BLOG: Repeated contact lens refits a disservice to patients with keratoconus
Key takeaways:
- Doctors must educate patients that early corneal cross-linking is the best chance of maintaining good vision.
- Cross-linking cannot restore best corrected vision that has already been lost.
In eyes with keratoconus, no contact lens — whether soft, gas permeable or scleral — can arrest progression of the underlying disease process, even when it does achieve the goal of helping the patient see better.
Ectasia can continue to progress despite good corrected visual acuity in the contacts.
I have seen a number of keratoconus cases in my career in which the patient has been fit in a specialty contact lens by their primary care optometrist and was able to see 20/20 with good quality vision. As the cornea continued to warp and deform over time, the provider simply increased the power of the lens or changed to a steeper base curve to maintain good visual acuity. The patient was referred to our surgical practice only when, after several refits, vision could no longer be adequately corrected.
Some people might consider this good patient service because the doctor has, perhaps for years, successfully addressed the patient’s primary concern — their vision. But I’d like to flip the script on that approach. It is our job as doctors to educate the patient with progressive ectasia that early corneal cross-linking provides the best chance of maintaining good vision in glasses or contact lenses throughout their lifetime and avoiding an invasive corneal transplant, with all the risks and restrictions that entails.
Contrary to common belief, patients do not have to become contact lens intolerant or have worse than 20/20 best corrected vision to qualify for cross-linking. This is a little confusing because some insurers do require patients to have “failed” contact lenses or “failed” conservative therapy before they will approve cross-linking. However, the cornea specialist will often differentiate between vision and disease treatment plans, noting that contact lenses will continue to be recommended for vision correction, while cross-linking is needed to stop disease progression, which is not affected by contact lenses.
In most cases, cross-linking cannot restore best corrected vision that has already been lost. By waiting until the patient has already lost lines of best corrected vision, the patient no longer has the opportunity to enjoy 20/20 vision, even after cross-linking and with specialty contact lenses.
Worse yet, with a late referral to a cornea specialist, the patient may no longer be a good candidate for cross-linking, or they may find that they can no longer wear contact lenses. As the cornea thins and the surface of the cornea becomes more irregular, the difficulty of lens fitting increases. Some patients may develop corneal hydrops (Figure), with a break in Descemet’s membrane that leaves a dense central scar, reducing visual potential to the point that a corneal transplant becomes necessary. Lens tolerance may decrease. Visual function during the hours before and after lens wear may become increasingly poor.
The moral of the story is that just because a patient can be fit in contact lenses doesn't mean they should be fit again and again — at least not without a referral for cross-linking. By seeking out good referral partners who can perform cross-linking and send the patient back to you for vision correction, you can continue to be a hero in addressing the patient’s vision, while knowing that you have done everything you can to protect their future visual potential, as well.
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For more information:
Mitch Ibach, OD, FAAO, is a cornea, glaucoma, cataract and refractive surgery specialist at Vance Thompson Vision in Sioux Falls, South Dakota. He can be reached at mitch.ibach@vancethompsonvision.com.
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