Corneal Involvement in Graves Ophthalmopathy: An in vivo Confocal Study

Abstract

Purpose: : To study clinical signs and symptoms of the ocular surface as well as the in vivo morphology of corneal cells and nerves in patients affected by active or inactive Graves Ophthalmopathy (GO).

Methods: : Twentysix consecutive patients with GO and 20 age- and gender- matched healthy control subjects were studied. GO was diagnosed according to the European Group On Graves’ Orbitopathy criteria and the disease activity was evaluated by the Clinical Activity Score (CAS). Each partecipant underwent a full eye exam including evaluation of symptoms (Ocular Surface Disease Index), tear break-up time, fluorescein and lissamine green staining, corneal apex sensitivity and Schirmer test. Confocal microscopy examination (Confoscan 3.0; Nidek Technologies, Vigonza, Italia) was performed at corneal apex to investigate epithelial and stromal corneal cells and sub-basal nerves number and morphology.

Results: : 43% of the patients (11/26) resulted to have an active GO. Statistically significant differences (ANOVA - LSD post hoc test) were found between GO patients and control subjects considering all the parameters evaluated, corneal sensitivity and nerves reflectivity excluded.Considering GO patients, only the number of hyper-reflective (activated) keratocytes showed a significant difference between active and inactive disease (P<0.001; ANOVA - LSD post hoc test). Corneal sensitivity showed an inverse correlation with proptosis (P<0.001, Spearman).

Conclusions: : GO patients show clinical and confocal corneal alterations. They present signs and symptoms partially related to dry eye disease. The ocular surface inflammation in GO seems to be claimed both to the dry eye and the autoimmune ophthalmopathy itself.

Keywords: cornea: tears/tear film/dry eye • inflammation • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)