Treating Hyperopia with LIKE Corneal Surgery

Lenticular intrastromal keratoplasty now ready to advance to a multicentre trial. Cheryl Guttman Krader reports

Promising results in a feasibility study investigating LIKE (Lenticular Intrastromal Keratoplasty) as a hyperopia treatment support plans to initiate a prospective multicentre study to further evaluate this additive, allograft-based procedure, reported Theo Seiler MD, PhD.

Presenting data from follow-up ranging from one to four years for a series of 15 eyes treated with LIKE for +3.5 to +8.0 D of hyperopia, Dr Seiler reported the achieved refraction was within 0.5 D of attempted in 87% of eyes and ±1.0 D in all eyes.

“These results are much better than with any LASIK treatment for hyperopia,” Dr Seiler said.

GENESIS AND EVOLUTION Dr Seiler and colleagues began investigating additive hyperopia correction by implantation of a pre-cut donor lenticule about 20 years ago. The idea to perform an additive procedure was based on recognition of the healing response after LASIK resulted in astigmatism and regression.

“Removing a doughnut-shaped tissue ring from the cornea leads to filling of the deficit by epithelium and stromal tissue,” he explained. “Therefore, we instead proposed to implant a prepared lenticule of donor tissue under a LASIK flap.”

Initially, the lenticule was prepared with an excimer laser, but that technique had poor reproducibility. A femtosecond laser obtained better precision for lenticule creation. The LIKE lenticule is cut to a diameter of 7 to 8 mm, keeping Bowman’s membrane intact. The lenticule is implanted under a LASIK flap that is 10 mm in diameter and about 110 μm thick. Based on image guidance (Verion™, Alcon), the lenticule is centred halfway between the Purkinje reflex and pupil centre.

After one month, retreatment with flap lifting and wavefront- or topography-guided ablation of the implanted lenticule is performed for refractive fine-tuning and regularisation of the optical condition. Dr Seiler demonstrated a need for the

“Because of the relifting of the flap, we felt having Bowman’s membrane in the lenticule is an integral part of the procedure.”

retreatment by presenting a graph showing high spread in the refractive outcomes one month before the fine-tuning procedure. He illustrated its benefit with a case of a patient whose uncorrected visual acuity was 0.3 just prior to the retreatment and 0.9 at two months after the procedure.

“Because of the relifting of the flap, we felt having Bowman’s membrane in the lenticule is an integral part of the procedure because it lets you see and then stretch any irregularity in the lenticule,” Dr Seiler said.

He added that as another benefit compared to LASIK, LIKE is a reversible procedure.

“In LIKE, only the lenticule is ablated, and it can be taken out if the patient is unhappy with the result,” Dr Seiler said.

He acknowledged the potential for BCVA loss after LIKE because the procedure results in loss of the magnification effect of the positive lens in the front of the eye. In the pilot study, BCVA loss of two lines occurred in one eye (6.5%), and two eyes (13%) had a one-line loss.

Dr Seiler presented the study at the ESCRS Symposium during the AAO 2022 Refractive Surgery Subspecialty Day meeting in Chicago, US.

Theo Seiler MD, PhD is the founder of IROC eye clinic in Zurich, Switzerland. theo.seiler@iroc.ch

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