Policy title: Computer-Assisted Corneal Topography

Policy number: MA 5.062

Effective date: 4/1/2026

Policy

Computer-assisted corneal topography is considered medically necessary for any of the following indications:

• Pre-operative evaluation for phototherapeutic keratectomy.
• Pre-operative evaluation for surgery to correct astigmatism resulting from trauma or from previous surgery.
• Assessment of post-operative complications associated with post-traumatic corneal scarring or complications of a transplanted cornea.
• Post-operative management of penetrating keratoplasty or cataract surgery.
• Documenting visual complications resulting from trauma or from previous surgery.
• Evaluation of patients with unexplained visual loss.
• Diagnosis and management of keratoconus, bullous keratopathy, or corneal dystrophy

Computer-assisted corneal topography is considered investigational for all other indications including when performed as part of pre-operative assessment of members with cataracts. There is insufficient evidence to support a general conclusion concerning the health outcomes or benefits associated with this procedure.

This medical policy applies to Medicare Advantage plans offered by Capital Blue Cross and its subsidiaries.

Description/Background

Corneal topography describes measurements of the curvature of the cornea. An evaluation of corneal topography is necessary for the accurate diagnosis and follow-up of certain corneal disorders, such as keratoconus, difficult contact lens fits, and pre- and postoperative assessment of the cornea, most commonly after refractive surgery.

Assessing corneal topography is part of the standard ophthalmologic examination of some patients. Corneal topography can be evaluated and determined in multiple ways. Computer-assisted corneal topography has been used for early identification and quantitative documentation of the progression of keratoconic corneas, and evidence is sufficient to indicate that computer-assisted topographic mapping can detect and monitor disease.

Various techniques and instruments are available to measure corneal topography: keratometer, keratoscope, and computer-assisted photokeratoscopy.

The keratometer (also referred to as an ophthalmometer), the most commonly used instrument, projects an illuminated image onto a central area in the cornea. By measuring the distance between a pair of reflected points in both of the cornea’s 2 principal meridians, the keratometer can estimate the radius of curvature of 2 meridians. Limitations of this technique include the fact that the keratometer can only estimate the corneal curvature over a small percentage of its surface and that estimates are based on the frequently incorrect assumption that the cornea is spherical.

The keratoscope reflects a series of concentric circular rings off the anterior corneal surface. Visual inspection of the shape and spacing of the concentric rings provides a qualitative assessment of topography.

A photokeratoscope is a keratoscope equipped with a camera that can provide a permanent record of the corneal topography. Computer-assisted photokeratoscopy is an alternative to keratometry or keratoscopy for measuring corneal curvature. This technique uses sophisticated image analysis programs to provide quantitative corneal topographic data. Early computer-based programs were combined with keratoscopy to create graphic displays and high-resolution, color-coded maps of the corneal surface. Newer technologies measure both curvature and shape, enabling quantitative assessment of corneal depth, elevation, and power.

Regulatory Status

A number of corneal topography devices have been cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process (Table 1). In 1999, the Orbscan^® (manufactured by Orbtek, distributed by Bausch and Lomb) was cleared by the FDA. The second-generation Orbscan II is a hybrid system that uses both projective (slit scanning) and reflective (Placido) methods. The Pentacam^® (Oculus) is 1 of a number of rotating Scheimpflug imaging systems produced in Germany. In 2005, the Pentacam HR was released with a newly designed high-resolution camera and improved optics.

Rationale

Summary of Evidence

For individuals who have disorders of corneal topography who receive computer-assisted corneal topography/photokeratoscopy, the evidence includes a single RCT and multiple nonrandomized studies. Relevant outcomes are test accuracy, other test performance measures, and functional outcomes. With the exception of refractive surgery, a procedure not discussed herein, no studies have shown clinical benefit (eg, a change in treatment decisions) based on a quantitative evaluation of corneal topography. In addition, a large prospective series found no advantage with use of different computer-assisted corneal topography methods over manual corneal keratometry. Computer-assisted corneal topography lacks evidence from appropriately constructed clinical trials that could confirm whether it improves outcomes. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

Definitions

NA

Disclaimer

Capital Blue Cross’ medical policies are used to determine coverage for specific medical technologies, procedures, equipment, and services. These medical policies do not constitute medical advice and are subject to change as permitted by law or applicable clinical evidence from independent treatment guidelines. Treating providers are solely responsible for medical advice and treatment of members. These polices are not a guarantee of coverage or payment. Payment of claims is subject to a determination regarding the member’s benefit program and eligibility on the date of service, and a determination that the services are medically necessary and appropriate. Final processing of a claim is based upon the terms of contract that applies to the members’ benefit program, including benefit limitations and exclusions. If a provider or a member has a question concerning this medical policy, please contact Capital Blue Cross’ Provider Services or Member Services.

Coding information

Note: This list of codes is not exhaustive and may change from time to time as permitted by law or applicable clinical guidelines. The inclusion of a code in this section is not a guarantee of coverage or payment. In addition, not all covered services are eligible for separate reimbursement.

Medically Necessary

Medically Necessary Diagnoses for Corneal Topography

References

1. Morrow GL, Stein RM. Evaluation of corneal topography: past, present, and future trends. Can J Ophthalmol. Aug 1992; 27(5):213-225. PMID 1393805.

2. Wilson SE, Klyce SD. Advances in the analysis of corneal topography. Surv Ophthalmol. Jan-Feb 1991; 35(4):269-277. PMID 2011820.

3. Martinez-Abad A, Pinero DP, Ruiz-Fortes P, et al. Evaluation of the diagnostic ability of vector parameters characterizing the corneal astigmatism and regularity in clinical and subclinical keratoconus. Cont Lens Anterior Eye. Apr 2017; 40(2):88-96. PMID 27931882.

4. Weber SL, Ambrosio R, Jr., Lipener C, et al. The use of ocular anatomical measurements using a rotating Scheimpflug camera to assist in the Esclera(R) scleral contact lens fitting process. Cont Lens Anterior Eye. Apr 2016; 39(2):148-153. PMID 26474924.

5. Bhatoa NS, Hau S, Ehrlich DP. A comparison of a topography-based rigid gas permeable contact lens design with a conventionally fitted lens in patients with keratoconus. Cont Lens Anterior Eye. Jun 2010; 33(3):128-135. PMID 20053579.

6. DeNaeyer G, Sanders DR, Farajian TS. Surface coverage with single vs. multiple gaze surface topography to fit scleral lenses. Cont Lens Anterior Eye. Jun 2017; 40(3):162-169. PMID 28336224.

7. Bandlitz S, Baumer J, Conrad U, et al. Scleral topography analysed by optical coherence tomography. Cont Lens Anterior Eye. Aug 2017; 40(4):242-247. PMID 28495356.

8. Lee H, Chung JL, Kim EK, et al. Univariate and bivariate polar value analysis of corneal astigmatism measurements obtained with 6 instruments. J Cataract Refract Surg. Sep 2012; 38(9):1608-1615. PMID 22795977.

9. de Sanctis U, Donna P, Penna RR, et al. Corneal astigmatism measurement by ray tracing versus anterior surface-based keratometry in candidates for toric intraocular lens implantation. Am J Ophthalmol. May 2017; 177:1-8. PMID 28185842.

10. Ophthalmic Technology Assessment Committee Cornea Panel American Academy of Ophthalmology. Corneal topography. American Academy of Ophthalmology. Ophthalmology. Aug 1999; 106(8):1628-1638. PMID 10442914.

11. American Academy of Ophthalmology (AAO). Refractive Surgery Preferred Practice Pattern^®. 2022.

12. Fan R, Chan TC, Prakash G, Jhanji V. Applications of corneal topography and tomography: a review. Clin Exp Ophthalmol. 2018; 46(2):133-146. doi:10.1111/ceo.13136. PMID 29266624.

13. Lambert SR, Kraker RT, Pineles SL, et al. Contact Lens Correction of Aphakia in Children: A Report by the American Academy of Ophthalmology. Ophthalmology. 2018; 125(9):1452-1458. doi:10.1016/j.ophtha.2018.03.014.

Policy history

• MA 5.062
• 04/01/2026 Policy creation.

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