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)
