Find if the retinal function is affected in both the nonsevere and the severe stage of Graves' ophthalmopathy (GO) by comparing the retinal oxygen saturation of GO patients with that of normal people.

Graves'ophthalmopathy (GO), also called thyroid-associated ophthalmopathy, is often mild and self-limiting, and probably declining in frequency, with only 3-5% of cases posing a threat to eyesight, remaining a pathogenetic enigma and a therapeutic dilemma. In its nonsevere expression, the symptoms and signs include Photophobia, Foreign body sensation, Eyelid retraction, increased intraocular pressure, Lagophthalmos, and Mild diplopia. In its severe expression, it is a disfiguring and invalidating disease with the optic nerve damaged. However, in this study, we want to find if the retinal vessels is affected in the early stage of the disease through observing the oxygen saturation of the retinal vessels and compare it with that of the normal people.

Inclusion Criteria for GO patients:

1. conforms to the diagnosis of Graves' ophthalmopathy;
2. age > 18;
3. volunteered to participate in this research, and sign the informed consent.

Inclusion Criteria for Control group:

1. age > 18;
2. diopter within + / - 3D;
3. volunteered to participate in this research, and sign the informed consent.

Exclusion Criteria for GO patients:

1. Fundus could not be seen clearly;
2. pregnant and lactating women;
3. could not tolerate the examination.

Exclusion Criteria for Control group:

1. with severe systemic disease and cause eye lesions;
2. have history of eye disease, ocular trauma and eye surgery impacting on visual function;
3. pregnant and lactating women;
4. could not tolerate the examination.

Controls- normal people; GO patients- patients with Graves' ophthalmopathy