Dry eye after LASIK

Neurotrophic epitheliopathy is hard on patients and difficult to treat

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Renato Ambrósio Jr MD, PhD
"Everyone who performs corneal refractive surgery knows that LASIK-associated dry eye is a major cause of patient dissatisfaction in the early postoperative period. But what about LASIK-induced neurotrophic epitheliopathy (LINE), which can result in a very unhappy patient many months after the surgery?” This question was posed by Renato Ambrósio Jr MD, PhD, Affiliated Professor of Ophthalmology at the Pontifical Catholic University of Rio de Janeiro and Federal University of São Paulo, Brazil, at a symposium during the XXXIV Congress of the ESCRS in Copenhagen, Denmark. It has been known since 2000 that the decrease, and subsequent return, of corneal sensation can be objectively measured using an esthesiometer, while regrowth of the nerves’ normal morphology can be documented with confocal microscopy. However, there are cases with long-term corneal sensitivity deficits after LASIK that do not recover for a much longer period. This is the situation in patients suffering from LINE, said Dr Ambrósio. Because of the challenge that treating LINE may impose, the initial focus should be on the prevention. Proper selection of the refractive procedure according to the patient avoids exacerbating pre-existent dry eye, which can worsen the symptoms of LINE. “Pre-existing tear dysfunction syndrome is a major risk factor for severe postoperative dry eye. This is very common, because patients who have difficulty wearing contact lenses self-select for refractive surgery,” he warned. The surgeon should be alert to the preoperative examination since the complaint profile and anamnesis. In addition, clinical evaluation should include ocular surface imaging, such as with the OCULUS Keratograph®, which allows for assessing tear film stability, the Meibomian glands and blinking dynamics. “Vital dyes, including fluorescein and Rose bengal or lissamine green, are important. We also found trypan blue to be very effective for examining the corneal and conjunctival surface,” said Dr Ambrósio. How can we minimise trauma to corneal nerves during refractive surgery? When performing LASIK, a thinner flap with lower diameter and larger hinge will reduce the impact on the corneal nerve fibres, he advised.
Pre-existing tear dysfunction syndrome is a major risk factor for severe postoperative dry eye
The small incision lenticule extraction (SMILE) procedure also has a lower impact on corneal nerves than LASIK, as there is no flap cut. He shared data that showed that corneal sensitivity is less affected and returns to baseline faster after SMILE. But what of the patients in which LINE has been diagnosed? His advice is to approach the condition with a comprehensive strategy, starting with patient education about this frustrating disorder. “Prescribing BAK-free artificial tears is important. Also, oral Omega-3 EFA supplementation with flaxseed and/or fish oil capsules, topical cyclosporine 0.05% and dexpantenol gel work well. In severe cases, autologous serum is needed,” he said. Renato Ambrósio Jr: dr.renatoambrosio@gmail.com