OCULAR OCULAR MANIFESTATIONS OF MANIFESTATIONS OF THYROID DISEASETHYROID DISEASE

Graves ophthalmopathyGraves ophthalmopathy

Other names: thyroid eye disease, thyroid Other names: thyroid eye disease, thyroid orbitopathyorbitopathy

Autoimmune inflammatory disorder whose Autoimmune inflammatory disorder whose underlying cause continues to be elucidatedunderlying cause continues to be elucidated

Signs and symptoms may progress and Signs and symptoms may progress and abate independently of other clinical featuresabate independently of other clinical features

Eye findings may occur even in the absence Eye findings may occur even in the absence of objective evidence of thyroid dysfunction of objective evidence of thyroid dysfunction (euthyroid Graves disease)(euthyroid Graves disease)

Graves ophthalmopathyGraves ophthalmopathy

o Ophthalmopathy may relate to Ophthalmopathy may relate to antibodies that cross-react with TSH-antibodies that cross-react with TSH-R antigens expressed on orbital R antigens expressed on orbital fibroblastsfibroblasts

PATHOGENESIS:PATHOGENESIS:

Theories:Theories:Glycosaminoglycans expressed from Glycosaminoglycans expressed from

fibroblasts causes secondary water fibroblasts causes secondary water retention and therefore, retrobulbar retention and therefore, retrobulbar swellingswelling

TSH-R as the antigenTSH-R as the antigen

Fusiform enlargement of extraocular Fusiform enlargement of extraocular muscles; sparing of tendons muscles; sparing of tendons

Little enlargement of extraocular muscles but Little enlargement of extraocular muscles but marked increased in the orbital fat may occur.marked increased in the orbital fat may occur.

Diagnostic criteria for Graves Diagnostic criteria for Graves ophthalmopathyophthalmopathy

Key points about Grave’s Key points about Grave’s disease:disease:

Most common cause of eyelid retractionMost common cause of eyelid retraction

Most common cause of bilateral or unilateral Most common cause of bilateral or unilateral proptosis.proptosis.

More common in womenMore common in women

Associated with hyperthyroidism in 90% of patients; Associated with hyperthyroidism in 90% of patients; 6% are euthyroid6% are euthyroid

Smoking is associated with increased risk and severity Smoking is associated with increased risk and severity of ophthalmopathy.of ophthalmopathy.

The course of ophthalmopathy does not necessarily The course of ophthalmopathy does not necessarily parallel the activity of the thyroid gland or the parallel the activity of the thyroid gland or the treatment of thyroid abnormalities.treatment of thyroid abnormalities.

Grave’s disease/Thyroid Grave’s disease/Thyroid OphthalmopathyOphthalmopathy

Clinical signsClinical signs Eyelid retraction- Eyelid retraction-

most common signmost common sign Lid lagLid lag ProptosisProptosis Restrictive Restrictive

extraocular extraocular myopathymyopathy

Optic neuropathyOptic neuropathy

Other clinical features:Other clinical features:

Most frequent ocular symptom is Most frequent ocular symptom is pain or discomfort (30%)- often the pain or discomfort (30%)- often the result of dry eyesresult of dry eyes

Diplopia- 17%Diplopia- 17%Lacrimation/photophobia- 15-20%Lacrimation/photophobia- 15-20%Blurring of vision- 7.5%Blurring of vision- 7.5%

Non-ocular clinical findings:Non-ocular clinical findings:

Thyroid dermopathy- 4%Thyroid dermopathy- 4%Thryroid acropachy-1%Thryroid acropachy-1%Myasthenia gravis- 1%Myasthenia gravis- 1%

A. Bilateral proptosis and upper eyelid A. Bilateral proptosis and upper eyelid retractionretraction

B. Marked chemosis, eyelid swelling and B. Marked chemosis, eyelid swelling and increased proptosisincreased proptosis

• Bilateral lid retraction • No associated proptosis

• Bilateral lid retraction • Bilateral proptosis

• Lid lag in downgaze • Unilateral lid retraction • Unilateral proptosis

Soft tissue involvementPeriorbital and lid swelling

Chemosis

Conjunctival hyperaemia

Superior limbic keratoconjunctivitis

Proptosis

Treatment options • Systemic steroids • Radiotherapy • Surgical decompression

• Occurs in about 60% • Uninfluenced by treatment of hyperthyroidism

Axial and permanent in about 70% May be associated with choroidal folds

Optic neuropathy• Occurs in about 6% • Early defective colour vision • Usually normal disc appearance

Caused by optic nerve compression at orbital apex by enlarged recti

Often occurs in absence of significant proptosis

• Occurs in about 40% • Due to fibrotic contracture

Restrictive myopathy

Elevation defect - most common Abduction defect - less common

Depression defect -uncommon Adduction defect - rare

Treatment:Treatment:

Correction of thyroid function abnormality- Correction of thyroid function abnormality- Anti-thyroid drugsAnti-thyroid drugs Radio active iodineRadio active iodine thyroidectomythyroidectomy

Orbital decompression- to treat optic Orbital decompression- to treat optic neuropathy, orbital congestion, advanced neuropathy, orbital congestion, advanced proptosisproptosis

Topical ocular lubricantsTopical ocular lubricants Corticosteroid treatmentCorticosteroid treatment Orbital radiotherapy- targets lymphocytes?Orbital radiotherapy- targets lymphocytes?

Treatment and Prognosis:Treatment and Prognosis:

Self limiting, but….Self limiting, but…. may run an active course of may run an active course of

exacerbation and remissionsexacerbation and remissionsTherapy directed toward decreasing Therapy directed toward decreasing

orbital congestion and inflammation orbital congestion and inflammation or expanding the bony volumeor expanding the bony volume

Treatment and Prognosis:Treatment and Prognosis:

Often improves with establishment of Often improves with establishment of euthyroid state, but eye disease may euthyroid state, but eye disease may continue to progresscontinue to progress

Elective orbital decompression, Elective orbital decompression, strabismus surgery and eyelid strabismus surgery and eyelid retraction repair usually are not retraction repair usually are not considered until a ophthalmic signs considered until a ophthalmic signs have been stable for 6-9 months.have been stable for 6-9 months.