Ocular Allergic Disease Dr Paramdeep Singh Bilkhu - PowerPoint Presentation

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Ocular Allergic Disease

Dr Paramdeep Singh Bilkhu

BSc(Hons)

PGCert

PhD MCOptom FBCLA DipTp(IP)

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Objectives

By the end of this lecture you should be able to:

Understand the mechanism of ocular allergy

Diagnose the different forms of ocular allergy

Appropriately treat ocular allergy

Slide3

What are allergies?

Defined as an “intolerance to environmental factors” or an “inappropriate response to innocuous foreign substances

Four major types of allergic reaction - Type I or immediate hypersensitivity reaction most common

Atopy

is the term given to those who have a hereditary pre-disposition to Type I hypersensitivity

Common Type I allergies includes asthma, rhinitis, dermatitis, gastro-intestinal disorders and

allergic conjunctivitis

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Ocular Allergies

Represents a group of allergies affecting the ocular tissue, typically the conjunctiva

Acute ocular allergy = Type I; Chronic ocular allergy = Type I and T-cell mediated response

20% of allergy sufferers have a form of ocular allergy, and up to 40% have experienced ocular allergy symptoms in their lifetime

8% prevalence of ocular allergies in patients attending optometric practice

60.8% of people with allergies in optometric practice have ocular reactions

Ocular symptoms 2X more likely to affect individual than nasal symptoms

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Epidemiology

Most common ocular condition seen in general practice

Affects 15-20% of the population – 50% of Europeans by 2015

Responsible for 3.4 million lost work days

Responsible for 2 million lost school days

Economic impact exceeds $18 billion annually

Responsible for diminished quality of life in 20 -25% of the US population

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Ocular Allergies

Significant quality of life and economic impact

Reduced income (days off work)

Reduced productivity

Reduced school performance

Healthcare costs

£64.61 per year for pensioner

£123.69 per year for employed

Ocular allergies pose a significant problem that needs to be tackled

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Type I Ocular Allergic Response Mechanism

Immediate allergic response mechanism

Mediated (predominantly) by

IgE

antibody

Involves multiple cell types and multiple chemical processes – very complex reaction

Is divided into 3 phases

Sensitization phase

Early (or activation) phase

Late phase

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Type I Ocular Allergic Response Mechanism

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Preformed Mast Cell Mediator Responses

Primary inflammatory mediator is Histamine

Blood vessel

Vasodilation

(H1 and H2) =

Redness

Increased permeability (H1) =

Swelling

Nerve

Nerve stimulation =

Itching

Epithelial cells

Epithelial cell activation = Recruitment of additional inflammatory cells and mediators

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Newly Formed Mast Cell Mediator Responses

Prostaglandins

PGD

2

contributes to

vasodilation

=

Redness and Swelling

Leukotrines

LTC

4

causes

vasoactivity

and mucous secretion =

Redness and Swelling

Platelet activating factor

Blood vessel

vasodilation

and increased permeability =

Redness and Swelling

Chemotaxis

and

Eosinophil

activation =

Late phase responses (allergic inflammation)

Cytokines

Multiple cellular effects =

Allergic inflammation

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Classification of Ocular Allergy

Typically manifested in the conjunctiva

Classified based upon cause, signs, symptoms, duration and severity of condition

Allergic conjunctivitis

Seasonal (SAC)

Perennial (PAC)

Vernal Keratoconjunctivitis (VKC)

Atopic Keratoconjunctivitis (AKC)

Giant Papillary Conjunctivitis (GPC)

Contact and Drug induced allergy

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Allergic Conjunctivitis

Acute (seasonal) or chronic (perennial)

Seasonal (SAC) accounts for 25-50% of all ocular allergy cases and is typically caused by pollen; affects up to 40% of population

Perennial (PAC) affects 0.03% of population, ~ 1% of ocular allergy cases – occurs all year round

Signs

Conjunctival

hyperaemia

Lid swelling and

chemosis

Stringy mucous discharge

Symptoms

Itchy eyes

Burning/stinging

Watery or dry eyes

Photophobia

Type I hypersensitivity

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Allergic Conjunctivitis

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Seasonal V Perennial Allergic Conjunctivitis

Seasonal – occurs in spring, fall or both

Perennial – occurs year round, may have periodic exacerbation (seasonal)

Seasonal – caused by grass, tree or ragweed pollen; outdoor moulds

Perennial – caused by animal dander, dust mites and indoor moulds

Signs and symptoms similar but less severe and more constant in perennial allergic conjunctivitis

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Avoidance Strategies

Allergen

Avoidance Measure

Pollen & Outdoor Moulds

Minimise outdoor

activities when symptoms known to develop

Monitor pollen levels using TV, internet and radio to plan outdoor activities

Wear close fitting sunglasses and avoid rubbing eyes

Wash hands after being outdoors and wash hair regularly before sleeping

Close windows and doors

Use AC and circulate air internally in car

House

Dust Mites

Wash bedding regularly at least at 60°C

Damp dust and vacuum weekly

Regularly

clean all areas that gather dust

Reduce humidity to 30-50% in the home using dehumidifier

Animal Dander

Avoid contact with animals

Remove

pets from home or not keep at all

Regularly vacuum and clean home

Wash hands, clothes and avoid rubbing eyes or nose after contact with animals

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Treatment of SAC and PAC

Often not possible to completely avoid allergens

Non-pharmacological treatments are useful during active phase of disease

Cold compress, artificial tears (Bilkhu et al., 2014)

Pharmacological treatments therefore become necessary

Mast Cell Stabilisers

Competitive antagonist of

IgE

bound to mast cell surface

Therefore prevent binding of allergen to mast cell and preventing allergic response

Loading dose often required

Best used as a prophylactic

E.g. Sodium

Cromoglygate

2% or 4%,

Nedocromil

2%,

L

odoxamide

0.1%

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Treatment of SAC and PAC

Antihistamines

Competitive antagonist of histamine receptors on blood vessels, nerves, and epithelial cells

Therefore prevents binding of histamine to receptor sites and allergic symptoms following mast cell degranulation

Fast acting (within 10 minutes)

Best used during an active phase of disease i.e. when symptoms and signs develop

E.g.

Azelastine

0.05%,

Antazoline

0.5%,

Emedastine

0.05%

M

ost are POMs

Oral antihistamines useful where other tissues involved

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Treatment of SAC and PAC

Dual Action Medications

Combine both mast cell stabilising and antihistaminic properties

Often reserved for cases unresponsive to conventional drugs

E.g.

Olopatadine

1mg/mL,

Epinastine

500µg/mL,

Ketotifen

250µg/mL

Only require twice daily dosing

Vasoconstrictors

Relieve redness and swelling

May be combined with antihistamine

Long term use not recommended (max 7 days)

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Non-IP options

P-only medications are available to prescribe

Must state treatment plan on record

Drug name, strength, dosage, duration

Sodium

cromoglycate

2% (up to 10ml)

Lodoxamide

(

Alomide

) 0.1% (up to 5ml)

Antazoline

+

xylometazoline

(

Otrivine-Antisitin

) up to 5ml

Oral antihistamines

Loratadine

Cetirizine

Chlorphenamine

(

Piriton

)

Acravastine

(Benadryl)

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Allergic Conjunctivitis & CL Wear

Allergens may bind to CL surface

May prolong symptoms

Management typically involves ceasing CL wear

But new anti-allergy drugs allow CL wear to be maintained

Brodsky (2000): lens wearing time and comfort following 2Xdaily 0.1%

olopadatine

Tx

Nichols et al. (2009): lens wearing time and comfort following 1 drop 0.05%

epinastine

prior to lens insertion compared to re-wetting drops

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Allergic Conjunctivitis & CL Wear

Other options include:

Increase lens replacement frequency

67% improved comfort with daily disposable versus 18% with new pair of habitual monthly lenses

Daily disposables; especially if enhanced lubricating properties (Wolffsohn &

Emberlin

, 2011)

Sx

of ocular allergy and their duration actually reduced with CL in situ compared to no lens wear, and was further reduced when lens contained enhanced lubricating properties

CLs may therefore offer a “barrier effect”

Slide22

Giant Papillary Conjunctivitis

Caused by combination of mechanical irritation and chemical reaction

Occurs most often in contact lens wearers due to build up of surface deposits

Signs

Conjunctival

hyperaemia

Mucous strands

Abnormal thickening and

opacification

of

palpebral

conjunctiva

Characteised

by large papillae (>1mm in diameter)

Symptoms

Mild itching on lens removal

Slight blurring of vision

Contact lens intolerance

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Giant Papillary Conjunctivitis

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Treatment of GPC

Optimise lens fitting

Change lens wear modality

Monthly to 2 weekly; 2 weekly to daily

Change material

Soft to rigid gas permeable

Or switch to soft with enhanced surface treatments to increase wettability and comfort

Often a combination of these

If severe, unresponsive to lens changes or cornea is involved, must initiate pharmacological therapy and cease

lens wear until

resolution

Mast cell stabilisers

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Vernal Keratoconjunctivitis

Chronic bilateral disease, usually affecting males 3-25 years old in warm climates

Accounts for 0.5% of ocular allergy cases

Peaks at puberty, then resolves but may manifest as atopic

keratoconjunctivitis

in later life

Most common in families with a history of

atopy

Signs

Characterised by large papillae in

palpebral

conjunctiva or

limbus

Ropy mucous discharge

Potential corneal involvement therefore sight threatening

Symptoms

Intense itching

Photophobia

Possibly pain

Type I hypersensitivity and Type IV (T-lymphocyte mediated) in later stages

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Vernal Keratoconjunctivitis

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Atopic Keratoconjunctivitis

Serious, sight threatening condition

Onset in teenagers to early 20s unless childhood VKC

Associated with a family history of

atopy

Associated with atopic dermatitis – 25-40% of AD patients have ocular involvement

Signs

Thickened, macerated and fissured eyelids

Conjunctival

hyperaemia

Flattened, velvety papillae

Possible

limbal

cystic lesions

Corneal scarring from corneal

epitheliopathy

, corneal ulcer (shield) and inflammatory cellular toxic effects can cause visual loss

Blepharitis

may also be present

Symblepharon

in advanced disease

Type I hypersensitivity and Type IV (T-lymphocyte mediated) in later stages

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Atopic Keratoconjunctivitis

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Treatment of VKC and AKC

Pharmacological treatments initiated immediately

Mast cell stabilisers and topical steroids

Steroids are powerful anti-inflammatory drugs

Interfere with cytokine and adhesion molecule production

Block release of enzymes used in metabolising

arachidonic

acid which would otherwise produce prostaglandins and

leukotrines

Steroid use requires close monitoring

Side

effects: IOP elevation, cataract formation, delayed corneal healing, secondary infection

E.g.

Loteprednol

etabonate

(

Alrex

0.2

%),

Rimexolone

1%,

Fluoromethalone

0.1% and 0.25%

Slide30

Treatment of VKC and AKC

Non-steroidal anti-inflammatory drugs (NSAIDs)

Alternative to corticosteroids

Inhibits cyclooxygenase pathway thus stopping the productions of prostaglandins and

thromboxanes

Prostaglandins are hypothesised to be

synergystic

with histamine, potentiating itching

Contraindicated in patients with asthma and nasal polyps

Can delay corneal healing by interfering with wound repair

E.g. Ketorolac

tromethamine

(

Acular

0.5%;

Acular

LS 0.4%) POM,

Diclofenac

0.1% POM

Slide31

Treatment of VKC and AKC

Effective alternative to corticosteroids

Immunosuppressive against T-lymphocytes and

IgE

Cyclosporin

(2% in oil)

Effective in VKC and AKC

Tacrolimus

(

Protopic

0.1% and 0.03%)

No systemic effects, but may cause mild local effects

Slide32

Treatment of VKC and AKC

Corneal ulcers may become infected

Scraping or swab often taken to identify infectious cause

Typically bacterial

Requires strong antibiotics (quinolones)

Ofloxacin

, Ciprofloxacin,

moxifloxacin

, levofloxacin

If left untreated, can lead to blindness and loss of the eye

Slide33

Contact Ocular Allergy

Comprises contact dermatitis and drug induced allergic conjunctivitis

Predominantly T-cell mediated (Type IV)

Hypersensitivity due to chemicals

Toxicity maybe due to incorrect usage

Contact lens solution preservatives e.g.

Benzalkonium

chloride,

thiomersal

Drugs e.g.

Pilocarpine

,

gentamycin

Cosmetics, shampoo, irritants

Sunlight exposure can induce photo-contact dermatitis

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Differential Diagnosis of Ocular Allergy

Itching

is

pathognomic

of ocular allergy

Dry eye

Blepharitis

Viral conjunctivitis

Bacterial conjunctivitis

Superior limbic

keratoconjunctivitis

Molluscum

Contagiosum

Medicamentosa

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Case Study 1

Patient arrives complaining of mild itching, mucous discharge from both eyes. Examination reveals history of monthly soft lens wear, and several large papillae on both tarsal conjunctiva. The cornea is unaffected. What would be the most appropriate course of action?

A)

Immediate referral to A&E

B)

Cease lens wear completely and initiate antihistamine therapy

C)

Cease lens wear completely and initiate 4x day mast cell stabilising therapy

D)

Change to 2 weekly enhanced comfort lens and 2x day mast cell stabilising therapy

Slide36

Case Study 2

Patient arrives complaining of intermittent itching in both eyes. History reveals sudden onset when outdoors, reduces when indoors, started in July. Examination reveals conjunctival redness and oedema. What is the likely diagnosis?

Perennial allergic conjunctivitis

Vernal

keratoconjunctivitis

Contact dermatitis

Seasonal allergic conjunctivitis

Slide37

Case Study 3

50 year old patient arrives complaining of itching, soreness and pain in both eyes. History reveals asthma and atopic dermatitis. Examination reveals bilateral thickened and inflamed eyelids, large papillae on tarsal conjunctiva and shield ulcer on left eye. What is the likely diagnosis?

Microbial keratitis

Atopic

keratoconjunctivitis

Vernal

keratoconjunctivitis

Giant papillary conjunctivitis

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Case study 4

For the patient in case study 3, what would be the appropriate course of action?

Topical mast cell stabilisers 4x day and review in 4 weeks

Topical NSAID and monitor closely

Topical mast cell stabilizer 4x day and topical steroid for 4 weeks and discharge

Topical mast cell stabiliser 4x day and topical steroid and monitor closely

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Case study 5

For the patient in case study 3, what would be the most appropriate way to alleviate the pain?

Topical anaesthetic

Topical

mydriatic

Topical

mydriatic

and anaesthetic

Topcial

mydriatic

and oral analgesic

Slide40

Case study 6

12 year old male patient arrives complaining of chronic intense itching, photophobia and mucous discharge. History reveals onset during spring and previous eczema. Examination reveals large papillae on tarsal conjunctiva and

limbus

. What is the likely diagnosis?

Atopic

keratoconjunctivitis

Seasonal allergic conjunctivitis

Perennial allergic conjunctivitis

Vernal

keratoconjunctivitis

Slide41

Summary

Allergy is the hypersensitivity to normally harmless substances

Ocular allergy encompasses a group of allergic conditions affecting the eye

Ocular allergy impairs quality of life

Ocular allergy, like all allergies are increasing in prevalence

Need to identify each type of ocular allergy and differentially diagnose to formulate effective management plan

Non-pharmacological treatments and allergen avoidance needs to be encouraged

Use of topical pharmacological agents however often becomes necessary

Wide range of medications available OTC and POM with different pharmacological actions

Majority of SAC, PAC and GPC can be treated by optometrists

VKC and AKC need to be managed in hospital setting

Systemic medications are useful where another tissue is affected alongside the conjunctiva

Slide42

Further Reading

Bilkhu

PS,

Wolffsohn

JS,

Naroo

SA.

A review of non-pharmacological and pharmacological management of seasonal and perennial allergic conjunctivitis.

Cont Lens Anterior Eye.

2012; 35(1): 9-16.

Bilkhu

PS,

Wolffsohn

JS,

Naroo

SA.

Ocular Allergy and Contact Lens Wear.

Optometry Today

. 2012; 52(6): 49-53.

Slide43

Thank you to:Dr Shehzad

Naroo

Prof

JamesWolffsohn

Thank

you

for listening!