Pterygium pathology: a prospective case-control study on tear film cytokines

Session Details

Session Title: Ocular Surface & Quality of Vision

Session Date/Time: Monday 24/09/2018 | 14:00-16:00

Paper Time: 14:30

Venue: Room A3, Podium 1

First Author: : M.Haagdorens BELGIUM

Co Author(s): :    S. Van Acker   J. Rozema   T. Possemiers   C. Koppen   V. De Groot   M. Tassignon     

Abstract Details

Purpose:

To investigate interleukin (IL)-6, IL-8 and vascular endothelial growth factor (VEGF) levels in the tear film as potential biomarkers in pterygium.

Setting:

Faculty of Medicine and Health Sciences: Dept of Ophthalmology, visual optics and visual rehabilitation & Dept of Ophthalmology, Antwerp University Antwerp University Hospital, Belgium.

Methods:

Our study included 38 eyes of 19 patients (primary pterygium (PPt), n=15; recurrent pterygium (RPt), n=8; pinguecula, n=5; and unaffected contralateral eyes (PHC), n=10) and 37 eyes of 19 age- and gender-matched healthy controls (HC). Pterygia were graded according to the Johnston, Williams & Sheppard's classification. Ocular photographs and tear film samples were collected pre-operatively, at 2weeks, 3months and 1year post-operatively. Tear film levels of IL-6, IL-8 and VEGF were determined through cytometric bead array analysis. Overall vascularized area (%) and pterygium size (%) were calculated using matlab-based processing software and ImageJ, respectively. Surgically resected tissues were processed for immunohistochemistry.

Results:

Pre-operative tear samples from affected eyes (AE, PPt+RPt) show a mild increase in IL-6, IL-8 and VEGF levels compared to HC. Cytokine secretions in unilateral AE (PPt+RPt) peak 2-weeks post-surgery, followed by a normalization to match healthy baseline levels. However, subgroup analysis of AE shows significantly higher levels of VEGF in PHC compared to HC. A positive correlation was detected between (I) IL-6 and VEGF secretion and (II) the corneal vascularized area (%) and size of pterygium (%). Age, gender and lesion grade were non-confounding factors. On histology, resected pterygium display tumour-like characteristics including epithelial-to-mesenchymal transition and loss-of-polarity.

Conclusions:

There was no overall significant difference between the AE group and the healthy control group for the three cytokines measured. However, it might be more relevant to consider the individual patients' cytokine level shifts from baseline over time as markers of disease resolution and/or recurrence. Further research on larger patient groups are needed to draw major conclusions. Nevertheless, the histological characteristics of resected tissue support the possibility that pterygium is a neoplastic-like growth disorder.

Financial Disclosure:

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