Ophthalmology

Question 1

The Eyelid - Definition/Functions

Answer 1

The eyelid acts as protection from excessive light. It also protects against foreign bodies as well as spreading lubrication secretions over the eyeballs.

• The eyelid consists mainly of voluntary muscle, with a border of thick connective tissue known as the tarsal plate. This plate is felt as a ridge when everting the eyelid.
• The eyelid also contains eyelashes which also help protect the eye. At the base of these eyelashes sebaceous ciliary glands release lubricating fluid; it is these glands that if infected cause styes.

Question 2

The Conjunctiva - Definition/Function

Answer 2

This is a transparent, this continuous mucous membrane that covers the inside of the eyelids (palpebral conjunctiva) and the sclera(bulbar conjunctiva).

• It acts as a protective layer to the eye.
• Dilaton and congestion of blood vessels of the bulbar conjunctiva cause red eye.

Question 3

The Sclera - Definition/Function

Answer 3

The sclera encircles the eye, apart from a small window at the very front of the eye where the cornea is located.
- It is often referred to as the white of the eye.
- It gives shape and ridgidity to the eyeball.

Question 4

The Cornea Definition/Function

Answer 4

The transparent cornea allows light to enter the eye and helps coverge light into the retina.

Question 5

The Iris - Definition/Function

Answer 5

The iris is the coloured part of the eye.
- Its main function is to regulate the amount of light entering the eyeball through the pupil.
- It is an incomplete circle with a hole in the middle for the pupil.
- The iris attaches to the ciliary body, which serves to hold the lens in place

Question 6

The Pupil - Definition/Function

Answer 6

Where light enters the eye.

Question 7

The Ciliary Body - Definition/Function

Answer 7

The ciliary body produces the aqueous, a watery solution that bathes the lens.
- THis is manufactured behind the iris, travels though the posterior chamber and the pupil before draining at the anterior chamber angle (where the iris meets the cornea). If this exit becomes blocked then the intraocular pressure of the eye becomes elevated.

Question 8

The Lens - Definition/Function

Answer 8

The lens is responsible for fine focusing light onto the retina. It posesses the ability to vary its focusing power. However this variable focus power is lost with increasing age, as the lens grows harder and less elastic.
- This is the reason so many need reading glasses as they get older.

Question 9

The Retina - Definition/Function

Answer 9

The retina is the light-sensitve layer of the eye and the start of the visual pathway.
- The functioning of the layer can be compromised by many factors, such as underlying disease states (e.g. age-related macular degeneration) and foreign bodies casuing retinal damage/detachment.

Question 10

Conjunctivitis

Answer 10

Conjunctivitis simply means inflammation of the conjunctiva(the membrane covering the anterior white part of the eye(sclera) and the inside of the eyelids)

• It is characerised by varying degrees of ocular redness(generalised with worse intensity towards corners of eye/away from pupil), irritation/Gritty/foreign body sensation,** itching** and discharge(the conjunctiva on the inside of the eyelids contain cells that produce mucus and glands that produce tears, and when inflammed more of these are secreted)
• Redness will be more generalised &/or be towards the fornices(corner of eye)
• Only one eye may be affected initially, but symptoms may afect both within a few hours
• It appears to affect both sexes equally.
• Seen in all ages but more common in children and the elderly.
• Can be Bacterial, viral or Allergic in origin.
• All three types are self-limiting, viral can be recurrent and last for many weeks though.
• It is difficult to differentiate between the types, particualry bacteria and viral.

Question 11

Types Of Conjunctivitis

3

Answer 11

Bacterial
Viral
Allergic

Question 12

Viral Conjunctivitis

Answer 12

Causes: Adenovirus is mose commonly implicated

**Differentiable Symptoms: **
Eyes Affected - both
Discharge - Watery
Pain - Gritty Feeling
Distribution of Redness - Gneralised
Associated Symptoms - Cough and cold symptoms

Management:
- No OTC products available
- Strict hygeine measures recommended; e.g. not sharing towels/pillows, washing hands frequently with warm soapy water; avoiding touching eye area…)

Counselling:
- Will be infectious until redness and weeping resolves.
- Usually lasts 10-12 days
- No need to saty off school/work but check individual compamny policy in case differs.

Question 13

Bacteria Conjunctivitis

Answer 13

**Causes: **
- Adults (Staphylococcus species(>50% cases); Streptococcus Pneumoniae (20%); Moraxella species(5%); Haemophilus influenzae(5%).
- Children (Streptococcus, Moraxella & Haemophilus most common).

**Differentiable Symptoms: **
Eyes Affected - Usually starts in one eye with the other often affected within first 24-48 hours.
Discharge - is purulent and sticky. Often eyes can be glued together in the absence of itching, espicially upon wakening.
Pain - gritty feeling
Distribution of Redness - Generalised & diffuse
Associated Symptoms - none

Management:
- Frequently self-limiting (resolves within 2-5 days without treatment).
- Self help measures generally advised: if symptoms arent improving within 5 days of using these though reassessment should be done and topical antibiotics considered.
- Topical antibiotics can help improve the rate of remission & decrease replase; Chloramphenicol eye drops 0.5%(Golden eye antibiotic drops/optrex infected eye drops.generic) (one drop into affected eye every 2 hours for first 48 hours then QTD to 5 days) or Chloramphenicol eye ointment 1%(generic/golden eye antibiotic ointment/optrex infected eye ointment) (QTD use for 5 days) can be given OTC as P meds to anyone over 2 years of age.
- Older treatment; Propramidine isetionate(Brolene eye drops/golden eye drops); Dibromopropamidine Isethinoate (golden eye ointment) in those 12Y+
- Symptoms usually settle down in a few days - 5 days of treatment is usually adequate and what would give OTC.

Counselling:
- Wash hands reguarly using warm soapy water, especially after touching eye area.
- Avoid sharing towels/pillows
- Use hot water and detergent to wash pillows/towels/face cloths.
- Avoid rubbing eyes
- Contact lenses - avoid wearing until infection completely cleared and been >24 hours since any treatment finished (serious unlceration can occur if lenses are left in with bacterial conjuncitivitis). Avoid reusing old lenses/lens cases as re-infection can occur, even if symptoms have resolved.
- If there is stickly discharge gently cleaning the outside of the affected eye(s) with a cotton wool soaked in water recommended.
- Lubricating drops and cold compresses to eye area can reduce discomfort.
- No need to stay off school/work; check individual nursery/school policy though.
- Drops/ointment can blurr vision, do not drive or oporate heavy machinary until vision clear.

Referral:
- Persists for >1 week (further investigations needed)
- Eye becomes markedly painful
- Photophobia
- Marked redness
- Vision affected

Question 14

Allergic Conjunctivitis

Answer 14

Causes: Pollen usually causes seasonal allergic conjunctivitis.

Differential Symptoms:
Eyes Effected - Both
Discharge - Watery
Pain - ithcing
Distribution of redness - Generalised but greatest in fornices.
Associated symptoms: Rhinitis (may also have family histroy of atopy/ often occurs in hay fever season, though can occur due to general allergy outwith these season e.g. pet allergy
- conjunctiva can sometimes become swollen/oedematous

Referral:
- Doubt over cause (e.g. if infection or allergy)

Management
- Avoid allergen as much as possible

Prophylatic Medication Advocated;
- Ocular mast cell stabilisers(sodium cromoglicate)
- Sympathomimetics (Naphazoline- e.g. optrex bloodshot eye drops/Murine itrritation and redness reilef drops/Murine bright and moist eyes/Optrex brightining drops)
- Antihistamines (Antazoline- e.g. otrivine Antistin eye drops in combo with sympathomimetic xylometazoline)

Question 15

Causes Of Red Eye & Their Relative Incidence In Community Pharmacy

Answer 15

Most Likely: Bacteria or Allergic Conjunctivitis.
Likely: Viral Conjunctivitis, Subconjuncctival haemorrhage.
Unlikely: Episcleritis, Scleritis, Keratitis, uvelitis
Very Unlikely: Acute Closed-angle glaucoma.

Question 16

Referral Criteria For Red Eye

Answer 16

• Redness not associated with subconjunctival haemorrhag/allergic conjuncitivits lasting more than 1 week
• Vomitting
• History of trauma/injury to eye
• Eye Pain
• Eye Inflammation associated with a rash on the face or scalp
• Vision affected
• Swelling around face/eye
• Suspected foreign body in eye(s)
• Recent eye infection, including conjunctivitis
• Pt has Glaucoma
• Pt has Dry eye syndrome
• Uncertainty surrounding diagnosis
• Pregnancy/Breastfeeding
• Contraindication to chloramphenicol/on drugs that interact with it.
• Using other eye drops/products
• Redness localised around pupil

**After starting treatment refer people: **
- If symptoms don’t improve after 48 hours of treatment with chloramphenicol
- If symptoms worsen within two days, or worsen at anytime
- If the person experiences any side effects.
- New infection occurs

**Urgent referral to a hospital eye casualty or accident and emergency department: **
- If the person is experiencing severe symptoms
- If the person has a cloudy looking eye, especially around cornea(sugests glaucoma)
- If the person has an unusual looking pupil, e.g. torn, irregular, dilated, or sluggish/non-reactive to light
- If the person has affected vision, e.g. vision loss, reduced vision, blurred vision, double vision and halos around lights 
- If the person has photophobia (abnormal sensitivity/intolerance to light)
- If the person has painful eye movements
- If the person has significant eye pain
- If the person has worsening symptoms despite chloramphenicol use
- If contact lenses have been worn in the shower, or the eye with the contact lens has come into possible contact with water
- If the person has an eye or head injury
- If the person had eye surgery or laser treatment within the past six months.

Question 17

Subconjunctival Haemorrhage

Condition To Eliminate In Red Eye - Likely Cause Of Red Eye

Answer 17

Definition: The rupture of a blood vessel under the conjunctiva causes subconjunctival haemorrhage.

**Symptoms/Features: **
- A segment of, or even the whole eye will appear bright red.
- There is no pain
- Sudden onset

Causes: It occurs spontaneously, but can be precipitated by coughing, straining or lifting.

Managerment:
- Symptoms should resolve in 10-14 days without treatment.

Referral Criteria:
- History of trauma to exclude ocular injury.
- high blood pressure suspected
- pain present
- unexplained bleeding/bruising elsewhere

Question 18

Episcleritis

Condition To Eliminate In Red Eye - Unlikely Cause Of Red Eye

Answer 18

Definition: The episclera lies just beneath the conjunctiva and adjacent to the sclera. If this becomes inflamed the eye appears red.

**Symptoms/Features: **
- Redness is segmental, affecting only part of the eye.
- Affects only ONE eye in majority of cases
- Usuall painless, but a dull ache may be present.
- Most common in young women
- Discharge is rare/absent

Managerment
- Self-limiting, resolving in 2-3 weeks (but can take 6-8 weeks for symptoms to disappear).

Question 19

Scleritis

Condition To Emilinate In Red Eye - Unlikley Cause Of Red Eye.

Answer 19

Definition: Inflammation of the sclera

Symptoms/Features:
- Often associated with autoimmune diseases
- Much less common than episcleritis
- Presents similarly to episcleritis
- Pain (generally severe) is a predominant feature, eye movement can worsen this
- Blurred vision also prominant feature
- Tends to affect older patients (mean presentation age is in the early 50s)
- Discharge is rare/absent

Question 20

Topical Chloramphenicol (golden eye antibiotic ointment, optrex infected eye, generic…)- Contrainidcations

OTC supply

Answer 20

• Children under 2 years
• Pregnant/Breastfeeding women
• Hypersensitivity or allergies to chloramphenicol or ony other ingredients
• Pt has experienced blood disorders or bone marrow problems during or after previous chloramphenicol use (e.g. myelosupression)
• Family History of: Bone marrow problems, Blood dyscrasias(e.g. aplastic anaemia).

Question 21

Topical Chloramphenicol - Administration Instructions

OTC Supply

Answer 21

Drops
- One drop into the affected eye(s) every 2 hours for the first 48 hours, then decrease the dose to every four hours for remaining 3 days
- during waking hours only

Ointment
- if using alone apply approximately one cm of ointment between the lower eyelid and eye THREE to FOUR times a day for 5 days.

Both - treatment is 5 days total, and 5 days should be completed even if feel better and symptoms have improved before the 5 days is up.
- if pt has been given both ointment and drops, drops should be used during the day and ointment at night.

Question 22

Topical Chloramphenicol - Side effects

Answer 22

Transient burning or stinging sensation in eye(s) after use.

Serious Side Effects - Referral Level
- Eye Disorders; blurred vision, pain, swelling, irritation
- Hypersensitivity Reactions; e.g. rashes, fever, angiooedema(a vascular reaction involving the deep dermis or subcutaneous or submucosal tissues, characterised bu the development of giant wheals), uticaria & anaphylaxis.
- Rashes; vesicular & maculopapular (characterised by bumps or blisters)
- Bone Marrow Problems, including the idiosyncratic type of irreversible and fatal aplastic anaemia recognised to occur with systmic therapy has been reported with the topical administration of chloramphenicol.
[chloramphenicol is absorbed systemically from the eye(s) - systemic toxicity has been reported]

Question 23

Topical Chloramphenicol - Pregnancy & Breastfeeding

Answer 23

• Cannot be used while breastfeeding
• Cannot be used in pregnancy
  [BNF has as avoid unless essential in both, therefore woiuld not give OTC if these were present]

Question 24

Topical Chloramphenicol - Interactions

Answer 24

Bone marrow depressant drugs.

• Refer anyone with a clinically relevant interactions to their prescriber.

Question 25

Topical Chloramphenicol - Storage Requirements Of Products

Answer 25

Drops: store in a refrigerator between 2-8 degrees c.

Ointment: store at no more tan 25 degrees c.

Any remaining products should be discarded after the 5 day course of treatment.

Question 26

Keratitis (Corneal Ulcer)

Condition To Eliminate In Red Eye - Unlikely Cause Of Red Eye.

Answer 26

Definition: Inflammation of the cornea.

**Causes: **
- Recent trauma (e.g. eye abrasion/foreign object/infection(bacterial/herpes simplex))
- Long term administration of steroid drops
- Overwear of soft contact lenses/contact lense use in general can increase risk; especially if poor hygiene with use/swimming with them.
- UV damage; sunbed/welding torch

**Symptoms/Features: **
- Pain; can be very severe, is a prominant feature - corena is especially sensitive
- Photophobia
- Worsening of redness around iris (limbal redness)
- Watery Discharge
- Loss of visual acuity on examination, often accompanied by a small pupil

Management
- Immediate to optometrist/GP(OOH if required)/A&E if suspected keratitis as loss of sight possible if left untreated due to permament scarring.
- Diagnosing will require using fluorescein drops under UV light if early ulcer.
- Superficial ulcers caused by such trauma will usually heal quickly. Through e.g. simply leaving the lens out if caused by these. Often a short course of antibiotic eye drops or ointment is also supplied to prevent secondary infection.
- Severe ulcers and keratitis caused by infection require assessment and treatment by specialists at an eye hospital.

Question 27

Uveitis (iritis)

Condition To Eliminate In Red Eye - Unlikely Cause Of Red Eye

Answer 27

Definition: Describes inflammation involving the uveal tract (iris, ciliary body & choroids).

**Causes: **The likley cause is an antigen-antibody reaction, which can occur as part of a systemic disease such as rheumatoid arthirits or ulcerative colitis.
- Sometimes just occurs as an isolated event with no obvious cause.
- In some cases, infection seems to be the trigger.

Symptoms/Features:
- Most commonly seen in individuals between 20 & 50 years.
- Photophobia
- Deep eye pain, which is felt more within the eye than the superficial gritty pain of conjunctivits.
- No discharge present.
- Redness; often localised to the limbal area (known as the ciliary flush - cornea)
- It mostly affects both eyes, but may be unilateral.
- Pupil irreguarly shaped due to muscel spasm, constriced/contracted or fixed
- Patient may have impaoired reading vision/blurred vision

Management:
- Immediate referral to a medical practitioner/specialsit is needed.
- will most likley require topical corticosteroids to reduce inflammation and products to paralyse and dilate the iris.

Question 28

Acute Closed-Angle Glaucoma

Condition To Eliminate In red Eye - Very Unlikely Cause Of Red Eye

Answer 28

Definition: Therea are 2 main types of glaucoma;
- Simple chronic open-angle glaucoma which dose not cause pain[this develops slowly, affecting the vision as the optic nerve is slowly damaged. Opticians can pick this up on examination of the eye, so its important people get regular eye check ups, especially if there is a family history of glaucoma].
- Acute closed-angle glaucoma which can present with a painful red eye.
- It is due to inadequate drainage of aqueous fluid from the anterior chamber of the eye, which results in a rapid increase in intraocular pressure.

**Causes: **
Fim light can precipate an attack

Symptoms/Features:
- Onset can be very quick
- Characteristically occurs in the evening
- Severe unilateral eye pain associated with a headache on the same side.
- Red eye
- May be cloudy
- Vision blurred/decreased
- Pt may experience haloes around lights
- Vomitting often experienced due to rapid risk in intraocular pressure
- Classically occurs in older, far sighted patients.

Management:
- Immediate referral to an emergency department for acute closed-angle glaucoma is required as the extreme pressure within the eye rapidly damaged the optic nerve.
- After lowering the pressure with drugs, surgery or lazer treatment is usually required to remove part of the iris - this lowers the pressure and should prevent it from re-occuring.

Question 29

Propamidine Isethionate (Brolene Eye Drops)

Bacterial Conjunctivitis Treatment

Answer 29

Indication/Activity: Propamidine isetionate is an aromatic diamidine disinfectant which is active against Gram-positive non-spore forming organisms, but less active against Gram-negative bacteria and spore forming organisms. It also has antifungal properties. It may be used topically for the treatment of minor eye infections such as conjunctivitis and blepharitis.
> 12Y+ age restriction

Administration: One or two drops up to four times daily. Medical advice should be obtained if there has been no significant improvement after two days.

Contraindications: Hypersensitivity to propamidine or any other component of the preparation.

Cautioned Use:
Brolene should be used with caution in dry eye patients and in patients where the cornea may be compromised - due to effect benzalkonium(exicipient) can have on tear and corneal surfaces.

Referral With Use:
- If vision is disturbed or symptoms become worse during therapy, discontinue use and consult a physician.
- If there is no significant improvement after two days’ therapy, discontinue use and consult a physician.

Side-Effects:
Benzalkonium chloride(exipient) has been reported to cause eye irritation, symptoms of dry eyes and may affect the tear film and corneal surface.
- Hypersensitivity
- Eye pain or irritation, usually in the form of a stinging or burning sensation, may also occur. In such cases, use should be discontinued immediately and a physician should be consulted.
- Blurred vision upon administration

Counselling:
- The eye drops are unsuitable for use with hard or soft contact lenses.Can discolour them, remove before use with product and for 15 minutes after.
- The drops should be discarded 28 days after first opening for domiciliary use or, when used under hospital conditions, seven days after first opening.

Pregnancy/Breastfeeding
- Not been established, only use if under directions of physician so not for OTC sale.

Question 30

Sodium Cromoglicate (Ocular Mast Cell Stabiliser)

Allergic Conjnctivitis Treatment

Answer 30

Indication: For the relief and treatment of seasonal and perennial allergic conjunctivitis.
> Contraindicated in under 2Y but also no relevant indication for use in children under 6Y so wouldnt sell for this age group either.

Administration:
Adults & Children 6+ = One or two drops to be administered into each eye four times daily.
- Is a prophylatic agent so needs to be given continuously while patient exposed to allergen to work.

Contraindications:
Hypersensitivity to the active substance or to any of the excipients listed in section

Cautioned Use:
Benzalkonium chloride(excipient) has been reported to cause eye irritation, symptoms of dry eyes and may affect the tear film and corneal surface. Should be used with caution in dry eye patients and in patients where the cornea may be compromised.

Counselling:
- Discard any remaining contents four weeks after opening the bottle.
- As with other ophthalmic solutions containing benzalkonium chloride, soft contact lenses should not be worn during the treatment period.

Side-Effects:
- Transient stinging and burning may occur after instillation. Other symptoms of local irritation have been reported rarely.
- Blurred vision upon administration

Interacgtions:
- none

Pregnancy/Breastfeeding
No information on subjuect but not thought to be harmful so ok to use.

Question 31

Naphazoline - Optrex Blood Shot Eye Drops
(Ocular Sympathomimetic)

Allergic Conjunctivitis Treatment

Answer 31

Indication: For temporary relief of redness of the eye due to minor eye irritations.
- 12Y plus

Administration:
12Y+) Gently squeeze one to two drops into the corner of each eye. No more than 4 times daily.

Contraindications
- Hypersensitivity to hamamelis water, naphazoline, or to any of the excipients.
- This product is contraindicated in persons suffering from closed-angle glaucoma.
- Do not take if you are suffering from serious eye disease or have had previous eye surgery.
- Do not use while taking monoamine oxidase inhibitors or within 14 days of stopping this medication.
- Not to be used in children younger than 12Y.
- This product must not be administered while soft (hydrophilic) contact lenses are worn. Soft contact lenses must be removed prior to use and reinserted after a minimum of 15 minutes.

Cautioned Use:
- Benzalkonium chloride may be absorbed by soft contact lenses and may change the colour of the contact lenses. You should remove contact lenses before using this medicine and put them back 15 minutes afterwards.
- Benzalkonium chloride has been reported to cause eye irritation, symptoms of dry eyes and may affect the tear film and corneal surface. Should be used with caution in dry eye patients and in patients where the cornea may be compromised. Patients should be monitored in case of prolonged use.
- If you are being treated for high blood pressure, depression, heart disease, arteriosclerosis, diabetes or increased thyroid activity consult your doctor before using the drops as naphazoline may exacerbate vasoconstriction. For the same reason this product should not be used as a long term ocular irrigant.
- Use of naphazoline in the eye may liberate pigment granules from the iris, especially when given in high doses to elderly patients

Interactions:
- May interact with other topically applied autonomic drugs used in the treatment of glaucoma.
- May interact with monoamine oxidase inhibitors and should not be used by patients receiving such treatment or within 14 days of ceasing therapy.
- May reverse the antihypertensive action of drugs used in the treatment of hypertension.
- There may be an increased risk of arrhythmias in patients receiving cardiac glycosides, quinidine or tricyclic antidepressants.

Side-Effects
- Hypersensitivity
- Headache, dizziness
- Eye irritation/eye pain/ocular hyperaemia
- Nausea
- Following long term use a rebound secondary hyperaemia may occur.

Counselling:
- Discard any eye drops remaining 28 days after opening the container.
- Continued use of this product may increase redness of the eye; rebound effects!!!
- If you experience eye pain, changes in vision or continued redness of the eye, or if the condition worsens or persists for more than 24 hours consult a doctor.
- If the solution changes colour or becomes cloudy do not use.
-Will not treat underlying pathology causing redness but reduce its appearance by constricitng blood vessels in the conjunctiva.

Pregnancy/Breastfeeding
Not studied, but not shown to be a risk so probably ok.

Question 32

Antazoline with xylometazoline - Otrivine Antistin
[Antihistamine + Sympathomimetic]

Answer 32

Indication: For the temporary relief of redness and itching of the eye due to seasonal and perennial allergies such as hay fever or house dust allergy.
- 12Y+

Administration:
Adult - 1 or 2 drops instilled 2 to 3 times a day.
Child 12Y+ - 1 drop instilled 2 to 3 times a day.
Elderly - 1 drop instilled 2 to 3 times a day.

Contraindications:
- Hypersensitivity to the active substances to any of the excipients listed in section
- Presence of narrow angle* glaucoma*
- Use with contact lenses
- Use in patients receiving monoamine oxidase inhibitors or within 14 days of stopping such treatment
- Not suitable for patients suffering from dry eyes without first seeking medical advice.

Cautions:
- Otrivine-Antistin may be absorbed systemically and occasionally cause systemic sympathomimetic effects such as hypertension, nervousness, nausea, dizziness, headache, insomnia, palpitations, tachycardia, and arrhythmia.
- Caution in elderly patients with severe cardiovascular disease, including arrhythmia, poorly controlled hypertension or diabetes.
- Use with caution in the presence of hypertension, cardiac irregularities, hyperthyroidism, diabetes mellitus or phaeochromocytomas.
- Patients with long QT syndrome treated with xylometazoline may be at increased risk of serious ventricular arrhythmias.
- Otrivine-Antistin should also be used with caution in patients with conditions causing urinary retention such as prostatic hypertrophy.
- Should also be used in caution in patients who are currently receiving other sympathomimetic drugs
- Rebound hyperaemia may follow prolonged frequent use.

Interactions
- This product should not be used in patients receiving monoamine oxidase inhibitors or within 14 days of stopping such treatment
- Sedating anti-histamines can enhance the sedating effects of CNS depressants including alcohol, hypnotics, opioid analgesics, anxiolytic sedatives and anti-psychotics. They also have an additive anti-muscarinic action with other anti-muscarinic drugs, such as atropine and some antidepressants. Otrivine-Antistin should be used with caution in patients receiving other medications such as digitalis, beta-adrenergic blockers, guanethidine, reserpine, methyldopa or anti-hypertensive agents
- Concurrent use with halogenated anaesthetic agents such as chloroform, cyclopropane, halothane, enflurane or isoflurane may provoke or worsen ventricular arrhythmia

Counselling
- Avoid allowing the tip of the dispensing container to contact the eye or surrounding structures as this may contaminate the solution.
- If more than one medication needs to be instilled in the eye, an interval of at least 5 minutes between application of the different medicinal products must be allowed.
- If the symptoms do not improve after 2 days, medical advice should be sought to rule out the possibility of a bacterial infection. Inflammation arising from infection should receive appropriate anti-bacterial therapy.
- Benzalkonium chloride may cause eye irritation, especially with dry eyes or disorders of the cornea. Patients should be instructed to talk to a doctor if they feel abnormal eye sensation, stinging or pain in the eye after using this medicine.

Side-Effects:
- Local Irritation; stinging, burning
- Potentially systemic symptoms.

Pregnancy/Breastfeeding
- Not recommended unless essential - this would be under practitioner advise not OTC therefore;
- Breast feeding should be interrupted for 48 hours after administration if used during.
Otrivine-Antistin may impair fertility in the future as it contains boron. It should therefore not be administered to a child less than 2 years old.

Question 33

General Eye Drop Administration Counselling

Answer 33

• Wash your hands
• Tilt your head backwards until you can see the ceiling
• Pull down the lower eyelid by pinching outwards to form a small pocket, and look upwards
• Hold the dropper in the other hand as near as possible to the eyelid without touching it
• Place one drop inside the lower eyelid, and then close your eye
• Wipe away any excess drops from the eyelid and lashes with the clean tissue
• Repeat steps 2–6 if more than one drop needs to be administered

Wait at least 5 minutes between products if need to administer more than one set of eye drops. If using an ointment, make sure you use drops first and then ointment.

Question 34

General Eye Ointment Administration Counselling

Answer 34

• Pull down the lower eyelid
• Place a thin line of ointment along the inside of the lower eyelid
• Close your eye, and move the eyeball from side to side
• Wipe away any excess ointment from the eyelids and lashes using a clean tissue
• After using ointment, your vision may be blurred but will soon be cleared by blinking

Question 35

Causes of eyelid disorders and their relative incidence in community pharmacy

Answer 35

Most likely: Blepharitis, Hordeola(stye)
Likely: Contact or Irritant Dermatitis
Unlikely: Chalazion, Ectropion, Entropion, Dacryocystitis
Very unlikely: Orbital cellulitis, Carcinoma

Question 36

Hordeola (Styes)

Answer 36

Definition:
- Styes are caused by bacterial infection (staphylococcal in 90%–95% of cases) & can be internal or external.
- External styes occur on the outside surface of the eyelid and are due to an infected gland, the Zeis gland (a type of sebaceous gland) or the gland of Moll (a type of sweat gland), both of which are located near the base of the eyelashes.
- An internal hordeolum is a secondary infection of the meibomian gland in the tarsal plate
- Occasionally, internal styes can evolve into a chalazion, a granulomatous inflammation that develops into a painless lump.

Differential Signs/Symptoms:
- Typically presents as an acute, painful, localised eye swelling that develops over a few days.
- If *external *the stye presents as a swollen upper or lowe lid which will be painful/sensitive to touch. A small yellow pus-filled lesion may be visible; this will spontaneously shrink and resolve or burst within a few days.
- If an internal stye is present; pt will present with similar symptoms to that of an external stye (pain, redness and swelling) but the pain tends to be more severe, and the pus filled lesions are not obvious due to inward growth. If the eye was to be inverted in these cases localised swelling should become visible.

Management:
- Topical application of ocular antibiotics does not result in speedier symptom resolution, but it might prevent a subsequent staphylococcal infection from a lash lower down.
- A warm compress applied for 5–10 minutes three or four times a day can bring an external stye to a head and, once it bursts, the pain will subside, and the symptoms will resolve.
- Painkillers for discomfort.
- The use of dibromopropamidine has been advocated in the treatment of styes but is of unproven benefit.

Counselling:
- Self-limiting (1-2 weeks duration typically)
- Although styes are caused by bacterial pathogens, the use of antibiotic therapy is not usually needed.
- Do not try to burst a stye or remove an eyelash yourself. This can spread the infection.
- Avoid wearning contact lenses/eye makup whilst have stye.
- Wash face/makeup off before bed
- Replace makeup every 6 months

Question 37

Blepharitis

Also a condition to eliminate in dry eyes - likley cause in this.

Answer 37

Definition: Inflammation of the margins of the eyelids.
- Three aetiologies; Staphylococcal, Seborrhoeic, Meibomian Gland Dysfunction
- Further Classification; sometimes used based on its anatomical location. For example, anterior blepharitis refers to staphylococcal and seborrhoeic causes because they primarily affect the bases of the eyelashes. Posterior blepharitis refers to meibomian gland dysfunction because these are situated on the posterior lid. Often presents with signs and symptoms for mixed aetiology.

**Symptoms/Features: **
- Involves the eyelids & eyelashes
- Typically a longstanding history of sore eyes
- Itchy, stinging, burning of the eyelid margins.
- Lids may appear red/raw; with redness/Inflammed area tending to covers most of the eyelid margin.
- Often accompanies with excessive tearing, crusty debris/skin flakes around the eyelashes.
- Tends to be bilateral
- Tends to be worse in the mornings, and some pts may complain of eyelids being stuck together.
- Tends to be a chronic condition, with intermittant symptoms of exacerbations/remission.
- Often in chronic cases madarosis(missing eyelashes) &/or trichiasis(inturned eyelashes- which can locally irritate and result in conjunctivitis) can occur.
- Some patients develop meibomian gland dysfunction with blockage or impairment of meibomian secretions which stop the lipid component of the tear film woerking effeciently and contributes to dry eye symptoms.
- Tends to be a chronic condition
- mean age of occurance is 50Y
- In some patients, there is an association with dry eye syndrome, acne rosacea or seborrhoeic dermatitis
- Conjunctivitis is a common complication of blepharitis.

A seborrhoeic aetiology is likely if greasy crusting of the lashes and oily scale predominate compared with eyelash loss or misdirection, which suggests a staphylococcal cause.

Management:
- Good eyelid hygeine; place warm cotton wool pad/flannel(or heated eye mask) on the closed eye for 5-10 minutes OD or BD to help loosen meibomian secretions; Massage eyelids gently for 30 seconds; and Clean the eyelids by wetting a cloth or cotton bud with cleanser(e.g. baby shampoo diluted 1:10 with warm water) and wiping along the lid margins BD to begin with and can be reduce to OD when symptoms improve. This washing helps clear the debris and reduced the inflammation of the eyelid margins and should be continued even when symptoms improved.
- Because blepharitis can cause dry eye, prescribing an ocular lubricant (e.g., hypromellose, carbomer) can be tried.
- Topical Antibiotics; sometimes used for flare ups/if there are signs of staphylococcal infection present (POM indication though - fusidic acid or systemic oxytetracycline treatment) so would need to refer pt on if suspected required. Longterm treatment is often required for this (6 weeks/+).

Counselling:
- Treatment is not to cure(condition cant be cured) but can control symptoms and prevent complications; however, periodic relapses and exacerbations can occur.
- Dont wear contact lenses while have symptoms
- Avoid makeup while have symptoms
- Cant be spread to other people
- Eye ointments can aggravate blepharitis; if so, careful lid cleaning in the morning will help.

Referral
- Topical Antibiotics required
- Confirmation of the diagnosis and initiation of treatment is best done by optometrist/GP/eye specialist

Question 38

Contact Or Irritant Dermatitis

Condition To Eliminate In Eyelid Disorders - Likely Cause Of An Eyelid Disorder

Answer 38

Many products – especially cosmetics – can be sensitizing and result in itching and flaking skin that mimics blepharitis. The patient should be questioned about recent use of such products to allow dermatitis to be eliminated

Question 39

Blepharitis Unresponsive To Therapy

Condition To Eliminate In Eyelid Disorders - Likely Cause Of An Eyelid Disorder

Answer 39

If the patient fails to respond to OTC treatment, or the condition recurs, it is possible that another cause, such as rosacea, might be responsible for the symptoms. If OTC treatment has failed, then medical referral is needed as topical antibiotics are probably needed

Question 40

Chalazion

Condition To Eliminate In Eyelid Disorders - Unlikely Cause Of Eyelid Disorder

Answer 40

Definition: A chalazion forms when the meibomian gland becomes blocked.

Symptoms/Features:
- It develops over a number of weeks
- Initially can cause discomfort but becomes painless.
- A lump should be clearly visible if the eyelid is everted.

Management:
- A chalazion is self-limiting, although it might take a few weeks to resolve completely.
- No treatment is needed unless the patient complains that it is particularly bothersome and is affecting vision.

Referral:
- Referral in these cases is needed for surgical removal
- Becoming really bothersome/affecting vision; may need treatment

Question 41

Entropion

Condition To Eliminate In Eyelid Disorders - Unlikely Cause Of Eyelid Disorder

Answer 41

Definition: Entropion is defined as an inversion of the eyelid margin.

Symptoms/Features:
- It can be unilateral or bilateral, with the lower eyelid more frequently affected.
- The in-turning of the eyelid causes the eyelashes to be pushed against the cornea, resulting in ocular irritation and conjunctival redness.
- It is most often seen in older adults due to aging changes making the musculature more lax.

Management:
- Referral/non-urgent just as soon as practical is needed for surgical repair to correct the problem.
- Taping down the lower lid to draw the eyelid margin away from the eye is sometimes employed as a temporary solution.

Question 42

Ectropion

Condition To Eliminate In Eyelid Disorders - Unlikely Cause Of Eyelid Disorder/Dry Eyes

Answer 42

Definition: Ectropion is the converse of entropion; the eyelid turns outward, exposing the conjunctiva and cornea to the atmosphere leading to dryness.

Symptoms/Features:
- Patients will often present complaining of a continually watering eye, but feel like they are dry and sore.
- Paradoxically, this can lead to dryness of the eye because the eye is not receiving adequate lubrication.
- Ectropion is seen with advancing age and often is noted in people who suffer from Bell’s palsy.

Management:
- Referral as soon as practical/not urgent as requires medical intervention to resolve.

Question 43

Dacryocystitis

Condition To Eliminate In Eyelid Disorders - Unlikely Cause Of Eyelid Disorder

Answer 43

Definition: This is an infection of the lacrimal sac caused by a blocked nasolacrimal duct.

Symptoms/Features:
- Symptoms are sudden in onset and cause pain, tenderness, and swelling over the lacrimal sac.
- Fever can also be present.

Question 44

Orbital Cellulitis

Condition To Eliminate In Eyelid Disorders - Very Unlikely Cause Of Eyelid Disorder

Answer 44

Definition: Inflammation of the skin surrounding the orbit of the eye.

Signs/Features:
- The patient will present with unilateral swollen eyelids, be unwell, and might show restricted eye movements.
- It is usually a complication from a sinus infection, although in extreme cases of stye.
- The infection can spread to involve the entire lid and even the periorbital tissues

**Management: **
- This has to be referred immediately A&E level because blindness is a potential complication.

Question 45

Basal Cell Carcinoma

Condition To Eliminate In Eyelid Disorders - Very Unlikely Cause Of Eyelid Disorder

Answer 45

Signs/Features:
- This is the most common form of eyelid malignancy and accounts for over 90% of cases.
- The lesion is usually nodular, with a reddish hue (due to permanent capillary dilation), and most frequently affects the lower lid margin.
- No pain or discomfort is present.
- Long-term exposure to the sun is the main cause.

Management
- Urgent Referral

Question 46

Referral Criteria For Blepharitis & Styes

Answer 46

• Chalazion suspected; may need surgical intervention [Non-urgent but as soon as practically possible for referral]
• Inward/Outward turning of the lower eyelid; Required medical intervention [Non-urgent but as soon as practically possible for referral]
• Patient with swollen eyelids & associated feelings of being unwell; Suggests orbital cellulitis [Immediate to emergency department]
• Middle-ages/elderly patient with painless nodular lesion or near the eyelid; suggests sinister pathology, possible carcinoma [urgent referral required]

Question 47

Keratoconjunctivitis Sicca (Dry Eyes)

Answer 47

Definition: Dry eyes is a frequent cause of eye irritation, causinf varying degrees of discomfort. It is a chronic condition without a cure.

Cause: Dry eye disease is a multifactorial ocular surface disease. It is caused by tear film instability that leads to a loss of homeostasis of the tear film. Environmental and patient factors can result in the instability of the tear film increasing electrolyte concentrations, resulting in dry eye.
- Increasing age
- Drug induced
- Trauma to eye
- Prolonged time between blinking [Usually hand in hand with Prolonged screen time, as tend to blink less here meaning secretions are not disrributed as often and the tear film is unstable]
- Low Humidity/air con

Symptoms/Features:
- Usually affects both eyes
- Symptoms of; burning, feeling tired, itchy, irritated, gritty(sand/gravel in eye), excess watering/blurred vision
- Symptoms worsened as day goes on and by dry air/wind/dust/smoke
- Typically, symptoms fluctuate in intensity and are intermittent, with symptom severity not always correlating with clinical signs.
- More common in women than men
- Prevalence increases with increasing age.
- Persistant issue (>3 month history) on first presentaion if not officially diagnosed.

Management:
Dry eyes are managed by the instillation of artificial tears and lubricating ointments.
- Most cases of dry eyes are mild to moderate and can be managed by the patient using self-care.
- Severe symptoms or those that do not improve with self-care should be referred to the GP or optometrist. Though NHS England in their ‘OTC’ policy advises GPs not to routinely prescribe prepara- tions for dry eyes. This policy states that patients should be encouraged to manage both dry eyes and sore eyes by implementing self-care measures, such as eyelid hygiene and avoidance of environmental factors.
- Extreme cases can result in considerable discomfort and eye ulceration.

Products in the UK consist of hypromellose, polyvinyl alcohol, carmellose, carbomer 980, sodium hyaluronate, and wool fats.
- Evidence of superior efficacy among any of the ophthalmic lubricants is lacking. Choice is based on patient acceptability and adherence as well as sensitivity/allergy to preservatives contained in the product.
- Drops are best for daytime use with ointments or gels reserved for use before bed, as these are most likely to cause temporary blurring of vision. Less viscous formulations are less likely to cause stinging and burning.
- The dosage of all products marketed for dry eye is largely dependent on the patient’s need for lubrication, and is therefore given on an as-needed basis. All products are pharmacologically inert and none are known to interact with any medicine, only cause minimal and transient side effects and can be given to all patient groups(including pregnancy/breastfeeding)
- If more than four to six applications are used daily, consider using a preservative-free product, as the risk of irritation from the preservative increases with the frequency of dosing.
- If a product causes irritation or if soft contact lenses are worn, consider switching to one that is preservative-free – hypromellose, carbomers, polyvinyl alcohol, sodium chloride, carmellose sodium, hydroxyethyl cellulose and sodium hyaluronate are available without preservatives.
- Ointments should not be used during contact lens wear.
- Hypromellose is often used as first-line treatment for most cases of mild-moderate acute dry eye.
- Ocular lubricants containing sodium hyaluronate, hydroxypropyl guar, or carmellose sodium can be used for moderate-to-severe dry eye, but are gener- ally used after a trial of other options.

Counselling/Non-Pharmacological Management:
1. Using warm compresses together with lid hygiene and massage: These can be especially helpful if blepharitis or meibomian gland dysfunction is present. The warmth helps loosen meibomian secretions and can be soothing.

2. Blinking more fully and consistently: Set a 20-min reminder when working at the computer: Stand up and look at a far object for 20 s * Gently close the eyes fully – count 1, 2; Squeeze the lids together – count 1, 2; Open the eyes – count 1, 2; Repeat the exercise five times

3. Indoor environment: Be aware of contributing factors and adjust them where possible:
* Using a humidifier at home and work can help keep the air moist. Opening windows, even for a short time, will refresh and moisten the air.
* If using a computer for long periods, position the monitor below eye level (this decreases eyelid aperture and exposes less of the eye surface to drying), and take frequent breaks (such as every 20 min) to close/ blink eyes – see in the earlier text.
* An air-conditioned environment dries the air and can make symp- toms worse. It will not always be possible to change this aspect of a work environment.

**4. **Outdoor environment: Wearing sunglasses (especially of a wrap-around style) outside will help to protect the eyes from the drying effects of sun and wind.

5. Alcohol and smoking: Excess alcohol will aggravate dry eyes. Stopping smoking and avoiding tobacco smoke should be advised.

6. Modify contact lens wear: Aim to limit contact lens use to shorter periods and remove lenses when dry eye symptoms occur. Changing lens type or solution may help.

7. Medication: Avoid drugs known to aggravate the condition (topical anti- histamine eye drops will make it worse).

8. Omega fatty acids in the diet: Findings from a systematic review sug- gested a possible role for long-chain omega-3 supplementation in managing dry eye disease. The evidence was not definitive, but some patients may wish to try including more foods rich in omega-3 fatty acids in their diet.

Question 48

Causes of dry eye and their relative incidence in community pharmacy

Conditions To Eliminate When Suspect Dry Eyes & The Likelyhood Of Their Presentation.

Answer 48

Most likely: Dry eye syndrome
Likely: Blepharitis, Sjögren syndrome, medicine-induced dry eye
Unlikely: Ectropion, Rosacea
Very Unlikely: Bells’s Palsy

Question 49

Sjögren’s Syndrome

Condition To Eliminate In Dry Eyes, Likley Cause Of Dry Eyes

Answer 49

Definition: This syndrome has an unknown aetiology but is associated with rheumatic conditions.

Symptoms/Features:
- It occurs in the same patient population as dry eye syndrome
- & has very similar symptoms, although symptoms tend to be more severe.
- It is also associated with dryness of other mucous membranes, especially the mouth.
- Tiredness is also common.

Management:
- Refer as soon as practical

Question 50

Medicine-Induced Dry Eye

Condition To Eliminate In Dry Eyes, Likley Cause Of Dry Eyes

Answer 50

Definition: A number of medicines can exacerbate or produce side effects of dry eyes as a result of decreased tear production

Causative Medicines:
- Diuretics
- Drugs that have an anticholinergic effect (e.g., tricyclic antidepressants [TCAs], antihistamines)
- Isotretinoin
- Hormone replacement therapy (HRT), particularly oestrogen alone
- Androgen antagonists
- Cardiac arrhythmic drugs, beta blockers
- Selective serotonin reuptake inhibitors (SSRIs)
- Preservatives in some topical treatments.

Management:
- If medication is suspected, the pharmacist should contact the patient’s doctor to discuss possible alternative therapies to alleviate the problem.

Question 51

Rosacea

Condition To Eliminate In Dry Eyes, Unlikley Cause Of Dry Eyes

Answer 51

Rosacea is a disease of the skin characterized by facial skin findings, including erythema, telangiectasia, papules, and pustules that mimic acne vulgaris, although many patients also suffer from marginal blepharitis and dry eyes.

Question 52

Bell’s Palsy

Condition To Eliminate In Dry Eyes, Very Unlikley Cause Of Dry Eyes

Answer 52

Bell’s palsy is characterized by unilateral facial paralysis, often with a sudden onset. A complication of Bell’s palsy is that the patient might be unable to close one eye or blink, leading to decreased tear film and dry eye.

Question 53

Referral Points In Dry Eyes

Answer 53

• Associated dryness of the mouth/other mucus membranes - sjogrens syndrom possible [refer as soon as practical]/possibly medicine induced
• Outward turning lower eyelid - requires medical attention [refer as soon as practical]
• Child
• Otc treatment not working/worsening symptoms

Question 54

Hypromellose[Aaculose/AaproMel/Evolve Hypromellose/Hydromoor/Generic/Hypromol/Lumecare/Mandanol/Ocu-Lube/Ocufresh/Tear-Lac/Teardew/Xailin Hydrate/Artelac/Puroptics]

Carmellose[Aqualube/Generic/Carmize/Cellusan/Celluvisc/Evolve/Eyeaze/Lumecare/Ocu-Lube/Ocufresh Comfort/Optho-Lique/Optive Plus/Tearvis/VIZcellose/VisuXL/Xailin Fresh]

All Eyedrops - some different strengths of the products &/or preserative free(unit dose typically) or preservative containing.

Treatment For Dry Eyes

Answer 54

Background Info:
- Been used for more than 50Y
- They possess film-forming and emollient properties, but unfortunately do not have ideal wetting characteristics, which results in up to hourly administration to provide adequate relief [this downside has lead to the development of the other products used for dry eyes]

Administration:
- The recommended dosage for adults, children and elderly is one or two drops topically instilled into the eye three times daily as needed, or as directed by a physician.
- All might require hourly or even half-hourly dosing initially, which should reduce as symptoms improve - OTC book

Side-Effects:
- May cause transient mild stinging or temporary blurred vision.

Counselling:
- If irritation persists or worsens, or headache, eye pain, vision changes or continued redness occur, patients should discontinue use and consult a physician or pharmacist
- In order to preserve the sterility, the dropper should not be allowed to touch any part of the eye or any other surface.
- Some formulation of Hypromellose eye drops contains 0.1mg/ml benzalkonium chloride as preservative which may be deposited in soft contact lenses. Hence, Hypromellose should not be used while wearing these lenses. The lenses should be removed before instillation of the drops and not reinserted earlier than 15 minutes after use.
- May cause transient blurring of vision on instillation. Do not drive or operate hazardous machinery unless vision is clear.

[Benzalkonium chloride has been reported to cause eye irritation, symptoms of dry eyes and may affect the tear film and corneal surface. Should be used with caution in dry eye patients and in patients where the cornea may be compromised. Patients should be monitored in case of prolonged use]

Interactions:
- Hypromellose prolongs the contact time of topically applied drugs commonly used in ophthalmology.

Prengnacy/Breastfeeding:
- No studies have been done to evaluate the effects in pregnancy/breastfeeding but the product is pharmacologically inert and systemic exposure is thought to be negligable so should be fine to use.

Question 55

Polyvinyl Alcohol 1.4% eye drops
[Liquifilm tears, Refresh Ophthalmic, Sno Tears]

• Some preservative containing/preservative free(unit dose typically)

Treatment For Dry Eyes

Answer 55

Background Info:
- Viscosity Enhancer
- At this concentration, the product has the same surface tension as normal tears, lending optimal wetting characteristics and hence less frequent dosing
- There is a lack of published data confirming its efficacy

Administration:
- QTD

Question 56

Carbomer 940
[GelTears, Liquivisc, Viscotears, Clinitas, ocufresh, Puroptics, Xailin, AaCarb, Aacomer,Artelac,* Generic*]

Answer 56

Background Info:
- lubricating film for cornea/conjunctiva with prolonged contact time compared with traditional tear substitutes.
- Carbomer has been shown to be more efficacious than placebo and as safe as, but better tolerated, than polyvinyl alcohol.
- In a comparison study between two proprietary brands, Viscotears and GelTears, both were found to be equally effective, although neither was significantly better than the other

Administration:
- 1 drop to be instilled into the conjunctival fold of each affected eye 3-4 times daily or as required, depending on the degree of discomfort.

Side-Effects:
- Benzalkonium is present in some products which can irritate, especially with prolonged use.
- Blurring can occur on administration.

Counselling:
- Blurred vision can occur if too much gel is instilled at one time, or if the gel is used too frequently. This effect can last for up to an hour. Recovery can be aided by blinking vigorously for a few seconds. If this fails, the lower eyelid should be manipulated until the gel returns to the lower fornix and normal vision is restored.
- Contact lenses should be removed during treatment with GelTears.

Pregnancy/Breastfeeding:
- not established so some manufacturer advises avoid, but no effects are anticipated with carbomer being an inactive ingredient and systemic absorption expected to be negligible.

Question 57

Sodium Hyaluronate
(e.g., Biotrue, Clinitas Soothe, Murine Professional Advanced Dry Eye Relief, Optrex Night Restore Gel Drops)

Answer 57

Background Info:
- Lubricant
- Sodium hyaluronate has been subject to a number of trials that have shown a reduction in symptom severity.
- It has also been compared with carbomer products and carboxymethylcellulose and found to be equally effective.

Administration:
- Dose is on an as needed basis (usually 2-3 times per day)

Question 58

Wool Fats (Lanolin)
-Lacrilube Eye Ointment & Xailin Night Eye Ointment

Answer 58

• These products contain a mixture of white soft paraffin, liquid paraffin, and wool fat.
• They are useful at bedtime when prolonged lubrication is needed, but because they blur vision, they are unsuitable for use during the day.
• Suitable for all patients including pregnacy/breastfeeding.

Question 59

Preservatives In Eye Drops & Dry Eyes
- Benzalkonium

Answer 59

Many eye drops contain benzalkonium chloride, which itself can cause eye irritation.
- If symptoms persist or are worsened by eye drops it may be worth trying a preservative-free formulation/single-dose unit preparations.

Question 60

Contact Lenses

Answer 60

Types:
There are two main types of lens: soft (hydrogel) and hard (gas permeable).
- Soft lenses are the most popular because of their comfort, and daily disposable contact lenses (‘dailies’) are the most commonly used in the UK.
- There are also two-weekly and monthly disposables, which are worn daily, cleaned and stored overnight.
- Extended wear (‘night and day’) disposables are worn continuously for up to a month without taking them out for sleeping or showering.

Issues With Lenses
- The risk of serious eye infections with overnight wear is higher than with daily wear lenses.
- For all contact lenses, keeping lenses in for longer than the recommended periods of time increases the chances of complications, such as corneal ulcers, ker- atitis and Acanthamoeba keratitis infection.
- Rubbing against the inside of the eyelid can cause a condition called papillary conjunctivitis.

Counselling:
- Wearing contact lenses while swimming, water sports and hot-tub use can be associated with complications and should be avoided, unless the patient is wearing tight-fitting goggles
- If lenses are worn for showering, the eyes should be kept firmly closed.
- Contact lenses should not be worn if the patient has conjunctivitis or is using certain eye drops (they should always check the patient information leaflet.
- Soft contact lenses can absorb the preservative benzalkonium chloride used in eye drops, and this can cause irritation and inflammation of the eye. Consequently, soft lenses should not be worn when using eye drops containing this preservative.