Thyroid Eye Disease

(Graves’ ophthalmopathy)

05 November 2004

Autoimmune infiltrative ophthalmopathy associated with autoimmune thyroid disease such as Graves & Hashimotos thyroiditis.

RISK FACTORS

1.      Smoker

2.      HLA-DQA1*501

3.      Codon 52 of TSH receptor with threonine to proline

CLINICALLY

Occurs in 10–30 % of Graves disease (10% Graves ophthalmopathy are euthyroid)

85% have ophthalmopathy & Graves disease occurring within 18 mths of each other

Evidence of generalized hyperthyroidism

Hyperthyroid eyes: lid lag, stare & retraction

Ophthalmopathy:          diplopia (up & out earliest affected)

                                                Inferior, medial, superior then lateral rectus with tethering

                                    Proptosis & complications (chemosis, keratitis)

                                    Compressive optic neuropathy

Infiltrative dermopathy ie pretibial myxedema in 10% Graves’ ophthalmopathy

Myasthenia gravis 5% overlap (myasthenia normally proceeds Graves disease)

NOSPECS GRADING SYSTEM

0 No physical signs or symptoms

1 Only signs (upper lid retraction, stare & lid lag), no symptoms

2 Soft tissue involvement (symptoms & signs)

3 Proptosis

4 Extraocular muscle involvement

5 Corneal involvement

6 Sight loss (optic nerve involvement) 

INVESTIGATIONS

Thyroid:            TFT

                        Antibodies: thyroperoxidase (microsomal), thyroglobulin, LATS, 64 kDa

                        Nuclear med or ultrasound of thyroid

Eyes:                Imaging:            CT preferred choice

                                                MRI

                                                Ultrasound

                                                90% have radiologic involvement but only 10% clinical

                        Acuity

                        Fields

                        Color testing

                        Exophthalmometry

                        VEP

TREATMENT

1. THYROID

            Carbimazole, propylthiouracil, radioactive iodine, thyroidectomy.

2. OPHTHALMOPATHY

MILD DISEASE

Gritty eyes, pressure behind the eye, periorbital swelling

Elevation of bedhead

Eye protection: natural tears, protective cover, dark glasses, eyelid surgery

Diuretics

MODERATE DISEASE

            Ophthalmoplegia, more severe pressure effects but no optic neuropathy

As above

Prism correction for diplopia

Immunosuppression:     steroids general vs retrobulbar

                                    Azathioprine, cyclosporine, cyclophosphamide

Radiotherapy

Plasmapharesis

Surgery for extraocular muscles or eyelids

SEVERE DISEASE

            Visual compromise through optic neuropathy, keratitis

As above

Surgery: 2 wall procedure for decompression

                        Orbital floor & medial orbital wall