Assessment of Corneal Endothelium After Collagen Cross Linking

Accelerated Corneal Collagen Cross Linking Clinical Trial

— CXL  

Official title:

A Specular Microscopic Study of Corneal Endothelium After Accelerated Corneal Collagen Cross Linking

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT04160338
• Other study ID #: corneal collagen cross linking
• Status: Not yet recruiting
• Start date: December 2019
• Est. completion date: March 2022

Study information

• Verified date: November 2019
• Source: Assiut University
• Contact: Naglaa MA Abdelmohsen, M.B.B.CH.
• Phone: +201095459579
• Email: dr.naglaa15[@]gmail.com
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The aim of this study is to assess the effect of accelerated corneal collagen cross linking on corneal endothelium using the specular microscopy

Description:

Keratoconus (KC) is a progressive, non-inflammatory corneal degenerative disease. It is a pathology characterized by a progressive thinning and protrusion of the cornea that ends in a cone‐shaped cornea. This results in progressive myopia and irregular astigmatism with associated progressive loss of vision and thus reduced quality of life.Collagen cross-linking (CXL) is a relatively new conservative approach for progressive corneal ectasia. The main indication for CXL is to slow the progression of corneal ectatic diseases, such as keratoconus, pellucid marginal degeneration (PMD), keratoglobus and iatrogenic ectasia.The basic principle of this method is the chemical interaction of ultraviolet A radiation (315-400nm ) and riboflavin to induce covalent bond formation between collagen fibers of the cornea. In this way, the stiffness and rigidity of the cornea are provided.Corneal collagen cross-linking (CXL) was first introduced by Wollensak with an ultraviolet-A (UVA) protocol of 3 medium wave mW/cm2 intensity at 370 nm over an exposure time of 30 minutes (now termed the "Dresden protocol"). Researchers have proposed accelerated CXL (ACXL) protocols, to improve convenience and comfort for patients. These ACXL protocols have the aim of decreasing UVA exposure time by increasing UVA fluency to achieve the same overall total UVA dosage.Despite corneal CXL is a safe and effective procedure with few known side effects .Persistent corneal edema and possible endothelial cell damage have been reported in a few cases after CXL. Based on the extent of endothelial damage, patients may require penetrating keratoplasty.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 25
• Est. completion date: March 2022
• Est. primary completion date: September 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 16 Years to 40 Years

Eligibility

Inclusion Criteria:

1. patients with mild to moderate corneal ectasia who are candidates for CXL.

Exclusion Criteria:

1. patients with advanced corneal ectasia with maximum keratometry readings <56 diopters.

2. corneal pachymetry >380um.

3. corneal scarring.

4. previous corneal surgeries (e.g intrastromal corneal ring segments)

Related Conditions & MeSH terms

• Accelerated Corneal Collagen Cross Linking

Intervention

Device:
• specular microscopy
An informed written consent will be obtained from all patients that will be included in this study. Patients in this study will undergo specular microscopic examination of corneal endothelium before CXL procedure. Patients will be assigned to undergo accelerated (epithelium-off ,transepithelial ) CXL . Follow up specular microscopy will be done 3 months and 6 months after corneal collagen cross linking procedure .

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Assiut University

References & Publications (8)

Kirgiz A, Eliacik M, Yildirim Y. Different accelerated corneal collagen cross-linking treatment modalities in progressive keratoconus. Eye Vis (Lond). 2019 Jun 3;6:16. doi: 10.1186/s40662-019-0141-6. eCollection 2019. — View Citation

Mencucci R, Marini M, Paladini I, Sarchielli E, Sgambati E, Menchini U, Vannelli GB. Effects of riboflavin/UVA corneal cross-linking on keratocytes and collagen fibres in human cornea. Clin Exp Ophthalmol. 2010 Jan;38(1):49-56. doi: 10.1111/j.1442-9071.2010.02207.x. — View Citation

Raiskup-Wolf F, Hoyer A, Spoerl E, Pillunat LE. Collagen crosslinking with riboflavin and ultraviolet-A light in keratoconus: long-term results. J Cataract Refract Surg. 2008 May;34(5):796-801. doi: 10.1016/j.jcrs.2007.12.039. — View Citation

Sedaghat M, Bagheri M, Ghavami S, Bamdad S. Changes in corneal topography and biomechanical properties after collagen cross linking for keratoconus: 1-year results. Middle East Afr J Ophthalmol. 2015 Apr-Jun;22(2):212-9. doi: 10.4103/0974-9233.151877. — View Citation

Subasinghe SK, Ogbuehi KC, Dias GJ. Current perspectives on corneal collagen crosslinking (CXL). Graefes Arch Clin Exp Ophthalmol. 2018 Aug;256(8):1363-1384. doi: 10.1007/s00417-018-3966-0. Epub 2018 Apr 6. Review. — View Citation

Vazirani J, Bagga B, Taneja M. Persistent corneal edema after collagen cross-linking for keratoconus. Am J Ophthalmol. 2013 Apr;155(4):775. doi: 10.1016/j.ajo.2013.01.003. — View Citation

Wen D, Li Q, Song B, Tu R, Wang Q, O'Brart DPS, McAlinden C, Huang J. Comparison of Standard Versus Accelerated Corneal Collagen Cross-Linking for Keratoconus: A Meta-Analysis. Invest Ophthalmol Vis Sci. 2018 Aug 1;59(10):3920-3931. doi: 10.1167/iovs.18-24656. — View Citation

Zhang X, Zhao J, Li M, Tian M, Shen Y, Zhou X. Conventional and transepithelial corneal cross-linking for patients with keratoconus. PLoS One. 2018 Apr 5;13(4):e0195105. doi: 10.1371/journal.pone.0195105. eCollection 2018. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	endothelial cell count by specular microscopy.	specular microscopy will be used to assess corneal endothelial cell count after accelerated corneal collagen cross linking	from preoperatively to 6 months postoperatively
Secondary	endothelial cell morphology by specular microscopy.	specular microscopy will be used to assess corneal endothelial cell morphology after accelerated corneal collagen cross linking	from preoperatively to 6 months postoperatively