EyeWorld India June 2017 Issue

June 2017 EWAP FEATURE 13 Institute, Bloomington, Minnesota. “Now they ask, ‘Can you get rid of my reading glasses?’ And we can actually say yes to that now.” KAMRA The KAMRA, which was approved in April 2015, operates based on the principle of small- aperture optics, much like a camera or pinhole effect. Placed in a femtosecond laser-made pocket in the patient’s non-dominant eye and centered over their pupil, this opaque, porous inlay made of polyvinylidene difluoride narrows the pupil’s aperture size to increase depth of focus. The 3.8-mm inlay with the central open space of 1.6 mm was approved for presbyopic patients with +0.5 D to –0.75 D of cycloplegic refractive spherical equivalent with 0.75 D refractive cylinder or less. According to AcuFocus, the patient should not rely on glasses or contact lenses for distance vision. Some surgeons will, however, perform LASIK in sequence with the inlay or simultaneously, said Daniel Durrie, MD , clinical professor of ophthalmology, University of Kansas, Overland Park, Kansas. AcuFocus, however, notes that the safety and efficacy of this combination is not known. Dr. Durrie also said that the KAMRA seems to perform better in patients who are slightly myopic, which is something the surgeon can create to maximize outcomes. Per AcuFocus’ Ophthalmic Devices Panel Executive Summary submitted to the FDA, 83.5% of the 478 patients included for evaluation in the pivotal study achieved uncorrected near visual acuity (UCNVA) of 20/40 or better 1 year postop. 4 At 36 months, 87.1% of the 417 subjects available for evaluation achieved UCNVA of 20/40 or better. Less than 1% of subjects had induced cylinder because of the procedure, and the mean endothelial cell loss was about 5% but it stabilized by 1 year. As for subjective, patient- reported symptoms, dryness was the most common. As with other procedures, Dr. Durrie said setting patient expectations for the KAMRA is important. While some patients see improvement in the first week, it may take 2 or 3 weeks for the majority to start experiencing the effects, with a small number taking up to 3 months. KAMRA patients might also struggle in low light situations, Dr. Durrie said. Raindrop The Raindrop, the latest to receive FDA approval in June 2016, is a hydrogel implant with a 32-μm central thickness placed under a LASIK flap at a depth of one-third corneal thickness, leaving at least 300 μm below the flap. The inlay steepens the optical zone to increase depth of focus. It is indicated for presbyopes with a manifest refractive spherical equivalent of +1 D to –0.5 D with adequate distance vision but requiring +1.5 D to +2.5 D of reading vision. Like the KAMRA, the safety and efficacy of the Raindrop combined with LASIK or PRK is unknown, according to the company. Clinical trials showed this inlay can tolerate up to 0.7 mm of decentration in any direction, but Dr. Chu said he finds it more forgiving to inferior nasal placement and overall more forgiving to decentration than the KAMRA. During the surgery, Jeffrey Whitman, MD , Key-Whitman Eye Center, Dallas, Texas, noted that the femtosecond flap should be wetted with balanced salt solution every 20 seconds to ensure it doesn’t dry out and develop striae. After the inlay is centered, has dried adequately (look for a dimpling effect like than of an orange peel), and the flap has been laid down, surgeons should expect a gutter opposite the hinge given a space- occupying implant under the flap. Dr. Whitman said this is normal and will be gone the next day. “Don’t play with it, don’t irrigate around it, don’t think you can minimize it. Just stroke a few times when laying the flap down,” Dr. Whitman said, noting that he does place a bandage contact lens for the patient’s comfort. What Dr. Whitman thinks is nice about the Raindrop is its similarities to LASIK. “If I know how to do LASIK, I can do the Raindrop. I’m not learning a new technique; I have lasers that can already make a LASIK flap, and I know how to work under a flap,” he said. However, Dr. Chu cautioned against treating inlay patients like LASIK patients completely. “They need closer follow-up,” Dr. Chu said, recommending these patients be followed closely for the long term. “Almost all of the complications that can happen from these inlays can be avoided if the patient is followed up earlier and treated appropriately before anything serious happens.” Initial clinical trials for FDA approval revealed 92% of patients could see 20/40 or better at near 2 years postop. 5 Central corneal haze was listed as one of the most common complications (16.6%), but it resolved in 89% of subjects. ReVision Optics is currently conducting further clinical studies on the use of the Raindrop inlay in pseudophakic patients as well as in a femtosecond laser-created pocket rather than under a flap. Flexivue Microlens This clear, corneal 3.2-mm inlay consists of a 1.6-mm central area with no refractive power and a peripheral ring with a refractive power ranging from +1.5 D to 3.5 D. “The design of the inlay results in a multifocal effect that allows the patient to experience good near vision and distance vision,” Edward Manche, MD , professor of ophthalmology, Stanford University School of Medicine, Stanford, California, said of the implant currently in Phase 3 clinical trials. Dr. Manche said he places the hydrophilic acrylic inlay in a 300-μm femtosecond laser-created pocket, using a custom mask provided by Presbia. This small temporal incision is self-sealing, and Dr. Manche said the 5- to 10-minute procedure is “completely painless.” Selecting the right power for patients is determined based on their age and functional needs for near vision. While Dr. Manche said his continued on page 14