Eyeworld

EW FEATURE 96 Advances in corneal inlays • March 2017 it's more functional before they go on to any type of surgery," he said. Likewise, Dr. Foster thinks that the health of the tear film has a significant impact on the outcome for corneal inlay patients, so analysis of the tear film is essential preop- eratively. "If it's less than ideal, we would postpone surgery until medical therapy restores a great tear film, then we would make the deci- sion about whether they're a good candidate for the inlay based on how difficult it was to achieve and sustain that." He relies on a good history and a slit lamp examination is essential to help determine that. "The HD Analyzer is helpful as it measures changes in light scatter during sustained non-blink periods. If the light scatter escalates in be- tween blinks, it demonstrates a poor quality tear film," Dr. Foster said, adding that the LipiView can also be helpful if the meibomian glands are in question. It's important to test for ideal inlay placement. For that, Dr. Durrie relies on software built into the HD Analyzer known as the AcuTarget HD. "It gives us the inlay centration and tells us that ahead of time," he said. "Postoperatively it's very helpful because you can measure whether the inlay is in the correct place." If patients have had a corne- al inlay and after surgery are still not functioning at their best, determin- ing if the inlay is in the right place can help, Dr. Durrie said. Overall, Dr. Foster advised using the same wisdom and judgment as you would in selecting a multifo- cus lens patient. "Most patients are happy rather quickly, and there are a few that aren't, but as you help them with their tear film manage- ment and ongoing healing, they achieve happiness." Then there is a small percentage that don't get the reading they desired, and these pa- tients are going to require extra care to get them through that process, he concluded. EW Editors' note: Dr. Foster has financial interests with AcuFocus. Dr. Durrie has financial interests with AcuFocus, Alcon (Fort Worth, Texas), Abbott Medical Optics (Abbott Park, Illinois), and Visiometrics. Contact information Durrie: ddurrie@durrievision.com Foster: gjlfos@gmail.com (Oculus, Arlington, Washington) or Galilei (Ziemer Ophthalmic Systems, Port, Switzerland) and pinpoint whether this is coming from the lens. In addition to the HD Analyzer, physicians can get information from other devices such as the Nidek OPD (Nidek, Gamagori, Japan), iTrace (Tracey Technologies, Houston), the Pentacam, and the Galilei, as well as from slit lamp photographs, Dr. Durrie noted. Dr. Durrie recommended evaluating the tear film. "Corneal inlays require a good ocular surface, so we've recently started using the LipiView/LipiScan [TearScience, Morrisville, North Carolina] on all of our patients to look at their mei- bomian gland structure very early in the exam," he said. "We would not put an inlay in someone who had poor meibomian gland struc- ture or function because with both of the inlays we're expecting the very center of the visual axis not to have light scatter." He finds that for those with dry eyes in general and evaporative dry eyes in particular, the inlay doesn't work as well. "We would rather identify that and treat it ahead of time to the point where get to stage 2, when they're starting to get some scatter of light, they're starting to get loss of contrast sensi- tivity, and the corneal inlays don't work as well," he said, adding that while you can still do them, you should alert patients that they're probably going to need lens replace- ment surgery. He also tests patients with the HD Analyzer, which shows how much light scatter there is. "We find that we use it on every patient," Dr. Durrie said, adding that even young- er patients who should have perfect results occasionally have scatter, which may point to keratoconus, dry eye, or some type of corneal lens opacity. Dr. Durrie also examines inlay patients' OCT to make sure that the retina is intact. He begins the work- up with the OCT and then moves to the HD analyzer. "If there is scatter on the HD Analyzer, then you need to look and see where that is coming from," he said. "Is it coming from the tear film, cornea, or the lens?" Asteroid hyalosis or bad floaters can cause such scatter, he continued. If there is scatter, then he looks further at the slit lamp and also may exam- ine the patient with the Pentacam when the lens starts turning yellow and a bit hazy, and at that point night vision is not as good and they need more light to read. When they reach stage 3, usually in their 70s and 80s, they must contend with a cataract." Testing essentials Dr. Foster concurs that dysfunctional lens syndrome is important. This, he said, comes into play in deciding the best way to solve patients' problems. "I use the HD Analyzer [Visiomet- rics, Barcelona, Spain] to help me differentiate which stage of dysfunc- tional lens syndrome they're in," Dr. Foster said. "In young patients who have a fully functioning lens, we usually will use LASIK to help them solve their visual issues," he said. "Once they move into the age where presbyopia is an issue, we will often use a combination of LASIK with the KAMRA inlay to give them both distance vision and reading." However, as they start having more advanced amounts of lens dysfunc- tion, it makes sense to solve their issues with a lens-based surgery, he has found. Likewise, Dr. Durrie said that the inlays work best in stage 1 when the lens is still clear. "As soon as you Testing continued from page 95 The KAMRA inlay (left) compared to a contact lens (right). The KAMRA inlay is 6 microns thick, 3.8mm in diameter, with a 1.6mm aperture. Source (all): Daniel Durrie, MD

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