Official ESCRS | European Society of Cataract & Refractive Surgeons


Is pellucid marginal degeneration (PMD) a variant of keratoconus (KC)? A structural, molecular and biomechanical study

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Session Details

Session Title: Moderated Poster Session: Refractive Surgery: Can Results Improve Even Further?

Venue: Poster Village: Pod 2

First Author: : P.Paritekar INDIA

Co Author(s): :    A. Ghosh   A. Sinha Roy   P. Khamar   P. Patel              

Abstract Details


To study pellucid marginal degeneration structurally molecularly and biomechanically and differentiate it from keratoconus.


A tertiary eye care institute in Bangalore, India.


We studied 20 eyes of 10 PMD & 50 eyes of 25 KC patients. Differential Corvis ST measurements were taken superiorly, centrally and inferiorly. Epithelium was collected from the ectatic and surrounding non-ectatic area & analysed for gene expression. The collected tears underwent flow cytometry & cytometric bead array. Confocal microscopy was used the imaging tool to analyse stromal architecture.


. Confocal microscopy revealed a fibrotic component in the inferior ectatic area in PMD which was distinct from KC. Gene expression from the ectatic tissue & matched periphery showed Lysyl Oxidase(LOX) & collagen levels significantly higher in the ectatic area in PMD compared to the cone in KC. This was supported by the differences in biomechanics measured on Corvis ST.


This study divulged that PMD & KC are probably different entities in all aspects. This may have a huge impact on treatment planning & surgical outcomes.

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