Abstract:Background: Thyroid-associated ophthalmopathy (TAO) is an autoimmune condition with an increase in the orbital volume and raised intraocular pressure (IOP). Subclinical retinal changes may be detected even before the clinical features of compressive optic neuropathy (CON) develop. Optical coherence tomography (OCT) is a non-invasive test to evaluate these retinal changes. Not many studies have been conducted to establish these subclinical changes.
Objectives: To assess the retinal nerve fiber layer thickness (RNFL), macula and optic disc parameters of TAO patients obtained by OCT and compare it with those of age and sex- matched healthy subjects. To assess the IOP in TAO patients and compare it with the IOP of healthy controls.
Participants: 28 patients diagnosed with TAO and 28 age-sex matched healthy controls.
Methods: All the patients were subjected to detailed ophthalmic examination which includes Visual acuity, slit-lamp examination of anterior segment, IOP using Goldmann applanation tonometer, Hertel’s exophthalmometer for proptosis, dilated fundoscopy using 78D/90D; optic disc, macula and retinal nerve fiber layer measurements using OCT and Clinical Activity score (CAS) for TAO activity.
Results: IOP was higher in TAO group when compared to the controls and it was statistically significant. Analysis of data revealed a significant RNFL and macular thinning in all the quadrants for the TAO group when compared with the control group. Cup-Disc (C/D) ratio was more in TAO group but not statistically significant.
Conclusion: Significant retinal changes were noticed in TAO patients without CON which can be detected through OCT. It is essential to evaluate these subclinical retinal changes for active intervention and to prevent severe complications associated with the disease.
