Sometimes the course of keratoconus progresses to a point where a corneal transplant is the best option. This is where the central scarred portion of your cornea is replaced with a clear donor cornea. The success rate of this procedure is very high (95%) since there are no blood vessels within the cornea that would lead to rejection. Now, there is technology to greatly speed the recovery and increase the chances of good vision with glasses after the procedure.
Femtosecond Enabled Keratoplasty (FEK)
This is an advanced form of penetrating (full thickness) or lamellar (partial thickness) keratoplasty. Conventional keratoplasty is performed using specialized blades called trephines to prepare the cornea. These blades are limited in that they can produce only a single type of cut. Femtosecond enabled keratoplasty (FEK) utilizes a femtosecond laser to precisely and accurately cut a more complex shape of both the donor and the host tissue so that they fit together like pieces of a jigsaw puzzle. Surgeons can choose the appropriate configuration for the corneal graft depending on the type of disease or opacity present. This produces a stronger union between the old and new cornea, allowing for fewer stitches that can be removed earlier, with less astigmatism and faster restoration of vision in most cases. In this procedure, the surgeon first prepares the patient’s cornea in the laser suite, while the eye bank prepares the donor cornea with identical laser settings. Then, the procedure is completed in the operating room where the donor tissue is sutured into place under sterile conditions.
The advantage of this procedure is the cornea is secured using fewer stitches, reducing the amount of induced astigmatism and allowing for better wound sealing and stronger wound healing, earlier suture removal and more rapid restoration of functional vision.
Topography-Guided Laser Ablation with Crosslinking
Irregular astigmatism in keratoconus can be partially corrected with the use of customized laser ablation that improves the optical performance of the anterior corneal surface. The application of customized topography-guided surface ablation has been used around the world in patients with stable or subclinical keratoconus with promising visual outcomes. The disadvantage of ablative procedures in the past with conditions such as keratoconus is that tissue removal (thinning of the cornea) might lead to further destabilization of corneal biomechanics and progression of the disorder. However, the combination of Crosslinking with laser ablation provides stability of the keratoconus cornea, making this the first corneal laser re-shaping procedure possible for patients with keratoconus.
The figure above demonstrates how the patient’s specific cornea shape derived from corneal mapping or topography is used to program the laser to create the best possible visual outcome. The detailed topography is used to create a custom treatment plan for your eye. This will help to reshape your cornea to improve the fit of or eliminate the need for rigid contact lenses.