The 2 most common questions I hear on a daily basis in the CLEI Center for Keratoconus are:

  1. Is my keratoconus getting worse?
  2. Do/Will I need a cornea transplant?

Clearly, these concerns are on the minds of many patients affected by keratoconus. I have had patients break down in tears over the mere thought of a corneal transplant. What are the facts when it comes to corneal transplants?

Keratoconus 3 month post op penetrating keratoplasty: photo: Gelles, J.

In reviewing the Eye Bank Association of America’s overall trends in corneal transplantation from 2005 to 2016, it is clear the overall rate of penetrating keratoplasty is reducing while the rate of endothelial keratoplasty is increasing and the utilization of anterior lamellar keratoplasty is low with a rate of utilization that is very slowly increasing. As surgical and tissue preparation techniques improve these rates have changed drastically. Gone are the days of full thickness grafts for fuch’s dystrophy and persistent corneal edema post cataract surgery. It leaves us with a question, in today’s day and age, what disease indicates intervention with a penetrating keratoplasty?

Eye Bank Association of America: 2016 Eye Banking Statistical Report

According to the Eye Bank Association of America’s 2016 Eye Banking Statistical Report, the overwhelming reported indication for penetrating keratoplasty and anterior lamellar keratoplasty was Keratoconus. These numbers could be skewed as there is a massive unreported category, 42.5% of indications are unreported, but clearly, Keratoconus is the leading reported indication making up 14.2% of penetrating keratoplasties and 30.7% of anterior lamellar keratoplasties performed in the US last year. If we eliminate the unreported category, of the reported 22,097 penetrating keratoplasty, Keratoconus is responsible for 24.7% of penetrating keratoplasties and 60.5% of anterior lamellar keratoplasties. 

Eye Bank Association of America: 2016 Eye Banking Statistical Report

By and large cornea transplantation is the most successful tissue transplantation procedure, due to the lack of direct blood flow to corneal tissue making for an immunoprivileged environment. However, an interesting note from the Eye Bank Association of America’s data is the second highest reported indication for penetrating keratoplasty is repeat corneal transplant, at 11.8% in the overall and 20.5% with the unreported category eliminated. Though there is not a sub-category to separate reasons for repeat cornea transplant, it is important to recognize that survival rates of corneal grafts are variable. Grafts can dehisce, decompensate, be subject to a rejection, and ultimately fail. Nonetheless, this is an incredibly important procedure and clearly, post-keratoplasty patients require lifelong monitoring and care.

Graft rejection, note keratic precipitates, khodadoust line, and edema: photo: Gelles, J.

Now that we know the number one indication for penetrating keratoplasty is keratoconus, we must ask a couple of questions. What are the common reasons patients with keratoconus undergo corneal transplant? Ultimately the decision to proceed with a keratoplasty comes down to inadequate best corrected visual acuity despite exhausting lens and less invasive refractive surgical efforts and/or contact lens intolerance. Contact lens intolerance is an interesting term, somewhat of a catch-all for patients that cannot successfully wear lenses due to a variety of reasons from pain and irritation during lens wear to inability to apply and remove lenses.

Many of the individuals referred to my clinic with keratoconus diagnosed with contact lens intolerance have been suffering from previous undiagnosed dry eye disease, have developed contact lens-related complications such as giant papillary conjunctivitis or are simply not fit in a lens ideally designed for their needs. Can our choices in managing these patients reduce utilization rates of corneal transplantation for patients with keratoconus? Theoretically, the answer is an emphatic YES and there are 2 main factors that may lead to this reduction: crosslinking and scleral lenses.

As of April 2016 crosslinking was FDA approved in the US and today in 2017, treatment of progressive keratoconus with crosslinking should now be considered the standard of care. Practitioners can do their part in preventing patients from reaching advanced levels of keratoconus that would necessitate corneal transplantation by diagnosing keratoconus early and in the progressive or at risk of progression population intervening with crosslinking to slow or prevent disease progression. Proper monitoring of keratoconus after treatment is essential as through treatment with FDA approved crosslinking is over 90% effective, some patients may progress necessitating a second treatment.

Crosslinking with Avedro KXL: gif: Gelles, J

For the patients that have already progressed to advanced levels of disease, severe keratoconus can make for a difficult, if not impossible, challenge to successfully fit with traditional lens options. Utilization of scleral lenses can make for successful lens wear in even the most severe of cases, allowing for a lens option when all else has failed.

Scleral lens vaulting over Keratoconus: Gelles, J

Let’s look at the literature in support of these theories. A newly published article out of Antwerp University Hospital, Coppen et al. studied the use of scleral lenses for individuals with severe keratoconus (maximum keratometry >70D) who would have otherwise undergone corneal transplantation, they found that 40 of 51 eyes were successfully treated with scleral lens wear avoiding the need for keratoplasty. At University Medical Center Utrecht, Godefrooij et al studied rates of utilization of keratoplasty in the Netherlands over a 3 year period prior to and after implementation of crosslinking finding that approximately 25% fewer corneal transplants were performed in the 3-year period following the introduction of crosslinking, suggesting that keratoplasty utilization rates may be significantly reduced as crosslinking becomes standard of care.

By embracing these components as a part of the modern management of keratoconus, using crosslinking to prevent advanced disease and scleral lenses to visual rehabilitate those with advanced disease, the utilization of keratoplasty may be significantly reduced. In future blogs, we will explore options for visual rehabilitation for keratoconus from contact lenses to refractive surgical options.