THYROID EYE DISEASE
Classification of TED
Introduction
Thyrotoxicosis
• Thyrotoxicosis (hyperthyroidism) is a condition involving excessive secretion of thyroid hormones.• Graves disease, the most common subtype of hyperthyroidism, is an autoimmune disorder in which IgG antibodies bind to thyroid stimulating hormone (TSH) receptors in thyroid gland and stimulate secretion of thyroid hormones.
• It is more common in females and may be associated with other autoimmune disorders.
1. Presentation is in the 3–4th decades with weight loss despite good appetite, increased bowel frequency, sweating, heat intolerance, nervousness, irritability, palpitations, weakness and fatigue.
2. Signs
(a) External
• Diffuse thyroid enlargement, fine hand tremor, palmar erythema, and warm and sweaty skin.
• Finger clubbing and onycholysis (Plummer nails).
• Pretibial myxoedema is an infiltrative dermopathy characterized by raised plaques on the anterior aspect of the le extending on to the dorsum of the foot.
• Alopecia and vitiligo.
• Myopathic proximal muscle weakness but brisk tendon reflexes.
(b) Cardiovascular
• Sinus tachycardia, atrial fibrillation and premature ventricular beats.
• High output heart failure.
3. Investigations.
• Thyroid function tests include:
➢ serum T3, T4, TSH
➢ thyroxine binding globulin (TBG)
➢ thyroid-stimulating immunoglobulin (TSI).
4. Treatment options include:
4. Treatment options include:
➢ Carbimazole
➢ Propylthiouracil
➢ Propranolol
➢ radioactive iodine
➢ partial thyroidectomy.
Risk factors for ophthalmopathy
➢ Female sex (4-6 times more common than males)
Risk factors for ophthalmopathy
➢ Female sex (4-6 times more common than males)
➢ Smoking (risk is directly related to the number of cigarettes smoked per day)
➢ Middle age (most cases occur in middle age)
➢ Autoimmune thyroid disease
➢ HLA-DR3 and HLA-B8
• Once a patient has Graves disease, the major clinical risk factor for developing thyroid eye disease (TED) is smoking.
• The greater the number of cigarettes smoked per day, the greater the risk, and giving up smoking seems to reduce the risk.
• Women are five times more likely to be affected by TED than men, but this largely reflects the increased incidence of Graves disease in women.
• Radioactive iodine used to treat hyperthyroidism can worsen TED.
Pathogenesis of ophthalmopathy
➢ Thyroid eye disease is being considered as auto-immune disease with orbital fibroblasts as the
primary target of inflammatory attack & extraocular muscles being secondarily involved.
• Once a patient has Graves disease, the major clinical risk factor for developing thyroid eye disease (TED) is smoking.
• The greater the number of cigarettes smoked per day, the greater the risk, and giving up smoking seems to reduce the risk.
• Women are five times more likely to be affected by TED than men, but this largely reflects the increased incidence of Graves disease in women.
• Radioactive iodine used to treat hyperthyroidism can worsen TED.
Pathogenesis of ophthalmopathy
➢ Thyroid eye disease is being considered as auto-immune disease with orbital fibroblasts as the
primary target of inflammatory attack & extraocular muscles being secondarily involved.
➢ It is probable that the target antigen is shared between the thyroid follicular cells & the orbital
fibroblasts.
fibroblasts.
➢ The activated T-cells probably act on the fibroblast-adipocyte lineage within the orbit & stimulate
adipogenesis, fibroblast proliferation, and glycosaminoglycan synthesis.
adipogenesis, fibroblast proliferation, and glycosaminoglycan synthesis.
➢ As a consequence, the extraocular muscles are enlarged due to edema & infiltration with round cells.
➢ The orbital soft tissue shows increased amounts of acid mucopolysaccharide and infiltration with
lymphocytes, plasma cells, macrophages 7 mast cells.
• Thyroid ophthalmopathy involves an organ-specific autoimmune reaction in which a humoral agent (IgG antibody) produces the following changes:
1. Inflammation of extraocular muscles
• Characterized by pleomorphic cellular infiltration, associated with increased secretion of glycosaminoglycans and osmotic imbibition of water.
• The muscles become enlarged, sometimes up to eight times their normal size, and may compress the optic nerve.
• Subsequent degeneration of muscle fibres eventually leads to fibrosis, which exerts a tethering effect on the involved muscle, resulting in restrictive myopathy and diplopia.
2. Inflammatory cellular infiltration with lymphocytes, plasma cells, macrophages and mast cells of interstitial tissues, orbital fat and lacrimal glands with accumulation of glycosaminoglycans and retention of fluid.
• This causes an increase in the volume of orbital contents and secondary elevation of intraorbital pressure, which may itself cause further fluid retention within the orbit.
Clinical manifestations
lymphocytes, plasma cells, macrophages 7 mast cells.
• Thyroid ophthalmopathy involves an organ-specific autoimmune reaction in which a humoral agent (IgG antibody) produces the following changes:
1. Inflammation of extraocular muscles
• Characterized by pleomorphic cellular infiltration, associated with increased secretion of glycosaminoglycans and osmotic imbibition of water.
• The muscles become enlarged, sometimes up to eight times their normal size, and may compress the optic nerve.
• Subsequent degeneration of muscle fibres eventually leads to fibrosis, which exerts a tethering effect on the involved muscle, resulting in restrictive myopathy and diplopia.
2. Inflammatory cellular infiltration with lymphocytes, plasma cells, macrophages and mast cells of interstitial tissues, orbital fat and lacrimal glands with accumulation of glycosaminoglycans and retention of fluid.
• This causes an increase in the volume of orbital contents and secondary elevation of intraorbital pressure, which may itself cause further fluid retention within the orbit.
Clinical manifestations
Clinical features
1. Lid signs. These are:
2. Conjunctival signs.
- Retraction of the upper lids producing the characteristic staring and frightened appearance (Dalrymple’s sign)
- Lid lag (von Graefe’s sign) i.e., when globe is moved downward, the upper lid lags behind
- Fullness of eyelids due to puffy oedematous swelling (Enroth’s sign)
- Difficulty in eversion of upper lid (Gifford’s sign)
- Infrequent blinking (Stellwag’s sign).
2. Conjunctival signs.
- These include ‘deep injection’ and ‘chemosis’.
3. Pupillary signs.
- These are of less importance and may be evident as inequality of dilatation of pupils.
4. Ocular motility defects.
- These range from convergence weakness (Mobius’s sign) to partial or complete immobility of one or all of the extrinsic ocular muscles.
- The most common ocular motility defect is a unilateral elevator palsy caused by an involvement of the inferior rectus muscle followed by failure of abduction due to involvement of medial rectus muscle.
5. Exophthalmos.
- It is a common and classical sign of the disease.
- As a rule both eyes are symmetrically affected; but it is frequent to find one eye being more porminent than the other.
- Even unilateral proptosis is not uncommon. In majority of cases it is self-limiting.
6. Exposure keratitis and symptoms of ocular surface discomfort.
- These include sandy or gritty sensation, lacrimation and photophobia.
- Corneal exposure has been attributed to upper lid retraction, exophthalmos, lagophthalmos, inability to elevate the eyes and a decreased blink rate.
7. Optic neuropathy.
- It occurs due to direct compression of the nerve or its blood supply by the enlarged rectus muscles at the orbital apex.
- It may manifest as papilloedema or optic atrophy with associated slowly progressive impairment of vision.
The five main clinical manifestations of TED are:
(a) soft tissue involvement(b) lid retraction(c) proptosis(d) optic neuropathy(e) restrictive myopathy.
• There are two stages in the development of the disease:
1. Congestive (inflammatory) stage in which the eyes are red and painful. This tends to remit within 3
years and only 10% of patients develop serious long-term ocular problems.
years and only 10% of patients develop serious long-term ocular problems.
2. Fibrotic (quiescent) stage in which the eyes are white, although a painless motility defect may be
present.
• Grittiness
• Photophobia
• lacrimation
• retrobulbar discomfort.
2. Signs
• Epibulbar hyperaemia is a sensitive sign of inflammatory activity. Intense focal hyperaemia may outline the insertions of the horizontal recti.
• Periorbital swelling is caused by oedema and infiltration behind the orbital septum; this may be associated with chemosis and prolapse of retroseptal fat into the eyelids.
• Superior limbic keratoconjunctivitis (Fig. 3.7C).
3. Treatment
(a) Lubricants for superior limbic keratoconjunctivitis, corneal exposure and dryness.
present.
Soft tissue involvement
1. Symptoms include:• Grittiness
• Photophobia
• lacrimation
• retrobulbar discomfort.
2. Signs
• Epibulbar hyperaemia is a sensitive sign of inflammatory activity. Intense focal hyperaemia may outline the insertions of the horizontal recti.
• Periorbital swelling is caused by oedema and infiltration behind the orbital septum; this may be associated with chemosis and prolapse of retroseptal fat into the eyelids.
• Superior limbic keratoconjunctivitis (Fig. 3.7C).
3. Treatment
(a) Lubricants for superior limbic keratoconjunctivitis, corneal exposure and dryness.
(b) Topical anti-inflammatory agents (steroids, NSAIDs, ciclosporin) are advocated by some authorities.
(c) Head elevation with three pillows during sleep to reduce periorbital oedema.
(d) Eyelid taping during sleep may alleviate mild exposure keratopathy.
Lid retraction
PathogenesisRetraction of upper and lower lids occurs in about 50% of patients with Graves disease as a result of the following postulated mechanisms:
1. Fibrotic contracture of the levator associated with adhesions to the overlying orbital tissues causes
lid retraction which is worse on downgaze.
Fibrosis of the inferior rectus muscle may similarly induce retraction of the lower eyelid via its capsulopalpebral head.
2. Secondary overaction of the levator-superior rectus complex in response to hypotropia produced by fibrosis and tethering of the inferior rectus muscle, evidenced by increased lid retraction from downgaze to upgaze.
1. Fibrotic contracture of the levator associated with adhesions to the overlying orbital tissues causes
lid retraction which is worse on downgaze.
Fibrosis of the inferior rectus muscle may similarly induce retraction of the lower eyelid via its capsulopalpebral head.
2. Secondary overaction of the levator-superior rectus complex in response to hypotropia produced by fibrosis and tethering of the inferior rectus muscle, evidenced by increased lid retraction from downgaze to upgaze.
Retraction of the lower eyelid resulting from overaction of the inferior rectus may also occur secondary to fibrosis of the superior rectus muscle.
3. Humorally-induced overaction of Müller muscle as a result of sympathetic overstimulation
secondary to high levels of thyroid hormones.
Supporting this hypothesis is the observation that lid retraction may sometimes be lessened by a topical sympatholytic drug such as guanethidine; against it is the absence of associated pupillary biochemical dilatation and the fact that lid retraction may occur without hyperthyroidism.
Signs
3. Humorally-induced overaction of Müller muscle as a result of sympathetic overstimulation
secondary to high levels of thyroid hormones.
Supporting this hypothesis is the observation that lid retraction may sometimes be lessened by a topical sympatholytic drug such as guanethidine; against it is the absence of associated pupillary biochemical dilatation and the fact that lid retraction may occur without hyperthyroidism.
Signs
• The upper lid margin normally rests 2 mm below the limbus.
• Lid retraction is suspected when the margin is either level with or above the superior limbus, allowing sclera to be visible.
• Likewise, the lower eyelid normally rests at the inferior limbus; retraction is suspected when sclera shows below the limbus.
• Lid retraction may occur in isolation or in association with proptosis which exaggerates its severity.
1. Dalrymple sign is lid retraction in primary gaze.
• Lid retraction is suspected when the margin is either level with or above the superior limbus, allowing sclera to be visible.
• Likewise, the lower eyelid normally rests at the inferior limbus; retraction is suspected when sclera shows below the limbus.
• Lid retraction may occur in isolation or in association with proptosis which exaggerates its severity.
1. Dalrymple sign is lid retraction in primary gaze.
2. Kocher sign describes a staring and frightened appearance of the eyes which is particularly marked on attentive fixation.
3. Von Graefe sign signifies retarded descent of the upper lid on downgaze.
Management
• Mild lid retraction does not require treatment because it frequently improves spontaneously.
• Control of hyperthyroidism may also be beneficial. Surgery to decrease the vertical dimensions of the palpebral fissures may be considered in patients with significant but stable lid retraction, but only after addressing proptosis and strabismus.
• In general, therefore the sequence of surgical procedures in TED is:
Management
• Mild lid retraction does not require treatment because it frequently improves spontaneously.
• Control of hyperthyroidism may also be beneficial. Surgery to decrease the vertical dimensions of the palpebral fissures may be considered in patients with significant but stable lid retraction, but only after addressing proptosis and strabismus.
• In general, therefore the sequence of surgical procedures in TED is:
(a) Orbital
(b) Strabismus
(c) Eyelid.
• The rationale for this sequence is that orbital decompression may affect both ocular motility and eyelid position, and extraocular muscle surgery may also influence eyelid position.
• The main surgical procedures for lid retraction are:
1. Müllerotomy (disinsertion of Müller muscle) for mild lid retraction. More severe cases may also
require recession/disinsertion of the levator aponeurosis and the suspensory ligament of the superior conjunctival fornix.
2. Recession of the lower lid retractors, with or without a hard palate graft, when retraction of the
lower lid is 2 mm or more.
3. Botulinum toxin injection aimed at the levator aponeurosis and Müller muscle may be used as a
temporary measure in patients awaiting definitive correction.
• The rationale for this sequence is that orbital decompression may affect both ocular motility and eyelid position, and extraocular muscle surgery may also influence eyelid position.
• The main surgical procedures for lid retraction are:
1. Müllerotomy (disinsertion of Müller muscle) for mild lid retraction. More severe cases may also
require recession/disinsertion of the levator aponeurosis and the suspensory ligament of the superior conjunctival fornix.
2. Recession of the lower lid retractors, with or without a hard palate graft, when retraction of the
lower lid is 2 mm or more.
3. Botulinum toxin injection aimed at the levator aponeurosis and Müller muscle may be used as a
temporary measure in patients awaiting definitive correction.
Proptosis
Signs• Proptosis is axial, unilateral or bilateral, symmetrical or asymmetrical, and frequently permanent.
• Severe proptosis may compromise lid closure with resultant exposure keratopathy, corneal ulceration and infection.
Management
• Management is controversial. Some favour early surgical decompression whereas others consider surgery only when non-invasive methods have failed or are inappropriate.
• Severe proptosis may compromise lid closure with resultant exposure keratopathy, corneal ulceration and infection.
Management
• Management is controversial. Some favour early surgical decompression whereas others consider surgery only when non-invasive methods have failed or are inappropriate.
1. Systemic steroids may be used in rapidly progressive and painful proptosis during the congestive phase, unless contraindicated (e.g. tuberculosis or peptic ulceration).
Oral prednisolone
• 60–80 mg/day is given initially.
• Reduction in discomfort, chemosis and periorbital oedema usually occurs within 48 hours, at which point, the dose should be tapered.
• Maximal response is usually achieved within 2–8 weeks.
• Ideally steroid therapy should be discontinued after about 3 months, although long-term low-dose maintenance may be necessary.
Intravenous methylprednisolone
(e.g. 0.5 g in 200–500 mL isotonic saline given over 30 minutes), which may be repeated after 48 hours, is usually reserved for acute compressive optic neuropathy, because of potential cardiovascular risks which mandate careful supervision by a physician.
2. Radiotherapy may be used in addition to steroids or when steroids are contraindicated or ineffective. A positive response is usually evident within 6 weeks, with maximal improvement by 4 months.
3. Combined therapy with irradiation, azathioprine and low-dose prednisolone may be more effective
than steroids or radiotherapy alone. Monoclonal antibody treatment with rituximab also shows very good results.
4. Surgical decompression
• It may be considered either as the primary treatment or when non-invasive methods are ineffective, such as for cosmetically unacceptable proptosis in the quiescent phase.
• Decompression aims to increase the volume of the orbit by removing the bony walls and may be combined with removal of orbital fat to increase the retroplacement of the globe.
• One-wall (deep lateral) decompression is effective (approximately 4–5 mm reduction in proptosis) and may reduce the risk of postoperative diplopia.
• Two-wall (balanced medial and lateral) decompression provides a greater effect but with a significant risk of inducing diplopia.
• Three-wall decompression includes the floor with a reduction in proptosis of 6–10 mm but may lead to hypoglobus and has a higher risk of infraorbital nerve damage and diplopia.
• Very severe proptosis may require additional removal of part of the orbital roof (four-wall decompression).
• Most surgery is undertaken via an external approach though the medial wall and the medial part of the floor can be reached endoscopically.
• 60–80 mg/day is given initially.
• Reduction in discomfort, chemosis and periorbital oedema usually occurs within 48 hours, at which point, the dose should be tapered.
• Maximal response is usually achieved within 2–8 weeks.
• Ideally steroid therapy should be discontinued after about 3 months, although long-term low-dose maintenance may be necessary.
Intravenous methylprednisolone
(e.g. 0.5 g in 200–500 mL isotonic saline given over 30 minutes), which may be repeated after 48 hours, is usually reserved for acute compressive optic neuropathy, because of potential cardiovascular risks which mandate careful supervision by a physician.
2. Radiotherapy may be used in addition to steroids or when steroids are contraindicated or ineffective. A positive response is usually evident within 6 weeks, with maximal improvement by 4 months.
3. Combined therapy with irradiation, azathioprine and low-dose prednisolone may be more effective
than steroids or radiotherapy alone. Monoclonal antibody treatment with rituximab also shows very good results.
4. Surgical decompression
• It may be considered either as the primary treatment or when non-invasive methods are ineffective, such as for cosmetically unacceptable proptosis in the quiescent phase.
• Decompression aims to increase the volume of the orbit by removing the bony walls and may be combined with removal of orbital fat to increase the retroplacement of the globe.
• One-wall (deep lateral) decompression is effective (approximately 4–5 mm reduction in proptosis) and may reduce the risk of postoperative diplopia.
• Two-wall (balanced medial and lateral) decompression provides a greater effect but with a significant risk of inducing diplopia.
• Three-wall decompression includes the floor with a reduction in proptosis of 6–10 mm but may lead to hypoglobus and has a higher risk of infraorbital nerve damage and diplopia.
• Very severe proptosis may require additional removal of part of the orbital roof (four-wall decompression).
• Most surgery is undertaken via an external approach though the medial wall and the medial part of the floor can be reached endoscopically.
Restrictive myopathy
Diagnosis• Between 30% and 50% of patients with TED develop ophthalmoplegia and this may be permanent.
• Ocular motility is restricted initially by inflammatory oedema and later by fibrosis. Intraocular pressure may increase in upgaze due to ocular compression by a fibrotic inferior rectus.
• In order of frequency the four ocular motility defects are:
1. Elevation defect caused by fibrotic contracture of the inferior rectus, which may mimic superior rectus palsy.
2. Abduction defect due to fibrosis of the medial rectus, which may simulate 6th nerve palsy.
3. Depression defect secondary to fibrosis of the superior rectus.
4. Adduction defect caused by fibrosis of the lateral rectus.
Treatment
1. Surgery
(a) Indication is diplopia in the primary or reading positions of gaze, provided the disease is quiescent and the angle of deviation has been stable for at least 6 months. Until these criteria are met diplopia may be alleviated, if possible, with prisms.
(b) Goal is to achieve binocular single vision in the primary and reading positions. Restrictive myopathy, which causes incomitant strabismus, often precludes binocularity in all positions of gaze. However, with time the field of binocular single vision may enlarge as a result of increasing vergences.
(c) Technique most commonly involves recession of the inferior and/or medial recti, using adjustable sutures for best results.
• The suture is adjusted later the same day or on the first postoperative day to achieve optimal alignment, and the patient is encouraged to practise achieving single vision with a distant target such as a television.
• It should be emphasized that a rectus muscle is never resected, only recessed in TED.
2. Botulinum toxin injection into the involved muscle may be useful in selected cases.
Treatment
1. Surgery
(a) Indication is diplopia in the primary or reading positions of gaze, provided the disease is quiescent and the angle of deviation has been stable for at least 6 months. Until these criteria are met diplopia may be alleviated, if possible, with prisms.
(b) Goal is to achieve binocular single vision in the primary and reading positions. Restrictive myopathy, which causes incomitant strabismus, often precludes binocularity in all positions of gaze. However, with time the field of binocular single vision may enlarge as a result of increasing vergences.
(c) Technique most commonly involves recession of the inferior and/or medial recti, using adjustable sutures for best results.
• The suture is adjusted later the same day or on the first postoperative day to achieve optimal alignment, and the patient is encouraged to practise achieving single vision with a distant target such as a television.
• It should be emphasized that a rectus muscle is never resected, only recessed in TED.
2. Botulinum toxin injection into the involved muscle may be useful in selected cases.
Optic neuropathy
• Optic neuropathy is an uncommon but serious complication caused by compression of the optic nerve or its blood supply at the orbital apex by the congested and enlarged recti.• Such compression, which may occur in the absence of significant proptosis, may lead to severe but preventable visual impairment.
Diagnosis
1. Presentation is with impairment of central vision. In order to detect early involvement, patients
should be advised to monitor their own visual function by alternatively occluding each eye, reading small print and assessing the intensity of colours, for example, on a television screen.
2. Signs
• Visual acuity is usually reduced, but not invariably, and is associated with a relative afferent pupillary defect, colour desaturation and diminished light brightness appreciation.
• It is important not to attribute disproportionate visual loss to minor corneal complications and miss optic neuropathy.
• Visual field defects may be central or paracentral and may be combined with nerve fibre bundle defects.
• These findings, combined with elevated intraocular pressure, may be confused with primary open- angle glaucoma.
• The optic disc is usually normal, occasionally swollen and rarely atrophic.
Treatment
• Initial treatment is usually with systemic steroids.
• Orbital decompression may be considered if steroids are ineffective or inappropriate.
Classification
American Thyroid Association (ATA) has classified Graves’ ophthalmopathy, irrespective of the hormonal status into following classes, characterised by the acronym ‘NOSPECS’.
Class 0 N: No signs and symptoms.
Class 1 O: Only signs, no symptoms (signs are limited to lid retraction, with or without lid lag and mild proptosis).
Class 2 S: Soft tissue involvement with signs (as described in Class-1) and symptoms including lacrimation, photophobia, lid or conjunctival swelling.
Class 3 P: Proptosis is well established.
Class 4 E: Extraocular muscle involvement
(limitation of movement and diplopia).
Class 5 C: Corneal involvement
(exposure keratitis).
Class 6 S: Sight loss due to optic nerve involvement with disc pallor or papilloedema and visual field defects.
• For practical purposes it has been described as:
Class 5 C: Corneal involvement
(exposure keratitis).
Class 6 S: Sight loss due to optic nerve involvement with disc pallor or papilloedema and visual field defects.
• For practical purposes it has been described as:
1. ‘Early’ (which include ATA Class 1 & 2) and
2. ‘Late Graves’ ophthalmopathy’ (Class 3 to 6).
Clinical course
• Thyroid eye disease (TED) is a self limiting disease that lasts from 1-5 years (longer in smokers as compared to non-smokers).
• Its clinical course is divided into 3 phases:
1. Active phase of increasing severity is characterized by active inflammation with marked lid edema,
conjunctival chemosis & congestion & increasing exophthalmos.
2. Regression phase is of declining severity in which all of the above signs slowly settles down.
3. Inactive plateau phase also known as quiescent burnt-out phase, ensues after regression phase.
• Reactivation of inflammation occurs in approximately 5-10% of patients over their lifetime.
• Rundles’s curve refers to the time course of the above phases can be plotted graphically for each patient.
• Based on this the patients can be broadly categorized in:
Clinical course
• Thyroid eye disease (TED) is a self limiting disease that lasts from 1-5 years (longer in smokers as compared to non-smokers).
• Its clinical course is divided into 3 phases:
1. Active phase of increasing severity is characterized by active inflammation with marked lid edema,
conjunctival chemosis & congestion & increasing exophthalmos.
2. Regression phase is of declining severity in which all of the above signs slowly settles down.
3. Inactive plateau phase also known as quiescent burnt-out phase, ensues after regression phase.
• Reactivation of inflammation occurs in approximately 5-10% of patients over their lifetime.
• Rundles’s curve refers to the time course of the above phases can be plotted graphically for each patient.
• Based on this the patients can be broadly categorized in:
(a) Mild
(b) Moderate
(c) Marked
(d) Severe disease
Differential diagnosis
• Clinical diagnosis is not difficult in advanced cases of Graves’ ophthalmopathy with bilateral proptosis.
• However, early cases having unilateral proptosis need to be differentiated from other causes of unilateral proptosis of adulthood onset.
Investigations
1. Thyroid function tests. These should include:
Differential diagnosis
• Clinical diagnosis is not difficult in advanced cases of Graves’ ophthalmopathy with bilateral proptosis.
• However, early cases having unilateral proptosis need to be differentiated from other causes of unilateral proptosis of adulthood onset.
Investigations
1. Thyroid function tests. These should include:
• serum T3, T4, TSH
• estimation of radioactive iodine uptake.
2. Positional tonometry. An increase in intra-ocular pressure in upgaze helps in diagnosis of
subclinical cases.
3. Ultrasonography. It can detect changes in extraocular muscles even in class 0 and class 1 cases and
thus helps in early diagnosis. In addition to the increase in muscle thickness, erosion of temporal wall of orbit, accentuation of retrobulbar fat and perineural inflammation of optic nerve can also be demonstrated in some early cases.
4. Computerised tomographic scanning. It may show proptosis, muscle thickness, thickening of optic nerve and anterior prolapse of the orbital septum (due to excessive orbital fat and/or muscle swelling).
5. MRI (T2-weighted & STIR) gives better soft tissue resolution & identifies active disease.
6. Orthoptic work-up may include field of binocular single vision, field of uniocular fixation and
Hess/Lee charting.
Treatment
(A) Non-surgical management
1. Smoking cessation should be insisted with the patients as it may markedly influence the course
of disease.
• estimation of radioactive iodine uptake.
2. Positional tonometry. An increase in intra-ocular pressure in upgaze helps in diagnosis of
subclinical cases.
3. Ultrasonography. It can detect changes in extraocular muscles even in class 0 and class 1 cases and
thus helps in early diagnosis. In addition to the increase in muscle thickness, erosion of temporal wall of orbit, accentuation of retrobulbar fat and perineural inflammation of optic nerve can also be demonstrated in some early cases.
4. Computerised tomographic scanning. It may show proptosis, muscle thickness, thickening of optic nerve and anterior prolapse of the orbital septum (due to excessive orbital fat and/or muscle swelling).
5. MRI (T2-weighted & STIR) gives better soft tissue resolution & identifies active disease.
6. Orthoptic work-up may include field of binocular single vision, field of uniocular fixation and
Hess/Lee charting.
Treatment
(A) Non-surgical management
1. Smoking cessation should be insisted with the patients as it may markedly influence the course
of disease.
2. Head elevation at night & cold compresses in the morning help in reducing periorbital edema.
3. Topical artificial tear drops in the day time and ointment at bed time are useful for relief of
foreign body sensation and other symptoms of ocular surface drying.
foreign body sensation and other symptoms of ocular surface drying.
4. Eyelid taping at night prevents complication of exposure.
5. Guanethidine 5% eyedrops may decrease the lid retraction caused by overaction of Muller’s
muscle.
muscle.
6. Prisms may be prescribed to alleviate annoying diplopia till the quiescent phase is reached.
7. Systemic steroids may be indicated in acutely inflamed orbit with rapidly progressive chemosis
and proptosis with or without optic neuropathy.
and proptosis with or without optic neuropathy.
8. Radiotherapy (2000 rads given over 10 days period). It may help in reducing orbital oedema in patients where steroids are contraindicated.
9. Combined therapy with low dose steroids, azathioprine & irradiation is reported to be more
effective than steroids or radiotherapy alone.
(B) Surgical management
• During active phase, orbital decompression may be required for an acutely progressive optic neuropathy &/or exposure keratitis, in patients who do not respond to energetic steroid therapy.
• During quiescent burnt-out phase the surgical management is required to improve function & cosmesis.
• A stepwise surgical approach, starting with orbital decompression (if required to restore normal globe position) followed by extraocular muscle surgery (for diplopia if still persisting) followed by eyelid surgery is recommended. Alteration of this sequence may lead to unpredictable results.
1. Orbital decompression may be carried out by an external or endoscopic approach & may
involve 2,3 or 4 walls:
• Two wall decompression in which part of the orbital floor and medial wall are removed, allows 3-6 mm of replacement of the globe.
• Three wall decompression involves removal of parts of the floor, medial wall & lateral wall & allows about 6-10 mm of retroplacement of the globe.
• Four wall decompression involves removal of lateral half of roof & large portion of sphenoid at the apex, in addition to three-wall removal as above. This allows 10-16 mm of retroplacement of the globe & is indicated very rarely in patients with severe proptosis.
2. Extraocular muscle surgery should always be carried out after the orbital decompression, since
the latter may alter extraocular motility. Extraocular muscle surgery is required to achieve binocular single vision in the primary gaze & reading position.
3. Eyelid surgery when required, should be undertaken last, as the extraocular muscle surgery may affect eyelid retraction. As temporary measures, before the definitive surgical correction, the botulinum toxin injection aimed at Muller’s muscle & LPS muscle may be used, if so desired by the patient. Eyelid surgery for definitive correction may include:
• Mullerotomy i.e. disinsertion of Muller’s muscle is required for mild lid retraction.
• Levator recession/disinsertion may be required for moderate to severe upper eye lid retraction.
• Scleral grafts with LPS recession may be required in very severe cases.
• Recession of lower eyelid retractors may be required to correct more than 2mm retraction of lower eyelid.
• Blepharoplasty. It may be performed by removal of excess fatty tissue and redundant skin from around the eyelids.
effective than steroids or radiotherapy alone.
(B) Surgical management
• During active phase, orbital decompression may be required for an acutely progressive optic neuropathy &/or exposure keratitis, in patients who do not respond to energetic steroid therapy.
• During quiescent burnt-out phase the surgical management is required to improve function & cosmesis.
• A stepwise surgical approach, starting with orbital decompression (if required to restore normal globe position) followed by extraocular muscle surgery (for diplopia if still persisting) followed by eyelid surgery is recommended. Alteration of this sequence may lead to unpredictable results.
1. Orbital decompression may be carried out by an external or endoscopic approach & may
involve 2,3 or 4 walls:
• Two wall decompression in which part of the orbital floor and medial wall are removed, allows 3-6 mm of replacement of the globe.
• Three wall decompression involves removal of parts of the floor, medial wall & lateral wall & allows about 6-10 mm of retroplacement of the globe.
• Four wall decompression involves removal of lateral half of roof & large portion of sphenoid at the apex, in addition to three-wall removal as above. This allows 10-16 mm of retroplacement of the globe & is indicated very rarely in patients with severe proptosis.
2. Extraocular muscle surgery should always be carried out after the orbital decompression, since
the latter may alter extraocular motility. Extraocular muscle surgery is required to achieve binocular single vision in the primary gaze & reading position.
3. Eyelid surgery when required, should be undertaken last, as the extraocular muscle surgery may affect eyelid retraction. As temporary measures, before the definitive surgical correction, the botulinum toxin injection aimed at Muller’s muscle & LPS muscle may be used, if so desired by the patient. Eyelid surgery for definitive correction may include:
• Mullerotomy i.e. disinsertion of Muller’s muscle is required for mild lid retraction.
• Levator recession/disinsertion may be required for moderate to severe upper eye lid retraction.
• Scleral grafts with LPS recession may be required in very severe cases.
• Recession of lower eyelid retractors may be required to correct more than 2mm retraction of lower eyelid.
• Blepharoplasty. It may be performed by removal of excess fatty tissue and redundant skin from around the eyelids.
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