MAASTRICHT, Netherlands — Photorefractive intrastromal cross-linking, or PiXL, is a novel treatment option that appears promising for low-grade myopia, according to one speaker here.
This new application of corneal cross-linking, developed by Avedro, is performed with the epithelium on under topical anesthesia. Isotonic riboflavin is applied every 90 seconds for 10 minutes, and a circular 4-mm central zone of the cornea is then irradiated with 30 mW/cm2 for 16:40 minutes, resulting in a total UVA dose of 15 J/cm2.
At the European Society of Cataract and Refractive Surgeons winter meeting, Anders Behndig, MD, PhD, presented the preliminary data of an ongoing study including 39 eyes of 20 volunteers with low-grade myopia, ranging between –0.5 D and –2.5 D.
“We divided patients in two groups and treated 12 eyes in room air and 27 eyes in high oxygen through application of an eye mask,” Behndig said.
Significantly better results were obtained in the high oxygen group, with an average decrease of 1.25 D of spherical equivalent and no sign of regression at 3 months.
“Myopia even decreases a little bit further between 1 and 3 months. The mean keratotomy value was also lower in the oxygen group, in correlation with the reduction of myopia. Endothelial cell count did not change significantly, showing that this method is safe for the endothelium,” Behndig said.
A downside of PiXL is the high variability of effects, even between the two eyes of the same patient, Behndig said.
“It requires fine-tuning to increase the efficacy and reduce the variability. However, it is a promising new option for patients with low-grade myopia who want to be free of spectacles but don’t want surgery,” he said. – by Michela Cimberle
Behndig A, et al. Photorefractive intrastromal cross-linking (PiXL) for low grade myopia. European Society of Cataract and Refractive Surgeons winter meeting; Feb. 10-12, 2017; Maastricht, Netherlands.
Disclosure: Behndig reports no relevant financial disclosures.