ESCRS - FPM10.01 - Comparative Analysis Of Corneal Densitometry Post Standard Epithelium- Off, Contact Lens Assisted And Transepithelial Cross Linking Technique Using Scheimpflug Imaging.

Comparative Analysis Of Corneal Densitometry Post Standard Epithelium- Off, Contact Lens Assisted And Transepithelial Cross Linking Technique Using Scheimpflug Imaging.

Published 2022 - 40th Congress of the ESCRS

Reference: FPM10.01 | Type: Free paper | DOI: 10.82333/9ars-jc13

Authors: Barkha Gupta* 1 , Chintan Malhotra 1 , Arun Jain 2 , Amit Gupta 2 , Monika Balyan 2 , Khushdeep Abhyapal 1

1Ophthalmology,Advanced Eye Centre, Post Graduate Institute of Medical Education and Research,Chandigarh,India, 2Ophthalmology,Advanced Eye Centre, Post Graduate Institute of Medical education and Research,Chandigarh,India

Purpose

To evaluate changes in corneal backscattering after collagen cross linking (CXL) for progressive keratoconus and compare its course with different techniques- standard epithelium- off CXL, contact lens assisted (CACXL), and transepithelial (TECXL) using Scheimpflug based corneal densitometry imaging on Pentacam (Oculus Optikgerate GmbH, Wetzlar, Germany).

Setting

Cornea and Refractive Services of Advanced Eye Centre, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India

Methods

A retrospective study, included 94 eyes in the study (standard CXL: 47, CACXL: 30 and TECXL: 17). Corneal haze was quantified using Scheimpflug tomography in anterior 120 µm, posterior 60 µm and middle stromal layer in a 12‑mm‑diameter area around the corneal apex divided in four concentric annuli: 0-2mm, 2-6 mm, 6-10 mm, and 10-12 mm. The imaging was done pre and post CXL at 1 month, 3 months, 6 months, and 12 months.

Results

The baseline mean density score at central anterior stromal layer was 16.14 ± 7.07, 15.85 ± 7.89 and 15.89 ± 7.2 in standard CXL, CACXL and TECXL respectively (p 0.93). Post standard CXL, it increased to 28.83 and 31.34 at 1month and 3months respectively (p<0.001), dropped at 6months (28.66, p<0.001) and 12months (23.72, p 0.003). Post CACXL and TECXL only a small increase in densitometry value was noted at 3months (p 0.14) and 1month (p 0.17) respectively returning to baseline thereafter. All three procedures showed comparable efficacy with mean flattening in Kmax of 1.75 ± 1.99D, 1.35 ± 1.77D and 1.37 ± 1.87D post standard CXL, CACXL and TECXL respectively (p 0.64). No correlation of haze with visual acuity or topographic change was seen.

Conclusions

Mean Corneal haze increased significantly after standard CXL peaking at 3 months, declining over 6- 12 months, returning to baseline at 12 months. Contrastingly, post TECXL and CACXL there was only a slight increase in anterior corneal haze which returned to baseline within 3- 6 months. CXL associated haze did not correlate with post CXL outcomes- both topographic as well as visual.