Features

Blepharitis
Blepharitis is characterised by inflammation of the eyelid margins. The condition is often chronic and can be difficult to manage because it tends to recur. The two main types of blepharitis are anterior and posterior (although both may co-exist).

In anterior blepharitis there is crusting and desquamation around the eyelash follicles (Figure1). In posterior blepharitis there is retention of the secretions of the meibomian glands and blockage of the meibomian gland orifices. Some of the pathology results from bacterial colonisation of the eyelids, causing direct microbial invasion of tissues, immune system-mediated damage, or damage caused by the production of bacterial toxins, waste products, and enzymes.

Predisposing conditions include staphylococcal colonisation, acne rosacea and seborrhoeic dermatitis.
Patients present with crusting of the eyelids, irritation, burning, foreign-body sensation, watering and photophobia, often worse in the morning. Examination of the lids reveals lid margin erythema and telangiectasia (dilated veins), rounding of the normally 'square' posterior lid margin, foamy meibomian gland secretions, inferior corneal punctate keratitis, with a poor tear film and short tear break-up time. Associated seborrhoeic dermatitis is typified by oily skin and flaking from the scalp or brows. Patients with acne rosacea also have acneiform spots, especially around the nose (Figure 2), with facial flushing and erythema, telangiectasia and eventually rhinophyma (enlargement and thickening of the nose soft tissues). Accompanying meibomian gland abnormalities, there may also be marginal keratitis, in which small white infiltrates (white cell precipitates) are seen in the cornea, near the limbus (usually with some clear cornea between), and which generally do not stain with fluorescein (main differential is microbial keratitis).
Eyelash abnormalities such as madarosis (loss of lashes), poliosis (whitening of the lashes) and trichiasis (misdirection of lashes) are often present in blepharitis.
Complications of blepharitis include:

<25C6> Epiphora
<25C6> Dry eyes
<25C6> Conjunctivitis
<25C6> Chalazion formation
<25C6> Trichiasis
<25C6> Ectropion
<25C6> Entropion
<25C6> Corneal disease in the form of punctate epithelial erosions, marginal infiltrates, recurrent erosions, marginal ulcers, pannus, keratitis or interference with contact lens wear.

Treatment involves keeping the lids clean and free of crusts. Warm compresses (a clean flannel soaked in hot water held against the closed eyelids for five minutes) can melt the waxy plugs and allow the trapped lipid secretions to be released. Lid hygiene involves cleaning of the lids with cotton buds or a clean flannel to mechanically remove crusts, and some people recommend cleaning gland orifices with surfactant such as baby shampoo or bicarbonate of soda diluted. This should be carried out twice a day initially and reduced to once a day when symptoms have improved. Lubricants for tear film abnormalities, and treatment of complications of blepharitis such as dry eye, trichiasis and entropion give the patient symptom relief.
Topical antibiotics, oral antibiotics and topical steroids all have a place in the management of blepharitis. Topical antibiotics - eg chloramphenicol, fusidic acid or polymyxin B combinations should be used if there is marked lid margin infection. Ointments are generally preferred to eyedrops as they are in contact with the eyelid margins for longer. Meibomian gland disease not adequately controlled by lid hygiene often responds to oral tetracycline, particularly in those associated with acne rosacea, but a prolonged course of three or six months is often required. Topical steroids (under specialist supervision) are reserved for severe cases of blepharitis or for complications such as marginal blepharitis.
Blepharitis rarely goes away completely, and the most important advice to patients is that it is chronic, that it almost never causes serious visual loss or other problems, and that they may need to maintain a long-term eyelid hygiene routine, varying its intensity according to symptoms.

Internal and External Hordeolum
A hordeolum (ie stye) is a localised infection or inflammation of the eyelid margin. An external hordeolum involves the eyelash follicle and associated glands of Zeis and Moll, while an internal hordoleum involves the meibomian glands, also known as a meibomian cyst or chalazion. Staphylococcus aureus infection is implicated in many cases. An internal hordeolum may point both inwards towards the conjunctiva or outwards towards the skin, unlike an external hordeolum which always points towards the skin side of the lid margin (Figure 3). Staphylococcal blepharitis, diabetes and seborrhoea increase the risk of developing a hordeolum.
Patients present with a localised painful swelling on one lid. Lid erythema and oedema accompany the localised swelling and may spread to involve most of the eyelid. Severe cases may be associated with a pre-septal cellulitis
Occasionally, a secondary conjunctivitis may be present.
The management of an external hordeolum is relatively straightforward. Most cases resolve spontaneously without treatment, or discharge anteriorly onto the eyelash line. Hot compresses may aid the discharge of the purulent material. Removal of the associated eyelash may aid resolution. Topical antibiotics (eg chloramphenicol) may be used for recurrent lesions and for those that are actively draining (to prevent bacterial conjunctivitis). Consider referral to the GP for systemic antibiotics if:

<25C6> The patient is pyrexial
<25C6> Has tender preauricular lymph nodes
<25C6> A pre-septal cellulitis is present.

Management of a chalazion is much the same, with most patients receiving a broad-spectrum topical antibiotic during the acute inflammatory phase. If the lump (in fact a chronic granulomatous reaction histologically) persists after the acute episode, it may require incision and curettage under local anaesthetic. Because the majority of chalazia resolve spontaneously, patients should be reassured and only referred if there is no resolution over a period of months.

Trichiasis
Trichiasis is defined as posterior misdirection of the lashes towards the globe. This is different from pseudotrichiasis, in which the lashes are directed posteriorly secondary to entropion. The primary causes of trichiasis are involutional (ageing) changes and scarring of the posterior lid lamella (superior or inferior). Several conditions predispose a patient to developing trichiasis:

<25C6> Chronic lid margin disease (blepharitis)
<25C6> Epiblepharon (common in Asian ancestry)
<25C6> Past herpes zoster ophthalmicus infection
<25C6> Trachoma
<25C6> Ocular cicatrical pemphigoid
<25C6> Stevens-Johnson syndrome
<25C6> Vernal keratoconjunctivis
<25C6> Chemical burns.

The misdirected eyelashes cause ocular irritation, pain and a foreign-body sensation. Examination may reveal tear film abnormalities, posterior lamellar scarring and involutional entropion. The cornea may have corneal abrasions (punctate epitheliopathy), microbial keratitis and eventually scarring.
The management of trichiasis involves removal of the offending lashes and then tackling any underlying condition. Epilation removes the lashes, giving the patient symptom relief. Electrolysis, cryotherapy and laser thermoablation aim to destroy the follicles of the offending lashes. Severe cases may need resection of the lash follicles.
Trachoma is caused by infection with the bacteria Chlamydia trachomatis. It has an incubation period of five to 12 days and begins slowly as conjunctivitis which leads to tarsal conjunctival scarring. The scarring distorts the upper tarsal plate and leads to entropion and trichiasis. The eyelashes may turn in and rub against the cornea. This can cause eye ulcers, further scarring, visual loss, and even blindness. Trachoma is endemic in Africa, Asia and the Middle East, in areas of most poverty. Six million people worldwide are blind from trachoma.

Entropion
Entropion is the inversion of the eyelid with the lid margin turned inwards toward the globe. It can be classified as involutional, cicatricial, congenital or acute spastic.

Involutional
<25C6> Most common type
<25C6> Typically affects only the lower lid
<25C6> Associated with ageing
<25C6> More common in women than men.
<25C6> Patients with involutional entropion have smaller-than-average tarsal plates for their ages
<25C6> Horizontal lid laxity is a feature, resulting from atrophy of the tarsus and canthal tendons
<25C6> This is demonstrable on the snap back test in which the central part of the lid is pulled downwards, and on release fails to 'snap back' onto the globe.

Cicatricial
<25C6> Shortening or loss of conjunctival tissue, which pulls the lid margin inwards toward the globe
<25C6> Causes include: trauma, chemical burns, Stevens-Johnson syndrome, ocular cicatricial pemphigoid (OCP), infections, or local response to topical medication
<25C6> Eversion of the lids is difficult in cases of cicatricial entropion, unlike involutional in which eyelid tissues are lax.

Congenital
<25C6> Very rare
<25C6> Results from improper development of the lower lid retractor aponeurosis insertion into the lower border of the tarsal plate
<25C6> This causes instability in the eyelid with consequent entropion.

Acute spastic
<25C6> Results from ocular irritation
<25C6> Causes include infection, inflammation or traumatic (eg surgical) processes
<25C6> It usually resolves spontaneously once the cause has been eliminated.

Patients with entropion complain of excessive tearing, irritation, redness and eye discomfort or pain. The discomfort and pain are due to the effects of the lashes which often rub against the conjunctiva and cornea.
Though the definitive treatment of entropion is surgical, there is a place for medical management in those declining surgery, or awaiting treatment or referral. Ocular lubrication and tear supplements are helpful for protecting the ocular surface and also may break the cycle in patients with spastic entropion due to dry-eye syndrome. Keeping the lashes away from the corneal surface will reduce irritation. This can be done by advising the patient to tape the lid to the skin of the cheek; other methods include epilation, a bandage contact lens, or even surgical tissue adhesive to a fold of skin just beneath the lower lid. These temporary measures may give the patient some comfort.
There are several surgical techniques, depending on the degree and position of lid laxity, and they include: eyelid-everting sutures to pull the eyelid margin away (usually temporary); removing a wedge of lower lid; tightening the canthal tendons; or operating on the inferior lid retractors.
Ectropion
Ectropion is the abnormal eversion of the lid from the globe. Without normal lid: globe apposition, corneal exposure, tearing, keratinisation of the palpebral conjunctiva and visual loss may result. Ectropion usually involves the lower lid and often has a component of horizontal lid laxity. Individualised treatment is based on appropriate identification of the aetiology.
Ectropion may be congenital or acquired. Congenital cases are rare and usually involve the lower lid, sometimes with associated congenital eye abnormalities such as blepharophimosis, or microphthalmos.
Acquired types include: involutional, paralytic, cicatricial and mechanical.

Involutional
<25C6> Most common type and is related to ageing
<25C6> Ectropion results from structural lid changes, including: disinsertion of the lower lid retractors; decreased tone of the preseptal/pretarsal orbicularis muscle in combination with medial/lateral canthal tendon laxity.

Paralytic
<25C6> Paralytic ectropion may occur with seventh nerve palsy from diverse causes such as Bell palsy, cerebellopontine angle tumours, herpes zoster oticus (viral ear infection), and infiltrations or tumours of the parotid gland.

Cicatricial
<25C6> Cicatricial ectropion occurs from scarring of the anterior lamella of the lid by conditions such as burns, trauma, or chronic dermatitis
<25C6> Less common causes of cicatricial ectropion include tumours.

Mechanical
<25C6> Mechanical ectropion may occur with lid tumors, such as neurofibromas, that evert the lower lid.

Patients may have lid deformity for months or even years before seeking medical attention. They often complain of irritated or red eyes with tearing. They may be constantly wiping their eyes, exacerbating lid laxity and therefore the ectropion.
Lubrication and glasses fitted with moisture shields are helpful if significant corneal exposure exists from the ectropion. In some cases, taping the lateral canthal skin supero-temporally provides temporary relief, especially in patients with new-onset seventh nerve palsy. The correct surgical treatment of ectropion depends on the aetiology, but often involves shortening of the lower lid and/or canthal plication (fold), under local anaesthetic.

Pre-septal cellulitis
Pre-septal cellulitis is a common infection of the eyelid and periorbital soft tissues characterised by acute eyelid erythema and oedema. It is a disease mainly affecting children, with 80 per cent of patients under the age of 10 and most under five. Periorbital pre-septal cellulitis must be differentiated from orbital cellulitis, as the severity of the conditions and their treatments differ considerably.
The orbital septum is a fibrous tissue layer arising from the periosteum of the skull, and inserts into the anterior aspect of the tarsal plates of the upper and lower eyelids (see Module 2). The septum separates the superficial eyelid from the deeper orbital structures, and it forms a barrier that often prevents infection in the eyelid from extending into the orbit. Pre-septal cellulitis differs from orbital cellulitis in that it is confined to the soft tissues that are anterior to the orbital septum. Pre-septal cellulitis may spread posterior to the septum and progress to form subperiosteal and orbital abscesses. Upper respiratory tract infections, especially paranasal sinusitis, commonly precede preseptal cellulitis. Causative organisms include Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus species and anaerobes all of which are common respiratory pathogens. Other causes include severe acute hordeolum and skin laceration.
Patients with pre-septal cellulitis will present with an acutely painful, swollen eyelid. They may also complain of blurred vision, conjunctivitis and tearing. When examined carefully they have normal ocular motility, visual acuities and pupillary reaction.
Proptosis is absent. Other causes of eyelid swelling such as insect bite, allergic reaction conjunctivitis, trauma, contact dermatitis and hordeolum need to be considered.
Bacterial orbital cellulitis, which is infection of the tissues posterior to the septum, is potentially more serious. The usual cause is spread of infection from an adjacent sinus, most commonly the ethmoid sinus, and patients may have a history of previous sinus problems or recent upper respiratory tract infection. Infection may also spread from adjacent dacrocystitis, or trauma or surgery in the area. Pathogens include Haemophilus influenzae (children under five), Staphlococcus aureus, Streptococcus pneumoniae, and Beta haemolytic streptococci.
Pain (particularly on eye movements), conjunctival chemosis, proptosis and ophthalmoplegia are the cardinal signs and symptoms of orbital cellulitis. The symptoms may advance at an alarming rate, with the risk of loss of vision due to compression of the optic nerve by infected material. Affected children are often systemically unwell with fever and malaise.
Management involves confirmation of the diagnosis and management of any predisposing conditions. Aggressive systemic antibiotic therapy is used.
Younger children or more severe cases are admitted for intravenous antibiotics. In cases where improvement is not prompt, further investigation with CT of the orbit and sinuses is indicated, and patients often end up having sinus surgery to drain pus. As complications can be severe, close monitoring is required. Therefore any practitioner suspecting orbital cellulitis should refer the patient to local eye or paediatric emergency unit, and patients with pre-septal cellulitis advised that they need systemic antibiotics urgently from their GP or hospital eye service.

Dacryocystitis
Dacryocystitis is infection or inflammation of the lacrimal sac. It occurs often in response to lacrimal sac obstruction. It may be acute or chronic. Acute dacryocystitis is manifested by the sudden onset of pain, erythema, and oedema overlying the lacrimal sac region. The tenderness is characteristically localised in the medial canthal region but may extend to the nose, cheek, teeth, and face. Frequently, a purulent discharge is noted from the punctum. Differentials include Actinomycosis (Streptothrix Israeli) dacryoliths and lacrimal sac tumour (if the mass extends above the medial canthal tendon). Purulent infection of the lacrimal sac and skin should be treated with systemic oral antibiotics. Acute dacryocystitis with orbital cellulitis requires hospital admission and systemic intravenous antibiotics. Chronic dacryocystitis invariably needs surgical treatment in the form of dacryocystorhinostomy or balloon dacrocystoplasty.

Epiphora
Many practitioners will be faced with the patient who complains of watery eyes, especially elderly patients. Epiphora is defined as the overflow of tears, and is more of a clinical sign than an absolute diagnosis - causes need to be established before appropriate intervention prescribed. Causes of epiphora include excess tear production (hyper-lacrimation), reduced tear outflow due to disturbed ocular tear pump (lid malposition), or outflow obstruction (blocked nasolacrimal duct). While all epiphora is worse in conditions when tear production is increased (for example, cold, windy days), if the epiphora only occurs in these conditions (the usual scenario), then it is unlikely to represent nasolacrimal duct obstruction. Complete obstruction of the nasolacrimal duct usually causes constant epiphora, in and outdoors, at any time of day.
Causes of increased tear production include trichiasis, superficial foreign bodies, ocular irritation due to eyelid malpositions, diseases of the eyelid margins, or tear deficiency/instability. Treatment is obviously directed at the cause of the increased tearing.
In the absence of the above, outflow obstruction is the most likely cause. Outflow problems are sub-divided into functional (poor lacrimal pump function) and anatomical (blockage at any point in the nasolacrimal system).
Examination of patients with epiphora may have prolonged or absent dye disappearance (2 per cent fluorescein), punctal stenosis, a pouting punctum with purulent material at opening (suggestive of a mucocoele, which is an enlarged lacrimal sac in the presence of nasolacrimal duct obstruction filled with mucopurulent material) and an increased tear meniscus height enhanced by fluorescein (greater than 2mm). It is important to identify causes of disturbed ocular surface tear flow such as lid malposition (euryblepharon, punctal ectropion, punctal phimosis) or ocular surface irritation (dry eye, blepharitis), to establish whether treatment of the latter in particular will relieve the patient's symptoms before referral. If the symptoms are persistent, hospital referral may be required. Investigations there include syringing and probing, dacryocystography and scintigraphy. Treatment depends on the cause and varies from simple procedures such as punctal dilation and three-snip procedure for punctal phimosis, to eyelid surgery to correct lid malposition, to dacryocystorhinostomy for nasolacrimal duct obstruction.
In babies, symptomatic nasolacrimal duct obstruction occurs in 5-6 per cent of infants, but the majority (up to 90 per cent) have spontaneous resolution by around 12 to 18 months of age, so parents should be advised to wait and to continue wiping the eye and massaging the lacrimal sac to express any associated mucocoele (to try to prevent dacryocystitis). Topical antibiotics are only required if the eye becomes red with conjunctivitis or the discharge is particularly purulent. Failure of resolution usually requires syringe and probing under general anaesthesia.

Tumours
Basal cell carcinoma
Basal cell carcinoma (BCC) is the most common eyelid tumour, accounting for over 90 per cent of all cancerous lid lesions. It usually presents on the lower eyelid (70 per cent) (Figure 4), but is also found in descending order of frequency on the medial canthus, upper eyelid and lateral canthus. The basal layer, or the deepest layer of the skin is thought to be the origin of the cancer, hence the name.
BCC is most common among those with light coloured skin who have had significant sun exposure. The incidence of BCC increases with age, peaking in the seventh decade of life, and other groups at risk include the immunocompromised, in particular patients who have had many years of immunosuppression (eg anti-rejection drugs in transplant patients). Men are at increased risk with a male-to-female ratio of 3:2.
BCC, or a rodent ulcer, is slow growing, destructive and locally invasive and rarely metastasizes. It may present as a non-healing ulcer with pearly white borders and ulcerated centre, and bleeding after minimal trauma. There are three main types of BCC:

<25C6> Nodular - appears as a small, translucent, raised area with poorly defined edges, and is firm to the touch
<25C6> Ulcerative - classic ulcerative presentation is a nodular lesion that over time has developed telangiectasia (a reddish hue caused by persistent, and virtually permanent, dilation of capillaries) along the surface and an atrophied inner portion, creating a 'pearly', indurated outer margin with an excavated centre
<25C6> Morphoeic (sclerosing) - has a firm, pale, waxy yellow plaque with indistinct borders, which may spread just underneath the skin surface.

Clearly, if a practitioner suspects BCC then referral is required. Although the current UK guidelines recommend urgent referral with patient review within two weeks if cancer is suspected, BCCs do not require this degree of urgency, because they do not spread, and are slow-growing. The most common treatment for lid BCCs is surgical removal. However, if the tumour is large, reconstructive surgery including skin grafting, may be required, thus emphasising the importance of early detection in its management. If surgical removal of the tumour is not an option, cryotherapy (freezing) or radiation therapy may be used. Prognosis is good with early detection and treatment. However, recurring BCC has a propensity to be aggressive and problematic to manage. Recurrence is rare. A 95 per cent five-year cure rate exists for lesions less than 10mm.

Squamous cell carcinoma
Squamous cell carcinoma (SCC) of the eyelids is rare, but may be a more aggressive malignancy than BCC. It is the second most common eyelid malignancy, accounting for 5 per cent of all eyelid neoplasms. It is most often encountered in elderly, fair-skinned individuals who have a history of chronic sun exposure, and occurs in association with other ultraviolet-related pre-cancerous lesions (eg actinic keratosis, Bowen dermatosis), in immunocompromised patients, in those with considerable exposure to oils or tar, and patients with the rare skin condition xeroderma pigmentosum. SCC can develop even if the history of sun exposure occurred decades prior to development of the skin lesion.
The clinical presentation is very similar to the BCC. Patients presenting with this lesion may demonstrate a roughened scaly patch of tissue on or near the lid margin or in the canthal region. The area is typically red, elevated and nodular, with crusted and/or bloody margins (Figure 5). Often, patients describe this lesion as 'a non-healing scab'. Squamous cell carcinoma in its early stages is easily confused with a multitude of other eyelid lesions, both malignant and benign. Some of these lesions include BCC, sebaceous gland carcinoma, follicular keratosis, actinic keratosis, seborrhoeic keratosis and keratoacanthoma.
SCC is a potentially invasive tumour derived from surface epithelium. In the early stages, the normal epithelial cells are replaced by atypical squamous cells throughout the epidermis, resulting in a loss of normal maturation. This stage is sometimes referred to as squamous cell carcinoma in situ. After the dysplastic squamous cells encroach beyond the borders of the basement membrane, the lesion is referred to as invasive SCC. In advanced cases, squamous cell carcinoma may metastasize (spread) to regional lymph nodes. If this occurs, the rate of morbidity and mortality rises exponentially. The diagnosis can only be confirmed after biopsy or excision and microscopic analysis of the tissue.
The management of SCC of the eyelid is virtually identical to that of BCC of the lid. However patients with SCC must be thoroughly investigated to ensure there is no metastasis of the disease. SCC may be treated with surgical excision, radiation therapy, chemotherapy or cryotherapy. The preferred course for most cases is surgery, with broad margins to ensure complete removal. Frozen tissue sections of the tumour borders are evaluated intraoperatively to further assure that the lesion is excised completely (Mohs' micrographic technique). This method offers the greatest success with the least incidence of recurrence. After excision, patients should be observed for recurrence of previously excised malignancy or development of other epithelial eyelid tumours.

Benign eyelid lesions
Cysts can arise from any of the glands around the eyelid margin. Cysts of Moll are benign, clear fluid-filled cysts occurring along the upper or lower lid margins. Cysts of Zeis derive from the small sebaceous glands associated with lash follicles. Blockage of the latter leads to an accumulation of the yellow/white sebaceous material. Patients should be reassured that these cysts of Moll and Zeis are benign and surgical removal (excision, cryotherapy) is only indicated for cosmetic reasons.
Molluscum contagiosum is a benign skin lesion caused by the poxvirus. It is contagious and spreads through direct contact. Lesions can be single or multiple and characteristically consist of a dome-shaped, waxy umbilicated nodule
2-3mm in diameter. They are generally asymptomatic, but continuous shedding of toxic viral products from such lesions can lead to a chronic follicular conjunctivitis. Molluscum lesions are usually self-limiting, but can be easily excised surgically.

Thyroid Eye Disease
Thyroid eye disease (TED) most commonly presents in women in their fourth to sixth decade, and is usually associated with Graves' disease (autoimmune thyrotoxicosis), although rarely it may precede the thyrotoxicosis. As well as the systemic symptoms of an overactive thyroid (tremor, mood change/irritability, weight loss, tachycardia), patients may present with 'staring' eyes due to proptosis, or lid retraction and lid lag. They often complain of irritation due to corneal dryness because of these problems, and can often be managed with lubricants. If there is considerable lid oedema and/or conjunctival chemosis, advise patients to raise the head of the bed, which may considerably reduce this. The serious complication of optic nerve compression, which occurs in less than 5 per cent of patients with TED (and older, male patients are more at risk) presents with the signs of optic neuropathy, such as reduced vision, reduced colour vision, visual field loss - practitioners should refer any suspect patient urgently. An important role for optometric practitioners is regarding patient education: TED is associated with smoking, and patients should be informed of the connection and strongly advised to stop. Patients with significant proptosis, diplopia or eye symptoms not improved with topical treatment may need hospital referral.
Many patients with lid or lacrimal problems can be managed in the community with the support of their optometrist. Blepharitis and tear-film insufficiency are very common, and supportive measures with lid hygiene and tear substitutes and advice/reassurance will be sufficient for most patients.

Further Reading
Bruce AS, Loughnan MS. Anterior eye disease and therapeutics A-Z. Butterworth-Heinemann, first edition, 2003.
McCulley JP, Shine WE. Changing concepts in the diagnosis and management of blepharitis. Cornea, 2000; 19: 650-58.
McCulley JP, Shine WE. Eyelid disorders: the meibomian gland, blepharitis, and contact lenses. Eye Contact Lens, 2003; 29:S93-95.
Driver PJ, Lemp MA. Meibomian gland dysfunction. Surv Ophthalmol, 1996; 40: 343-67.
Basar E, Ozdemir H, Ozkan S, Cicik E, Mirzatas C. Treatment of trichiasis with argon laser. Eur J Ophthalmol, 2000; 10: 273-75.
Elder MJ, Collin R. Lid surgery: the management of cicatricial entropion and trichiasis. Dev Ophthalmol, 1997; 28: 207-18.
Vallabhanath P, Carter SR. Ectropion and entropion. Curr Opin Ophthalmol, 2000; 11: 345-51.
Lessner A, Stern GA. Pre-septal and orbital cellulitis. Infect Dis Clin North Am, 1992; 6: 933-52.
Guzek JP, Ching AS, Hoang TA, Dure-Smith P, Llaurado JG, Yau DC, Stephenson CB, Stephenson CM, Elam DA. Clinical and radiologic lacrimal testing in patients with epiphora. Ophthalmology, 1997; 104: 1875-81.
Van Haeringen NJ. Ageing and the lacrimal system. Br J Ophthalmol, 1997; 81: 824-26.
Westfall CT. Lacrimal disease. Curr Opin Ophthalmol, 1995; 6: 100-4.
Haber-Spitzy V, Steinkogler FJ, Huber E, Arocker-Mettinger E, Schiffbanker M. Acquired dacrocystitis: microbiology and conservative therapy. Acta Ophthalmol, 1992; 70: 745-49.
Donaldson MJ, Sullivan TJ, Whitehead KJ, Williamson RM. Squamous cell carcinoma of the eyelids. Br J Ophthalmol, 2002; 86: 1161-5.
Margo CE, Waltz K. Basal cell carcinoma of the eyelid and perioperative skin. Surv Ophthalmol, 2003; 18: 243-47.
Mizen TR. Thyroid eye disease. Semin Ophthalmol, 2003; 18: 243-47.

<25C6> Mfazo Hove is a senior house officer and Christopher Hammond consultant ophthalmologist at West Kent Eye Centre, Princess Royal University Hospital, Bromley Hospitals NHS Tru

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