Novel myopic refractive correction with transepithelial very high-fluence collagen cross-linking applied in a customized pattern: early clinical results of a feasibility study

Abstract

BackgroundThe purpose of this study is to report the safety and efficacy of a new application of collagen cross-linking using a novel device to achieve predictable refractive myopic changes in virgin corneas.MethodsFour cases were treated with a novel device employing very high-fluence collagen cross-linking applied in a myopic pattern. Prior to treatment, riboflavin solution was applied to the intact epithelium. The collagen cross-linking device was then engaged for a total of 12 J/cm2, to be applied transepithelially in a predetermined pattern. Cornea clarity, corneal keratometry, and corneal topography were evaluated by both Placido disc and Scheimpflug imaging, along with cornea anterior segment optical coherence tomography and endothelial cell counts.ResultsAn average of 2.3 diopters was achieved in the first week in all four cases treated with the very high-fluence myopic collagen cross-linking intervention. There was a slight regression to 1.44 diopters at 1 month, which remained stable at 6-month follow-up. The mean keratometry change was from 44.90 diopters to 43.46 diopters. There was no significant change in endothelial cell counts or corneal clarity. There was some mild change in epithelial thickness distribution, with the treated area showing a slight but homogeneous reduction in mean thickness from 52 μm to 44 μm.ConclusionThis report describes the novel application of very high-fluence collagen cross-linking with a predictable well defined myopic refractive (flattening) corneal effect. This technique has the advantages of essentially no postoperative morbidity, immediate visual rehabilitation, and the potential for tapering until the desired result is achieved.

Presbyopic PiXL Cross-Linking

“…Recently, the application of variable fluence, topographically modified CXL, may predictably offer small refractive changes on normal corneas [18 …”

Slowing the Progression of Keratoconus - Turning to Corneal Crosslinking

“…[40] More topographic flattening occurs in eyes with centrally located cones and the least flattening effect of the cone occurs when the cone is located peripherally. [9][10][11] A great challenge today is the management of the keratoconus in patients with more advanced or decentered ectasia, intolerant to rigid gas permeable contact lenses and poor spectacles corrected visual acuity.…”

“…[9][10][11] A great challenge today is the management of the keratoconus in patients with more advanced or decentered ectasia, intolerant to rigid gas permeable contact lenses and poor spectacles corrected visual acuity. [40,41] The refraction of these patient is always difficult because spectacle correction is unable to correct HOA and irregular astigmatism, especially in peripheral cones, and a comfortable contact lens fitting sometimes is hard to reach or not possible at all and could cause corneal scarring or infection. These patients become the natural candidates to lamellar or penetrating keratoplasty.…”

“…[40][41] The target of customized ablation is to improve the quality of visual acuity reducing the lower-order aberrations and the HOA with partial or total treatment of corneal irregular astigmatism. Wave-front-guided ablation takes into account the aberration of full eye while topography-guided treatment considers only the corneal aberration.…”

Keratoconus - A Refractive Surgery

“…PiXL (Photorefractive Intrastromal CXL) allows Customisable, differential CXL application to specific corneal areas which induces predictable refractive changes. 15,16 It radically increases the use of CXL not just for stabilising , but also as a refractive surgery by reshaping the cornea. Continuing with the above example, we would perform advanced laser surface ablation in the patients with a cornea which has adequate strength and no scar but requires shape modification for achieving vision.…”