Eyeworld

Reporting from the 2016 ESCRS Congress, September 10–14, Copenhagen, Denmark EW MEETING REPORTER 154 October 2016 "What about the patient with chronic pain even years after LASIK? … This unhappy patient could have—and maybe it even started before surgery—ocular surface dis- ease or dry eye disease. But the other kind of patient … is a patient who we are not certain of the etiology, and this falls into that category of neuropathic pain," Dr. Asbell said. Patients with this type of pain, which is not induced by a stimulus, don't have symptoms to match what is seen at the slit lamp. When pro- voked with pain, they might have a lower threshold to an otherwise normal stimulus or an enhanced response to a noxious stimulus, Dr. Asbell said. If the pain is due to lesion of nerves, a physician might be able to see the damage if it is in peripheral nerves but is unlikely to observe it if it is at central nerves. There are many different ways neuropathic pain can develop, Dr. Asbell ex- plained. An easy test for a patient with possible neuropathic pain is using a topical anesthetic. Dr. Asbell said to ask patients how they feel prior to a drop of proparacaine and then following the drop. "If the pain is gone, the chance is this is ocular surface disease and something you need to address," she said. The mechanism for dry eye after cataract surgery includes corneal sensitivity impairment, inflamma- tion and goblet cell loss, and meibo- mian gland dysfunction. "All of these mechanisms are tightly interlaced," Rita Mencucci, MD, Florence, Italy, said. There is also an uncertain effect of incision location on dry eye markers relative to location of corne- al nerves, and incision shape seems to also have an effect on dry eye, Dr. Mencucci said. In addition to these factors, Dr. Mencucci said diabetic patients are at higher risk for postop dry eye after cataract surgery, even if they didn't present symptoms preopera- tively. However, complete resolution is usually seen within 3 months. The presence of dry eye, un- treated preoperatively, could lead to an off-target refractive outcome. Dry eye postoperatively could make pa- tients unhappy with their procedure despite an otherwise perfect surgery. "Hopefully the innovations in diagnostic and surgical techniques will help in reducing the recovery time and severity of dry eye after IOL procedures," Dr. Mencucci said. Penny Asbell, MD, New York, discussed the various factors that could lead to dry eye but went into specific detail about neuropathic pain and how it could relate to dry eye. It is well known that dry eye is one of the most common post-LASIK complaints, Renato Ambrósio Jr., MD, Rio de Janeiro, Brazil, said. "LASIK, because of the flap cut and because of the ablation, it creates a problem of the nerves [and] we don't have any evidence that LASIK was the real cause of the problem … or if the cases merely represent individuals who suf- fered progression of an underlying subclinical dry eye condition," Dr. Ambrósio said. With that in mind, the issue of LASIK-related dry eye starts preop- eratively. Just talking to patients and understanding why they want refractive surgery could reveal some underlying issues that indicate dry eye that should be better understood or addressed prior to surgery. When a patient presents post- LASIK with dry eye complaints, listening to symptoms, asking about any systemic diseases or medica- tions, and conducting ocular surface imaging, advanced testing for osmolarity, Schirmer's testing, and a thorough ocular surface exam can help determine the next mode of action for management. As with dry eye treatment, optimizing the ocular surface in- cludes nutritional supplementation, artificial tears and ointments, lid hygiene, topical steroids, short-term antibiotics, growth factors, and more. Surgical strategies to reduce LASIK-related dry eye specifically could include making a thinner flap with a larger hinge, Dr. Ambrósio said. Performing femtosecond laser LASIK over using a microkeratome also results in less dry eye. Choos- ing another refractive procedure with less incidence of postop dry eye, such as small incision lenticule extraction (SMILE) or phakic IOLs, is an option as well, especially for patients with more risk for dry eye. Addressing dry eye preopera- tively is also important for positive outcomes in refractive cataract surgery because the effect of dry eye on the ocular surface can throw off measurements and lead to inaccu- rate IOL calculations. View videos from ESCRS 2016: EWrePlay.org Graham Barrett, MD, discusses challenges and fixes for toric IOL calculations.

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