Common Eye Diseases and their Management - part 3 doc

Conjunctivitis Inflammation of the conjunctiva is extremely common in the general population and the general practitioner is often expected to find out the cause and treat this condition..

Common Diseases of the Eyelids 41

Hot steaming, again, is effective treatment and

once the pus is seen, the eyelash can be gently

epilated, with resulting discharge and

sub-sequent resolution of the infection

Children aged from about six to ten years

sometimes seem to go through periods of their

lives when they can be dogged by recurrent styes

and meibomian infections, much to the distress

of the parents Under these conditions, frequent

baths and hairwashing are advised and

some-times a long-term systemic antibiotic might be

considered.Recurrent lid infections can raise the

suspicion of diabetes mellitus but in practice,

this is rarely found to be an underlying cause

Eyelid infections such as these rarely cause

any serious problems other than a day or two off

work and it is extremely unusual for the

infec-tion to spread and cause orbital cellulitis

Recur-rent swelling of the eyelid in spite of treatment

can indicate the need for a lid biopsy because

some malignant tumours can, on rare occasions,

present in a deceptive manner

Blepharitis

This refers to a chronic inflammation of the lid

margins caused by staphylococcal infection The

eyes become red rimmed and there is usually an

accumulation of scales giving the appearance of

fine dandruff on the lid margins The condition

is often associated with seborrhoea of the scalp

Sometimes it becomes complicated by recurrent

styes or chronic infection of the meibomian

glands The eye itself is not usually involved,

although there could be a mild superficial

punc-tate keratitis, as evidenced by fine staining of the

lower part of the cornea with fluorescein In

more sensitive patients, the unsightly

appear-ance can cause difficulties, but in more severe

cases, the discomfort and irritation can interfere

with work Severe recurrent infection can lead

to irregular growth of the lashes and trichiasis

In the management of these patients, it is

important to explain the chronic nature of the

condition and the fact that certain individuals

seem to be prone to it Attention should be

given to keeping the hair, face and hands as

clean as possible and to avoid rubbing the eyes

When the scales are copious, they can be gently

removed with cotton-wool moistened in

sodium bicarbonate lotion twice daily Dandruff

of the scalp should also be treated with a

suit-able shampoo A local antibiotic can be applied

to the lid margins twice daily with good effect

in many, but not all, cases In severe cases withulceration of the lid margin, it might be neces-sary to consider prescribing a systemic anti-biotic, preferably after identifying the causativeorganism by taking a swab from the eyelids.Local steroids when combined with a localantibiotic are very effective treatment, but theprescriber must be aware of the dangers ofusing steroids on the eye and long-term treat-ment with steroids should be avoided Steroidsshould not be used without monitoring theintraocular pressure

Molluscum Contagiosum

This is a viral infection usually seen in children.The lesions on the eyelids are discrete, slightlyraised and umbilicated and usually multiple.There are also likely to be lesions elsewhere onthe body, especially the hands, and brothers orsisters might have the same problem It is rarefor the eye itself to be involved In persistentcases, an effective form of treatment with chil-dren is careful curettage of each lesion under ageneral anaesthetic; in adults, cryotherapy isused for individual lesions, especially if they areadjacent to the lid margin with the propensity

to cause conjunctivitis

Orbital Cellulitis

Although this is not strictly a lid infection, itmay be confused with severe meibomitis Theinfection is deeper and the implications muchmore serious In a child, where the condition ismore common, there is eyelid swelling, pyrexiaand malaise; urgent referral is needed Thisapplies especially if there is diplopia or visualloss, because a scan will be required to decidewhether surgical intervention is going to beneeded to drain an infected sinus

sometimes keratinised These lesions are caused

by the papilloma virus and are easily excised,

but care must be taken if excision involves the

lid margin (Figure 5.12)

Naevus

This is a flat brown spot on the skin; it might

have hairs, and rarely becomes malignant

Haemangioma

Seen as a red “strawberry mark” at or shortlyafter birth, this lesion can regress completelyduring the first few years of life Figure 5.13shows a gross example of the rare cavernoushaemangioma, which might be disfiguring.This also can regress in a remarkable way “Portwine stain” is the name applied to the capillaryhaemangioma This is usually unilateral andwhen the eyelids are involved, there is a risk ofassociation with congenital glaucoma, haeman-gioma of the choroid and haemangioma of themeninges on the ipsilateral side (Sturge–Webersyndrome) Children with port wine stainsinvolving the eyelids need full ophthalmologicaland neurological examinations

Dermoid Cyst

These quite common lumps are seen in or adjacent to the eyebrow They feel cystic and are sometimes attached to bone Typically, theypresent in children as a minor cosmeticproblem The cysts are lined by keratinised

Figure 5.12 Lid margin papilloma.

Figure 5.13 a Large disfiguring haemangioma in infancy b The same lesion, which in this case had remained untreated, showing

spontaneous regression.

Common Diseases of the Eyelids 43

epithelium and can contain dermal appendages

and cholesterol A scan might be needed

before removal because some extend deeply into

the skull

Xanthelasma

These are seen as yellowish plaques in the skin;

they usually begin at the medial end of the lids

They are rarely associated with diabetes,

hyper-cholesterolaemia and histiocytosis Usually,

there is no associated systemic disease

Malignant Tumours

Basal Cell Carcinoma

This is the most common malignant tumour of

the lids, usually occurring on the lower lid It

appears as a small lump, which tends to bleed,

forming a central crust with a slightly raised

hard surround The tumour is locally invasive

only but should be excised to avoid spread into

bone.Even large lesions can be approached

surg-ically (Figure 5.14) and “Mohs” micrographic

surgery is recognised as a tissue-sparing

gold-standard approach in many centres

Radio-therapy is only occasionally used with a greater

risk of recurrence than formal surgical excision

Squamous Cell Carcinoma

This tends to resemble basal cell carcinoma

and biopsy is needed to differentiate It can also

be mimicked by a benign self-healing lesion

known as keratoacanthoma

Malignant Melanoma

This raised black-pigmented lesion is highlymalignant, but rare

Allergic Disease of the Eyelids

This can present as one of two forms or a mixture of both The more dramatic is acuteallergic blepharitis in which the eyelids swell uprapidly, often in response to contact with a plant

or eyedrops The cause must be found and inated and treatment with local steroids might

elim-be needed Chronic allergic blepharitis is seen inatopic individuals, for example hay fever suffer-ers or patients with a history of eczema Thediagnosis might require a histological examin-ation of the conjunctival discharge Drop treat-ment to alleviate symptoms includes mast cellstabilisers (such as lodoxamide) and histamineantagonists (such as emedastine), and theseagents could take weeks to take effect Patientswith seasonal allergic conjunctivitis might require medication for a prolonged period overthe spring and summer months each year

Lid Injuries

One of the commonest injuries to the eyelids iscaused by the presence of a foreign body underthe eyelid – a subtarsal foreign body A smallparticle of grit lodges near the lower margin ofthe lid, but to see it the lid must be everted.Every medical student should be familiar withthe simple technique of lid eversion This is per-formed by gently grasping the lashes of theupper lid between finger and thumb and at thesame time placing a glass rod horizontallyacross the lid The eyelid is then gently everted

by drawing the lid margin upwards and wards The manoeuvre is only achieved if thepatient is asked to look down beforehand, andthe everted lid is replaced by asking the patient

for-to look upwards If a small foreign body is seen,

it is usually a simple matter to remove it using

a cotton-wool bud (Figure 5.15)

Cuts on the eyelids can be caused by brokenglass or sharp objects, such as the ends of screw-drivers The important thing here is to realisethat cuts on the lid margin can leave the patientwith a permanently watering eye if not sewn up

Figure 5.14 Cystic basal cell carcinoma that has extended to

involve most of the upper eyelid.

with proper microscopic control and using finesutures The lids can also be injured by chemi-cal burns or flash burns Exposure to ultravioletlight, as from a welder’s arc or in snow blind-ness, can cause oedema and erythema ofthe eyelids This might appear after an hour ortwo but resolves spontaneously after about two days.

Figure 5.15 Everting the upper eyelid.

Haemorrhage

This is common and tends to occur

spontaneo-usly or sometimes after straining, especially

vomiting It can also occur in acute

haemor-rhagic conjunctivitis caused by certain viruses

and occasionally bacterial conjunctivitis.The eye

becomes suddenly red and although the patient

might experience a slight pricking, the condition

is usually first noticed in the mirror or by a

friend The haemorrhage gradually absorbs in

about 14 days and investigations usually fail

to reveal any underlying cause Rarely, it is

necessary to cauterise the site of bleeding if the

haemorrhage is repeated so often that it becomes

a nuisance to the patient (Figure 6.1)

Conjunctivitis

Inflammation of the conjunctiva is extremely

common in the general population and the

general practitioner is often expected to find out

the cause and treat this condition If we consider

that the conjunctiva is a mucous membrane,

which is exposed during the waking hours to

wind and weather more or less continuously,

year in, year out, then it is not surprising that

this membrane is rather susceptible to

inflammation Furthermore, the conjunctiva

can be compared with the lining of a joint, the

eye being considered as an unusual type of

ball-and-socket joint The analogy takes on moremeaning when the relation between conjunc-tivitis and some joint diseases is seen

There are a large number of different specificcauses of conjunctivitis Some of these are inter-esting but rare and it is important that the studentobtains an idea of the relative importance andfrequency of the different aetiological factors.For this reason, in this chapter a more or less categorical list is given of the different causes Inthe chapter on the red eye (Chapter 7), you willfind a plan of approach to the red eye that dealswith the importance and more common causes

of conjunctivitis seen in day-to-day practice.Although the conjunctiva is continuouslyexposed to infection, it has special protectionfrom the tears, which contain immunoglobulinsand lysozyme The tears also help to wash awaydebris and foreign bodies and this protectiveaction can explain the self-limiting nature ofmost types of conjunctivitis

6

Common Diseases of the Conjunctiva and Cornea

45

Visual acuity is usually normal in

conjunctiv-itis The conjunctiva appears hyperaemic and

there can be evidence of purulent discharge on

the lid margins, causing matting together of the

eyelashes The redness of the conjunctiva

extends to the conjunctival fornices and is

usually less marked at the limbus When a rim

of dilated vessels is seen around the cornea, the

examiner must suspect a more serious

inflam-matory reaction within the eye.Apart from being

red to a greater or lesser degree,the eyes also tend

to water, but a dry eye might lead one to suspect

conjunctivitis results from inadequate tear

secretion Drooping of one or both upper lids is

a feature of some types of viral conjunctivitis

and this can be accompanied by enlargement

of the preauricular lymph nodes The

ophthal-mologist should train himself or herself to feel

for the preauricular node as a routine part of the

examination of such a case Closer inspection of

the conjunctiva might reveal numerous small

papillae, giving the surface a velvety look, or the

papillae may be quite large Giant papillae under

the upper lids are a feature of spring catarrh, a

form of allergic conjunctivitis Close inspection

of the conjunctiva might also reveal follicles or

lymphoid hyperplasia Being deep to the

epith-elium, they are small, pale, raised nodules and

are commonly seen in viral conjunctivitis

Fol-licles under the upper lids are especially

charac-teristic of trachoma

Microscopy

The examination of a severe case of

conjunc-tivitis of unknown cause is not complete until

conjunctival scrapings have been taken A drop

of local anaesthetic is placed in the conjunctivalsac and the surface of the conjunctiva at the site

of maximal inflammation is gently scraped withthe blade of a sharp knife or a Kimura spatula.The material obtained is placed on a slide andstained with Gram’s stain and Giemsa stain Theinfecting organism can thus be revealed or the cell type in the exudate might indicate theunderlying cause

Conjunctival Culture

In most cases of conjunctivitis, it might be goodmedical practice to take a culture from the con-junctival sac and the eyelid margin, but such ameasure might not always be possible if amicrobiological service is not near at hand Thecultures can be taken with sterile cotton-tippedapplicators and sent to the laboratory, in anappropriate medium, as soon as possible

• Unknown cause

Bacterial Conjunctivitis

In the UK, the commonest organisms to cause

Haemo-philus spp and Staphylococcus aureus The last

mentioned is normally associated with chroniclid infections, and the acute purulent conjunc-tivitis, known more familiarly as “pink eye”, isusually caused by the pneumococcus Chronicconjunctivitis can also be caused by Moraxella lacunata but this organism is rarely isolated

from cases nowadays An important but rareform of purulent conjunctivitis is that caused by

Neisseria gonorrhoeae; this is still an occasional

cause of a severe type of conjunctivitis seen inthe newborn babies of infected mothers.Untreated, the cornea also becomes infected,leading to perforation of the globe and perma-

Figure 6.1 Subconjunctival haemorrhage.

Common Diseases of the Conjunctiva and Cornea 47

nent loss of vision Purulent discharge, redness

and severe oedema of the eyelids are features of

the condition, which is generally known as

oph-thalmia neonatorum (Figure 6.2) Ophoph-thalmia

neonatorum can also be caused by staphylococci

and the chlamydia (see inclusion conjunctivitis

of the newborn) The disease is notifiable and

any infant with purulent discharge from the

eyes, particularly between the second and

twelfth day postpartum, should be suspect At

one time, special blind schools were filled with

children who had suffered ophthalmia

neonato-rum An active campaign against this cause of

blindness began at the end of the last century

when Carl Crede introduced the principle of

careful cleansing of the infant’s eyes and the

instillation of silver nitrate drops Blindness

from this cause has now disappeared in the UK

but there is still a low incidence of ophthalmia

neonatorum Those affected require treatment

with both topical medication (e.g.,

chloram-phenicol 0.5% eye drops) and intramuscular

benzylpenicillin (a cephalosporin, such as

cefo-taxime, is an alternative) Both parents of the

child should also be assessed

Pink eye is the name given to the type of acute

purulent conjunctivitis that tends to spread

rapidly through families or around schools The

eyes begin to itch and within an hour or two

produce a sticky discharge, which causes the

eyelids to stick together in the mornings If the

disease is mild, it can be treated by cleaning

away the discharge with cotton-wool, and it

does not usually last longer than three to five

days More severe cases might warrant the

pre-scription of antibiotic drops instilled hourly

during the day for three days followed by four

times daily for five days A conjunctival culture

should be taken before starting treatment.Commonsense precautions against spread ofthe infection should also be advised, althoughthey are not always successful

Attempts to culture bacteria from the tival sac of cases of chronic conjunctivitis do notyield much more than commensal organisms.One particular kind of chronic conjunctivitis

conjunc-in which the conjunc-inflammation is sited maconjunc-inly near

to the inner and outer canthi is known asangular conjunctivitis with follicles on the superior tarsal conjunctiva Another feature ofthis is the excoriation of the skin at the outercanthi from the overflow of infected tears Theclinical picture has been recognised in associa-tion with infection by the bacillus M lacunata.

Often, zinc sulphate drops and the application

of zinc cream to the skin at the outer canthusare sufficient treatment in such cases Tetracy-cline ointment might be more effective

Chlamydial Conjunctivitis

The chlamydia comprise a group of “largeviruses” that are sensitive to tetracycline anderythromycin and that cause relatively minordisability to the eyes in northern Europe and theUSA when compared with the severe and wide-spread eye infection seen especially in Africaand the Middle East Inclusion conjunctivitis(“inclusion blenorrhoea”) is the milder form ofchlamydial infection and is caused by serotype

is usually, but not always, sexually transmitted.The conjunctivitis typically occurs one weekafter exposure It can cause a more severe type

of conjunctivitis in the newborn child, whichcan also involve the cornea The infection isusually self-limiting but often has a prolongedcourse, lasting several months The diagnosisdepends on the results of conjunctival cultureand examination of scrapings and the associa-tion of a follicular conjunctivitis with cervicitis

or urethritis

Chlamydial conjunctivitis responds to ment with tetracycline In children and adults,tetracycline ointment should be used at leastfour times daily In adults, the treatment can besupplemented with systemic tetracycline, butthis drug should not be used systemically inpregnant mothers or children under seven years

treat-of age Azithromycin and other macrolide biotics are known to be particularly effective

anti-Figure 6.2 Ophthalmia neonatorum.

in treating systemic chlamydial infection;

azithromycin can be given conveniently as a

one-off dose A referral to genitourinary

med-icine is advisable on presentation, as a screening

measure, because reinfection from partners can

trigger a recurrent infection

Trachoma

Although a doctor practicing in the UK might

rarely see a case of trachoma, and even then

only in immigrants, it is the commonest cause

of blindness in the world and, furthermore, the

disease affects about 15% of the world’s

pop-ulation It is spread by direct contact and

per-petuated by poverty and unhygienic conditions

Trachoma is caused by C trachomatis serotypes

A, B and C and affects underprivileged

popula-tions living in condipopula-tions of poor hygiene

The disease begins with conjunctivitis, which,

instead of resolving, becomes persistent,

esp-ecially under the upper lid where scarring and

distortion of the lid can result The

inflam-matory reaction spreads to infiltrate the cornea

from above and ultimately the cornea itself can

become scarred and opaque (Figure 6.3) At one

time, trachoma was common in the UK,

esp-ecially after the Napoleonic wars at the end of

the eighteenth century It had been eliminated

by improved hygienic conditions long before the

introduction of antibiotics

Adenoviral Conjunctivitis

Acute viral conjunctivitis is common Several of

the adenoviruses can cause it Usually, the eye

symptoms follow an upper respiratory tractinfection and, although nearly always bilateral,one eye might be infected before the other Theaffected eye becomes red and discharges;characteristically, the eyelids become thickenedand the upper lid can droop The ophthalmolo-gist’s finger should feel for the tell-tale tenderenlarged preauricular lymph node In somecases, the cornea becomes involved and subep-ithelial corneal opacities can appear and persistfor several months (Figure 6.4) If such opacitiesare situated in the line of sight, the vision can beimpaired There is no known effective treatmentbut it is usual to treat with an antibiotic drop toprevent secondary infection

From time to time, epidemics of viral junctivitis occur and it is well recognised thatspread can result from the use of improperlysterilised ophthalmic instruments or even con-taminated solutions of eye drops, and poorhand-washing techniques

con-Herpes Simplex Conjunctivitis

This is usually a unilateral follicular tivitis with preauricular lymph node enlarge-ment In children, it might be the only evidence

conjunc-of primary herpes simplex infection

Acute Haemorrhagic Conjunctivitis

Acute haemorrhagic conjunctivitis is caused byenterovirus 70 (picornavirus) and usuallyoccurs in epidemics The disease is hugely con-tagious but self-limiting

Figure 6.3 Trachoma trichiasis of upper lid and corneal

vasc-ularisation (with acknowledgement to Professor D Archer).

Figure 6.4 Adenoviral keratoconjunctivitis.

Common Diseases of the Conjunctiva and Cornea 49Other Infective Agents

The conjunctiva can be affected by a wide

variety of organisms, some of which are too rare

to be considered here, and sometimes the

infected conjunctiva is of secondary importance

to more severe disease elsewhere in the rest of

infection, which causes small umbilicated

nodules to appear on the skin of the lids and

elsewhere on the body, especially the hands It

can be accompanied by conjunctivitis when

there are lesions on the lid margin The

infec-tion is usually easily eliminated by curetting

pubis (the pubic louse) involving the lashes and

lid margins can initially present as

conjunc-tivitis but observation of nits on the lashes

should give away the diagnosis

Allergic Conjunctivitis

Several types of allergic reaction are seen on the

conjunctiva and some of these also involve the

cornea They may be listed as follows:

Hay Fever Conjunctivitis

This is simply the commonly experienced red

and watering eye that accompanies the sneezing

bouts of the hay fever sufferer The eyes are itchy

and mildly injected and there might be

con-junctival oedema If treatment is needed,

vasoconstrictors, such as dilute adrenaline or

naphazoline drops, can be helpful; sodium

cromoglycate eye drops can be used on a more

long-term basis Systemic antihistamines are of

limited benefit in controlling the eye changes

Atopic Conjunctivitis

Unfortunately, patients with asthma and eczema

can experience recurrent itching and irritation

of the conjunctiva Although atopic

conjunc-tivitis tends to improve over a period of many

years, it might result in repeated discomfort and

anxiety for the patient, especially as the cornea

can become involved, showing a superficial

punctate keratitis or, in the worst cases, ulcer

formation and scarring

The diagnosis is usually evident from the

history but conjunctival scrapings show the

presence of eosinophils Patients with atopic

keratoconjunctivitis have a higher risk thannormal for the development of herpes simplexkeratitis; the condition is also associated withthe corneal dystrophy known as keratoconus orconical cornea They are likely to develop skininfections and chronic eyelid infection bystaphylococcus The recurrent itch and irrit-ation (in the absence of infection) is relieved byapplying local steroid drops, but in view of thelong-term nature of the condition, these should

be avoided if possible because of their sideeffects (Local steroids can cause glaucoma inpredisposed individuals and aggravate herpessimplex keratitis.)

Vernal Conjunctivitis (Spring Catarrh)

Some children with an atopic history candevelop a specific type of conjunctivitis charac-terised by the presence of giant papillae underthe upper lid The child tends to developseverely watering and itchy eyes in the earlyspring, which can interfere with schooling.Eversion of the upper lid reveals the raisedpapillae, which have been likened to cobble-stones In severe cases, the cobblestones cancoalesce to give rise to giant papillae (Figure6.5) Occasionally, the cornea is also involved,initially by punctate keratitis but sometimes itcan become vascularised It is often necessary

to treat these cases with local steroids, forexample, prednisolone drops applied if neededevery two hours for a few days, thus enabling thechild to return to school The dose can then bereduced as much as possible down to a main-tenance dose over the worst part of the season.More severe cases can derive some benefit from

Figure 6.5 Vernal conjunctivitis (spring catarrh) papillary

reaction.

topical cyclosporin drops, or eyelid injections of

triamcinolone to control the inflammatory

response Less severe cases can respond well to

sodium cromoglycate drops; these can be

useful as a long-term measure and in

prevent-ing but not controllprevent-ing acute exacerbations

Other medications with a similar modest

benefit in symptoms include lodoxamide (a

mast cell stabiliser) and emedastine (a topical

antihistamine)

Secondary Conjunctivitis

Inflammation of the conjunctiva can often

be secondary to other more important

pri-mary pathology The following are some of the

possible underlying causes of this type of

Lacrimal obstruction can cause recurrent

unilateral purulent conjunctivitis and it is

important to consider this possibility in

recal-citrant cases because early resolution can be

achieved simply by syringing the tear ducts

Corneal ulceration from a variety of causes is

often associated with conjunctivitis and here

the treatment is aimed primarily at the cornea

Occasionally, the presence of one of the two

common acquired lid deformities, entropion

and ectropion, can be the underlying cause

Sometimes the diagnosis may be missed,

esp-ecially in the case of entropion, when the

defor-mity is not present all the time Other lid

deformities can also have the same effect A

special type of degenerative change is seen in

the conjunctiva, which is more marked in hot,

dry, dusty climates It appears that the

com-bination of lid movement in blinking, dryness

and dustiness of the atmosphere and perhaps

some abnormal factor in the patient’s tears or

tear production can lead to the heaping up of

subconjunctival yellow elastic tissue, which is

often infiltrated with lymphocytes The lesion is

seen as a yellow plaque on the conjunctiva in the

exposed area of the bulbar conjunctiva and

usually on the nasal side Such early

degener-ative changes are extremely common in all

climates as a natural ageing phenomenon, butunder suitable conditions the heaped-up tissuespreads into the cornea, drawing a triangularband of conjunctiva with it The eye becomesirritable because of associated conjunctivitisand in worst cases the degenerative plaqueextends across the cornea and affects the vision.The early stage of the condition, which iscommon and limited to a small area of the con-junctiva, is termed a pingueculum and the moreadvanced lesion spreading onto the cornea isknown as a pterygium (Figure 6.6) Pterygium

is more common in Africa, India, Australia,China and the Middle East than in Europe It israrely seen in white races living in temperate cli-mates Treatment is by surgical excision if thecornea is significantly affected with progressiontowards the visual axis; antibiotic drops might

be required if the conjunctiva is infected infective inflammation of pterygium is treatedwith topical steroids

Non-Finally, when considering secondary causes

of conjunctivitis, one must be aware thatredness and congestion of the conjunctiva withsecondary infection can be an indicator of sys-temic disease Examples of this are the red eye

of renal failure and gout, and also polycythemiarubra The association of conjunctivitis, arthri-tis and nonspecific urethritis makes up the triad

of Reiter’s syndrome Some diseases causeabnormality of the tears and these have alreadybeen discussed with dry eye syndromes, themost common being rheumatoid arthritis.However, there are other rarer diseases thatupset the quality or production of tears, such assarcoidosis, pemphigus and Stevens–Johnsonsyndrome Thyrotoxicosis is a more common

Figure 6.6 Pterygium.