Ophthalmology - Eyelids, Orbit and Lacrimal System

Question 1

What is a “stye”?

Answer 1

“Stye” is a word used more by patients than doctors for referring to inflammatory lid swellings. Hordeolum externum is an abscess or infection, usually staphylococcal, in a lash follicle; these may also involve the glands of Moll (sweat glands) and of Zeis (sebum producing glands attached directly to lash follicles). They point outwards and may cause inflammation. Treatment is with topical antibiotics - e.g. fusidic acid. (Note, “stye” implies infection: if this is not present the term marginal cyst - of Zeis or Moll - may be used.

Question 2

What is hordeolum internum? How is it treated?

Answer 2

This is much less common than hordeolum externum. It is an abscess of the Meibomiam glands. These point “inwards”, opening on to conjunctiva, causing less local reaction but leave a residual swelling called a chalazion or Meibomian cyst when they subside.

Vision may be decrease if corneal flattening occurs, but this is rare. Residual swellings should be treated by incision and curettage under local anaesthesia.

Question 3

What is blepharitis?

Answer 3

This means lid inflammation - e.g. from staph, seborrhoeic dermatitis or rosacea.

Eyes have a burning, itching red margins, with scales on the lashes. Patients also complain of “gritty eyes”.

Question 4

How is blepharitis treated?

Answer 4

Firstly, cleaning crusts off the lashes is essential (use cotton wool buds), +/- tears Naturale. Fusidic acid, steroid drops or oral doxycycline is the antibiotic of choice. IN children with blepharokeratitis consider oral erythromycin.

Question 5

What is the definition of pinguecula? How are they treated?

Answer 5

Pinguecula are degenerative, vascular yellow-grey nodules on the conjunctiva either side of the cornea. The typical patient is an adult male. These can become infected, in which case topic steroids are used. They can invade the cornea and surgery may be needed.

Question 6

What are pinguecula associated with?

Answer 6

They are associated with increased hair and skin pigmentation and sun related skin damage.

Question 7

What is entropion?

Answer 7

Entropion is a malposition of the eyelid (usually lower) in which the lid margin is turned inwards towards the globe, and the lashes abrade the cornea. Entropion may be intermittent and only demonstrable on forcible lid closure. The most common cause of entropion is aging (involutional) change of the lid tissues, but scarring processes can also alter the position of the lid margin. The definitive management of entropion is surgical correction (although botulinum injections can be trialed). It is rare in patients <40 years old.

Question 8

What is ectropion?

Answer 8

Ectropion is an eyelid malposition in which the life margin is rotated away from the globe and is no longer in correct apposition with the ocular surface.

Ectropion may lead to lagophthalmos and corneal exposure, hypertrophy of the conjunctiva and epiphora. The definitive management is surgical correction.

Question 9

What is ectropion associated with?

Answer 9

Aging (involutional) changes of the lid tissues
Cicatricial processes
Paralysis of the 7th cranial nerve

Question 10

How do patients with Meibomian cysts present?

Answer 10

Meibomian glands secrete lipids involving in stabilising the tear film. These glands can become blocked, particularly if blepharitis is present. Patients usually present with acute onset of a red, painful, swollen life and the inflamed “pea sized” cystic area (chalazion) is often apparent.

Question 11

What is the definition of ptosis? What causes it?

Answer 11

The term psotis is used to describe malposition of the upper eyelid in which the lid position is abnormally low.

Ptosis can be congenital or acquired. Acquired causes include senile (involutional) change in the levator muscle/ aponeurosis; myogenic disease (e.g. myasthenia), neurogenic pathology (e.g. 3rd nerve palsy) and Horner’s syndrome and traumatic and mechanical causes. Senile ptosis is associated with a high upper lid crease and frontalis overaction with raised eyebrows.

Congenital ptosis is corrected surgically early if the pupil i.e. the visual axis is covered (risk of ambylopia).

Question 12

What is pseudoptosis?

Answer 12

This is where ptosis is caused by the globe’s hypertropic position rather than intrinsic levator weakness.

Question 13

What is trichiasis?

Answer 13

In trichiasis lashes are turned inwards against the globe which cause an uncomfortable, chronic gritty sensation. Persistent trichiasis leads to corneal epithelial damage (identified by staining with minims fluorscein) and scarring. Causes of trichiasis include cicatricial lid diseases such as trauma, trachoma, pemphigoid and rosacea. Management options include recurrent epilation, electrolysis, and lid cryotherapy.

Question 14

What is lagophthalmos?

Answer 14

This means difficulty in lid closure. Causes include exophthalmos; mechanical impairment of lid movement; leprosy; paralysed orbicularis oculi giving a sagging lower lid. Corneal ulcers and keratitis may follow.

Question 15

What are the features of basal cell carcinoma of the eyelid?

Answer 15

Basal cell carcinomas are the most common periorbital neoplasm and 70% occur in the region of the lower eyelid. The most important risk factor is actinic damage in fair-skinned individuals. Lesions are usually painless and present as nodular or plaque-like areas with irregular, rolled “pearly edges” with associated telangectasia and central ulceration.

Metastasis are RARE. The principle of management is to achieve complete excision, to avoid destructive local invasions of the orbit and CNS. Histology is essential.

Question 16

Where do most squamous cell carcinomas of the eyelid arise?

Answer 16

Most SCCS arise from pre-existing lesions such as an area of actinic keratosis. Lesions may appear very similar to those seen in basal cell carcinoma with more scaling and fissuring of the skin. The key to management of SCCs is early diagnosis because the potential for metastasis. It is essential to achieve complete excision of the lesion, and this often means that extensive oculoplastic lid reconstruction is required.

Question 17

In the elderly, a rapidly growing purple nodule may be….

Answer 17

Merkel cell cancer.

Note - Kaposi’s sarcoma also presents with purple nodules but are almost always associated with AIDS

Question 18

What are the key features of sebaceous gland carcinomas?

Answer 18

These comprise 1-2% of malignancies and are commoner on the upper lid in males and with increasing age. They arise from Meibomian glands or glands of Zeis. Mortality is 10%.

Question 19

How does allergic dermatitis present?

Answer 19

Allergic dermatitis is seen most commonly in associated with an allergic reaction to a component of an eye drop, either the active drug or one of the preservative compounds. The periocular skin has an eczematous type reaction with erythema, oedema, scaling and fissuring of the lid skin, and marked itching. The most effective treatment is to STOP all topical drops and use a simple emollient on the skin. It takes several weeks for full recovery.

Question 20

How do tears drain through the lacrimal system?

Answer 20

The tear film excreted over the eye drains via the lacrimal puncta (found in the medial side of the upper and lower eyelid) through the lacrimal sac, lacrimal duct and inferior meatus (just lateral to the inferior turbinate) into the nasal passages. The lacrimal glands are located on the superior temporal side of the orbits. Dry eyes may be due to insufficient tear secretion, and watering eyes may be due to blockage of the drainage system or pump failure.

Question 21

Define dacryocystitis

Answer 21

This is an acute infection of the lacrimal sac due to obstruction at the level of the nasolacrimal duct. Patients present with an extremely painful abscess in the medial canthal region, which may discharge through the skin. There may be pre-existing history of a water eye. Initial treatment is with hot compress and systemic antibiotics followed usually by lacrimal drainage surgery (dacryocystorhinostomy) at a later date.

Question 22

What is nasolacrimal duct non canalization?

Answer 22

The nasolacrimal duct may not be canalised at birth and may not open fully until 1 year old. The child will have persistent water eye(s) and may be prone to attacks of conjunctivitis. If the duct fails to canalize, probing of the duct under GA is done.

Question 23

What is chronic dacryocystitis? How should it be managed?

Answer 23

This typically occurs in the middle-aged and elderly. The lacrimal sac distends, discharges mucopus into the eye and nasolacrimal duct becomes blocked.

Treat any infection promptly. A CT of the orbit is needed if orbital cellulitis is present. If the nasolacrimal duct is permanently blocked, dacryocystorhinostomy establishes communication between the lacrimal sac and the nasal cavity. An important differential is squamous cell ca of the lacrimal drainage system.

Question 24

What is dacroadenitis?

Answer 24

Lacrimal gland inflammation causes pain and swelling on the temporal side of the upper eyelid which may become “S” shaped.

Causes are either viral (mumps, measles, influenza) or gonococcal. Chronic swelling can occur in sarcoid, TB, lymphatic leukaemia or lymphosarcoma.

Question 25

What are the causes of dry eye?

Answer 25

Dry eye syndrome/ keratoconjunctivitis sicca are extremely common. Causes include lacrimal gland problems, for example involutional change, connective tissue disease (e.g. Sjogrens), sarcoidosis, amyloidosis, haemachromotosis, mumps, lymphoma and cicatricial disease of the conjunctiva for example trachoma and pemphigoid. Very rare causes of dry eyes include: - excessive evaporation of tears - mucin deficiency in tears (avitaminosis A, Stevens-Johnson syndrome)

Question 26

How should dry eyes be investigated?

Answer 26

Schirmer's test is a simple measure of aqueous tear production involving the use of a small strip of absorben filter paper. Tears should soak >15mm in 5 min. Initial therapy for dry eyes is replacement with artificial tears.

Question 27

What are the common causes of epiphora? How can it be investigated?

Answer 27

Epiphora means water eye, and is a very common symptom. Causes include emotion, corneal injury, entropion, conjunctivitis, iritis, and acute glaucoma. When an obstruction in the nasolacrimal drainage system is suspected, one can perform dacryocystography (DCG) to identify the site of obstruction. A radio-opaque dye is injected into the canaliculi and outlines the anatomy of the nasolacrimal drainage system.

Question 28

What is the most common cause of water eyes in the first year of life?

Answer 28

The most common cause of watery eyes in the first year of life is congenital obstruction of the nasolacrimal duct, caused by failure of canalization of its lower end. Abnormalities of facial bone structure may result in dacryostenosis. However, the most significant cause of watery eyes in neonates and infants is congenital glaucoma. In newborns and infants, large watery eyes associated with photophobia may be signs of congenital glaucoma.

Question 29

A mother presents saying her child has watery eyes. You suspect either congenital obstruction of the nasolacrimal duct or congenital glaucoma. What additional questions do you wish to ask?

Answer 29

The perinatal history is important to exclude a history of birth trauma or forceps delivery. Enquire whether the watering is associated with photophobia and worse in bright lights (suggestive of glaucoma). Have the parents noticed enlargement of their childs eyes. Is there a sticky mucopurulent discharge suggestive of conjunctivitis.

Question 30

What clinical examination would you perform on a baby with watery eyes?

Answer 30

Press on the area over the lacrimal sac and look for regurgitation of mucoid or mucopurulent fluid. This is typical of nasolacrimal duct obstruction. Important signs of congenital glaucoma include enlargement of the eye(s) and corneal opacification. Dilated fundoscopy is essential to exclude posterior segment pathology. Cycloplegic refraction should be performed to detect myopia, which may develop as a result of enlargement of the eyes.

Question 31

The mother of a baby who presents with watery eyes wants to know what can be done about her sons condition?

Answer 31

Management can either be conservative or surgical. Conservative management: delayed canalization occurs in 90 percent of infants by their first birthday, and any surgical intervention should be delayed until then. Daily massage of the lacrimal sac will prevent accumulation of debris and may reduce the risk of dacryocystitis. Surgical management: if recanalization does not occur and surgery becomes necessary, a syringe and probe of the nasolacrimal duct are performed under GA. Sometimes this needs to be repeated. Rarely intubation of DCR is necessary. Congenital glaucoma is very rare and should be managed by specialists.

Question 32

What is preseptal cellulitis?

Answer 32

Preseptal cellulitis is an infection of the tissues anterior to the orbital septum. The orbital contents are NOT involved in the process in contrast to orbital cellulitis. There is often a history of peri-orbital trauma or signs of a focus of infection, for example a lid margin sty. It is extremely important to exclude signs of orbital cellulitis. Systemic antibiotics are the treatment of choice.

Question 33

What is orbital cellulitis?

Answer 33

This is an infection of the orbital contents POSTERIOR to the orbital septum and is an emergency infection. Patients often have marked pain, pyrexia, proptosis, reduced vision, restriction of extraocular movements and lid swellings. There may be an associated infection of the paranasal sinuses which may need surgical drainage. Urgent (same day) admission for investigation of the underlying cause and medical management is required. It is most commonly caused by Staph, Strep pneumoniae, Strep pyogenes or milleri. If left untreated, the following outcomes are possible: a) 40% mortality rate due to intracranial infection and cavernous sinus thrombosis, and b) blindness. Rule out underlying rhabdomyosarcoma.

Question 34

What is a carotico-cavernous fistula? What are its features?

Answer 34

This may follow carotid aneurysm rupture with reflux of blood into the cavernous sinus. Causes are spontaenous, trauma, post spetorhinoplasty. There is enlargement of the eye vessels + lid and conjunctival oedema. Exophthalmos may be pulsatile, with loud bruit over the eye + tinnitus. Arterial ligation or embolization may occassionally be tried.

Question 35

How common are orbital tumours?

Answer 35

Primary neoplasia is rare (angioma, dermoid, meningioma or optic nerve glioma are some examples). 3% of orbital lesions are metastatic (from breast, lung, prostate, gut, kidney etc). In children, unilateral proptosis may be the 1st sign of neuroblastoma. Nasopharyngeal tumours can invade the orbit as may mucocoeles of ethmoid and frontal sinuses. CT scan pictures give a clear representation of the orbit.

Question 36

What is HZO? What is the natural history? How is it treated?

Answer 36

HZO, or herpes zoster ophthalmicus is a severe infection of the tissues of the eye, orbit, periorbital region and skin in the distribution of the first division of the trigeminal nerve due to the Herpes zoster virus. Pain and neuralgia in the distribution of the cranial nerve V1 dermatome precedes a blistering inflammed rash with conjunctivitis, keratitis and anterior uveitis. In 50% of those with HZO the globe is affected (corneal signs + iritis in >40%). Nose tip involvement (Hutchinson's sign) means involvement of the nasociliary branch of the trigeminal nerve which also supplies the globe and makes it likely that the eye will be affected. Occular disease may result in permanent reduction of visual function. If HZO is suspected in the early stages of the disease, systemic antiviral therapy may be very helpful in limiting disease duration and post-herpetic neuralgia. Famciclovir offers the best dose schedule (750mg once daily for 1wk; SE vomiting, headache) but is much more expensive than aciclovir (800mg 5 times daily for 7 days - it has more serious side effects such as hepatitis and renal failure). Start within 4 days of onset.

Question 37

What are the clinical features of thyroid eye disease?

Answer 37

Hyperthyroidism is associated with both lid retraction and lid lag. Thyroid eye disease (TED) is an autoimmune condition in which there is an inflammatory lymphocytic infiltration of orbital tissues, especially orbital fat and extraoccular muscles, with increased fibroblasts activity and glycosaminoglycan deposition. TED occurs in Grave's disease and may lead to swelling of the lids, proptosis, restriction of extraoccular movements and optic nerve compression. Thyroid eye disease is the most common cause of both unilater and bilateral proptosis. TED may also follow treatment of hyperthyroidism with radioactive iodine.

Question 38

How can thyroid eye disease lead to permanent visual impairment?

Answer 38

There are 2 main ways. First, compression of the optic nerve by swollen extraoccular muscles at the orbital apex, and secondly, severe corneal exposure and ulceration due to the globe proptosis. Patients may also have diplopia secondary to involvement of extraocular muscles in the inflammatory disease process. Transverse head/ orbit CT gives very clear pictures of muscle enlargement.

Question 39

What is a blow out fracture of the orbit?

Answer 39

Direct blunt trauma to the globe or orbital rim may produce a fracture of the orbital wall. The medial wall and orbital floor are the commonest sites of fracture. Patients may have diplopia if orbital contents are trapped in the fracture and enophthalmos may be apparent. There may be restricted eye movements on the affected side, particularly upgaze. Reduced infraorbital sensation is associated with floor fractures. There may be co-existing damage to the eye. All cases need ophthalmic assessment.