Keratoconus typically starts at puberty and progresses until the third or fourth decade of life. At initial diagnosis, younger patients with the steepest corneal curvature (Kmax) of over 55 D have a significantly greater risk of progression. Keratoconus seen at this age is more aggressive, leading to more severe cases. Without any management, the corneal curvature becomes more conical in shape, which can cause worsening of vision, thinning and scarring of the cornea, and possible development of hydrops. However, it tends to stabilize after 20 years from the first diagnosis.
To detect keratoconus progression, some corneal parameters need to be evaluated.
WHAT THE EYE DOCTOR IS LOOKING FOR?
- -Increase maximum corneal refractive power (Kmax) by more than 1 Diopter within one year.
- -An increase in (corneal) myopia by more than 3 Diopter or astigmatism by more than 1.5 Diopter within one year.
- -An average corneal refractive power increase by more than 1.5 Diopter within one year.
- -A reduction in minimal corneal thickness of more than 5% within one year.
- -An increase of more than 1D in the anterior corneal curvature of the area other than the cone (KCE- keratoconus enlargement)
WHAT YOU MAY FEEL?
Vision changes may or may not depict progression as patients with keratoconus usually experience variation in vision. In addition, some vision changes may be compensated with contact lenses, so a routine corneal topography must be done to compare the current to the baseline measurements objectively.
If you wear conventional rigid gas permeable lenses or scleral contact lenses, you may feel irritation or discomfort, which signals a clinic follow-up. Of course, discomfort can be due to the current lens condition, but it may also mean that your lens may warrant a change in fit.
Fortunately, nowadays, the standard of care is to present a corneal cross-linking (Riboflavin-UVA cross-linking) option to patients, which can help strengthen the corneal fibers through a photochemical effect to stabilize the disease. Of course, avoiding rubbing your eyes is also crucial to prevent progression.
Can I wait for 2-3 more years before doing a cross-linking procedure?
If your condition is mild, you probably may have some leeway to wait. However, we have seen aggressive progression happening in as short as two years. There is a cut-off point on whether your cornea can still undergo cross-linking. When your cornea becomes too thin due to the progression, you may not be eligible for the procedure, hence, forfeiting the opportunity to stabilize your keratoconus.
Ultimately, whether you have symptoms or not, remember to go to your annual follow-up to know if your condition remains stable.
References:
- https://iovs.arvojournals.org/article.aspx?articleid=2188463
- https://pubmed.ncbi.nlm.nih.gov/26142151/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6503175/
- https://www.aaojournal.org/article/S0161-6420(18)33287-1/fulltext
- https://www.nature.com/articles/s41598-021-00649-0
We appreciate you sharing this content. Those who have keratoconus should read this in particular. It is better to have an annual checkup, whether or not there are symptoms, in order to determine whether your condition is still stable. -Aris Vision CDMX https://arisvisionmexico.com/
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