Minimally Invasive Repetitive UVA Irradiation along with Riboflavin Treatment Increased the Strength of Sclera Collagen Cross-Linking.

Bo Xiao,Quanhong Han,Hongyan Wang,Yanhua Chu

doi:10.1155/2017/1324012

Abstract

Objective This study aimed to investigate the efficacy of minimally invasive repetitive UVA irradiation along with riboflavin treatment on sclera collagen cross-linking in rabbits. Method Forty-eight healthy adult New Zealand white rabbits were randomly divided into four groups: pseudosurgery group (group I), single-irradiation group (group II), duplicate-irradiation group (group III), and triplicate-irradiation group (group IV), with 12 rabbits in each group. For the single-irradiation group, a specially made LED light source was inserted through a minimally invasive conjunctival incision to gain close contact with the sclera for irradiation, and for the repetitive irradiation groups, the above experimental procedure was repeated once or twice every other week. Biomechanical parameters of the sclera including ultimate stress (σ) and 8% Young's modulus (E) were compared among the groups. Results In comparison with control group I, the ultimate stress of group II, group III, and group IV increased by 80.1%, 107.9%, and 182.1%, respectively, and their 8% Young's modulus increased by 106.1%, 159.5%, and 208.5%, respectively, one day after surgery (P < 0.01). Conclusion Repetitive minimally invasive UVA irradiation with riboflavin significantly increased biomechanical strength of the sclera in the irradiated area, and biomechanical strength increased with repeated times of irradiation.

Highlights

Pathological myopia is one of the most common factors leading to visual acuity loss and blindness, with a lack of effective therapy
We proposed a method for sclera collagen cross-linking via minimally invasive riboflavin/UVA by conducting repetitive irradiation on rabbit posterior sclera and equatorial sclera, studied the efficacy of this method, and explored whether it would be possible to enhance sclera mechanical strength by increasing irradiation times while keeping single-irradiation time and dose unchanged
In comparison with group I, the sclera ultimate stress in groups II, III, and IV increased by 80.1%, 107.9%, and 182.1%, respectively (P = 0 00)

Summary

Introduction

Pathological myopia is one of the most common factors leading to visual acuity loss and blindness, with a lack of effective therapy. Previous techniques of sclera collagen cross-linking using conventional UVA irradiance devices have required relatively large conjunctival incisions, postoperative stitching and intense intraoperative pulling of the extraocular muscles, and rotation of the eye ball to expose the equatorial sclera and less effectively the posterior sclera which is most prone to damage and staphylomas [5]. These adverse factors prevented the development and application of sclera collagen cross-linking induced by riboflavin/UVA, making it difficult to implement repetitive irradiation. We proposed a method for sclera collagen cross-linking via minimally invasive riboflavin/UVA by conducting repetitive irradiation on rabbit posterior sclera and equatorial sclera, studied the efficacy of this method, and explored whether it would be possible to enhance sclera mechanical strength by increasing irradiation times while keeping single-irradiation time and dose unchanged

Methods

Results

Conclusion