Comparison Of Corneal Densitometry Changes After Transepithelial Corneal Cross Linking Using Hpmc Riboflavin Versus Riboflavin Containing Vitamin E Tocopheryl Polyethylene Glycol Succinate(Tpgs) In Patients With Progressive Keratoconus
Published 2025 - 43rd Congress of the ESCRS
Reference: PP16.08 | Type: Free paper | DOI: 10.82333/hr2v-1j08
Authors: Amadeu Carceller Guillamet* 1 , Ramin Khoramnia 2 , Kathleen Moore 3 , Grace Lytle 4 , Chloe Xia 4 , Toon Van Gorp 5
1Hospital Quirón Barcelona,Barcelona,Spain, 2University of Heidelberg,Heidelberg,Germany, 3University of Oklahoma Health Sciences Center ,Oklahoma City,United States, 4AbbVie Inc.,North Chicago,United States, 5University Hospital Leuven,Leuven,Belgium;KU Leuven, Leuven Cancer Institute,Leuven,Belgium;Belgium and Luxembourg Gynaecological Oncology Group (BGOG),Leuven,Belgium
Purpose
To compare the corneal densitometry changes after accelerated transepithelial corneal cross linking (TECXL) using two different riboflavin solutions i.e. riboflavin with HPMC and riboflavin with Vitamin E TPGS in patients having progressive keratoconus (KCN).
Vitamin E TPGS has been shown to enhance permeation across biological membranes and hence may offer the potential benefit of deeper stromal penetration of riboflavin in TECXL. It also protects biological membranes from damage by free radicals and this may offer another advantage since oxygen free radicals generated in during the CXL process have been implicated in corneal haze and deep scarring. Corneal densitometry changes may be reflective of haze formation in the cornea.
Setting
The prospective, randomised, interventional, comparative study has been conducted in Advanced Eye Centre, Post Graduate Institute of Medical Research and Education, Chandigarh,India.
Methods
24 patients of 16 years and above with progressive keratoconus with thinnest pachymetry of 360µ and above on Scheimpflug imaging were enrolled into two equally divided groups ( twelve in each group) after randomisation. They were subjected to accelerated TECXL (9Mw/cm² X 10minutes of UV-A exposure) with either Vitamin E TPGS-Riboflavin (applied every 1 minute) or HPMC Riboflavin (applied every 2 minutes)during both the saturation phase (20 minutes) and irradiation phase (10 minutes).
Results
HPMC riboflavin group, total corneal densitometry at baseline was 12.89±1.25GSU and at 3 months 12.42±1.11GSU which was comparable with P=0.150.
In Vitamin E-TPGS group, the total anterior densitometry at baseline was 16.91±55GSU and at 3 months 16.07±0.93GSU with P=0.064. Total central ,posterior and total densitometry at baseline was (11.16±0.98GSU, 9.98±0.93GSU and 12.68±1.07GSU) respectively and at 3 months it was (10.44±0.80GSU, 9.39±0.82GSU and 11.98±0.74GSU ) with P values =0.025 , 0.029 and 0.037, respectively which was significant.
However there was no significant difference in cell density at 3 months between the two groups( 2582.90±206.09 cells/mm² )with P = 0.466.
Conclusions
Vitamin E group shows lesser corneal densitometry changes as compared to HPMC Riboflavin group. Corneal densitometry changes may be reflective of haze formation in the cornea. Vitamin E TPGS has been demonstrated in earlier studies to exert a protective role on biological membranes against reactive oxygen species. Hence , it provides photoprotection against UVA and free radicals generated during the photo-induced process of CXL.