The American Thyroid Association NO SPECS Classification of Eye Changes in Graves' Disease

Description

Dr S Werner proposed a formal classification system for orbital involvement in Graves' disease, which was approved by the American Thyroid Association (ATA), being published in 1969.

Acronym based on first letters of classes: NO SPECS

(1) Classes 0 and I (NO): "no threat"; Class I = formerly "mild" or "noninfiltrative"

(2) Classes II-VI (SPECS): "serious"; formerly "severe" or "infiltrative

Two forms presented:

(1) abridged

(2) detailed

Class	Abridged Definition
0	No signs or symptoms
I	Only signs, no symptoms
II	Soft tissue involvement (signs and symptoms)
III	Proptosis
IV	Extraocular muscle involvement
V	Corneal involvement (primarily due to lagophthalmos)
VI	Sight loss (due to optic nerve involvement)

The higher the class with positive findings, the more extensive the involvement. Each class usually includes involvements indicated in the preceding classes.

Signs:

(1) upper lid retraction

(2) stare

(3) with or without lid lag

(4) with or without proptosis

Symptoms for Classes 0 to II:

(1) excessive lacrimation

(2) sandy sensation

(3) retrobulbar discomfort

(4) photophobia

(5) no diplopia

Class I	Only Signs	Grade
absent	proptosis <= 20 mm	o
minimal	proptosis 21-23 mm	a
moderate	24-27 mm	b
marked	>= 28 mm	c

Class II	Soft Tissue Involvement	Grade
absent		o
minimal	edema of conjunctivae and lids, conjunctival injection, fullness of lids, often with orbital fat extrusion, palpable lacrimal glands, or swollen extraocular muscle palpable laterally beneath lower lids	a
moderate	minimal findings, plus chemosis, lagophthalmos, lid fullness	b
marked		c

Class III	Proptosis	Grade
absent	20 mm or less	o
minimal	21-23 mm	a
moderate	24-27 mm	b
marked	>= 28 mm	c

where:

• proptosis grades limited to Classes II to VI

• specify if inequality of 3 mm or more between eyes

• specify if progression of 3 mm or more under observation

Class IV	Extraocular Muscle Involvement	Grade
absent		o
minimal	limitation of motion, evident at extremes of gaze in one or more directions	a
moderate	evident restriction of motion without fixation of position	b
marked	fixation of position of a globe or globes	c

where:

• Class IV is usually associated with diplopia.

Class V	Corneal Involvement	Grade
absent		o
minimal	stippling of cornea	a
moderate	ulceration	b
marked	clouding, necrosis, perforation	c

Class VI	Sight Loss	Grade
absent		o
minimal	disc pallor or choking or visual field defect; vision 20/20 - 20/60	a
moderate	disc pallor or choking or visual field defect; vision 20/70 - 20/200	b
marked	blindness with failure to perceive light; vision < 20/200	c

Activity descriptors are applied once the class of involvement is determined:

(1) active

(2) static

(3) inactive

Limitations:

• A variety of modifications to the schema have been proposed over the years to address perceived shortcomings in classification.

• One need was the distinction between patients with active, progressive disease from those with inactive, unchanging disease.

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Description

Specialty

ICD-10