If after a UV-Crosslinking we can show that the keratocone has stabilized, for example via topography, a surgery to visual rehabilitate patients can be considered, this can be done by means of a topography guided surface laser treatment (TG-PRK) or a toric Artisan or Artiflex lens implantation (PIOL).
Patients with contact-lens intolerance are interested in this kind of surgery. The goal is to provide visual rehabilitation and not to achieve emmetropy : the treated eye will see reasonably without systematically depend on a pair of glasses or contactlenses.
It is of the utmost importance that the patient realizes that the quality of his vision before the surgery with a correction will always be better than his visual acuity after the surgery without any correction.
For patients over 30 years old with a stabilized keratocone visual rehabilitation can be considered not sooner that 3 months after the UV-Crosslinking or the TG-PRK can be combined with UV-Crosslinking.
For younger patients with a progressive keratocone the treatment can be considered only 2 years after the original UV-Crosslinking.
To sort out if PIOL or is TG-PRK the right procedure depends on different parameters like the spherical equivalent, the degree of astigmatism and the thickness of the cornea.
In TG-PRK surgeries, 75% of the cylinder is corrected and a part of or the entire sphere depending on the thickness of the cornea. Maximally 50µm is removed. The optical zone must at least be 50 MM.
In a certain number of patients the TG-PRK was combined with the UV-Crosslinking treatment : in first instance the cornea is reshaped, next the sublayers are treated via UV-Crosslinking.
The effect is not only the stabilization of the keratocone but also a visual improvement and a bigger comfort for the patient as only one procedure is necessary. This approach is more experimental.
For 23 eyes there is a post-operative follow-up (number of gained lines of visual acuity, maximal keratometry, sphere equivalent, astigmatism …) over 6 months after the treatment for visual rehabilitation. These patients have filled in a satisfaction questionnaire which indicate their need for glasses/contactlenses, global satisfaction and secondary effects (light circles, complains concerning the night vision, dubbel sight).
The results of this study are encouraging but patients expectations must be realistic. The visual acuity before the surgery with a correction will always be better than after surgery without correction.
Combination of TG-PRK with PIOL is possible but there are no long-term results yet.
Where every technique fails we can still decide to perform a DALK (Deep Anterior Lamellar Keratoplasty) or PKP (Penetrating Keratoplasty) for those patients.
If you want more information, or would like to make an appointment:
Contact us or call 0032 (0)2 741 69 99