Correcting presbyopia with allogenic corneal inlay

Early results of an ongoing clinical trial indicate that implantation of a sterile allograft corneal inlay (Transform, Allotex) in the non-dominant eye (Transform, Allotex) is a promising option for presbyopia correction in emmetropic patients.

At the ASCRS-ASOA annual meeting, being held May 3-7 at the Convention Center in San Diego, CA, Aylin Kiliç, MD, presented data from the first ten patients enrolled in a prospective trial investigating the lenticule. She explained that it has a refractive add power of +2.5 D and is designed to improve near vision by increasing depth of focus and corneal power.

Analyses of data collected at three months supported the safety, biocompatibility, and effectiveness of the inlay. All patients achieved near uncorrected visual acuity (UCVA) better than 20/40, and although seven of the 10 implanted eyes lost 1 line of distance UCVA as a result of a slight myopic refractive shift, all patients maintained 20/20 binocular distance UCVA. The same good outcomes have been seen during follow-up that now extends to one year, reported Dr. Kiliç, associate professor of Ophthalmology, Medipol University, Istanbul, Turkey.

Minimally invasive

“Options available for correcting presbyopia include corneal laser ablation with an excimer laser, multifocal IOL implantation, and synthetic corneal inlays, but they all have some limitations and are not very well accepted,” she said. “The sterile allograft inlay surgery is a minimally invasive, short procedure that involves no tissue removal, it is easy reversible and easy to exchange, and compared with a multifocal IOL, the inlay causes less optical side effects.”

Dr. Kiliç added that the early results from the clinical trial indicate that the sterile allograft inlay enhances the visual performance of patients for near vision needs.

“Now, larger clinical studies are needed to demonstrate the effectiveness and safety with long-term follow-up,” she said.

The inlay is prepared from eye bank cornea tissue. It is a piece of acellular cornea that is sterilized with electron beam radiation and precisely shaped using an excimer laser.

Dr. Kiliç presented a video to illustrate the implantation procedure in which a corneal flap was created using a femtosecond laser (iFS 150 kHz, Johnson & Johnson Vision). After raising the flap and under visualization through the surgical microscope of an excimer laser (Star S4 IR, Johnson & Johnson Vision), the corneal inlay was transferred onto the exposed stromal bed and centered over the pupil using a loop-like instrument.

“The instrument used to deliver the lenticule has an inner diameter of 3 mm and holds the lenticule by water surface tension,” said Dr. Kiliç. “The lenticule integrates with the stroma and becomes almost invisible. If we are not satisfied with the position of the lenticule, however, its location can be changed after applying a drop of water.”

Outcomes at three months

The ten patients enrolled in the clinical trial had a mean age of approximately 52 years (range 46 to 57 years). Representative images from the slit-lamp showed that the lenticule was essentially invisible, and a corneal topography difference map showed the surgery resulted in 2.5 D of central steepening of 2.5 D.

Comparisons of preoperative data with three-month postoperative results showed that mean near UCVA and mean distance corrected near visual acuity improved significantly. There were no significant changes in mean corneal thickness or best corrected distance visual acuity. Mean SE changed significantly from +0.06 D preoperatively to -0.47 D at three months.

Dr. Kiliç reported that there were no cases of clinically relevant haze or corneal opacities during the available follow-up of up to one year.

Disclosures:

Dr. Kiliç has no relevant financial interests to disclose.