Garbage In = Garbage Out
The Truth About Scleral Profilometry
The ability to take good measurements and get usable data is an invaluable ability when empirically designing scleral lenses or when creating freeform scleral lenses from profilometry.
Since the invention of devices able to measure the ocular surface, there was the ability to collect data that can aid in designing contact lenses. With that also came ability to collect false or unreliable data.
So much can contribute to obtaining good quality data, such as dryness, stability, aperture, device calibration and more. And while these technologies are improving, technical issues are still a factor in the success of using data to aid in fitting contact lenses.
Profilometry has come a long way to improving, however it is not always perfect. In the beginning of our lab working with profilometry data, the first scans we received were barley usable, missing huge sections of data and the chord diameter was only large enough in some cases to make a mini scleral lens. We had to extrapolate missing data, which would not always result in the best lens design. It didn’t give us any better understanding of how a lens would fit on the eye than a diagnostic lens would and would often result in more lens remakes than if the lens with fit the using a diagnostic fitting set. Today’s scans are much more complete and can give us a lot of information about the anterior surface that can provide intel as to why a diagnostic lens is fitting or behaving in a certain way. But if the scan quality is subpar, the data can hinder our understanding of the fitting relationship.
Valley Contax X EYEXY
Valley Contax has been making freeform scleral lenses since 2020 in collaboration with EYEXY.
The Gaudi lens has seen many challenging patients successfully fit. But the truth remains that the scan quality is one of the most prominent factors in achieving a successful fit with the fewest remakes.
Tips to Scan to Lens Success 🔵
The most successful practices using profilometry have spent time training and perfecting scans and analyzing the scan quality.
Take more than one scan, the more options we have to work with, the better chances of a successful fit.
Working closely with the profilometer manufacturer to understand the software is an incredible resource that should not be looked over. When you get a bad scan, send it to them and ask for feedback.
Taking feedback from your lens consultation team to see how your scans are translating into lens orders is also quite helpful.
Making sure your patient is washed out of their current lens. Compression rings and poor fitting lenses can cause the eye to be reshaped and will result in a scan with unreliable data.
Always put on a diagnostic lens and analyze it. Profilometry should be a tool to assist in a better/faster lens fitting.
The long term goal of this technology is to eventually not need the use of diagnostic lenses, however there are still these challenges that we must consider. I believe using this technology in conjunction with diagnostic lenses is helpful in determining the quickest route to the best fitting lens.
June 25th, 2024
Written by:
CharliRae Edmunds
Valley Contax Professional Services Director