Eyeworld

EW REFRACTIVE 68 September 2018 Refractive editor's corner of the world by Michelle Stephenson EyeWorld Contributing Writer which are the reflections from the LED lights, and the standard devia- tions of corneal measurements from the LENSTAR [Haag-Streit, Koniz, Switzerland] because those are good measures of the accuracy of my cor- neal readings," Dr. Koch said. Meibomian glands Dr. Doane said he is a minimalist in evaluating the meibomian glands as well. "I do fluorescein and tear breakup time. I am more on the qualitative end than getting into the weeds with quantitative, which I think varies so much. I also get some benefit from Schirmer's," he said. Dr. Doane added that he will assess meibomian gland secretions if he sees any sign of acne rosacea. "I think it's important to get on top of that if you decide to do surgery," he said. Dr. Koch performs a slit lamp examination to observe the mei- bomian glands to see if they are Diagnostics in refractive cataract surgery: Tear film analysis T he air/tear interface is the most powerful focusing element of the eye. As we all know, corneal shape and regularity along with tear film health dictate tear film power, smoothness, and stability and together have a profound effect on image quality. The importance of a quality tear film is well known in vision and must be considered completely prior to performing any surgery on the focusing elements of the eye. John Doane, MD, Eric Donnenfeld, MD, and Douglas Koch, MD, do a wonderful job of bringing practical information to anterior segment surgeons on how to examine the tear film for both optical quality and physical health along with the tests and technologies that help them do so. How our refractive and cataract surgery measurements are affected by tear film abnormalities is also discussed. A great result in refractive and cataract surgery starts with a great tear film. Ideally it is opti- mized prior to surgery for optimal healing and vision. EyeWorld thanks these doctors for sharing their expertise on this powerful liquid focusing element that does way more than moisturize the ocular surface. Vance Thompson, MD, Refractive editor Rose bengal conjunctival staining in a patient with dry eye disease Lissamine green conjunctival staining in a patient with dry eye disease Source (all): Eric Donnenfeld, MD P atients undergoing refrac- tive cataract surgery have high expectations. To ob- tain the best outcomes for these patients, it is imper- ative to optimize the ocular surface prior to surgery. The first step in this process is tear film analysis. "Tear film analysis in any form is critical," said John Doane, MD, Leawood, Kansas. "A healthy tear film is essential for good vision. For patients undergoing surgery and even for patients trying to see with or without glasses, if you do not have a good tear film, game over." Eric Donnenfeld, MD, Garden City, New York, agreed and noted that he routinely uses point-of-ser- vice tear film analysis in evaluating all dry eye patients and the great majority of patients presenting for cataract or refractive surgery. Types of tear film analysis Dr. Doane said that he is a minimal- ist when it comes to tear film analy- sis. He uses topography and pho- tokeratoscopy. "Photokeratoscopy specifically images the first Purkinje image, and that is the tear film. For me, that is a critical qualitative test. I immediately know if the tear film is good or not. Photokeratoscopy has always been wonderful, and if I'm ever worried about a patient, I will put him or her behind a manual keratometer, so I can assess how effective the tear film is in real time blink to blink and between blinks," he said. Dr. Donnenfeld uses tear osmo- larity as the baseline testing that is performed on all patients. "I think it gives me the most information, but I do MMP-9 as well. Although it's not a tear film analysis, I've started performing gland imaging on the great majority of my patients. I think performing LipiView [John- son & Johnson Vision, Santa Ana, California] on my surgery patients is helpful in evaluating meibomian gland dysfunction," he said. Douglas Koch, MD, Houston, first looks at the mires from the Galilei (Ziemer, Port, Switzerland) measurement that he takes on every new and preop patient. "If the mires are good, that tells me that the tear film is good. The next thing I do is a basic slit lamp examination to look at the height of the tear film meniscus. If I have any questions, then I'll get a tear breakup time. I have found that if I have a good tear breakup time with no staining, good tear meniscus, and good mires on the Galilei, I don't need to go any further in terms of diagnosis or treatment," he said. If he observes abnormalities in the mires and he determines that the condition is not epithelial basement membrane dystrophy or Salzmann's nodular dystrophy, and hence attributable to tear film issues, he will treat and continue to treat until he obtains good, clean measurements. "I also rely on the mires from the IOLMaster 700 [Carl Zeiss Meditec, Jena, Germany],

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