Hydrogel Corneal Inlay Promising in Pseudophakic Presbyopia

Laird Harrison

April 20, 2015

SAN DIEGO — A transparent hydrogel corneal inlay is a novel way to correct the vision of patients with pseudophakic presbyopia, a new study shows.

"The Raindrop inlay improved near and intermediate vision significantly," said Dan Tran, MD, an ophthalmologist in Orange, California, who presented the finding here at the World Cornea Congress.

Current solutions for improving pseudophakic presbyopia have their drawbacks, explained Dr Tran.

The monovision technique can cause a lack of depth perception or imbalanced vision if the difference between corrections of the eyes is too great. And if the difference is too small, the technique can be insufficient to correct vision.

In addition, intraocular lenses can cause halos, glare, and loss of contrast, or lack a full range of vision.

A corneal implant could be an effective alternative, said Dr Tran.

The Raindrop inlay is similar to the cornea in terms of water content and refractive index. It is implanted at one-third the corneal thickness, and centered over the light-constricted pupil. "It's fairly easy to remove by just lifting the flap and removing the inlay," he said.

The advantage of this over LASIK, intraocular lenses, etc., is that it's potentially reversible.

The strongest curvature is in the central region, providing near vision. The curvature gradually decreases toward the periphery, creating regions that provide intermediate and distance vision.

To assess its effectiveness, Dr Tran and his team implanted the inlay in the nondominant eyes of 47 patients in Vietnam who had previously undergone monofocal intraocular lens implantation.

Six months after the procedure, patients had gained a mean of four lines of near vision and two lines of intermediate vision. In addition, their distance vision was "minimally" compromised, Dr Tran reported.

Reports of ocular dryness increased from 4% to 7% of the patients, but reports of visual glare decreased from 9% to 2%, and visual halos decreased from 2% to 0%.

One patient had the inlay removed because of haze after 3 months, and two patients had their inlays exchanged for new ones. Three cases of trace haze were treated with steroids.

Six months after the procedure, 91% of patients said they were satisfied or very satisfied with their vision, and 9% were neutral; none of the patients were dissatisfied.

The Raindrop is "exciting technology," said session discussant Stephen Kaufman, MD, PhD, from the State University of New York Downstate Medical Center in New York City.

"The advantage of this over LASIK, intraocular lenses, etc., is that it's potentially reversible," he told Medscape Medical News.

However, in light of results with similar approaches over the past decade, longer-term studies are needed on the biocompatibility of the inlay, Dr Kaufman explained. For example, he reported, after a few years, fibrotic tissue might form around the implant, and patients might have decreased corneal sensation or epithelial abrasion.

This study was funded by ReVision Optics. Dr Tran is a consultant for ReVision Optics, Alcon, and WaveTec Vision. Dr Kaufman has disclosed no relevant financial relationships.

World Cornea Congress (WCC) VII. Presented April 16, 2015.


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