At our clinic, management of active inflammation in TO depends on the grade and evidence of progression. If the grade is less than 4 out of 8, and there is no deterioration based on history or sequential clinical examination, we would manage conservatively with cool compresses, head elevation with sleeping, and nonsteroidal anti-inflammatories. In general, if the inflammatory grade is 5 or more, or if there is subjective or objective evidence of progression in the inflammation, we would offer more aggressive therapy, including oral or intravenous steroids, immunosuppressive agents, or radiotherapy.

Strabismus

The symptoms for strabismus include a progression from no diplopia, intermittent diplopia, diplopia with horizontal or vertical gaze, and diplopia in straight gaze.

Ocular ductions can be graded from 0 to 45 in three directions (abduction, adduction, and infraduction) using the Hirschberg principle (upgaze is usually measured from 0 to 30 ). The patient is asked to look as far as possible up, down, right, and left while the observer studies the light reflex on the surface of the eye. If the light reflex hits the edge of the pupil, the eye has moved 15 , between the pupil edge and the limbus, 30 , and at the limbus, 45 . These points can be used as grading points for research purposes or to quantify response to therapy.

Strabismus can be measured objectively by prism cover testing in different gaze directions.

Ancillary testing includes using the Goldmann perimeter to quantify ocular ductions in four directions (6).

Management of strabismus depends on whether the orbitopathy is actively inflamed (measured in the previous section) or with evidence of progression in symptoms and signs. If inflammation is present, this is managed first, either with conservative treatment or with anti-inflammatories or radiotherapy. During this stage, the strabismus can be managed with patching one eye or with Fresnel prisms. Once the inflammatory score has dropped to 0 and there is no evidence

of progression, management of strabismus might include prisms or surgical alignment with adjustable sutures.

Appearance=Exposure

Symptoms in this category include bulging of the eyes, eyelid retraction, and fat pockets in the lid, as well as exposure complaints of foreign body sensation, glare, dryness, or secondary tearing.

Objective measures of appearance change include lid retraction (measured in millimetres), proptosis (measured with the Hertel exophthalmometer), and documentation of redundant skin and fat prolapse. Measures of exposure include corneal staining or ulceration.

Photographs can document the appearance changes. Management of appearance and exposure changes

depend on the inflammatory stage of the disease. During the inflammatory phase, lubricant drops and ointments can relieve ocular irritation. Rarely a tarsorrhaphy or emergency orbital decompression may be required for severe exposure or corneal ulceration. Once the inflammatory phase has settled, management for proptosis might include orbital decompression and for eyelid retraction may include upper lid mu¨ llerectomy or lower lid elevation with spacer materials. These surgical measures often relieve many of the exposure complaints.

DISCUSSION

This classification system clusters the four functions disrupted by TO in a logical sequence for recording and management. Subjective input and reproducible objective measurements are recorded for each section and a global severity grade can be assigned for each function. The subjective and objective progress and tempo of disease can be documented to reflect disease activity. All of these factors meet the Working Group’s criteria for a classification system for thyroid orbitopathy. The layout of the form is designed to organize measurements to help in clinical management or for

research purposes. Although the forms store a lot of information, they may be completed in as much or little detail as the clinician chooses.

The sequence of the sections (V-I-S-A) reflects the order in which the problems should be managed. Vision dysfunction from optic neuropathy is the first priority, and depending on whether inflammation is present, might be treated with steroids, radiotherapy, and=or orbital decompression. Inflammation, graded by the inflammatory score (a derivative of Mourits et al.’s clinical activity score), is the next priority, and is treated with steroids, immunosuppressives, and=or radiotherapy. Strabismus and appearance changes are usually managed medically and expectantly until the signs of inflammation and disease activity have subsided. Once the inflammation has settled, strabismus can be managed with prisms or surgery while proptosis, lid retraction, and dermatochalasia can be managed surgically.

REFERENCES

1. Bartley GB. Evolution of classification systems for Graves’ ophthalmopathy. Ophthalmic Plastic Reconstr Surg 1995; 11:229–237.

2.Werner SC. Classification of the eye changes of Graves’ disease. Am J Ophthalmol 1969; 68:646–648.

3.Bahn RS, Gorman CA. Choice of therapy and criteria for assessing treatment outcome in thyroid-associated ophthalmopathy. Endocrinol Metab Clin North Am 1987; 16:391–407.

4.Mourits MP, Koorneef L, Wiersinga WM, et al. Clinical criteria for the assessment of disease activity in Graves’ ophthalmopathy: a novel approach. Br J Ophthalmol 1989; 73:639–644.

5.Pinchera A, Wiersinga W, Glinoer D, et al. Classification of eye changes of Graves’ disease. Thyroid 1992; 2:235–236.

6.Dolman P, Kendler D, Rootman J. Measuring ocular excursions in thyroid-related orbitopathy (Abst). International Congress of Ophthalmology, 1994.