Corneal Remodeling
Defines medical necessity, experimental/investigational status, and coding guidance for corneal remodeling procedures (e.g., corneal relaxing incisions, PTK, keratoplasty, collagen cross-linking, refractive surgeries) for Aetna members.
No material clinical or coverage changes in this revision.
Coverage Criteria
Post-Cataract Post-Transplant Corneal Surgery
Post-cataract or post-penetrating keratoplasty correction of surgically induced astigmatism is covered when ALL of the following are met:
Post-surgical astigmatism correction criteria
- Astigmatism magnitude and intolerance: The degree of astigmatism is 3.00 diopters or greater AND the member is intolerant of glasses or contact lenses.>= 3.00 D
- Prior surgery timeframe: Member had prior penetrating keratoplasty within the past 60 months OR prior cataract surgery within the past 36 months.penetrating keratoplasty ≤ 60 months OR cataract surgery ≤ 36 months
Both surgery timing and clinical thresholds must be met.
Phototherapeutic Keratectomy (PTK)
Phototherapeutic keratectomy (PTK) is considered medically necessary when the member has ANY of the following conditions:
Conservative measures should be attempted and documented for recurrent erosions prior to PTK.
Collagen Cross-Linking (CXL) for Keratoconus/Keratectasia
Collagen cross-linking is covered when performed as epithelium-off photochemical CXL with riboflavin and UVA for the following:
Epithelium-off (standard/Dresden) riboflavin + UVA technique is the established method supported by guidance; epithelium-on (transepithelial) CXL and CXL combined with other procedures (CXL‑plus) are considered experimental/investigational for other indications.
Epithelium‑on CXL has inadequate evidence of safety and efficacy per NICE and may require additional justification or be considered investigational.
Refractive Surgery (general stance)
Refractive surgical procedures coverage stance:
Specific FDA/AAO‑accepted indications and plan contractual exclusions may further define applicability; some procedures (e.g., astigmatic keratotomy) are medically necessary when performed to correct surgically induced astigmatism after cataract removal or corneal transplant.
Policy references FDA/AAO ranges and recommends using spectacle/contact lens correction when appropriate.
Covered when selection criteria are met vs Refractive surgery NMN
Overall stance and conditional coverage
Coverage is contingent on meeting documented clinical selection criteria and plan contract provisions; appropriate CPT/HCPCS/ICD documentation should accompany requests.
Procedural selection criteria (background-derived)
Procedural indications and selection notes extracted from clinical background and regulatory guidance:
Supported by small case series (Mauriello & Pokorny).
Reflects FDA HDE criteria.
Device‑dependent FDA guidance should be followed.
Document prior graft history and rationale; compare alternatives such as repeat donor transplantation.
Keratoprosthesis candidate considerations
Clinical considerations influencing coverage decisions include:
Centers vary in whether one or multiple graft failures are required; document clinical justification.
Endothelial keratoplasty
Endothelial keratoplasty (DSEK/DSAEK/DMEK) considerations:
AAO and NICE assessments support EK but note potential complications and varying long‑term data.
Collagen crosslinking
Corneal collagen crosslinking (CXL) coverage considerations:
NICE (2013) and CADTH assessments favor epithelium‑off CXL; combination 'CXL‑plus' procedures lack sufficient evidence.
CXL and related techniques
Evidence-based considerations and coverage stance for corneal cross-linking and related remodeling procedures
Document procedural parameters and corneal thickness when billing/authorization requested.
May require prior authorization and additional documentation.
Topical pharmacologic CXL agents are experimental and not medically necessary for routine use.
Post-LASIK epithelial ingrowth management
Management options for post-LASIK epithelial ingrowth and flap complications
Document prior treatments and extent of ingrowth; consider based on severity.
Considered salvage; limited data.
Alternative to suturing in selected cases.
Use clinical judgment and document follow‑up.
Endothelial keratoplasty options
Endothelial keratoplasty approaches for endothelial decompensation and acute corneal hydrops
Evidence limited to small retrospective series.
Consider when conservative measures or gas tamponade are unlikely to succeed.
Limited case reports/series; document imaging and rationale.
Tissue-additive and laser reshaping techniques
Novel and tissue-additive procedures for keratoconus
Preliminary technique; further standardization and evidence needed.
Considered investigational pending larger standardized studies.
Genetic susceptibility testing
Genetic testing and predisposition
Not established as a clinical diagnostic or predictive test pending broader validation.
Procedures performed solely to correct refractive errors (for example, many uses of penetrating or lamellar keratoplasty, photorefractive keratectomy [PRK], LASIK, radial keratotomy [RK], and related refractive procedures) are excluded or considered not medically necessary unless the member’s benefit plan explicitly includes coverage for refractive surgery. The policy distinguishes PTK (a therapeutic use of the excimer laser for corneal disease) from PRK (a refractive procedure) to emphasize that surface-laser procedures intended only to change refractive status are not covered under standard benefits.
Refractive surgical procedures intended to correct refractive error (e.g., PRK, LASIK, RK, astigmatic keratotomy, keratomileusis, epikeratophakia, intrastromal ring implants) are considered not medically necessary for routine refractive correction because spectacles or contact lenses provide more accurate and predictable refractive outcomes. Where a plan does not explicitly exclude refractive surgery, these procedures remain not medically necessary or investigational except for FDA/AAO-accepted indications; clinical examples and evidence supporting limited accuracy of surgical refractive correction versus lenses are noted.
Methods of thermokeratoplasty other than FDA‑approved conductive keratoplasty (for selected presbyopia/hyperopia indications) — such as holmium:YAG laser thermokeratoplasty (LTK), the hot‑needle technique, and other historical thermokeratoplasty methods — and orthokeratology are not proven effective for routine correction of refractive errors or for keratoconus and are reported as abandoned or not recommended due to unpredictable wound healing, scarring, and instability. Scleral expansion surgery for presbyopia likewise lacks robust evidence and is not recommended.
Guidance and systematic reviews indicate that evidence supporting epithelium-on (transepithelial) CXL is inadequate to establish its safety and efficacy compared with the established epithelium‑off (Dresden) technique. NICE (2013) concluded that most evidence relates to epithelium‑off CXL and that epithelium‑on approaches and ‘‘CXL‑plus’’ combinations have limited supporting data; therefore transepithelial CXL should be considered limited or investigational unless further robust evidence is provided.
Several procedures and combination approaches are considered to have insufficient evidence for routine coverage and are described as investigational or experimental. These include elective combined PRK with prophylactic CXL for mild keratoconus (reports of progressive remodeling have been published), epithelium‑on (transepithelial) CXL, ‘‘CXL‑plus’’ combination techniques without supporting randomized data, and topical pharmacologic cross‑linking agents or other unvalidated CXL delivery methods. When such procedures are proposed, documentation and justification should be provided; absent convincing evidence, they are generally not supported for routine reimbursement.
This Clinical Policy Bulletin provides a partial description of plan benefits related to corneal remodeling procedures and is intended to assist in administering plan provisions. It does not guarantee coverage, does not replace a member’s benefit contract, and specific coverage decisions should be based on the member’s plan documents and any prior authorization determinations.
No explicit set of additional coverage criteria or changes beyond those summarized in this policy excerpt are provided in the document segment; reviewers should refer to the full policy and the member’s benefit plan for any additional criteria or exclusions.
Phototherapeutic keratectomy (PTK) is considered experimental and investigational for the treatment of infectious keratitis and for indications not listed as medically necessary in this policy. PTK is medically necessary only for the specific corneal surface conditions enumerated (e.g., corneal scars/opacities, epithelial membrane dystrophy, Salzmann’s nodular degeneration, recurrent erosions after failed conservative therapy, and superficial corneal dystrophies).
Refractive surgical procedures are considered not medically necessary primarily because spectacles or contact lenses provide more accurate and reversible correction of refractive errors. The policy notes lower precision of surgical refractive outcomes and potential for optical complications; therefore, coverage for elective refractive surgery is generally not supported unless the member’s plan specifically includes refractive benefits or exceptional medical indications exist.
Orthokeratology and scleral expansion surgery are not recommended for routine use. Orthokeratology has not been proven effective and is considered unpredictable and poorly controlled; scleral expansion surgery for presbyopia lacks quality evidence and was recommended by NICE not to be used.
There is an evidence gap comparing artificial corneas (keratoprostheses) with repeat donor corneal transplantation: no randomized controlled trials directly compare outcomes and complications between keratoprosthesis devices and repeat donor grafting. This lack of high‑quality comparative data may affect coverage decisions and supports careful documentation of prior graft failures and rationale when considering an artificial cornea.
Topical pharmacologic cross‑linking agents and other nonstandard or unvalidated CXL delivery methods (including experimental agents identified in early reports) remain investigational. Although preclinical and early clinical work has identified candidate compounds and novel delivery strategies, further controlled trials are required before these approaches are considered medically necessary for routine care.
Within this document segment there are no additional explicit statements labeled as 'not medically necessary' beyond the refractive surgery exclusions and investigational procedure listings already summarized. Providers should consult the full policy and member benefit contract for any further 'not medically necessary' provisions.
Coding
| S0812 | Phototherapeutic keratectomy (PTK). |
| H52.201 - H52.229 | Astigmatism. |
| H18.601 - H18.629 | Keratoconus. |
| H17.00 - H17.9 | Corneal scars and opacities. |
| Z94.7 | Corneal transplant status. |
| Z98.41 - Z98.49 | Cataract extraction status. |
| V2100 - V2499 | Spectacle lenses. |
| V2500 - V2599 | Contact lens. |
| 65756 | Keratoplasty (Corneal Transplant); endothelial. |
| 65757 | Backbench preparation of corneal endothelial allograft prior to transplantation (list separately). |
| 0402T | Collagen cross-linking of cornea (including removal of the corneal epithelium and intraoperative pachymetry when performed). |
| J2787 | Riboflavin 5'-phosphate, ophthalmic solution, up to 3 mL. |
| 65785 | Implantation of intrastromal corneal ring segments (INTACS). |
| 92070 | Fitting of contact lens for treatment of disease, including supply of lens. |
| 92310 - 92326 | Contact lens services. |
| 66840 | Removal of lens material; aspiration technique, 1 or more stages. |
| 66940 | Extracapsular (other than 66840, 66850, 66852). |
| 66985 | Insertion of intraocular lens prosthesis (secondary implant). |
| C1780 | Lens, intraocular (new technology). |
| Q1004 | New technology intraocular lens category 4. |
| Q1005 | New technology intraocular lens category 5. |
| ALDH3A1/LOX/SPARC testing | ALDH3A1, LOX, and SPARC polymorphism testing – no specific CPT code; listed as not covered. |
Provider Actions & Prior Authorization
Prior authorization required for PTK
Prior authorization is required for phototherapeutic keratectomy (PTK, HCPCS S0812). Submit documentation that demonstrates the indication meets medical necessity (e.g., corneal scars/opacities, epithelial membrane dystrophy, recurrent erosions after conservative therapy has failed, Salzmann's nodules, superficial corneal dystrophy). Conservative measures (lubricants, hypertonic saline, patching, bandage contact lenses, gentle debridement) should be attempted and documented prior to PTK.
- Affected code: HCPCS S0812
- Document prior conservative therapy and lack of response
Prior authorization required for covered corneal procedures
Prior authorization is required for covered corneal procedures and will be contingent on meeting the policy's selection and documentation criteria. Provide relevant operative reports, prior treatment history, and diagnoses supporting medical necessity.
Keratoprosthesis prior authorization and required documentation
For keratoprosthesis (e.g., Boston K‑Pro, OOKP), prior authorization is required. Authorization should document prior graft attempts, ocular comorbidities, and peri‑operative glaucoma management plan.
- Document number and timing of prior graft failures
- Provide indications (failed grafts, high‑risk ocular surface disease) and prior donor/autogenous graft attempts
Glaucoma evaluation required prior to KPro authorization
A glaucoma evaluation and documentation of peri‑operative glaucoma management are required before authorization for keratoprosthesis. Because glaucoma is common and may progress after KPro, document baseline glaucoma status and planned monitoring/management (medical and/or surgical).
- Document pre‑op intraocular pressure assessment, optic nerve status, visual fields/imaging if available
- Plan for glaucoma drainage device or other interventions if indicated
Prior authorization for limited‑evidence CXL techniques
Prior authorization is required for collagen cross‑linking (CXL) techniques that have limited, mixed, or insufficient evidence (for example, epithelium‑on/transepithelial approaches, novel accelerated or 'CXL‑plus' combinations). These techniques may be considered investigational or require additional documentation to support medical necessity.
- Document rationale for using a limited‑evidence technique vs. conventional epithelium‑off (Dresden) CXL
- Reference to NICE and CADTH findings on evidence limitations
Prior authorization guidance and provider responsibility
This bulletin provides guidance to help administer benefits but does not itself establish coverage. Use the prior authorization requirements described here to support benefit determinations; providers remain responsible for clinical decision‑making and treatment.
- Prior authorization requirements referenced in this section should be followed when applicable
- Clinical Policy Bulletins are not guarantees of coverage
Coverage exclusions: refractive surgery
Refractive surgical procedures (e.g., LASIK, PRK, radial keratotomy, phakic IOL solely for refractive correction) are considered not medically necessary for routine correction of refractive error; spectacles or contact lenses are the preferred corrective modalities. When requesting authorization for procedures with refractive intent, include justification showing medical necessity per policy criteria.
INTACS indication constraints — documentation required
INTACS candidacy should meet FDA/clinical criteria: age ≥21, progressive deterioration with inadequate vision using spectacles/contact lenses, clear central cornea, corneal thickness ≥450 μm at the incision site, and corneal transplantation considered the only remaining option. Include these data when requesting authorization for INTACS.
- Document age, central cornea clarity, corneal thickness at site (≥450 μm), and failed conservative/optical measures
- Note limited evidence for INTACS in ectasias not secondary to keratoconus
Evidence gaps may affect authorization
Evidence gaps (for example, absence of randomized controlled trials comparing keratoprosthesis versus repeat donor grafts, or limited comparative data for artificial corneas) may affect authorization and coverage decisions. Provide detailed clinical rationale and supporting literature when evidence is limited.
- For artificial cornea (KPro) requests, document prior graft history and rationale for selecting prosthesis vs repeat graft
- Acknowledge that lack of RCTs may prompt case‑by‑case review
Epithelium‑on CXL — evidence limitation and authorization expectations
Epithelium‑on (transepithelial) CXL has limited evidence of safety and efficacy compared with the conventional epithelium‑off (Dresden) technique. When epithelium‑on CXL is proposed, prior authorization should include justification and supporting data; preference is given to conventional epithelium‑off CXL when criteria are met.
- Document why epithelium‑on technique is selected instead of Dresden protocol
- Include any available outcome data or justification for accelerated/modified protocols
No automatic denial triggers in this document segment
There are no explicit denial triggers listed within this document segment; administrative review and clinical judgment will guide individual coverage decisions. Providers should nevertheless supply complete documentation to avoid delays.
- Complete clinical documentation reduces administrative delays
- Follow prior authorization instructions in this bulletin
Coding and diagnosis documentation required
When submitting prior authorization requests or claims, include appropriate coding and diagnosis documentation. Use the applicable CPT/HCPCS codes and ICD‑10 diagnosis codes that match the procedure and indication.
Documentation required when requesting CXL
For CXL requests, include diagnosis codes for keratoconus or corneal ectasia and document procedural parameters: corneal thickness, UVA irradiance and duration, riboflavin protocol used, and whether epithelium was removed. These details support medical necessity and appropriate billing.
- Document corneal thickness (minimum 400 μm for conventional Dresden protocol)
- Record irradiation parameters (e.g., 3 mW/cm2 for 30 minutes = 5.4 J/cm2) and whether an accelerated protocol was used
Phakic IOL documentation requirements
For phakic intraocular lens (IOL) procedures, prior authorization requests should document stability of refraction and biometric criteria per device labeling (e.g., anterior chamber depth, refractive range, and stability over required interval).
- Document stability of refraction (e.g., ≤0.5 D change over required timeframe)
- Include anterior chamber depth and device‑specific eligibility details
Required clinical documentation for complex corneal procedures
Required clinical documentation for high‑risk procedures (e.g., keratoprosthesis, repeat grafts, complex corneal surgery) includes prior graft failure history, number/timing of prior grafts, and ocular comorbidities (glaucoma, optic neuropathy) that affect prognosis and management.
- Provide dates and type of prior grafts and reasons for failure
- List comorbid ocular conditions and prior glaucoma interventions
CXL procedural parameters to document
When reporting conventional (Dresden) CXL, document procedural parameters: corneal thickness at time of treatment, riboflavin formulation and concentration, UVA wavelength and irradiance, exposure time, and cumulative energy delivered. These details are necessary for clinical review and coding.
- Minimum corneal thickness typically ≥400 μm for epithelium‑off Dresden protocol
- Record UVA irradiance (e.g., 3 mW/cm2 × 30 min = 5.4 J/cm2) and any deviations from standard protocol
Providers responsible for medical advice and clinical decisions
Providers remain responsible for medical advice and treatment decisions. This Clinical Policy Bulletin is a summary to assist benefit administration and does not replace clinical judgment. Ensure that patient care decisions are based on current clinical evidence and individualized assessment.
- BP: Bulletin does not constitute a contract or guarantee of coverage
- Provide full clinical documentation to support requests
Reference: review history and definitions
Refer to the policy header for review history and policy definition references. Prior authorization requirements and policy interpretations may be updated; check the document's review history and effective/next review dates when preparing submissions.
- Effective date: 1995‑08‑03; Next review: 2024‑01‑11 (as listed)
- Use Review History and Definitions links in the policy for further administrative guidance
Sequence of surgical options and documentation prior to KPro
Before pursuing keratoprosthesis, consider sequence of surgical options: attempt autogenous or donor graft and, where clinically appropriate, repeat keratoplasty prior to keratoprosthesis. Document prior graft attempts, timing, and reasons for graft failure to justify prosthetic cornea use.
- Document prior graft type(s), number, and intervals between grafts
- Explain why repeat donor graft is unlikely to succeed when proposing KPro
Background
Background: Corneal remodeling comprises a range of surgical and laser techniques intended to treat corneal disease, correct surgically induced refractive error, or stabilize progressive ectatic disorders. Covered therapeutic procedures include corneal relaxing incisions for post‑surgical astigmatism when specific thresholds are met (for example, astigmatism ≥ 3.00 diopters and defined time windows after prior surgery), phototherapeutic keratectomy (PTK) for specified surface diseases, endothelial and lamellar keratoplasty for appropriate indications, and conventional epithelium‑off collagen cross‑linking (CXL) with riboflavin and UVA for progressive keratoconus/keratectasia when selection criteria are satisfied. Conversely, elective refractive procedures intended solely to correct refractive errors are generally not covered, and less established techniques (e.g., transepithelial CXL, combined CXL‑plus procedures, novel pharmacologic cross‑linkers) are considered investigational pending stronger evidence.
Definitions
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