Keratoconus: An Urgent Call for Earlier Intervention

 More than a decade after the US FDA approved epithelium-off CXL for the treatment of progressive keratoconus, the disease is still often diagnosed only after vision loss has occurred. An analysis of AAO IRIS (Intelligent Research in Sight) Registry data on 66,199 patients with newly diagnosed keratoconus showed a substantial increase in CXL use between 2015 and 2020.¹

Late diagnosis is a major part of the problem. Much of the resultant vision loss is preventable. Currently available diagnostic tools are able to detect keratoconus earlier, and treatment can be initiated before irreversible visual damage occurs.

Every week, we see patients who sustained preventable vision loss before their first referral to a cornea specialist or specialty contact lens expert. A recent case involved a 23-year-old man with advanced keratoconus who requires a corneal transplant. He has permanent corneal thinning and scarring, and his BCVA is worse than 20/40 in the better-seeing eye and 20/400 in the contralateral eye. The delay in his referral missed an opportunity for earlier intervention. This case is not a rarity. In one study, 70% of eyes had reached stage 2 or higher on the Topographic Keratoconus Classification scale by the time the disease was diagnosed.²

Even after diagnosis, treatment is not always prompt. This is of particular concern in young patients, who are at greater risk of disease progression.³ Up to 20% of patients with keratoconus may eventually require corneal transplantation.⁴

Despite the negative impact of keratoconus on patients' lives, some of these individuals do not pursue treatment because of a fear of surgery, a reluctance to treat the second eye after an unpleasant experience with the first eye, disruption to their work or school schedules during recovery from epithelium-off CXL, or financial concerns. Additionally, patients may prioritize vision correction with glasses or contact lenses over treatment because they do not understand the importance of halting the underlying disease. Many of these avoidable delays are due to a lack of understanding and patient education.

More must be done to ensure that patients with keratoconus are diagnosed early, referred promptly for treatment when appropriate, and provided with effective vision correction. Earlier detection is the critical first step.

Better Screening Is Urgently Needed

We would like corneal imaging with topography, tomography, or both to be used more routinely in primary eye care because these technologies are among the most effective tools for detecting keratoconus before vision loss or slit-lamp signs become apparent. In ophthalmology and optometry practices, these technologies are also used for specialty contact lens evaluation and design, toric IOL planning, the evaluation of ocular surface disease, myopia management, and other applications. The development of multifunctional devices that combine topography with keratometry, wavefront aberrometry, or other diagnostic technologies may make corneal imaging increasingly accessible to practices. Affordable, easy-to-use topographic devices are essential to improving keratoconus screening in optometric and pediatric practices and school-based programs.

Identifying Patients at Risk

At a minimum, practices without access to in-house topography can consider referring keratoconus suspects for topography or tomography. These include patients with conditions associated with keratoconus, such as Down syndrome, connective tissue disorders, and multiple atopic conditions, as well as those with a family history of keratoconus. In our practices, clinical findings that prompt further evaluation for keratoconus include the following:

• Rapidly changing astigmatism;
• Greater than 2.00 D of astigmatism;
• A scissoring reflex on retinoscopy;
• Less than 20/20 BCVA in a young patient;
• Keratometry readings of 47.00 D or greater;
• Suspicious findings (eg, apical scarring, inferior corneal thinning, a Fleischer ring, Vogt striae, hydrops, or Munson sign) at the slit lamp; and
• A new diagnosis of amblyopia.

Simply moving amblyopia—a diagnosis of exclusion—down and keratoconus up the list of differential diagnoses for unexplained poor vision would likely help clinicians detect cases of keratoconus that might otherwise be missed.

Education and Prompt Referral

Eye rubbing remains one of the strongest modifiable risk factors associated with keratoconus progression, yet many patients are unaware of the behavior's potential impact. Clinicians should actively evaluate patients for allergic eye disease, atopy, and chronic ocular irritation while counseling them to avoid rubbing their eyes and treating the underlying inflammation when present.

Once keratoconus has been diagnosed, young patients (in particular) require a prompt referral to an ophthalmologist who performs CXL because the disease can progress rapidly in this population. In one study, 52 of 59 eyes (88%) in a pediatric cohort experienced disease progression within 12 months without CXL treatment.⁵

Vision Correction Remains Essential

Disease treatment and vision correction are complementary. Patients with keratoconus need both. Those whose vision has deteriorated substantially urgently require vision correction with specialty lenses. Scleral and other specialty lenses can improve the quality of life of many of these individuals by restoring their functional vision for driving, school, work, and daily activities.

Specialty lenses, however, do not address the underlying disease, so it remains important to educate patients and families about the need for treatment.

Reducing Barriers to CXL

Just as glaucoma treatment is not delayed until the disease reaches an advanced stage, intervention for keratoconus should be initiated before substantial vision loss occurs if possible. The introduction of a US FDA-approved epithelium-on, oxygen-enriched CXL treatment (Epioxa, Glaukos) may help in this regard.

Documenting Progression

Historically, a requirement to document keratoconus progression before treatment has presented a barrier, particularly in newly diagnosed patients. Epioxa is indicated for the treatment of keratoconus rather than progressive keratoconus, although payer coverage requirements may vary.

Preserving the Epithelium

Keeping the epithelium intact may hasten healing, shorten patients' time away from school or work, and improve their overall experience. These potential advantages may encourage earlier intervention in appropriate patients. Maintaining an intact epithelium may also allow patients to resume contact lens wear sooner after treatment.⁶ Ongoing real-world experience with Epioxa and long-term follow-up data should help inform patient selection and outcomes.

Cost and Coverage

Financial barriers remain an important consideration. Patient assistance and copay programs may reduce out-of-pocket costs for eligible individuals, and payer coverage for the procedure continues to evolve.

Coordinating Long-Term Care

Patients with keratoconus require lifelong management, and they can benefit from having both an ophthalmologist and an optometrist involved in their care. Effective collaboration and appropriate screening and referral protocols are especially important for young patients.

Greater collaboration among ophthalmologists and optometrists could shift the paradigm away from delayed diagnosis and treatment and toward earlier intervention to preserve patients' vision. This partnership is essential for best management over the lifetime of a keratoconus patient, as needs evolve over time.