Contact Lenses vs. Surgery for Keratoconus
Contact lenses with a rigid surface are the undisputed gold standard for restoring vision in keratoconus. Despite recent advances in surgical treatment — including collagen cross-linking, intracorneal ring implants (Intacs), and partial-thickness corneal transplants — none of the currently available surgeries can make the distorted keratoconic cornea quite as smooth as the surface of a rigid contact lens. The uniform surface of a rigid lens masks the distorted, irregular cornea in keratoconus, allowing light to properly focus into the eye. Simply put, the rigid surface neutralizes the optical turbulence of the keratoconic eye. This is why many of the top corneal surgeons first refer their keratoconus patients to a contact lens specialist before operating. Of course surgical treatment has its place. However surgery for keratoconus often has a secondary role in relation to less invasive contact lens treatments.
A historical challenge with rigid or “hard” contact lenses is that some wearers, even those without keratoconus, have difficulty overcoming the initial awareness of the lens edge interacting with the eyelid. If you have keratoconus and can’t wear even optimally prescribed rigid lenses, you may be stuck between a rock and a hard place. That’s because glasses and corneal surgery by themselves can’t approach the quality of vision afforded by rigid optics, at least not typically. Furthermore, while soft contacts are initially more comfortable than their rigid counterparts, the soft material conforms to the irregular “peaks and valleys” of the keratoconic cornea, leaving the visual distortions largely unaddressed.
So what can your eye doctor do in the aforementioned situation? Your doctor may recommend UltraHealth or ClearKone® hybrid contact lenses which combine the clarity of a rigid center with the comfort of a soft outer skirt. These lenses were designed specifically for keratoconus. For selected patients, properly prescribed UltraHealth lenses can afford a new-found freedom that no other treatment can approach. UltraHealth is an important option for some keratoconus patients who are unable to wear rigid lenses. Yet UltraHealth also has a role for many other keratoconus patients, especially those active in sports where resistance against lens dislodgement and visual stability are desirable. Many of the contact lens specialists at the forefront of keratoconus treatment are certified to prescribe UltraHealth. These contact lens specialists tend to interact regularly with corneal surgeons, using a team-approach to treat keratoconus both non-surgically and surgically as dictated by the particulars of each case.
Another alternative is scleral lenses, which are rigid contacts that are unusually large — larger in diameter than most soft contacts. Scleral lenses often provide improved initial comfort over smaller diameter rigid lens designs, however they can require greater expertise by the practitioner and patient for successful wear.
For those already wearing more common rigid lenses, but who are experiencing the unavoidable rubbing on the sensitive corneal surface from the lenses, your eye doctor may prescribe a “piggyback” system. In piggyback systems, breathable soft lenses are worn underneath the rigid lenses not for improving vision, but for protecting against mechanical chaffing and the resulting discomfort. Your eye care professional can determine the appropriate contact lens modality for your specific circumstance, including whether lens wearing discomfort is due to sensitivity of the lens edges, lens chaffing of the cornea, or some other reason.
Ultimately, the practitioner’s experience and skill are more important than the contact lens design used for treating keratoconus. Many eye doctors do not routinely prescribe medically-necessary contact lenses and will refer you to one of their colleagues with such expertise. Since the pattern of corneal distortion in keratoconus is as unique as a fingerprint, there isn’t a single lens design that works for every eye. Contact lens prescribing for keratoconus is a process which can span many visits before all refinements to the lens parameters are completed. Due to the chair-time required and custom nature of the prescribing, it’s not uncommon for the services and lenses to cost over $1,500 without third party coverage. Many medical insurances fail to understand that contact lenses for keratoconus are non-elective and medically-necessary for rehabilitating vision. Consequently, keratoconus patients often shoulder most of the financial responsibility for their contact lens treatment.