BLOG: How to prepare patients for contact lens wear after cross-linking
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In the U.S., FDA-approved corneal cross-linking is performed with Glaukos’ iLink system as an epithelium-off procedure to slow or halt the progression of keratoconus.
Because the epithelium has been débrided centrally and must be allowed to heal, patients will have a bandage contact lens on the cornea for about 1 week. In addition to this contact lens, patients will be prescribed a topical antibiotic, steroid and sometimes a nonsteroidal anti-inflammatory medication, each with its own treatment course during the first few weeks.
Comanaging optometrists may see diffuse central haze related to the treatment response in corneal tissue. Sometimes these changes affect visual quality, but the haze is generally temporary and typically fades within a few months. A demarcation line, indicative of treatment penetration extent, will also be visible on corneal imaging within the first 6 months after cross-linking (Moramarco A, et al), and also will gradually fade away.
Resuming contact lens wear
Contact lens wear can be resumed sooner after cross-linking than many people might assume, especially in established wearers. New wearers, who are less familiar with application and removal techniques, may be prone to overmanipulate the epithelium or cause minor trauma to the cornea. So, it may be best for them to wait a little longer before beginning contact lens wear.
See the accompanying table for my recommendations for both established and new wearers.
The time at which a patient can resume or start contact lens wear following cross-linking differs from the time at which lens prescription and fit stabilizes following the procedure. This corneal treatment leads to remodeling and stiffening of the stromal tissue and typically flattens the cornea by 1 to 2 D (Chang CY, et al).
Because the corneal shape changes over time, the prescription for glasses and soft toric lenses — and to a lesser degree for specialty lenses — may continue to fluctuate until the cornea is stable. Most change occurs in the first 2 to 3 months, but there can be ongoing, slower change, especially in the amount and axis of astigmatism, through 6 to 12 months after cross-linking (Chang CY, et al).
I’ll explain what to expect with different types of lenses.
Soft toric lenses
Mild keratoconus patients may be candidates for soft toric lenses, which sit directly on the cornea and mold to the irregular shape of a keratoconic eye. Patients in this type of lens will experience more fluctuations in fit and vision than those in other lens types.
While established wearers can often resume wear at 1 month, they will likely experience a prescription change within the first 2 to 3 months: They may or may not be able to resume wearing their previous contact lenses, depending on shift in corneal shape and astigmatism.
These patients should try to wear their habitual glasses and postpone lens refitting until about 3 months after cross-linking. Even then, patients might not want to purchase an annual supply, as their prescription may continue to change slightly over time.
Gas permeable, hybrid lenses
A lens that is entirely rigid, or rigid in the center, helps neutralize the irregular cornea, limiting effects of the cone and of any flattening induced by cross-linking on visual quality. In most keratoconic eyes, there is some degree of apical touch because gas-permeable or hybrid lenses do rest directly on the cornea.
After cross-linking, you might see less apical touch and potentially a better or more comfortable fit. This will be most noticeable in mild keratoconus, where a 1 to 2 D flattening will have a greater proportional effect on cornea shape than it will in a very steep and advanced cornea.
As long as the epithelium has healed, established wearers can resume gas-permeable or hybrid lens wear about 1 month after cross-linking. Small adjustments to the prescription or fit may be needed, but habitual lenses from before cross-linking can often be used successfully.
Scleral lenses
Scleral lenses do not touch the cornea, so they can be utilized quite soon after cross-linking. A recent study demonstrated that scleral lens wear had been resumed in dry eye patients as early as 1 week after cataract surgery (Ma KK, et al), which is a more invasive procedure than cross-linking itself. For established wearers highly dependent on vision through scleral lenses, it may be possible to resume wear in their previous scleral lenses 2 to 3 weeks after cross-linking.
Flattening of the cornea may create a slightly higher vault, but in my experience, it rarely requires a new fit. Small changes in the fit or prescription — not unusual any time I order new scleral lenses for a patient — can sometimes wait until the lenses need to be replaced anyway.
Information about contact lenses often is not covered in much detail by the corneal surgeon, so it is imperative that optometrists “own” this portion of the preoperative counseling so patients are prepared for ongoing changes in their vision and contact lens prescription for weeks and months after the procedure.
Patients should be aware that they will need to wear glasses initially. They won’t have crisp vision immediately after cross-linking and it will take time for the cornea to heal. They should also be advised that there will be new fees associated with contact lens refitting and ordering that are separate from the cross-linking procedure itself.
For the optometrist, it is helpful to understand that a specialty lens order is not a one-shot opportunity, as many labs offer a global period during which changes can be made. And for patients, it is very reassuring to know that their optometrist has a clear plan for their visual recovery after cross-linking.
References:
- Chang CY, et al. Eye Contact Lens. 2014;doi:10.1097/ICL.0000000000000094.
- Ma KK, et al. Eye Contact Lens. 2021;doi:10.1097/ICL.0000000000000747.
- Moramarco A, et al. J Cataract Refract Surg. 2015;doi:10.1016/j.jcrs.2015.04.033.
For more information:
Gloria Chiu, OD, FAAO, FSLS, is an associate professor of clinical ophthalmology at Keck Hospital at the University of Southern California. She is a fellow of the Scleral Lens Education Society and an expert on specialty lenses. Chiu can be reached at gloria.chiu@med.usc.edu.
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