Evaluation of Ocular Surface (Conjunctiva and Cornea) Characteristics in Patients with Thyroid Associated Ophthalmopathy

Abstract

Background: Thyroid associated ophthalmopathy (TAO) is one of the most common orbital inflammatory disorders also affecting ocular surface.  This study was planned to investigate the effect of severity of TAO on corneal hysteresis, and grades of squamous metaplasia.

Methods: This is a tertiary centre based observational study. 31 consecutive patients of TAO were enrolled. Grading of TAO done as per European Group of Graves’ Orbitopathy classification. Corneal hysteresis obtained on Ocular Response Analyser. Impression cytology samples obtained and evaluated for grades of squamous metaplasia.

Results: 71% patients had moderate grade TAO. Bimodal age distribution was noted. Average corneal hysteresis in mild and moderate grade TAO was 10.7 and 9.3 and average grading of squamous metaplasia in mild and moderate grade TAO was 1.8 and 2.3 respectively. The variance of corneal hysteresis and squamous cell metaplasia with severity of TAO was statistically significant. Furthermore, correlation between corneal hysteresis and intraocular pressure was also significant.

Conclusion: In this study we highlight the fact that severe grades of TAO are associated with lower values of CH, thus adversely affecting the biomechanical property of cornea. Further we reported that mild TAO patients had lesser grades of squamous metaplasia as compared with moderate TAO.