Correlation between Findings of Visual Field, Optical Coherence Tomography and Orbital Computerized Tomography in Thyroid Eye Disease with or without Dysthyroid Optic Neuropathy

Abstract

Purpose: The aim of this study is to evaluate the findings of optical coherence tomography, visual field and orbital computerized tomography in thyroid eye disease, correlate the findings with the clinical data for early detection and anticipation of dysthyroid optic neuropathy. Setting and Design: This is a comparative observational cross-sectional study that was conducted at the Outpatient Clinic of the Ophthalmology Department of Tanta University Hospital. Patients and Methods: This study was carried out on 30 eyes of patients with TED and 15 eyes of age-matched normal subjects.  Of the 30 eyes with thyroid associated orbitopathy (TAO) 15 eyes had DON (group 1: TED with DON) and 15 eyes didn’t have DON (group 2: TED without DON) and the third group included normal (control) age and gender-matched individuals. for each patient we used OCT for measurement of PRNFL thickness, VF and orbital CT for measurement of amount of proptosis in the three groups. Results: The mean PRNFL thickness was significantly lower in group (1) patients compared to group (2) (p-value = 0.004) and higher in group (1) compared to group (3) (p-value < 0.001) but no statistically significant difference between group (2) and group (3) (p-value = 0.551). Visual field MD was significantly lower in group (1) patients compared to group (2) (p-value = 0.002) and higher in group (1) compared to group (3) (p-value < 0.001) but no statistically significant difference between group (2) and group (3) (p-value = 0.777). Amount of proptosis was significantly higher in group (1) compared to group (2). (p value <0.001), and higher in group (1) compared to group (3). (p value<0.001) but not statistically significant between group (2) and group (3). (p value=0.265). Conclusion: Peri-papillary nerve fiber layer act as an auxiliary tool for the early diagnosis of DON, VF testing is considered as reliable indicator of DON. Amount of proptosis not correlated with severity of DON.