BLOG: The OD’s role in preauthorization for corneal cross-linking
In our OD-MD practice, cross-linking is performed in-house, and the optometrists do the bulk of the work in documenting progression of keratoconus or ectasia changes over time.
But even in a primary care optometry practice where the patient is being referred to a surgical practice for cross-linking, it is important to know how the records you send with the patient can help them in their journey — or put up roadblocks to timely treatment.

For most commercially insured patients, the FDA-approved iLink (Glaukos) epithelium-off corneal cross-linking is a covered procedure, but one that requires preauthorization by the insurance company. Typically, that means that the doctor must demonstrate that the condition is progressive and the treatment is medically necessary.
Each insurance company has its own criteria for documenting progression and medical necessity, although there are commonalities across insurers. The most common requirements for documenting progression are just one of the following: A change of at least 1.0 D in Kmax, a change of at least 1.0 D in cylinder or a change of at least 0.5 D in manifest refraction.
Depending on your practice setting and comanagement relationships, it may or may not be your responsibility to meet the documentation requirements, but there are things every optometrist can do to make the process easier for their patient.
Detecting keratoconus
If you are referring the patient on a suspicion of keratoconus that will be verified by another provider, the diagnosis code will be decided after the referral. As optometrists, we have the capability to detect keratoconus based on changes in keratometry, topography, pachymetry and even refraction.
If you have diagnosed keratoconus and identified that the cornea is still changing, take care that the diagnosis is coded as “unstable keratoconus” (ICD-10 code H18.621, 622 or 623) rather than as “stable keratoconus” (H18.611, 612 or 613), and be sure that your documentation clearly mentions progression.
Historical records
In most cases, the cornea specialist or surgery center staff will be responsible for sending all the documentation to the insurance company. However, referring optometrists can play a very important role in collecting and forwarding historical records.
Although full records with imaging are appreciated, even being able to provide the patient’s spectacle prescriptions or manifest refractions from prior years can make the difference between the treatment being quickly authorized or not. Provide relevant information whenever possible, whether that is by fax, through a health care portal or directly to the patient to take to their referral appointment.
By sending records proactively, you can help your surgical partner avoid follow-up calls to obtain records and potentially save the patient from unnecessarily waiting for treatment while the cornea specialist verifies progression themselves.
However, don’t feel that you need to document progression. If you suspect keratoconus, refer and send along the records you do have.
Keep close tabs on new patients
With a new patient that I’m seeing for the first time, I know that no matter how severe the disease, they will not be preauthorized for cross-linking without at least two data points separated in time. I will request exam notes, testing results (keratometry, topography, etc.) and refractions from previous doctors. Again, the referring optometrist does not have to wait to obtain the second data point themselves before referring for a cornea consult if progressive keratoconus is suspected.
Sometimes there are no previous records at all. I have seen teen or young adult patients who have obvious keratoconus but who cannot remember if or when they last saw an eye care provider.
Because keratoconus in children is more aggressive than in adults, seeing younger patients sooner to establish progression is paramount. In fact, the recommended wait time for cross-linking after diagnosis for patients younger than 18 years is no longer than 6 weeks (Romano V et al.).
Hence, younger patients should be seen again within 3 months and older patients in 6 months to look for worsening refraction (namely, astigmatism), thinning pachymetry measurements, steepening of the cornea or other changes that would indicate progression.
While this is particularly important with young patients, we cannot assume that an older patient has stopped progressing; they should also be followed to determine whether they are stable or unstable. I also encourage patients with keratoconus to call our office if they feel that their acuity or quality of vision has changed before their next scheduled visit.
Making the extra effort to track down records and schedule more frequent visits can be inconvenient at times. But what I try to keep in mind is that without insurance coverage for cross-linking, many of my patients could not afford to have it done.
By ensuring that we obtain and pass along the documentation needed for insurance authorization, we can help our patients get access to care in a timelier fashion, and that can be the difference for them maintaining another line of vision on the eye chart.
References:
- Buzzonetti L, et al. Cornea. 2020;doi:10.1097/ICO.0000000000002420.
- Romano V, et al. J Refract Surg. 2018;doi:10.3928/1081597X-20180104-01.
For more information:
Katie L. Greiner, OD, MS, MBA, FAAO, is a specialty lens fitter at Northeast Ohio Eye Surgeons, a large MD-OD practice in the Akron-Canton area and a division of Midwest Vision Partners (MVP). She also is vice president of physician engagement for MVP and serves as a clinical attending optometrist at The Ohio State University College of Optometry. She can be reached at kgreiner@midwestvision.com.
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