The stages of treatment:
– By glasses then by contact lenses more and more,
– By UV CXL irradiation before or after,
– The surgical stage of which there are several modalities.
The choice depends on the severity of the disease and the visual imperatives. In general, it is important to distinguish between the rough forms that are fairly easily corrected and the evolutionary or evolved forms that are the source of many attempts.
1 – Optical correction by glasses
Prescription glasses is often difficult and requires lengthy trial and error.
2 – Optical correction by contact lenses
The contact lens is the classic correction mode of keratoconus, but it should not be adapted too early, when the solution by glasses is acceptable, that is to say giving good visual acuity.
When the peripheral part of the cornea not reached by the cone presents astigmatic deformations, the limits of the spectacle correction have been reached. Only expert doctors can equip the advanced stages, because the experience takes precedence.
The interest of this type of lens is improved comfort due to the presence of the peripheral soft lens. It is difficult to obtain a stable junction zone between two materials of very different chemical nature.
The materials used today are very efficient, the reproducibility of excellent lenses. The finishing and polishing of these lenses is no longer a problem.
Research on the possibility of recovery or surface treatment improving the comfort of these is underway.
The development of explorations of the ocular system by aberrometry allows a better apprehension of the visual quality of the patients. These works are, in the immediate future, oriented towards soft lenses.
3 – Superficial corneal photoablation PKR
If the lasik is cons indicated, this is not the case of frust or suspicious forms that can be processed in PKR, most often associated with simultaneous or offset cross linking. We now know that the risk is extremely low if the indication is well posed.
4 – The transplant of the cornea
The indication of DEEP LAMELLAR keratoplasty is logical when the patient can not obtain useful vision with contact lenses because of central or paracentral opacity. As the endothelium is normal it is useless, in the majority of cases, to go to the transfixant keratoplasty.
However, the complexity of producing the lamellar makes the transfixant keratoplasty possible if the lamellar fails, which is not rare technically.Frequent indication is contact lens intolerance possibly associated with opacification of the top of the cone in the visual axis or within 1 mm of it.
The cornea is a transparent tissue of the eye enjoying an “immune privilege” due to the absence of vessels. This tissue is therefore most often relatively “unknown” of the recognition and defense system of the body, allowing a tissue exchange between individuals in optimal conditions.
The transplant is well tolerated in 90% of cases. The risk of rejection is permanent. The waiting list is not very long. The graft can be kept one week at a temperature of 4 degrees, or a month at 31 degrees; in special circles. Its quality is controlled in specialized eye banks, under the authority of the French Eye Bank and the French Transplant Institution.
A very strict list of criteria must be observed to carry out the sampling in order to guarantee the biological safety of the fabric. Final visual recovery takes up to a year to reach a time to remove the sutures.
Postoperative treatment usually includes cortisone eye drops for a period of two months to one year. Monitoring every two months for one year, then every six months is a good guarantee of graft survival. Sometimes, immunosuppressive treatment may be associated in high-risk transplants (cyclosporine …).
Recently the femtosecond laser allows these grafts in a less random way because the permanent danger, even with the best surgeon, is to perforate the posterior plane. This risk is almost eliminated with the laser.
The keratoconus transfixing keratoplasty is losing speed because it poses a risk of rejection and it makes it necessary to transplant the endothelium which is still healthy in this affection but it remains of certain indication when the cornea has a very strong astigmatism.
With this process we can expect a visual acuity of 6/10 after 2 years. You should know that it is sometimes necessary to put lenses on an operated eye, to improve the vision. In all cases visual recovery is very slow from 1 to 2 years.
Keratoplasty by the Keraflex XXL System
The device delivers pulses retracting a fraction of the corneal tissue, without ablation, so as to reshape the shape of the cornea. The process is in investigation.