Clark Chang, OD, MSA, MSc, FAAO, meets with Optometry Times to discuss HOA-correcting scleral lens at AOA in Washingtion, DC.
Clark Chang, OD, MSA, MSc, FAAO, met with Optometry Times, at AOA 2023 in Washington, DC, to give a sneak peak of one of his case studies, which pertains to a new HOA-correcting scleral lens.
Editor's note: This transcript has been lightly edited for clarity.
Clark Chang, OD, MSA, MSc, FAAO:
Hi, everyone. I'm Clark Chang coming to you live from AOA in DC, and I want to give you a sneak peek of the top 5 poster sessions that I'm presenting today. It's a case report series that involves patients after corneal cross-linking—keratoconus, patients after corneal cross-linking, who require higher-order aberration correcting optics in their scleral lenses.
So, let's talk about one of the reports and some of the main takeaways that I would like to share with you. This is a 33-year-old female who came to Wills Eye Hospital in our cornea service from out of state. Her history included corneal cross-linking roughly about 2 years ago, as well as the Intacs implantation about 2 to 6 months after. [She also had] removal a few months after, due to the fact that her best-corrected vision was affected, both in her uncorrected and best-corrected, including her corneal GP lenses. They've already tried scleral lenses and other types of lenses, and were not able to achieve what her vision was before. So, they decided to explain the Intacs, however, still ended up with a corneal GP with reduced vision, more so than before, at about 20/70.
So given that long-standing history [and] knowing that her cornea has been stable for the last 2 years [after] going through her records from the surgical center, I was comfortable in being able to come up with a more permanent visual correction option for her. We discussed the higher-order aberration correcting optics, which is very new, at least to us in optometry—especially to contact lenses, in terms of scleral lenses, it's relatively new.
When she came back, she already improved. She reported [that] within a week or 2, she could see improvement in her vision, without me doing anything in the meantime. When she came back to [the] clinic with an over-refraction, she was 20/25. The next visit, we optimized the HOA just slightly with a small amount over refraction, [and] she was 20/20. She cried in my chair. So, that's what we live for, our patients. [We] want to give them the best outcome.
So, what are some of the key takeaways? Newer adaptation [is] very important. Don't give up at the first sign of something surprising happening. Especially because we did an objective measurement of aberrometer over her high HOA lens, when she went to 2200. We saw that there's improvement in the HOA RMS, and that was what made us feel competent that newer adaptation would at least improve that outcome.
Surprisingly, in my diagnostic fitting in the chair doing over-refraction, I was able to already get her to 20/50 with a scleral lens. Given her history of dry eye, we thought that was a good idea to retry scleral lens again. I [was] very excited thinking if I'm already getting better than her corneal GP at 20/70, maybe there's a chance that I don't even have to worry about constructing complicated optics to correct for residual higher-order aberration. So on Thea dispensing, she went to 2100. We thought, okay, it is higher-order aberrations, [so we are] going to get variable results, depending on lighting [and] on her state of accommodation. We thought that's continuous, she didn't accept any over-refraction, [she] actually varied from +3 to -5. Again, [this is] a sign of a higher-order aberration in place, so they could never really find a definitive optical endpoint. [We] went to higher-order aberration correction optics, dispense that first HOA lens, her vision drop yet again to 2200. I'm not freaking out yet, and luckily, because I'm not, [the] patient's not. We talked about the fact that she just has a lot of higher-order aberration. Her RMS HOA was over one micron, so really high. We decided that she needed to go home, neuro adapt first and come back.
Number 2, control the status of the progressive disease when you can. Anything in the media that disperses light is going to cause high-order operation, including tear [and] a deposit on the surface of the lens in keratoconu—with cross-linking, now that we're able to stabilize the cornea. So, whatever you can do to manage and stabilize the disease, whatever that is on the ocular surface, is going to help you sustain the longevity of your treatment options so that you're not giving [your] patient a great option for 6 to 12 months, and then something changes. If you have to restart, that's going to lead to patient noncompliance.
So fit the patient, fit the whole person, and don't give up at the first sign of resistance. I'll see you at the next meeting, thank you.