Visionary Optics recently introduced the Latitude scleral lens. According to the company’s research, most patients’ corneal and scleral shapes do not conform to scleral lens designs based upon peripheral curve systems. Its answer to this dilemma was to create the Latitude lens, which has no peripheral curve system; rather, it is a freeform lens designed to contour uniformly to each eye. The company says that it is the first such lens that is completely custom made to exactly fit the corneal and scleral surfaces based upon scleral topography (sMap3D) measurements.
The Latitude lens conforms to the scleral shape at the landing zone and is designed to even out the central, midperipheral, and limbal clearances regardless of the degree of corneal irregularity, including asymmetric ectasias in which uneven clearances are especially obvious, according to the company. Visionary Optics says that this uniformity of lens-to-ocular-surface clearance is critical to ocular surface health because it ensures that oxygenation to the cornea and limbus is optimized. Data required to fit the lens is based upon a no-ocular-touch, three- to five-minute corneal-scleral topography examination.
I recently talked with three practitioners who are actively fitting the Latitude scleral lens in their practices. Here we share their clinical experiences.
Please tell us about your general experience with Visionary Optics’ Latitude lens in your practice.
Edward Boshnick, OD, from Miami says that he has been very satisfied overall with the Latitude lens. “Patient comfort has been excellent. Optics have been excellent. The design is really form fit so every hill and valley of the ocular surface is replicated onto the back surface of the lens” he notes. “I’m very impressed with it.”
He also notes that the lens fills a hole not previously filled for scleral lens wearers. “There is no scleral lens technology that will work on every single person. It is just not possible,” he explains. “But, this lens really works with a large segment of the high-need population ... such as patients who have keratoconus, dry eye, and various types of corneal diseases, dystrophies, and degenerations. It works in a very high percentage of such cases.”
Robert Lopez, OD, from Chicago, concurs. “Latitude has been what scleral lens fitting has needed since the beginning but, obviously, wasn’t available. It has been a real game-changer for my scleral lens practice,” Dr. Lopez says.
“Previous scleral lens designs required some degree of guessing and a trial-and-error process. We are now able to boil it down right away and get the best possible fit much faster. It cuts down on chair time significantly, which is a huge help,” he continues. “A lot of practitioners are dipping their toes in the scleral lens modality, and they are going to have some success, but they will invariably get some complicated cases. This really simplifies everything.”
Thanh Mai, OD, from Costa Mesa, CA, notes that the Latitude lens is now his go-to lens for more complex cases. “The first fit is extremely accurate, and the patient response has been overwhelmingly positive,” he says. “During consultations, we discuss how the lens design is different from the previous generations of scleral lenses, and they are very impressed with the technology.”
Who are the best candidates for this lens and why?
All three practitioners agree that any patient could benefit from the Latitude lens, but that those who have complex scleral shapes would benefit the most.
“You really don’t know what people need until you map the sclera. The process used to be that you would put a lens on a patient and see how it behaved and make adjustments to it,” notes Dr. Lopez. “And some were very simple, straightforward cases—those were the easy successes. But eventually, if you do enough scleral lens cases, you are going to find the complicated ones that you can’t get to fit properly.”
According to Dr. Boshnick, the Latitude lens is well designed to fit any eye that has a corneal issue. “It could be a patient who has keratoconus or dry eye or who has experienced complications due to laser-assisted in situ keratomileusis (LASIK) or a corneal transplant,” he says.
However, Dr. Mai notes that cost is a consideration when deciding whether to fit the Latitude lens. “Technically, every patient could benefit from a Latitude lens. However, there is an added cost to it, so I generally reserve it for my more complicated fits,” he says. “High amounts of scleral toricity, pingueculas, or other scleral irregularities are the usual suspects whom I would start with a Latitude lens.”
Patients who have previously failed in scleral lenses are another population to consider, says Dr. Mai. “I have refit a few patients who have failed in scleral lenses at other offices. These patients were referred from other scleral lens practitioners when conventional lens designs had already failed,” he says. “Not only are the patients ecstatic with the lenses, but the practice also benefits as referral sources more confidently tell other patients who can benefit.”
Tell us about the fitting process for the Latitude scleral lens and what has worked best for you.
To fit the Latitude lens, practitioners must take three images: one straight on, one in up-gaze, and one in down-gaze. “The key [to getting a good scan] is that in the straight-on image, you have to make sure that there is 360º of limbus in that image. Then, when we do the up and the down images, we want to get at least 50% of the limbus as well so that it lines up properly. If you do that, you generally get a pretty good map. Obviously, the better the map, the better the fit will be,” says Dr. Lopez.
Dr. Mai explains that this initial fitting process is done via an sMap3D scleral topography scan. “Afterward, the software will suggest an initial lens to place on the eye to perform an over-refraction. There is no more guessing and ‘bracketing’ to find the right initial diagnostic lens,” he says. “We send the scleral topography and the over-refraction based on the diagnostic trial that we used to the lab directly through the software. Afterward, once you receive the lens, you will finalize or troubleshoot as you normally do,” he adds.
Dr. Lopez also notes that there is a bit of a learning curve involved with fitting the Latitude lens. “I have had to train several people how to do it. But eventually, they get the hang of it,” he says.
How has the Latitude lens helped with troubleshooting for particular patients? Tell us about any success stories in that regard.
Dr. Boshnick tells of a long-term patient who has undergone two LASIK surgeries and developed ectasia. “He had horrible dry eye and a very distorted cornea,” he says. “I fit him with a number of different lens designs toward the end of 2018 but with mixed success.
“He came to the office in February after the Latitude lens was introduced. I tried that lens on him, and it was a completely different situation,” he continues. “He was very comfortable and had excellent vision.”
Dr. Lopez also had a 20-year patient who had failed with other lenses in the past. “She had undergone [radial keratotomy] (RK) surgery in the early ’90s. In some of the earlier, larger-incision RKs, they become very unstable and the eyes start to shift to farsightedness with a lot of irregular astigmatism. So, her vision really started to deteriorate during the time she was my patient. It was probably seven or so years ago when I had just started fitting some scleral lenses that I suggested it to her, and she was very excited; but we tried it, and it failed,” he explains. “Even when we went to the steepest position that the manufacturer could make, it was still was not fitting. Her eyes were rather small, so we could not get it to align with her sclera; it was still too flat of a fit.
“Then, we gave up on that. Years later, there was the ability to incorporate toric haptics, and I had even gotten a scleral topography device. And even though I could see the scleral shape, there was no laboratory that could match a lens to it,” he adds. “When we tried another lens with toric haptics and all of the other adjustments that I could make, we still couldn’t get a lens to fit her. So, she was really discouraged and we gave up on it.
“And then when I got the sMap3D, I said ‘Hey, let’s try this one more time.’ She almost didn’t want to because of all of the previous experiences that she’d had,” he says. “With the first map, we knew exactly the curvature of her eye and we were able to mimic it exactly, and the lens fit perfectly—the first one. And then we tweaked the over-refraction a bit, and she has been great ever since.” CLS