This article was originally published in a sponsored newsletter.

Corneal topography plays a vital role in contact lens fitting, in particular orthokeratology (ortho-k), but there are other uses for it as well. Let’s explore what these are, and where they can be best utilized.

Most, if not all, functions that will be discussed can be performed by the staff. Specifically, a trained technician can be responsible for capturing these images to provide the diagnostic information to the principal eyecare provider, saving the provider time, while generating income for the practice.

Corneal Topography in Ortho-k

In ortho-k treatment, the corneal topographer helps the clinician to determine whether a patient is a suitable candidate for ortho-k. Also, the technology can play the critical role of calculating the initial lens parameters. Then, following overnight wear, the topographer’s subtractive (difference) maps in axial and tangential interpretation can analyze the success of treatment and guide the clinician as to whether changes in the lens are necessary and what modifications should be made.

The topographer’s role in ortho-k treatment cannot be overstated. When good quality maps are taken, ortho-k can achieve as high as a 95% first fit success.¹ The better quality the initial maps taken, the higher the success of a first fit and the overall success of treatment (Figure 1).

Additionally, ortho-k can pay for the topographer in approximately eight to 13 patients, depending on the model chosen (based on average U.S. year one bundled fees).² For instance, fitting just one ortho-k patient a month could pay off your instrument quickly, and the tool is available for other applications. 

Other Uses for Corneal Topography

In our practices, corneal topographers are used in many ways—for corneal analysis, to aid in disease detection, contact lens selection, mapping over contact lenses, ortho-k, and for refractive surgery assessment.

Additionally, the images taken can be digitally shared with your specialty lens consultant to assist with the fitting process. This can improve the accuracy and efficiency of your contact lens practice.

Corneal topographers can also be a valuable tool in diagnosing dry eye disease (DED) in your practice. This is because myopia has recently been shown associated with the presence of diagnosed DED and short tear breakup time.³

Additionally, using white, cobalt, and infrared light sources, the corneal topographer becomes a multimodal tool for DED that can image and categorize a wide range of related signs using meibography, noninvasive tear film breakup time (NITBUT), tear film surface quality, tear meniscus height, fluorescein and lissamine green stain grading, and lid margin analysis. For example, the latest topography models include tools that can perform NITBUT testing.⁴ By reflecting off the tear film layer, the instrument can objectively provide the quality and percentage of surface area in NITBUT.

Another unique analysis display option on corneal topography is the “axial” interpretation, which aids the clinician in understanding whether the patient has regular or irregular astigmatism (Figures 2 and 3). In aiding in the assessment of early signs of keratoconus, the instrument can be critical to diagnosing the condition and ensuring the patient is referred for corneal cross-linking, where appropriate, to protect corneal health and visual function.

Accompanying CPT Codes

When it comes to the usage of a topographer for DED management, various CPT codes exist that might be used to accompany the topography code (92025). When completing meibography, use 0507T and anterior segment imaging of 92285. As always, ensure that coding is accurate by looking up the specifics of each code. Many clinicians also charge an out-of-pocket code for advanced DED diagnostics that do not have specific codes. While a common practice, make sure the coding complies with your insurance contracts and carriers.

If your practice is set up to treat DED, the corneal topographer can drive treatment revenue, while relieving signs and symptoms, as illustrated above.

Opportunities Abound

There is an opportunity to use this multifunction tool for a wide range of applications, in addition to aiding in the management of orthokeratology patients.

References:

1. Tan Q, Ng AL, Cheng GP, Woo VC, Cho P. Combined atropine with orthokeratology for myopia control: study design and preliminary results. Curr Eye Res. 2019 Jun;44:671-678.
2. Lipson MJ, Curcio LR. Fitting of Orthokeratology in the United States: A Survey of the Current State of Orthokeratology. Optom Vis Sci. 2022 Jul 1;99:568-579.
3. Hirayama OI, Ayaki M, Yotsukura E, Torii H, Negishi K. Dry eye disease and high myopia in teenagers; a reciprocal relationship. Invest Ophthalmol Vis Sci. 2022 Jun;63:1442-F0400.
4. Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II Diagnostic Methodology Report. Ocul Surf. 2017 Jul;15:539-574.

DAVID KADING, OD, FAAO owns several practices in the Seattle area. He has consulted, performed research, and spoken and/or written for Alcon, Allergan, Avellino, Bausch + Lomb, BioTissue, CooperVision, Dompé, Eyevance, Eye Promise, Euclid, Horizon, Lumenis, Oculaphire, Orasis, Oculus, Medmont, Novartis, Sun Pharma, JnJ TearScience, Thea, Trukera Medical, Valley Contax, Visus Therapeutics, and Zeiss.