Eyeball position in Graves orbitopathy and its significance for eyelid surgery

Abstract

The goal of this article is to investigate the effect of Graves orbitopathy and orbital decompression on the position of the eyeball, and to relate this to a straight upper eyelid contour, observed in several patients after correction of upper eyelid retraction. The positions of the pupil center and the upper and lower eyelid margin were measured in relation to a reference line through the medial canthi, on slides obtained from 120 eyelids before and after correction of upper eyelid retraction, and on similar slides obtained from 90 control eyelids. In control subjects, the distance between the reference line and the pupil center was, on average, 4.5 mm (SD 1.2 mm). In decompressed patients, the pupil center was, on average, 2.2 mm lower (SD 1.3 mm), and in nondecompressed patients it was, on average 1.0 mm lower (SD 1.2 mm). A relatively straight upper eyelid contour after otherwise satisfactory correction of upper eyelid retraction was observed in 14 eyelids of 8 patients. All cases occurred in decompressed patients with a distance between the pupil center and the reference line of 2 mm or less. No significant difference was found in the position of the lateral canthal angle between the three groups. Many patients with Graves orbitopathy show a downward shift of the pupil center in relation to a reference line through the medial canthi. This is partially caused by orbital decompression, but also by other factors discussed by the authors. If the distance between this reference line and the pupil center is 2 mm or less, otherwise satisfactory correction of upper eyelid retraction may cause visible straightening of the upper eyelid contour.