must be adhered to, including maintaining a sterile field while performing enucleation or in-situ corneal excision.2 Standard protocols include:
• pen torch examination of the eyes for foreign objects and other defects
• preparing the face and eyes of the donor using povidone iodine
• employing aseptic techniques for in situ corneal excision or enucleation
• immediate preservation of the excised eye or cornea in an appropriate cornea preservation medium
• drawing blood to screen the donor for infectious diseases. Each eye bank must decide the most appropriate serological tests needed but at a minimum they must test for HIV, hepatits B, and syphilis.

Whole eyes can be stored in a moist chamber at two to eight degrees Celsius. This is the simplest and least expensive way to store whole eyes, but the eyes have to be used within 48 hours. Such a storage method may be suitable for some eye banks with limited resources.
Excised corneas can be stored in intermediate-term preservation media, such as McCary Kaufman medium (MK medium) or Optisol, both maintained at four degrees Celsius. Corneas can be stored for 96 hours in the MK medium and ten days in Optisol.
With the availability of MK medium and Optisol, eye banks should ideally switch over from enucleation to in situ corneal excision procedures. This will enable better viability of donated corneas during storage. With increased resistance to the antibiotics used in preservation media, inclusion of alternative antibiotics must be considered.3
After corneas reach the eye bank, they are examined using a slit lamp to check for corneal and stromal pathology. The endothelial cell density is also examined by specular microscope; this is necessary as donor corneas with a low number of endothelial cells are likely to fail soon after surgery. The processing of whole eyes must be done within a laminar flow hood maintained in sterile conditions.
The suitability of a cornea for transplantation is assessed by the corneal surgeon, who will consider the donor screening report, slit lamp and specular microscopic results, and serology reports. Following processing and evaluation of corneas and serological testing, transplantable corneas are transported to hospitals individually sealed and packaged, maintaining the cold chain at four degrees Celcius. The vial containing the cornea must be labelled properly with the eye bank name, tissue number, name of the preservative medium, medium lot number, expiry date of the medium, and date and time of the donor’s death. The surgeon must also be provided with the donor screening, tissue evaluation, and serology reports. It is important that the eye bank follows a fair and equitable system of tissue distribution.

Eye banks should develop and adhere to acceptable standards. This reduces the risk that grafts will fail or that infection will be transmitted. It may help to refer to the technical guidelines and acceptable minimum medical standards of the European Eye Banking Association

Even with an effective eye bank, finding enough people willing to donate their corneas can be difficult.
Public awareness programmes play an important role. They must emphasise that corneas can be donated by anyone, whatever their age, religion, or gender, and that neither enucleation nor in situ corneal excision causes disfigurement of the face or any delays in funeral arrangements. Family pledging is also becoming more important as family consent is usually needed before eyes or corneas can be removed. Some of these problems may be circumvented by favourable legislation for eye donation, such as a ‘required request’ law. This law requires hospital authorities to identify potential cornea donors and obtain consent from bereaved family members. Another law employed in some countries, such as the United States and Ethiopia, is a ‘presumed consent’ law. Under this law, every person who dies while in hospital is presumed to be an eye donor unless this is actively rejected by their next of kin.
Hospital cornea retrieval programmes can meet some of the immediate need. In these programmes, trained eye donation counsellors approach family members of the deceased and motivate them to consider eye donation. Training these counsellors in the art of grief counselling assists them in approaching family members at an appropriate time, sharing their grief, and preparing them to take the positive step of giving permission for eye donation on behalf of their loved one.

Corneal topographers are fast devices that do not make contact with the eye; however, they are not as accurate as corneal tomographers on irregular corneas.
• Though slower and more expensive than corneal topographers, corneal tomographers are also noncontact and are capable of producing three-dimensional images of the entire anterior segment of the eye. They also allow for pachymetry measurements.
• Ultrasound biomicroscopes require contact of a probe on the patient’s eye, but are capable of imaging corneal details at the the cellular level.
• Confocal microscopy can evaluate corneal nerves in vivo.
• Though all of the above devices individually are very reliable and repeatable, reciprocity of results may not always be in agreement when interchanging between devices in comparison studies because each manufacturer uses their own algorithms to produce their results.

Artificial corneas, sometimes called a keratoprosthesis (K-pro), have been used for over 50 years. However, it has only been within the last few years that these devices have become reliably successful. For most patients, human donor tissue still provides the best results. But in patients who are at high risk for failure with a human donor, a keratoprosthesis can provide excellent visual results with a good risk-to-benefit ratio.

Some indications for K-pros include:
• Multiple previous graft failures
• Severe ocular surface disease, such as after chemical burns, Stevens Johnson syndrome, limbal stem cell deficiency, congenital aniridia, or severe dry eyes.

Currently, we recommend the Boston keratoprosthesis for patients who need an artificial cornea.