RNFL Study in Graves Orbitopathy

Purpose:to determine changes of retinal nerve fiber layer (RNFL) in a group of patients with serious thyroid-related immune orbitopathy and compare it with a group of patients with moderate Graves orbitopathy.

Methods:in this study, 17 eyes of 9 patients with severe Graves orbitopathy (Group 1) and 12 eyes of 6 patients with moderate Graves orbitopathy (Group 2) underwent complete ocular examinations (visual acuity, tonometry, esoftalmometry, biomicroscopy)and underwent analysis of retinal nerve fiber layer with a polarimeter GDx VCC (Zeiss). During the ocular examination a equipe of endocrinologist determineted the disease’s activity.

Results:in patients with a severe Graves orbitopathy was detected a mean reduction of retinal nerve fiber layer (Group 1). In contrast in patients with a moderate Graves orbitopathy was not individuated a significant reduction of RNFL. These results was not correlated with an intraocular pressure elevate. Besides in a group 1 patient was detected an alteration of RNFL representation during orbitopathy inflammation. This variation was reduced when was resolved this inflammation.

Conclusions:in patients with a severe Graves orbitopathy (Group 1) was observed a statistically significant RNFL reduction. This alteration was not associated with an IOP elevated. These datas showed a likely vascular cause of progressive retinal nerve fiber layer reduction. We suspected a reduction of vascular contribution in optical nerve head caused by a connective tissues increase. In patients with a moderate Graves orbitopathy (Group 2) was not observed a statistically reduction of RNFL, besides in these patients was not individuated an inflammation condition and a connective tissues increase.