New ablation profile may allow for deep PRK ablation without use of mitomycin C
MARRAKECH, Morocco — A new ablation algorithm for transepithelial PRK effectively reduces haze formation and allows for the correction of even high myopia and myopic astigmatism without the use of mitomycin C, according to a study.
“The use of topical mitomycin C has been considered mandatory in order to prevent corneal haze, especially in deeper ablations. In collaboration with Schwind, we developed for the Amaris laser a new algorithm that enhances surface smoothness, reducing inflammation even in deep ablations,” Emilio Torres-Netto, MD, said at the European Society of Cataract and Refractive Surgeons Winter Meeting.
In a study performed at the Elza Institute in collaboration with the Laboratory for Ocular Cell Biology of the University of Zurich, Switzerland, corneal haze was assessed in patients who underwent transepithelial PRK with a stromal ablation of more than 100 µm without the use of MMC.
Slit lamp corneal haze analysis showed clinically insignicant haze at 1 month and 3 months after surgery. Corneal densitometry showed a signicant decrease in the anterior 120 µm and no signicant changes in the intermediate layer and the posterior 60 µm. Only the central 2 mm of the intermediate layer showed a signicant increase in densitometry, not correlated with clinical findings.
“The new ablation profile allows us to perform deep PRK ablation without the use of mitomycin C, broadening the indications of PRK to a wider myopic range,” Torres-Netto said.
MMC has been a helpful adjunct to surface ablation, but the possible long-term effects of the drug remain a concern.
“The present study may indicate that in a central European setting and with a novel excimer laser ablation prole, the use of mitomycin C in deep ablation PRK may not be essential. However, it is important to specify that this study was performed in Switzerland and that our findings may not apply to parts of the world with a higher exposure to sunlight,” Torres-Netto said. – by Michela Cimberle
Abdshahzadeh H, et al. Assessment of postoperative haze after deep transepithelial photorefractive keratectomy (trans-PRK) without mitomycin using a new ablation algorithm to smoothen the stromal would bed. Presented at: European Society of Cataract and Refractive Surgeons Winter Meeting; Feb. 21-23, 2020; Marrakech, Morocco.
Disclosure: Torres-Netto reports no relevant financial disclosures.