Comparative evaluation of oculometric variables in graves' ophthalmopathy

ABSTRACT

OBJECTIVES: To estimate oculometric parameters of Graves' ophthalmopathy in comparison to healthy eyes using digital photography and digital image analysis. INTRODUCTION: Graves' ophthalmopathy is the main cause of eye proptosis. Because these protrusions cause clinically perceived distortions in orbital architecture, digital photographs can be used to detect and quantify these changes. METHODS: We carried out a cross-sectional study comprising 12 healthy volunteers and 15 Graves' ophthalmopathy patients with the purpose of evaluating the use of simple, non-invasive digital photography to estimate oculometric parameters of Graves' ophthalmopathy and compare them with the parameters of unaffected eyes. Facial photographs of cases and controls were taken in a standardized manner. Oculometric parameters were compared between the groups and then correlated to proptometer measures. RESULTS: All estimated oculometric variables showed significant differences between the groups, in particular with regard to mediopupilar aperture, lateral height, distance from the iris edge to the lateral boundary of the palpebral fissure, and distance from the higher point of the iris to the lateral limit of the palpebral fissure. The product of medial aperture and horizontal palpebral fissure also revealed greater discrepancy between the groups. Proptometer measures showed significant linear correlation between the distance from the iris edge to the lateral boundary of the palpebral fissure and between the distance from the higher point of the iris to the lateral limit of palpebral fissure (p<0.05). CONCLUSIONS: Comparative analysis of oculometric parameters in Graves' ophthalmopathy suggests that eye proptosis is related to an asymmetric increase in lateral oculometric measures. Standardized digital photographs can be used in clinical practice to objectively estimate oculometric parameters of Graves' ophthalmopathy patients.