Stage related Therapy for Keratoconus

Information about a stage related therapy that we propose: For the last 15 years we are working on conventional and surgical therapy of keratoconus. We have come to the conclusion that the present customary suggestion to use contact lenses up to the last stage of the disease is not substantiated and should no longer be recommended.

This recommendation is meant to help patients to bridge the problems of their initial keratoconus to the stage III or IV. A penetrating keratoplasty must then be performed. The problem of this treatment is, that the endothelium of the donor button

which is the most important layer of the cornea - as it feeds the cornea with oxygen - degenerates within a few years. The frequency of re-operations after 10 years reaches more than 50% (The Australian Corneal Graft Registry 2004 Report, research on 11.000 operations). Numbers cited there correspond to our experience on 5.000 corneal transplants carried out here. The disease is not healed by the transplantation of a donor cornea in full thickness, which may only lead to a temporary improvement.

In almost all of the Keratoconus patients the endothelium is healthy and should be preserved. Any possible healing of the disease can only be achieved by maintaining these patient's own internal layers. Therefore we think that suggestions to postpone a disease-stopping therapy are no longer justifiable.

Goal of the stage-related therapy therefore is to maintain the patient's own cornea.

There are the following possibilities:
Under the prerequisite of staging the disease like shown in the following table, we recommend for stage I and II the procedures that bring the cone into a standstill.

In conclusion: Contact lens is not a therapy of Keratoconus but rather leads to wrong assumptions about the seriousness of the lensewearer's KK-disease. 

For patients not tolerating contact lenses the general recommendation is Cross Linking (CXL). This method uses Ribloflavin - an off-spring from vitamins - that is burnt into the cornea with UV-light.

The cornea in many instances becomes stiffer and may become less irregular protrusiones.

Our opinion:

The procedure is doubtful in its desired efficiency. There are no relevant controlled studies proving the wanted effect of the procedure in the respective stage of the disease. No doctor can tell, what chance you may have to see better by CXL. At is unclear and doubtful, if there is a permanent effect. Research has not been done according to the single stages of the disease.

CXL is offered in different applications without that one knows the final results of long-time studies.

Unfortunately we have to warn against this procedure as we have reason to assume that lamellar transplantations may no longer be possible in CXL-treated eyes. We have published a paper in the main corneal journal "Cornea".

Link to paper

Clinical classification of Keratoconus

by stages

Stage Characteristics
Stage 1
  • eccentric steepening
  • induced myopia and/or astigmatism of ≤ 5.0 D
  • k-reading ≤ 48.0 D
  • Vogt's lines, typical topography
Stage 2
  • induces myopia and/or astigmatism > 5.0 D to ≤ 8.0 D
  • k-reading ≤ 53.0 D
  • pachymetry ≥ 400µm
Stage 3
  • induced myopia and/or astigmatism > 8.0 D to ≤ 10.0 D
  • k-reading > 53.0 D
  • pachymetry 200 to 400µm
Stage 4
  • refraction not measurable
  • k-reading > 55.0 D
  • central scars
  • pachymetry ≤ 200 µm

Stage is determined if one of the characteristics applies

Corneal thickness is the thinnest measured spot of the cornea.

Published in Klinische Monatsblätter für Augenheilkunde

Published in Journal of Refractive Surgery


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