Peter is anxious about COVID-19. Diagnosed with severe eye dryness, he must be adapted into scleral lenses as part of his treatment. When I tell him that I have to put reusable diagnostic lenses on his eye, he panics, believing that there is a risk that tears may be a vehicle for the virus.

Fortunately, it is now possible to profile the ocular surface accurately and to extrapolate empirically the first-lens-to-fit parameters. Scleral profilometry data also provides best-fit corneal radius of curvature, which makes it easy to predict the lens power. The devices that currently achieve this efficiency are based on the analysis of fluorescein reflection or on Scheimpflug technology. Some have a limited list of lens design options, while others offer a greater variety of possibilities.

Does It Work in Practice?

Based on the experiences of Aaron Wolf, OD, the answer is “certainly.” He uses scleral profilometry to design his lenses. For example, Figure 1 shows an empirical fitting of a patient who has presumed Sjögren’s and a prominent pinguecula.

For a dry ocular surface, larger lenses should be used to cover most of the surface, and then it is imperative to safely fit around surface obstacles for both long-term ocular health and patient comfort. Using a scleral profilometer, Dr. Wolf precisely fit this eye in a scleral lens with nasal edge vault to protect the ocular surface and to align perfectly over the raised pinguecula with the first lens ordered. Note that even the limbal redness (and dryness) is relieved in this now happy eye (Figure 2).

Dr. Wolf also uses imaging to refine his contact lens fits. By using anterior segment photography and a red-free filter, you can assess the accuracy of the lens alignment to the peripheral profile of the eye (Figure 3). Additionally, an analysis using optical coherence tomography makes it possible to measure (in microns) the adjustments that need to be made. Contact lens laboratories can also produce quadrant-specific lens profiles or use freeform design around or over conjunctival surface irregularities.

In Conclusion

The use of profilometry has several advantages: precision of the measurements, increased efficiency, and more confidence in fitting challenging cases. For a few labs, you can send scans, and their consultants will calculate lens parameters for you.

For Peter, or for any other patient who is a candidate for these lenses, it has become increasingly obvious that there is very little reason to use diagnostic lenses to adapt scleral lenses in your practice. CLS