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Computerized Corneal Topography

Policy Number: MP-729

Last Review Date: April 2024

Category: Vision


Effective for dates of service on and after 9/11/2020:

Computerized corneal topography (CCT) may be considered medically necessary for any of the following conditions:

  • Bullous keratopathy
  • Complication of ocular prosthetic device
  • Complication of transplanted cornea
  • Congenital corneal malformation
  • Corneal ulcer, including Mooren’s ulcer
  • Hereditary corneal dystrophies (including epithelial basement membrane dystrophy [EBMD])
  • Keratoconus (screening / monitoring)
  • LSCD (Limbal stem cell deficiency)
  • Nodular corneal degeneration (including Salzmann nodules)
  • Peripheral corneal degeneration
  • Post-penetrating keratoplasty surgery
  • Post-traumatic corneal scarring
  • Pre-operative evaluation of irregular astigmatism for intraocular lens power determination with cataract surgery
  • Pseudopterygium
  • Pterygium
  • Severe dry eye

All other uses of computerized corneal topography (CCT) are considered not medically necessary (including, but not limited to):

  • in relation to a non-covered eye procedure (e.g. refractive surgery)
  • in relation to contact lens fitting
  • routinely prior to cataract surgery
  • to detect or monitor cataracts
  • routine follow-up or screening


Computer-assisted corneal topography (also called photokeratoscopy or videokeratography) provides a quantitative measure of corneal curvature. Measurement of corneal topography is being evaluated to aid the diagnosis of and follow-up for corneal disorders such as keratoconus, difficult contact lens fits, and pre- and postoperative assessment of the cornea, most commonly after refractive surgery.

Detection and Monitoring Diseases of the Cornea

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 a 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.

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 two principal meridians, the keratometer can estimate the radius of curvature of two 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.


The literature search for this policy was performed through January 18, 2024.

Summary of Evidence

For individuals who have disorders of corneal topography who receive computer-assisted corneal topography/photokeratoscopy, the evidence includes a single randomized clinical trials (RCTs) and multiple nonrandomized studies. Relevant outcomes are test accuracy, other test performance measures, and functional outcomes.

One study has been identified evaluating computer-assisted corneal topography as a clinically valid solution for diagnosing certain disorders of corneal topography. In this study, authors concluded that TD and ORA, two vector parameters that can serve to detect clinical and subclinical keratoconus, were beneficial tools for detecting the disorder. The evidence is sufficient to determine that the technology results in an improvement in the net health outcomes.

Computer-assisted corneal topography lacks evidence from appropriately constructed clinical trials that can confirm whether it improves outcomes in other certain disorders, including microphthalmia, contact lens fitting, cataracts and glaucoma. The evidence is insufficient to determine that the technology results in an improvement in the net health outcomes.

Practice Guidelines and Position Statements

American Academy of Ophthalmology

A 1999 American Academy of Ophthalmology (AAO) assessment indicated that computer-assisted corneal topography evolved from the need to measure corneal curvature and topography more comprehensively and accurately than keratometry and that corneal topography is used primarily for refractive surgery. The corneal astigmatism simulated keratometry (AAO) assessment indicated several other potential uses: (1) to evaluate and manage patients following penetrating keratoplasty, (2) to plan astigmatic surgery, (3) to evaluate patients with unexplained visual loss and document visual complications, and (4) to fit contact lenses. However, the corneal astigmatism simulated keratometry AAO assessment noted the lack of data supporting the use of objective measurements (as opposed to subjective determinants, like subjective refraction) of astigmatism.

The American Academy of Ophthalmology’s guidelines on “Primary open-angle glaucoma” (AAO, 2020) mentioned no role for corneal topography in the management of patients with open-angle glaucoma.

The American Academy of Ophthalmology Cornea/External Disease Panel’s Preferred Practice Pattern on “Dry Eye Syndrome” (AAO, 2018) had no recommendation for computerized corneal topography.

U.S. Preventive Services Task Force Recommendations

Not applicable.


CCT, Computer assisted corneal topography, photokeratoscopy, videokeratography, corneal curvature, corneal disorders


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 one 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. FDA product code: MXK.

Table 1. Corneal Topography Devices Cleared by the U.S. Food and Drug Administration



Date Cleared

510.k No.


MS-39 C.S.L. S.R.O. 09/01/2023 K221601 To capture scans of the anterior segment of the eye
MYAH VISIA Imaging S.R.L. 03/01/2022 K211868 To measure the axial length of the eye in a population age 5 and above; to capture and store digital images of the meibomian glands in adults
Myopia Master OCULUS OPTIKGERATEGMBH 07/14/2021 K202989 To measure the axial length of the eye
Pentacam AXL Wave OCULUS OPTIKGERATE GMBH 10/21/2020 K201724 To scan, map and display the geometry of the anterior segment of the eye

Galilei G6 Lens Professional




To scan, map and display the geometry of the anterior segment of the eye

VX130 Ophthalmic Diagnostic Device




To scan, map and display the geometry of the anterior segment of the eye

Pentacam AXL




To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye





To scan, map and display the geometry of the anterior segment of the eye


Coverage is subject to member’s specific benefits. Group-specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP contracts: Special benefit consideration may apply.  Refer to member’s benefit plan. 


CPT codes:


Computerized corneal topography, unilateral or bilateral, with interpretation and report


  1. American Academy of Ophthalmology (AAO).Glaucoma Panel. Primary open-angle glaucoma. Preferred Practice Pattern. November 2020. 
  2. American Academy of Ophthalmology (AAO), Anterior Segment Panel. Cataract in the adult eye. Preferred Practice Pattern. November 2021.
  3. American Academy of Ophthalmology (AAO). Corneal topography. Ophthalmology. 1999; 106(8):1628-1638.
  4. American Academy of Ophthalmology Cornea/External Disease Panel. Preferred Practice Pattern® Guidelines. Dry Eye Syndrome. San Francisco, CA: American Academy of Ophthalmology; 2013.
  5. 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.
  6. 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.
  7. Cavas-Martinez F, De la Cruz Sanchez E, Nieto Martinez J, et al. Corneal topography in keratoconus: State of the art. Eye Vis (Lond). 2016; 3:5.
  8. Choi JA, Kim MS. Progression of keratoconus by longitudinal assessment with corneal topography. Invest Ophthalmol Vis Sci. 2012; 53(2):927-935.
  9. 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.
  10. 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.
  11. Garcia-Ferrer FJ, Akpek EK, Amescua G, et al; American Academy of Ophthalmology Preferred Practice Pattern Cornea and External Disease Panel. Corneal Ectasia Preferred Practice Pattern. Ophthalmology. 2019; 126(1):P170-P215.
  12. Gokul A, Vellara HR, Patel DV. Advanced anterior segment imaging in keratoconus: A review. Clin Exp Ophthalmol. 2018; 46(2):122-132.
  13. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  14. Hu PH, Gao GP, Yu Y, et al. Analysis of corneal topography in patients with pure microphthalmia in Eastern China. J Int Med Res. 2015; 43(6):834-840.
  15. 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): 1608-15.
  16. 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.
  17. Morrow GL, Stein RM. Evaluation of corneal topography: Past, present and future trends. Can J Ophthalmol. 1992; 27(5):213-225.
  18. Tummanapalli SS, Potluri H, Vaddavalli PK, Sangwan VS. Efficacy of axial and tangential corneal topography maps in detecting subclinical keratoconus. J Cataract Refract Surg. 2015; 41(10):2205-2214.
  19. Weber SL, 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.
  20. Wilson SE, Ambrisio R. Computerized corneal topography and its importance to wavefront technology. Cornea. 2001; 20(5):441-454.
  21. Wilson SE, Klyce SD. Advances in the analysis of corneal topography. Surv Ophthalmol. 1991; 35(4):269-277.
  22. Wolffsohn JS, Peterson RC. Anterior ophthalmic imaging. Clin Exp Optom. 2006; 89(4):205-214.


Medical Policy Group, July 2020 (9): This technology was previously allowed as detailed in policy statement section “effective for dates of service prior to 9/11/2020” and was investigational for other indications per MP#495: Investigational Criteria. New policy created 9/11/2020.

Medical Policy Administration Committee, August 2020

Available for comment 7/28/2020 through 9/11/2020.

Medical Policy Panel, March 2021

Medical Policy Group, March 2021 (9): 2021 Updates to Key Points, References. No change to policy statement.

Medical Policy Group, January 2022 (9): Update to References.

Medical Policy Panel, March 2022

Medical Policy Group, March 2022 (9): 2022 Updates to Key Points, Description, References. No change to policy statement.

Medical Policy Panel, March 2023

Medical Policy Group, April (9): Updates to Key Points and Benefit Application. No change to policy statement.

Medical Policy Panel, March 2024

Medical Policy Group, April 2024 (9): Updates to Description, Key Points, Approved by Governing Bodies, Benefit Application, and References. Policy section updated by removing policy statement “effective for dates of service prior to 9/11/2020,” no change to policy intent.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.