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Cross-linking and scleral contact lenses: First steps in treating keratoconus
Preventing keratoplasty and achieving good vision are both possibilities for patients with keratoconus.
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Welcome to another edition of CEDARS/ASPENS Debates. CEDARS/ASPENS is a joint society of cornea, cataract and refractive surgery specialists, here to discuss some of the latest hot topics in ophthalmology.
Corneal cross-linking for treatment of keratoconus and post-LASIK ectasia was approved in the U.S. in 2016. Corneal surgeons have the dilemma as to who and when to treat. While early treatment to prevent progression and vision loss has been well accepted, there is still a place for treatment in the advanced keratoconus patient who may be facing a transplant. This month, William B. Trattler, MD, and Elise Kramer, OD, FAAO, FSLS, discuss their strategy for managing advanced keratoconus before proceeding with surgery. We hope you enjoy the discussion.
Kenneth A. Beckman, MD, FACS
OSN CEDARS/ASPENS Debates Editor
Patients at any age with any degree of keratoconus have more treatment options than an eventual corneal transplant. At a minimum, patients can achieve improved vision, and keratoplasty can potentially be prevented.
For one, scleral contact lens technology has revolutionized visual results in patients with keratoconus, so even patients with the most severe keratoconic conditions can still obtain excellent vision, as good as 20/20.
A scleral contact lens is particularly suited to steep corneas because the large diameter lens vaults over the cornea, allowing for a fluid layer between the lens and cornea and minimizing the irritation that could result from lens-to-cone contact.
When patients present with keratoconus to the physician’s office, unless there is severe central scarring, they can typically benefit from improved vision with a scleral lens. So, instead of patients automatically going straight for the transplant, as a first step, we should determine whether they can achieve good vision with a scleral lens. Scleral lens experts can fit any patient with keratoconus, whether their condition be mild, moderate or severe. As well, many patients may still end up wearing a scleral lens following a transplant, so determining whether a scleral lens provides adequate vision may allow some patients to delay or completely avoid a transplant.
The latest advancements incorporate computer-aided design and software integration to precisely guide the customization of each lens. The drawback is in the experience-intensive nature of fitting the lenses because the advanced technologies require extra time and specialized expertise, which can vary among scleral lens specialists. But in the end, if a patient with severe keratoconus can see well with a scleral lens, then he or she does not require corneal transplant surgery.
The excellent visual results that can be attained are demonstrated in the case provided by Elise Kramer, OD, FAAO, FSLS, of a 22-year-old African-American woman with advanced keratoconus in both eyes (Figure 1). Presenting uncorrected visual acuity was 20/400 in the right eye and 20/700 in the left eye. After fitting with scleral lenses from Visionary Optics, her visual acuity was 20/20 in the right eye and 20/30 in the left eye (Figure 2).
Cross-linking
While scleral lenses may allow for excellent vision, they do not stop progression of keratoconus. Cross-linking, on the other hand, is effective at stopping progression.
Source: William B. Trattler, MD, and Elise Kramer, OD, FAAO, FSLS
Cross-linking does two things: It stabilizes the cornea and often improves corneal shape over time. Some patients can experience improvement in vision after the cross-linking procedure. Improvements in corneal shape and vision can occur over many years.
One additional challenge for keratoconus patients is that following a corneal transplant, keratoconus can recur. Patients who have had corneal transplants should be monitored annually, and if corneal ectasia is identified, cross-linking should be performed. Another option is to consider cross-linking in patients who are scheduled for corneal transplant procedures since this will help maintain a stable cornea following the transplant procedure.
It is important to point out that patients with keratoconus can progress at any age. As well, because cross-linking can result in improvement of corneal shape, it can be performed in patients with mild cataracts with the expectation that in the future when the patient has cataract surgery, the corneal shape will be improved. Alternatively, cross-linking may be deferred in an older stable patient if the scleral lens alone provides satisfactory vision, and the transplant can still be avoided.
As the scleral lens case by Dr. Kramer demonstrates, patients with advanced keratoconus can end up with very good vision. In keratoconus patients who have not yet been fit with a scleral lens, the typical plan is to first undergo the cross-linking procedure to stabilize the cornea. Two to three weeks following the procedure, the patient can often be fit with a scleral lens. This sequence has allowed many advanced keratoconus patients the opportunity to experience very good vision without the need for corneal transplant surgery.
- For more information:
- William B. Trattler, MD, can be reached at Center for Excellence in Eye Care, 8940 N. Kendall Drive, Suite 400-E, Miami, FL 33176; email: wtrattler@gmail.com.
- Elise Kramer, OD, FAAO, FSLS, can be reached at Miami Contact Lens Institute, 2627 NE 203rd St. #116, Miami, FL 33180; email: elise@miamicontactlens.com.
Disclosures: Trattler reports he is a consultant for and has financial interests in Avedro and CXLO. Kramer reports she has a financial interest in Spectrum International.