8. Lid, Orbit and Trauma Flashcards
Describe the structure of the skin of the eyelids?
Skin
Epidermis
Skin appendages
a. Sebaceous glands located in the caruncle
b. Meibonian glands are modified sebaceous glands
c. Glands of Zeis, modified sebaceous glands in lash follicles
d. Glands of Moll, modified apocrine sweat glands
What is the function of sebaceous glands?
The function of the sebaceous glands located in the lacrimal caruncle is to secrete tears onto the surface of the conjunctiva.
What is the function of meibonian glands?
Special kind of sebaceous gland at the rim of the eyelids inside the tarsal plate, responsible for the supply of meibum, an oily substance that prevents evaporation of the eye’s tear film. Meibum prevents tear spillage onto the cheek, trapping tears between the oiled edge and the eyeball, and makes the closed lids airtight.
What is the function of the glands of Zeis?
Secretion of oily substance into the middle follicle of eyelash
What is the function of the glands of Moll?
Modified sweat glands, Glands of Moll empty into the adjacent lashes. Glands of Moll and Zeis secrete lipid that adds to the superficial layer of the tear film, retarding evaporation.
What conditions affecting the eyelids have been studied?
Benign & malignant lesions Blepharitis Ptosis Ectropion & entropion Watery eye
What conditions affecting the orbit have been studied?
Orbital Cellulitis
What injuries to the ocular areas have been studied?
Orbital wall fracture
Trauma to the globe
What are the clinical characteristics of benign lid lesions?
Lack of induration & ulceration Uniform colour Limited growth Regular outline Preservation of normal lid margin structure
What is the Tx for benign lid lesions?
Excision (+Biopsy)
Marsupialization, remove the top of the cyst allowing drainage
Ablation with laser or cryotherapy
Chronic, sterile, inflammatory lesion caused by retained sebaceous secretion
Chalazion (Meibomian cyst)
A chalazion secondarily infected referred to as an internal hordeolum
What are the clinical features of malignant eyelid tumours?
Ulceration (>3months, suspect malignancy)
Lack of tenderness
Induration
Irregular borders
Destruction of lid margin architecture (now irregular)
What is the most common human malignancy?
Basal Cell Carcinoma
Who does BCC usually affect?
Most frequently affects elderly with fair skin, inability to tan & exposure to sun light
Where does BCC usually manifest?
90% = Head+Neck
10% of those are on the lower lid (more common than upper)
What are the clinical types of BCC?
a. Nodular BCC
b. Noduloulcerative (rodent ulcer)
c. Sclerosing BCC
What should be ensured following excision of BCC?
Clinically appears much smaller, since continuous under the skin. Margins must be left clear following removal (check in lab) as recurrence may occur.
What are the clinical characteristics of squamous cell carcinoma?
Much less common than BCC
More aggressive than BCC with metastasis to regional LN
Exhibit perineural spread to intracranial cavity
Grow out fast, which is distinct from BCC.
What are the clinical types of SCC?
a. Nodular SCC
b. Ulcerative SCC
c. Cutaneous horn
What is SCC often mistaken for?
Squamous CC can appear similar to benign, which is why we always remove+biopsy suspected benign lesions.
Where does melanoma rarely develop?
On the eyelids…
What are the clinical characteristics of Melanoma of the eyelids?
Potentially lethal
Half of them are non-pigmented
Signs
a. superficial spreading melanoma
b. nodular melanoma
What is Blepharitis?
Common eye condition characterized by often chronic inflammation of the eyelid, generally the part where eyelashes grow. It generally presents when very small oil glands near the base of the eyelashes don’t function properly, resulting in inflamed, irritated, itchy, and reddened eyelids.
What are the clinical characteristics of blepharitis?
Often Staph Aureus
Very common ocular discomfort, grittiness & photophobia
With remission & exacerbation
Usually bilateral & symmetrical
Associated with tear film instability = dry eyes
Mild papillary conjunctivitis & hyperaemia
Stye formation & marginal keratitis
What is the prevelance of blepharitis?
Very Common, esp in elderly
Affects 60% of people above the age of 70
What are the two types of chronic blepharitis?
Chronic Anterior Blepharitis
Chronic Posterior Blepharitis
What are the characteristics of chronic anterior blepharitis?
Staphylococcal infection with hard scales & crusting around the bases of the eyelashes.
What are the characteristics of chronic posterior blepharitis?
Meibomian gland dysfunction
With capping of the meibonian glands
(Inflammation more than infection. Tear fluid evaporate quickly. Complains of dry eyes yet excessive tearing since
tears of poor quality.)
What is the treatment for blepharitis
a. lid hygiene
b. antibiotics topical & systemic tetracycline
c. tear substitutes with weak topical steroid
Difficulty is as soon as treatment ceases, the condition returns.
What is Ptosis?
Abnormally low position of the upper lid which may be congenital or acquired
Describe the classification of Ptosis?
- Neurogenic: either 3rd n. palsy or Horner syndrome
- Myogenic: either congenital myopathy of levator muscle or acquired as in mysthenia gravis, myotonic dystrophy
- Aponeurotic: a defect in the levator aponeurosis (longer)
- Mechanical: gravitational effect of a mass or scarring
What are the clinical characteristics of neurogenic ptosis?
THIRD N. PALSY Third nerve affecting the levator palpebrae muscle Ptosis Eye looks down & out Dilated pupil
HORNERS SYNDROME Sympathetic nerves affecting the Muller’s muscle Ptosis Miosis Anhydrosis
What are the clinical features of simple congenital ptosis?
Usually younger than 2/3yrs
Unilateral or bilateral ptosis
Absent upper lid crease & poor levator function. ie.e When we ask the patient to look down, the ptosic lid would be higher than the other.
Lid lag in down gaze is because of poor relaxation of the levator muscle
How would you assess and manage a simple congenital ptosis?
Check visual axis, treat amblyopia & refractive errors (some pt’s have a squint as well).
If the visual axis is blocked then surgery.
If no blockage, then wait an see.
What are the clinical characteristics of Involutional (aponeurotic) ptosis?
Age related condition (revious history of catarax surg
or similar eyelid surg)
Stretching of the levator aponeurosis
High lid crease
Good function of the levator muscle
What is the Tx for aponeurotic ptosis?
Treatment is surgery which repairs the upper neurosis of the LevSup Muscle
What are the clinical characteristics of mechanical ptosis?
Impaired mobility of the upper lid Either due to dermatochalasis Large tumours as neurofibromatosis Heavy scar tissue Severe oedema (Can be caused by allergy. If oedema chronic then fibrosis occurs and it becomes permenant)
What is Ectropion?
Excessive tearing due to drainage.
What are the different types of ectropion?
Involution Paralytic Ectropion (FN palsy) Cicatricial Ectropion (caused by scarring and contraction of skin) Mechanical Ectropian (Tumours near lid margin, Worse when mouth open. Tx is removal of mass/mech obstruction)
What causes involution ectropion? What are the potential complication?
Due to laxity.
Eyelashes in contact with cornea cause chronic irritation
What causes cicatricial ectropion? What are the potential complications?
Due to scarring of palpebral conjunctive caused by cicatricial conjunctivitis, trachoma, trauma & chemical injuries
Cover the cornea with contact lens to protect eye before surgery.
What are the possible causes of watering eye?
- Hypersecretion secondary to ocular inflammation or surface disease
- Defective drainage either due to
a. Malposition of lacrimal puncta
b. Obstruction along the drainage system
What is nasolacrimal duct obstruction?
Better termed delayed canalization since it often resolves spontaneously. This membrane is the last to be patent.
What is the prevalence of NLDO
20% of newborns have excessive tearing. Due to lack of patency (opening) in drainage duct leading to excesive drainage of tears and therefore unilateral (or bilateral) excessive tearing.
What are the signs of nasolacrimal duct obstruciton?
Signs: epiphora & matting of lashes
Gentle pressure over the lacrimal sac causes reflux of purulent material
Acute dacryocystitis is uncommon
What is the Tx for NLDO?
Tx is massaging of the lacrimal duct 10 strokes to open membrane.
(Massaging of the lacrimal sac increases the pressure & ruptures membranous obstruction, place the index finger over the common canaliculus then massage firmly downwards. Ten strokes four times daily, with lid hygiene.)
Probing of the lacrimal system is delayed until the age of 12-18 months
What are the two orbital infections studied?
- Preseptal Cellulitis
2. Bacterial Orbital Cellulitis
What is preseptal cellulitis?
Infection of the subcutaneous tissues anterior to the orbital septum
What are the clinical signs of preseptal cellulitis?
Pain over the eye but no general malaise, no fever. Infection only of skin and soft tissue, not of the orbit itself.
What is the Tx for preseptal cellulitis?
Treatment is with oral co-amoxiclav 500/125mg t.d.s
IV antibiotics for severe infection
What is bacterial orbital cellulitis?
Life-threatening infection of the soft tissues behind the orbital septum
In whom is boc more common?
More common in children, but can occur at any age
What are the common causative agents in BOC? To what are most BOC infections related?
Most causative organisms are S. pneumoniae, S. aureus, S. pyogenes and H. Infleunzae.
The source of infection is usually sinus-related
What are the clinical characteristics of BOC?
Rapid onset of severe malaise, fever, pain & visual impairment
Unilateral tender warm & red periorbital & lid oedema
Proptosis, often obscured by lid swelling
Optic nerve dysfunction
CT shows opacification posterior to the orbital septum
What signs of BOC present on CT scan?
Opacification posterior to the orbital septum
How is BOC managed?
Hospital admission (alway in children due to meningitis, brain risk)
IV antibiotics
Monitoring of optic nerve function
Investigation: blood culture, CT orbit
How is a blow-out fracture caused?
Caused by a sudden increase in orbital pressure by a fist or a tennis ball.
What are the clinical signs of a blow-out fracture?
Periocular signs: ecchymosis, oedema & subcutaneous emphysema
Infraorbital n. Anaesthesia
Tear Drop Sign on X-RAY
Diplopia either due to
a. haemorrhage & oedema that restrict movement of the globe
b. mechanical entrapment of a muscle
c. direct injury to a muscle
Enophthalmos
Ocular damage should be ruled out
CT scan
Connection of the maxillary sinus to the subcutaneous tissue you get sub cut emphysema Don’t blow nose as air forced out of sinus into subcut tissue.
Tx for Blow-Out #?
2 weeks for the oedema to resolve, may help along with steroids Only then will we resolve fracture, as if we try with oedema present you risk occular nerve oedema
What are the two types of trauma to the globe?
Blunt
Penetrating
How is orbital trauma assessed?
Determination of the nature & extent of any life threatening problems.
History of the injury
Thorough examination of the eyes
Eye globe 10-20mmhg above air, any breaks may cause prolapse of retinal contents outward
How is a ruptured globe managed?
Full thickness corneal or scleral wound (Surgery type will depend on the layers affected.)
Protect the eye with a shield (Eye shield, not ipad, since want air circulating. )
CT scan of brain & orbit to rule out foreign body
Admit the patient to hospital, keep him fasting
Systemic broad spectrum antibiotics
Administer tetanus toxoid
Arrange for surgical repair
Do not apply pressure. If you apply pressure (for example to meaure IOP), would worsen prolapse. Instead cover eye, begin fasting, admin BSIVABs, and prepare for surgery.
How is blunt trauma to the globe managed?
Anterior hyphaema: check IOP, bed rest, topical steroid
A thorough posterior segment examination is made to rule retinal detachment
