Keratoconus & Corneal Disease
Clear vision starts with a healthy Cornea
How is keratoconus treated by an ophthalmologist?
Different procedures can be combined:
1. With collagen cross linking your ophthalmologist uses a special UV light and eye drops to strengthen the tissues of the cornea. Doing this helps to flatten your cornea, keeping it from bulging further. It also slows down progression.
2. An intra-stromal corneal ring segment is a very small curved device that your ophthalmologist puts in your cornea with the help of a femto-second laser. These ring segments help flatten the curve of your cornea to improve vision.
3. Photorefractive keratectomy (PRK) is laser surgery and corrects mild to moderate refractive error left after cross linking and corneal intra-stromal rings.
4. Intra ocular lenses can correct from low to high refractive error associated with keratoconus.
For optimal results these procedures are combined depending on the specific case:
- The Athens protocol addresses the irregular cornea at the time of cross linking. This consists of combined, same day, topography guided partial PRK and collagen cross linking. This does not only stabilize the cornea but also improves vision.
• Double procedures (Corneal ring & Cross linking or Cross linking & Intra ocular lens)
• Triple procedure (Corneal rings followed by cross linking and PRK or Intra ocular lens)
• Four-Stage procedure includes all four of the abovementioned treatment options For older patients one can also stabilize the cornea with cross-linking & corneal rings followed by cataract surgery with an intra ocular lens to improve refraction further.
Corneal transplant for advanced keratoconus
When symptoms are severe, your ophthalmologist may suggest a corneal transplant. This surgery replaces all or part of your diseased cornea with healthy donor cornea tissue. For keratoconus patients the options are:
Penetrating Keratoplasty (PKP) – The full thickness of the central part of cornea is replaced with donorcornea and sutured in place. Sutures are removed after one year and vision improves over this period. One year later additional refractive laser surgery may be necessary to further improve vision.
Deep Anterior Lamellar Keratectomy (DALK) – Only the outer layers of the central part of the cornea is replaced with donor cornea. Keratoconus patients are usually young with a healthy endothelium. With this procedure there is no graft rejection. Similar to PKP sutures are removed after one year and refractive surgery may be necessary another year later.
Typically for reading as in most patients the power of the Mono-focal lens is selected to correct for distance vision. Some Mono-focal lenses can be implanted through a slightly smaller incision. This promotes wound healing and reduces inflammation.