Appeal type: Experimental/Investigational
Decision: Overturned

Diagnosis:  Post Surgical Corneal Ectasia.
Treatment:  Topography-Guided Corneal Collagen Crosslinking.

The insurer denied the Topography-Guided Corneal Collagen Crosslinking.  The denial is overturned. 

The patient is a female with post-LASIK (laser-assisted in situ keratomileusis) corneal ectasia for whom coverage of topography-guided PTK (phototherapeutic keratectomy) corneal collagen crosslinking (CXL) is requested. 

The patient's ocular history is notable for hyperopic LASIK and subsequent central islands and recurrent corneal erosions of each eye requiring phototherapeutic keratectomy (PTK) treatments.  She experienced increased irregular astigmatism on the front surface of her cornea, along with focal thinning causing decreased best corrected vision and contact lens intolerance.  An exam documents vision corrected to 20/25+1 OD (right eye) and 20/40 OS (left eye).  With a manifest refraction of +8.50 -0.75 x 139 OD and +7.50 -0.75 x 95 OS, vision was 20/20-1 OD and 20/30-2 OS.  Keratometry was reported as 43.4 x 44.1 @ 101 OD and 45.0 x 46.5 @ 22 OS.  A slit lamp exam found corneas to be clear with stable flaps.  Topography found central elevation/asymmetry.  Topography Guided PRK (photorefractive keratectomy) and Crosslinking to both eyes was performed.

Yes, the health plan should cover the Topography-Guided Corneal Collagen Crosslinking.

Yes, the Topography-Guided Corneal Collagen Crosslinking is likely to be more beneficial than any other treatment(s) identified for the insured's unique condition.

In this case, Topography-Guided Corneal Collagen Crosslinking is the subject of review.  This procedure describes two separate procedures, corneal collagen crosslinking (used in this case to address post-LASIK corneal ectasia) and topography-guided PRK/phototherapeutic keratectomy (used in this case to address irregular astigmatism in a patient, who is contact lens intolerant) which are performed in combination.  Therefore, these services are reviewed for medical appropriateness individually and in combination.  

Post-LASIK ectasia is considered in patients who developed increasing myopia, with or without increasing astigmatism, loss of uncorrected visual acuity, often loss of best-corrected visual acuity, with keratometric steepening, with or without central and paracentral corneal thinning, and topographic evidence of asymmetric inferior corneal steepening after LASIK procedure.  The U.S. Food and Drug Administration (FDA) has approved Avedro's Photrexa Viscous (riboflavin 5'-phosphate in 20% dextran ophthalmic solution) and Photrexa (riboflavin 5'-phosphate ophthalmic solution) as specifically indicated for use with the System in corneal collagen cross-linking (CXL) for the treatment of progressive keratoconus and corneal ectasia following refractive surgery.  Such treatment is not subject to IRB (institutional review board) approval, and there is reliable evidence showing that corneal collagen crosslinking is effective in slowing progression of post-LASIK ectasia.

Yildirim et al. reported a retrospective case series of 20 patients showing the long-term results of corneal collagen crosslinking (CXL) treatment for post-laser in situ keratomileusis (LASIK) ectasia.  Consecutive patients with ectasia after LASIK were treated with CXL.  The main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical and cylindrical refractions, and simulated keratometry (K) values.  They found that corneal collagen crosslinking yielded long-term stability in cases with post-LASIK corneal ectasia without significant side effects.  Improvements were observed in visual acuity, cylindrical refraction, and maximum K values.

Similarly, Richoz et al. reported a retrospective interventional case series involving 26 patients, which included the long-term results of corneal collagen cross-linking (CXL) in ectasia after LASIK and photorefractive keratectomy (PRK).  They also found that ectasia after LASIK and PRK was arrested by CXL with stabilization or improvement of CDVA and K(max) after a mean follow-up of 25 months.

Most recently, Hersh et al. published the results of a prospective, randomized, multicenter, controlled clinical trial to evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of corneal ectasia after laser refractive surgery.  One hundred seventy-nine subjects with corneal ectasia after previous refractive surgery were included.  The treatment group underwent standard CXL, and the sham control group received riboflavin alone without removal of the epithelium.  In the crosslinking treatment group, the maximum K value decreased by 0.7 diopters (D) from baseline to one year, whereas there was continued progression in the control group (1.3 D difference between treatment and control, P < 0.0001).  In the treatment group, the maximum K value decreased by 2.0 D or more in 14 eyes (18%) and increased by 2.0 D or more in 3 eyes (4%).  The CDVA improved by an average of 5.0 logarithm of the minimum angle of resolution (logMAR) letters.  Twenty-three eyes (32%) gained and 3 eyes (4%) lost 10 or more logMAR letters.  The UDVA improved 4.5 logMAR letters.   Corneal haze was the most frequently reported crosslinking-related adverse finding.  The authors concluded that corneal collagen crosslinking was effective in improving the maximum K value, CDVA, and UDVA in eyes with corneal ectasia one year after treatment, with an excellent safety profile.  CXL is the first approved procedure to diminish progression of this ectatic corneal process.

In this case, the patient is identified as having developed corneal ectasia following LASIK such that vision is best corrected to 20/20-1 OD and 20/30-2 OS with shadowing due to high hyperopia and significant irregular astigmatism. The patient has focal corneal thinning. Therefore, medical appropriateness would be established for corneal collagen crosslinking per standard of care.

In this case, best corrected visual acuity is also limited by the patient's highly irregular astigmatism.  Irregular astigmatism is nonuniform corneal steepening, which can result from a variety of causes that cannot be corrected by cylindrical lenses.  Irregular astigmatism decreases best spectacle-corrected visual acuity and may reduce contrast sensitivity and increase visual aberrations, depending on the magnitude of irregularity.  Rigid gas-permeable and hard contact lenses can correct visual acuity reductions resulting from corneal irregular astigmatism by bridging the irregular corneal surface and the contact lens with the tear film. 

In this case, the patient has a history of contact lens intolerance, so treatment options are limited.  For such patients, topography-guided transepithelial PRK, as reported by Allan and others, is a safe and effective option.  Therefore, topography-guided transepithelial PRK is established as medically appropraite.

According to Al-Mohaimeed et al., corneal CXL effectively arrests the progression of keratoconus by enhancing corneal rigidity.  However, functional vision is not improved by cross-linking.  Combining CXL with refractive surgeries, such as topography-guided PRK or transepithelial PRK, is found to be a safe and effective method in providing corneal stability, as well as significantly improving functional visual acuity with few minor complications.  This combined technique also prevents regression of keratoconus and reduces the risk of keratectasia.  Therefore, as the medical appropriateness of each procedure is established in this patient, and the safety and efficacy of combining the procedures is established, the requested service(s) are established as medically appropriate in this case per standard of care.