Keratoconus - A progressive corneal disease
Keratoconus describes as a progressive thinning and conical bulging forward of the cornea of the human eye. In many cases keratoconus is a hereditary disease.
The first symptom is a slow-progressing visual loss of one eye within weeks to months. The first suspicion is usually made by the optometrist or optician, when the patient is requesting new glasses with a higher astigmatic correction. An increase in corneal astigmatism in your glasses is highly suspect of keratoconus, which should let you consider consulting an ophthalmologist soon. The onset of keratoconus is usually within or shortly after puberty. This is also the reason why parents of affected teenagers play a major role in the adequate treatment of keratoconus. The earlier the keratoconus is diagnosed the better the long-term outcome is!
Keratoconus specialists at IROC eye clinic in Zurich have the longest experience in Switzerland in diagnosing and modern treating keratoconus and IROC is considered an international keratoconus- and crosslinking- reference center.
Keratoconus usually starts unilaterally, but the other eye is likely to be also affected. As a side diagnosis, keratoconus patients often become short-sighted as well. Statistically speaking the chance to be affected by keratoconus as a male is twice as a high as a female. Overall, the disease occurs in one out of 2,000 members of our society, however, in Near-East populations keratoconus is much more frequent (1:300). Until the year 2000, the only therapy of keratoconus consisted of the replacement of the cornea (corneal transplantation), however, such an operation is an organ transplantation with the associated risks and complications. Appropriate visual acuity is achieved by this type of operation only approx. 2 years after the corneal transplantation.
In 1996 the IROC eye clinic medical director Professor Theo Seiler and his research team introduced the new technique of corneal crosslinking for the treatment of keratoconus. It took another 3 years until he treated successfully the first keratoconus patient worldwide using this innovative technique. Today, the IROC eye clinic in Zurich is still conducting research, which resulted in the latest development of customized crosslinking together with Avedro Inc.
In contrast to corneal transplantation, corneal crosslinking is a less invasive procedure with a lower complication rate for the treatment of keratoconus. In mild to moderate keratoconus IROC ophthalmologists recommend in general the procedure of customized crosslinking, whereas in severe keratoconus a corneal transplantation might be the better option to achieve a permanent long-term visual improvement and rehabilitation.
An important fact for you as the patient is to know that not all eyes affected by keratoconus require treatment. In some cases keratoconus stabilizes without intervention and only follow-up examinations are indicated to monitor the disease.
Keratoconus treatment procedure & healing process
The aim of customized crosslinking is to stabilize the progressive thinning and bulging forward of the cornea, to "freeze" the current shape. In particular, this induced increase in rigidity is achieved by the combination of UVA radiation and riboflavin eye drops (vitamin B2).
The customized crosslinking (CXL) procedure is almost painless and performed in local anesthesia. However, due to the nature of the procedure a high percentage of cases suffer from postoperative pain during the first 48 hours after the crosslinking operation. Postoperative pain management is part of our postoperative care by our keratoconus specialists to minimize discomfort. Getting back to regular activities and work is usually possible after 7-10 days. Due to the high technical requirement of the procure, IROC eye clinic in Zurich is currently the only provider of customized crosslinking in Switzerland.
Comparison Customized vs. Standard or Accelerated Crosslinking
In comparison to "standard" or "accelerated" crosslinking, the "customized" approach is not treating the entire cornea, but only the affected part of it. First, a smaller area of epithelium is removed resulting in a shorter and less painful postoperative phase. This lowers the risk of infections resulting in a higher safety of the procedure. Second, the cornea is not uniformly irradiated, but the irradiation pattern is custom-tailored for each patient's cornea. IROC ophthalmologists only perform "customized" crosslinking since 2016. Multiple international studies reported an improvement of the keratoconus within the first postoperative 12 months after surgery in more than 60% of the cases compared to only less than 40% in "standard" or "accelerated" crosslinking. It was also demonstrated that if an improvement occurs, this improvement is significantly stronger using the "customized" procedure.
In severe keratoconus cases, crosslinking might not be the best way to improve the patients visual situation on a long-term basis and corneal transplantation might be the better alternative. In those rare cases IROC corneal surgeons perform a new and innovative version of corneal transplantation called "Deep Anterior Lamellar Keratoplasty" (DALK), which has in contrast to the conventional penetrating keratoplasty the benefits of a faster visual rehabilitation and of lower graft rejection rate. All keratoplasties performed at IROC eye clinic in Zurich are femtosecondlaser-assisted to guarantee the highest precision!
If you have already been diagnosed with a keratoconus, our team of ophthalmologists is at your service to take care of your case. Using modern imaging techniques and biomechanical examinations, our keratoconus specialists get to know your cornea individually to guarantee the best-possible eye care that can be offered to you. As the IROC eye clinic is an international reference center in keratoconus disease, we also offer second opinions prior to surgical interventions if requested.
Get additional information about keratoconus and CXL in our Q/A section.