Orbit Flashcards
What is thyrotoxicosis and its risk factors
- autoimmune disorder which presents in 30-40s
Risks:
- smoking
- female
- radioactive iodine used to treat hyperthryroidism
What are the clicical manifestations of TED
- soft tissue involvement
- lid retraction
- proptosis
- restrictive myopathy
- optic neuropathy
What are the two stages in the development of the disease
congestive
- inflammatory stage
Fibrotic
-Quiescent stage (inactive stage)
Symptoms of soft tissue involvement (TED)
- Grittiness
- photophobia
- lacrimation
- retrobulbar discomfort
Signs of soft tissue involvement (TED)
- epibulbar hyperaemia
- periorbital swelling
- superior limbic keratoconjunctivitis
- keratoconjunctivitis sicca (dry eyes)
Mangaement for soft tissue involvement (TED)
- lubircants for superior limbic conjunctivitis, corneal exposure and dryness
- head elevation with three pillow during sleep to reduce perioorbital oedema
- eyelid taping during sleep may alleviate mild exposure keratopathy
What are the signs of lid retraction (TED)
upper lid retraction- when lid margin is lvl with or above limbus, showing scerla
lower lid retraction- scerla shows below limbus
may occus in isolation. w proprtosis which exaggerates severity
What is the management for lid retraction (TED)
- mild lid retraction requires no treatment, improves spontaneously
- consider surgery for significant but stable lid retraction
What is proptosis (TED) and how to determine it
- Abnormal protrusion of the globe, detected by looking down at patient from above and behind
- measure using exophthalmometer/ frm lateral orbital margin w plastic ruler
What are the signs of proptosis
- is axial, uni/bilateral, a/symmetrical n freq. permanent
- sever proptosis may comprimise lid closure. W resultant exposure keratopathy, corneal ulceration and infection
What is the management of proptosis
- systemic steroids (maybe used in rapidly progressive and painful proptosis)
- radiotheraphy (maybe used in addition to steroids or when steroids are contraindicated/ ineffective)
- surgical 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)
What is restrivtive myopathy (TED) and its different type of defects
- ophthalmoplegia (paralysis of muscles within or surrounding the eye)
where ocular motility is restrited intially by inflammatory oedema, and later fibrosis
Ocular motility defects:
- elevation (freq)
- adduction (freq)
- abduction
- depression
What is the mangament for restrictive myopathy
- surgery if dilopia is present in primary/ reading position of gaze. If disease is quiescent n angle of deviation has been stable for at least 6 months
- If not, diplopia may be alleviated with prisms
- Botox injection into affect muslce may be useful in some cases
What is optic neuropathy (TED) caused by
compression of optic nerve or its blood supply at the orbital apex by congested and enlarged recti muscle
What could optic neuropathy (TED) lead to and what is its presentation with
- Severe permanent but preventable visual impairment
- presentation is with impairment of central vision
How to detect optic neuropathy (TED)
- Advise patients to self monitor visual function
- occulde each eye, read small print and asses the intensity of colours
What is the sign of optic neuropathy (TED)
- reduced visual acuity, with RAPD, colour desaturation, diminished light brightness appreciation
- visual field defects may be centeral or paracentral, maybe combined with nerve fibre bundle defects
- optic disc is usually normal, occasionally swollen
What is the mangament for optic neuropathy (TED)
refer for systemic steriods. Surgical decompression may be considered
Name the infections of the orbit
preseptal cellulitis
bacterial orbital cellulitis
What is preseptal cellulitis
An infection of subcutaneous tissues anterior to orbital septum
Occasionally rapid progression to orbital cellulitis may occur
What are the causes of preseptal cellulitis
- skin trauma from lacerations or insect bites
- spread of local infection such as acute horeolum or dacryocystitis
- from remote infection of upper respiratory tract or middle ear by haematogenous spread
What are the signs of preseptal cellulitis
- unilateral, tender, red periorbital oedema
- CT shows opacification anterior to orbital septum
what is the management for preseptal cellulitis
refer to opthalmologist for antibiotics therapy
What is bacterial orbital cellulitis
Life threatening infection of the soft tissues behind the orbital septum (more common in children)
What are the causes of bacterial orbital cellulitis
- Sinus related
- Extension of preseptal cellulitis
- Local spread
- Haematogenous spread
- Post- trauma
- Post- surgery
What are the signs and symptoms of bacterial orbital cellulitis
- rapid onset of severe malaise, fever, pain and visual impairment
- Unilateral, tender, warm, red periorbital and lid oedema
- Proptosis is often obscured by lid swelling
- painful opthalmoplegia (paralysis of EOM)
- optic nerve dysfunction
- CT scan shows opacification posterior to the orbital septum
What is the management of bacterial orbital cellulitis
- refer to the emergency department
- Hospital admission with otolaryngological assessment and frequent ophthalmic review is mandatory. (antibiotic therapy n monitoring of optic nerve function via every 4h test pupillary reactions, VA, colour vision and light brightness appreciation)
What is capillary haemangioma
Common tumour of the orbit and periorbital area in childhood
Girls affected more commonly
What are the signs of capillary haemangioma
- usually in first few months of life
- Unilateral, raised, red lesion
- typically blanches on pressure may swell with crying
- characterized by rapid growth 3-6 mths after diagnosis, followed by a slower phase of natural resolution
What is the managment of capillary haemangioma
- treatment is inficated principally for amblyopia secondary to induced astig, ansiometropia, occlusion, strabismus (eyes dont line up)
