Allergic eye disease Flashcards
what is an ocular allergic response a result from
from exposure to foreign substances (allergens)
allergic response of the ocular surface to extraneous antigens = antigens that are in the outside e.g. hay fever as a response to grass pollen
which parts of the eye does a hypersensitivity reaction mainly affect and which parts may in also involve
conjunctiva but may also involve the lids and cornea
what 4 conditions of ocular allergies are there
- allergic conjunctivitis
- giant papillary conjunctivitis GPC
- contact dermatoconjunctivitis
- keratoconjunctivitis
what 3 conditions is allergic conjunctivitis classified into
- acute allergic conjunctivitis
- seasonal allergic conjunctivitis SAC
- perennial allergic conjunctivitis PAC
what is the ocular manifestation of hay fever
seasonal allergic conjunctivitis SAC
what 2 conditions is keratoconjunctivitis classified into
what structures are affected
what action should be taken if this is seen and why
- atopic keratoconjucntivitis AKC
- vernal keratoconjucntivitis VKC
- as well as the conjunctiva, the cornea is also affected
- refer these patient to HES
- as its a sight threatening condition and frequently needs steroid control
why is giant papillary conjunctivitis GPC not as common as it used to be
as it used to happen when people wore soft CLs for years, this accumulated deposits and there was an allergic response to the deposits
also common in prosthetic eyes
what structures are affected in contact dermatoconjunctivitis and what is it a response to
- affects the conjunctiva and the skin adjacent
- as a response to drugs or cosmetics i.e. something put in/around the eye
what 5 reactions will show signs of an allergic eye disease with the conjunctiva
describe how each one occurs and what they look like
- Oedema (chemosis)
can over lap the cornea, but cornea will still be clear - Hyperaemia
- Papillae
inflammatory spots, tiny elevations of the conjunctiva surface - Follicles
collections of lymphoid tissue just under the surface of the conjunctiva (more common in toxic reactions) - Mucus discharge
from conjunctiva goblet cells that are stimulated to produce more mucous
what 4 reactions will show signs of an allergic eye disease with the lids
- Oedema
- Hyperaemia
- Blepharitis
- Ptosis
what 6 reactions will show signs of an allergic eye disease with the cornea/limbus
- Keratitis
- Infiltrates
- Ulceration
- Plaques
- Scarring
- Trantas dots: follicles around the limbus
what are Trantas dots
follicles around the limbus
list 6 symptoms that occur in an allergic eye disease
- Itching
- Irritation
- Burning
- Epiphora
- Photophobia
- Blurred vision
what is the strongest symptom that someone with allergic eye disease will complain about
itching
what type of photophobia will someone with an allergic eye disease have
mild
not as bad as something like uveitis
when may a patient with an allergic eye disease complain about blurred vision
if the cornea is involved, which is rare
or it may be because the eyes are watering a lot
what is the aetiology of an acute allergic conjunctivitis and give 2 examples of allergens that can cause this
what is a predisposing factor
what is the main symptom
what are the 3 signs
what is your management (name 3 things)
Aetiology:
- Urticarial reaction to an allergen that comes in contact with the lid or conjunctiva
reaction is very quick, within minutes, can be bilateral if the allergen connected both eyes
- Type I hypersensitivity reaction
- Allergens include grass pollen, animal dander
Predisposing factor:
- History of atopy
Main symptom:
- Itching
May be unilateral if contact response
Signs:
- Lid oedema and erythema
- Chemosis
- Epiphora
Management:
- Usually resolves after a few hours
- Cool compress
- Allergen avoidance
when does Perennial Allergic conjunctivitis cause symptoms and in response to what
- causes symptoms throughout the year
- in response to allergens such as house dust mite or animal dander
what is the same for seasonal allergic conjunctivitis SAC
and perennial allergic conjunctivitis PAC
the symptoms experienced
what is the prevalence on hay fever in the UK
what do 40% of those affected have
when is the peak hayfever season
symptoms in which part of the body predominate
what can hay fever affect in children
- 15.5% of the UK population suffered from hay fever (7.2 million)
- 40% had symptoms so severe as to affect their work
- Peak hayfever season May/June
- Eye and nasal symptoms predominate
- Hay fever can have an adverse effect on children’s learning ability (as symptomatic during school days)
what are people who have hay fever symptoms in the spring allergic to
and what are people who have hay fever symptoms in the summer allergic to
- spring = tree pollen
- summer = grass pollen
what is the aetiology of Seasonal and Perennial allergic conjunctivitis and examples of what can cause this
what is a predisposing factor
what is the 2 main symptoms
what are the 5 signs
what 4 things can you do for management
Aetiology:
Type I
- Seasonal: seasonal allergens
- Perennial: allergens such as house dust mite, symptoms throughout the year
Predisposing factor:
- Family history
Symptoms:
- Itching
- Epiphora
Signs:
- Hyperaemia
- Chemosis
- Lid oedema
- Diffuse papillary reaction
- No corneal involvement
Management:
- Allergen avoidance
- Cool compresses
- Sodium chromoglicate
- Topical and systemic antihistamines
explain how family history is a predisposing factor for seasonal/perennial conjunctivitis
genetics determines how your immune system responds to the allergens
they produce a IGe response = an antibody response
IGe binds to the surface of the mast cells and the pollen then causes cross linking and subsequent degranulation
the mast cell mediators cause the symptoms and signs e.g. redness, swelling, oedema etc
list 6 non-pharmacological management options for allergic conjunctivitis
- Allergen avoidance
- Allergen exclusion (difficult to do)
- Cold compresses
- Lid-hygiene (not relevant to hay fever)
- Artificial tears (will wash out some allergens that was in contact with the ocular surface)
- Contact lens fit and hygiene (to allow px to wear CLs)
list 6 ways of allergen avoidance
and 2 ways on allergen exclusion
Avoidance
- Limit outdoor activities
- Use air conditioning
- Reduce humidity (to reduce house dust)
- Protective eyewear
- Barrier cover for mattress and pillows
- Remove reservoirs for allergen e.g. carpets (harbour lots of dust, wooden floors are better)
Exclusion
- Occlusive glasses (prevents allergen to contact ocular surface)
- Induced ptosis
list the 3 pharmacological management options for allergic conjunctivitis
- Antihistamines (oral and topical)
- Mast cell stabilisers
- Combination AH/MCS
how often does someone with allergic conjunctivitis usually have to instil topical antihistamines and when can this not be used
- 4x a day
- cannot use with CLs as contains preservatives
how do mast cell stabilisers work for allergic conjunctivitis
it stabilises mast cell membrane and reduces degranulation
what pharmacological drug can be used for allergic conjunctivitis with CLs and why
- Combination AH/MCS
- because you only need to put it in twice a day, so once before inserting CLs and once after removing CLs
- only available on prescription
what is the 3 possible aetiologies of Giant papillary conjunctivitis GPC
what are 2 possible predisposing factors
what is the 3 main symptoms
what are the 4 signs
what is a ddx
what 3 things can you do for management
Aetiology
- Contact lens wear (trauma and deposits)
- Exposed sutures
- Filtration bleb
Predisposing factors
- History of atopy
- Poor lens hygiene (deposits)
Symptoms
- Mild irritation
- Itching
- Increased lens awareness (leading to intolerance)
Signs
- Papillae, variable in size (> 1mm), variable in position
- Tops of papillae may stain with fluorescein
- Palpebral conjunctival hyperaemia
- Increased mucus discharge
Differential diagnosis
- Vernal keratoconjuntivitis
Management
- Lens hygiene (if wear lenses for more than 1 day)
- Disposable lenses
- Mast cell stabilisers
how does RGP lenses cause GPC
it is seen in every RGP wearer, bit because or deposits, but because to mechanical structure of the lens
how does exposed sutures cause GPC
in the old days, during the time of standard cataract surgery when IOLs were big and couldn’t be folded up, so had to make incision in cornea, so the sutures caused a mechanical GPC
how does a filtration bleb cause GPC
from surgery for glaucoma
it is the consequence of a trabeculectomy procedure = the creation of a new channel for aqueous drainage
this produces a little vesicle of aqueous on the surface called a bleb = a raised bit
what will you need to do if the management options e.g. mast cell stabilisers don’t work on a px with GPC
px to be referred to take topical steroids
what is another name for contact dermatoconjunctivitis
Conjunctivitis Medicamentosa
what is the 2 possible aetiologies of contact dermatoconjunctivitis/Conjunctivitis Medicamentosa
what are the 3 signs
what is the 3 main symptoms
what 2 things can you do for management
Aetiology
- Eyedrops
- Cosmetics applied to the eyelids
Signs
- Lid oedema and erythema
- Chemosis
- Follicular conjunctivitis
Symptoms
- Burning
- Stinging
- Epiphora
Management
- Identify and withdraw allergen (if its eyedrops, then use different one)
- Systemic anti-histamines
what is the possible aetiology of Atopic keratoconjunctivitis
what is a possible predisposing factor and give 2 examples of this
what is the 4 main symptoms
what are the 4 signs
what is a ddx
what things can you do for management, for mild, for severe and 2 other general options for both types
Aetiology
- Adult equivalent of vernal keratoconjunctivitis
- Young adult males
- Perennial with exacerbations (all year round)
Predisposing factors
- Atopic history
e. g. eczema, asthma
Symptoms
- Itching
- Epiphora
- Blurred vision
- Mucus discharge
Signs
- Eyelids thickened, crusted and fissured
- Blepharitis
- Conjunctival hyperaemia
- Corneal involvement
Differential diagnosis
- Vernal keratoconjunctivitis
Management
- Mild: sodium chromoglicate
- Severe: with corneal involvment, steroids/immunosuppressants
- Lid hygiene
- Antibiotics (if risk of concurrent infection)
what is the possible aetiology of vernal keratoconjunctivitis
what 3 possible predisposing factors
what is the 4 main symptoms
what are the 8 signs
what 5 management options are there
Aetiology
- Uncommon allergic disorder of children
Predisposing factors
- Onset below 10 years
- Exacerbations during spring (but can be all year round)
- Atopic history
Symptoms
- Itching
- Epiphora
- Blurred vision
- Photophobia
Signs
- Mucus discharge
- Giant papillae
- Hyperaemia
- Trantas dots
- Punctate corneal staining
- Erosion
- Plaque
- Scarring
Management - Cold compresses - Mast cell stabilisers - Corticosteroids - Mucolytics - Ciclosporin need strong systemic immunosuppresent drug difficult condition to treat, so needs referring to specialist ophthalmologist to treat
why is vernal keratoconjunctivitis a serious condition and what does it require if seen in practice
- cornea is involved so is sight threatening
- needs referring to specialist ophthalmologist to treat
