Marco Lombardo1, Sebastiano Serrao2, Marianna Rosati2, Pietro Ducoli2, Giuseppe Lombardo2. 1. From the Fondazione G.B. Bietti IRCCS (M. Lombardo, Serrao, Rosati, Ducoli), Vision Engineering Italy s.r.l. (G. Lombardo), Rome, and the CNR-IPCF Unit of Support of Cosenza (G. Lombardo), Rende, Italy. Electronic address: mlombardo@visioeng.it. 2. From the Fondazione G.B. Bietti IRCCS (M. Lombardo, Serrao, Rosati, Ducoli), Vision Engineering Italy s.r.l. (G. Lombardo), Rome, and the CNR-IPCF Unit of Support of Cosenza (G. Lombardo), Rende, Italy.
Abstract
PURPOSE: To evaluate the corneal response to variable intraocular pressure (IOP) in human eye globes after ultraviolet-A (UVA) transepithelial corneal crosslinking using iontophoresis. SETTING: Fondazione G.B. Bietti IRCCS, Rome, Italy. DESIGN: Experimental study. METHODS: Four human donor eye globes were treated with transepithelial crosslinking using iontophoresis and rapid UVA corneal irradiation, and 4 globes had standard crosslinking. Inflation experiments were performed on the globes before and after crosslinking. Topographic maps of the anterior and posterior cornea were acquired using Scheimpflug topography. Images were obtained using a mechanical regimen to analyze corneal strain in response to cyclic stress. Corneal shape changes were analyzed as a function of IOP, and corneal stress-strain curves were generated. RESULTS: Before crosslinking, instillation of hypotonic riboflavin-5-phosphate sodium 0.1% solution using iontophoresis increased corneal thickness by 5% and instillation of dextran-enriched riboflavin 0.1% solution decreased corneal thickness by 13%. Five minutes after treatment, both crosslinking procedures reduced corneal thickness by 2%. Young's modulus (E) of the anterior cornea increased by a mean of 1.8 times (from 1.6 to 2.9 MPa) and 1.9 times (from 1.3 to 2.5 MPa) after transepithelial crosslinking using iontophoresis and standard crosslinking, respectively. The E value of the posterior cornea also increased after both procedures (mean 1.7 times versus 3.1 times). CONCLUSIONS: Transepithelial crosslinking using iontophoresis increased the biomechanical strength of human corneal tissue in inflation testing of donor eye globes. The effect on corneal stiffness was almost comparable to that of standard crosslinking. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
PURPOSE: To evaluate the corneal response to variable intraocular pressure (IOP) in human eye globes after ultraviolet-A (UVA) transepithelial corneal crosslinking using iontophoresis. SETTING: Fondazione G.B. Bietti IRCCS, Rome, Italy. DESIGN: Experimental study. METHODS: Four humandonor eye globes were treated with transepithelial crosslinking using iontophoresis and rapid UVA corneal irradiation, and 4 globes had standard crosslinking. Inflation experiments were performed on the globes before and after crosslinking. Topographic maps of the anterior and posterior cornea were acquired using Scheimpflug topography. Images were obtained using a mechanical regimen to analyze corneal strain in response to cyclic stress. Corneal shape changes were analyzed as a function of IOP, and corneal stress-strain curves were generated. RESULTS: Before crosslinking, instillation of hypotonic riboflavin-5-phosphate sodium 0.1% solution using iontophoresis increased corneal thickness by 5% and instillation of dextran-enriched riboflavin 0.1% solution decreased corneal thickness by 13%. Five minutes after treatment, both crosslinking procedures reduced corneal thickness by 2%. Young's modulus (E) of the anterior cornea increased by a mean of 1.8 times (from 1.6 to 2.9 MPa) and 1.9 times (from 1.3 to 2.5 MPa) after transepithelial crosslinking using iontophoresis and standard crosslinking, respectively. The E value of the posterior cornea also increased after both procedures (mean 1.7 times versus 3.1 times). CONCLUSIONS: Transepithelial crosslinking using iontophoresis increased the biomechanical strength of human corneal tissue in inflation testing of donor eye globes. The effect on corneal stiffness was almost comparable to that of standard crosslinking. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
Authors: Alberto Artola; David P Piñero; Pedro Ruiz-Fortes; Roberto Soto-Negro; Rafael J Pérez-Cambrodí Journal: Int J Ophthalmol Date: 2017-04-18 Impact factor: 1.779
Authors: Cristina Labate; Marco Lombardo; Maria P De Santo; Janice Dias; Noel M Ziebarth; Giuseppe Lombardo Journal: Invest Ophthalmol Vis Sci Date: 2015-06 Impact factor: 4.799