A corneal transplant, also known as a corneal graft, or as keratoplasty, involves the removal of the central portion (‘button’) of the diseased cornea and replacing it with a matched donor ‘button’.

A common indication for keratoplasty is keratoconus. The ophthalmologist must decide when to recommend keratoplasty for the patient with keratoconus. This is often not a simple, straightforward decision. Keratoplasty for keratoconus is highly successful; however, there is a long recovery period and a risk of severe ocular complications. A number of factors must be considered in deciding when to do a keratoplasty. One of the most important is the patient’s functional vision.

If the best acuity with their contact lenses prevents them from doing their job or carrying out their normal activities, a transplant must be considered. The actual measured visual acuity may be quite different for different patients. One patient may find that he/she cannot do his or her job with 20/30 acuity while another patient may be very satisfied with 20/60 acuity.

Very careful contact lens fittings are necessary before recommending a corneal transplant. One study found that 69% of patients with keratoconus, most referred for transplant, could be successfully fit with contact lenses if special lens designs were used. Thus, prior to corneal transplant surgery, every effort should be made to optimally fit the patient with contact lenses, especially if there is not significant corneal scarring affecting vision.

However, a few patients become intolerant to contact lenses, and require a transplant earlier than otherwise would be necessary. If the patient has a large area of thinning, a very red cone or significant blood vessel growth into the usually clear cornea, called neovascularisation, a transplant may be performed earlier than otherwise indicated by the visual performance, as these factors may require a larger than normal transplant button size and/or increase the chance of rejection if allowed to advance too far.

The healing process following transplant of a full penetrating corneal graft is long, often taking a year or longer – depending on what technology is used. The time from surgery to the removal of the stitches is commonly 6 to 17 months. The patient may be on steroids for months. Initially following surgery, the donor button is swollen and even following healing the button is usually thicker than the corneal bed in which it rests.

Graft rejection reactions occur in a small percentage of patients. Signs of graft rejection include red and watery eyes, blue haze around the iris, watery spots inside the cornea, light sensitivity, pain and discomfort and any other changes in your vision and eye sight when compared to the post-operative period. Glare and glittering of light and significant change in refractive error.

Signs of graft rejection are reported to occur from one month to five years following surgery. The rejection rate for bilateral grafts is higher than if only one eye is grafted. In the bilateral cases, when a rejection reaction occurs it is commonly in both eyes. If the second eye is to be grafted, there is usually a period of at least a year between grafts. If signs of rejection occur, aggressive treatment with steroids is begun. Usually the reaction is overcome and the graft remains clear.

Over 90% of the corneal grafts are successful with some studies reporting 97% to 99% success rates at 5 and 10 years (Kirkness et al 1990, Troutman and Lawless 1987, Epstein).

Large amounts of astigmatism (irregular corneal curvature) can be present after corneal transplant. The patient’s spectacle prescription may fluctuate for some months following surgery. Refractive changes and keratometry (measuring the curvature of the cornea), or corneal topography can be used to follow the healing process.

The latest Femtosecond Laser technology is used to create bladeless surgery. The laser can be set to remove just the damaged section or layers of recipient cornea and to remove the exact sections of healthy donor cornea to be implanted onto your cornea. This procedure is less invasive, it uses less heat and energy, the procedure is more accurate, precise and predictive, and healing is accelerated. With less corneal tissue removed and less donor corneal tissue needed to be transplanted, the rejection rate is diminished and healing is accelerated.

In the case of performing a full penetrating corneal graft with Femtosecond laser, the entire central area with all layers of the patient’s cornea (button) is removed with the laser, (a bladeless cut), but the way the precision laser ‘cuts’ the button is done in such a way that the donor cornea has a more snug and even fit onto the recipient’s existing cornea after surgery – again causing a better result.