22. Ocular Allergies I Flashcards
What is allergy?
Definition: ...
and is pure ...
.
Allergens: ...
, ...
, ...
, ...
, etc.
Atopy is the ...
.
What is allergy?
Definition: reaction to a substance in the environment that is harmless to most people
and is pure inflammation
.
Allergens: dust mites
, pollen
, food
, medication
, etc.
Atopy is the genetic tendence to develop allergy
.
Who treats the following inflammatory conditions?
Inflammatory conditions of skin and eyelids - ...
Dermatological, conjunctival, and corneal inflammation - ...
Anterior ocular inflammation - ...
Everything above? - ...
Who treats the following inflammatory conditions?
Inflammatory conditions of skin and eyelids - dermatologists
Dermatological, conjunctival, and corneal inflammation - GP
Anterior ocular inflammation - optometrists
Everything above? - ophthalmologists
What is the difference between Type I, Type IV, and non-immune-mediated inflammation?
Type I and Types IV are immune mediated. Type I have mast cells, histamine, and eosinophils as main mediators (chemical) and Type IV have lymphocytes and macrophages as main cell mediators.
Non-immune-mediated inflammation is based around direct injury and/or pharmacological.
What is the main inflammatory mediator and what does it do?
Mast cells are the main mediator and they activate other cells.
Seasonal Allergic Conjunctivitis (SAC) (1)
It is common and affects up to ...
% of the population. It is a ...
and not a ...
.
Seasonal meaning active from ...
to ...
, mostly known as ...
. It is a ...
hypersensitivity and therefore ...
-mediated.
Seasonal Allergic Conjunctivitis (SAC) (1)
It is common and affects up to 20
% of the population. It is a minor annoyance
and not a significant health crisis
.
Seasonal meaning active from spring
to early summer
, mostly known as hayfever
. It is a Type I
hypersensitivity and therefore IgE
-mediated.
Seasonal Allergic Conjunctivitis (SAC) (2) and Perennial AC (1)
Signs: ...
, ...
, ...
, and ...
. The lids may also be ...
and ...
with ...
and no ...
damage.
Differential diagnoses: ...
, ...
, other mechanisms of ...
.
Assessed via ...
, ...
, ...
, and ...
.
Seasonal Allergic Conjunctivitis (SAC) (2) and Perennial AC (1)
Signs: bilateral
, conjunctival papillae
, hyperaemia
, and oedema
. The lids may also be oedematous
and serous
with mucoid discharge
and no corneal
damage.
Differential diagnoses: allergic conjunctivitis
, dry eye-related surface disease
, other mechanisms of conjunctivitis
.
Assessed via history
, slit lamp
, fluorescein
, and lid eversion
.
Seasonal Allergic Conjunctivitis (SAC) (3) and Perennial AC (2)
Treatment
* ...
, we’re not trying to ...
but instead ...
* Non-pharmacological: ...
and ...
* Pharmacological: ...
, ...
, ...
or combinations which include ...
and ...
Follow up
* ...
as ...
Seasonal Allergic Conjunctivitis (SAC) (3) and Perennial AC (2)
Treatment
* allergen avoidance
, we’re not trying to save tissue
but instead relieve symptoms
* Non-pharmacological: cold compresses
and lubricants
* Pharmacological: oral anti-histamines
, topical antihistamines
, mast cell stabilisers
or combinations which include vasoconstrictors
and astringents
Follow up
* patient driven
as season starts
What is the difference between Seasonal Allergic Conjunctivitis and Perennial Allergic Conjunctivitis?
SAC is acute and often during spring time. PAC persists all year due to a perennial allergen.
Non-pharmacological treatment for SAC and PAC
Allergen avoidance - ...
, ...
, ...
Cold compresses - reduces ...
and ...
Artificial tears - ...
to antigen, ...
of antigen, ...
antigen, ...
is preferable
Non-pharmacological treatment for SAC and PAC
Allergen avoidance - change environment
, air filter
, cleaning
Cold compresses - reduces chemosis
and hyperemia
Artificial tears - barrier
to antigen, dilution
of antigen, flushes
antigen, preservative-free
is preferable
Patanol vs Zaditen
Both combinations of ...
and ...
. Patanol (...
) is more ...
and ...
with quicker ...
, improved ...
, better ...
, and fewer ...
. However, it is S...
so potentially less available, costs ...
and does not have a ...
.
Patanol vs Zaditen
Both combinations of antihistamines
and mast cell stabilisers
. Patanol (olopatadine
) is more efficacious
and comfortable
with quicker relief
, improved symptoms
, better QoL
, and fewer side effects
. However, it is S4
so potentially less available, costs more
and does not have a preservative-free option
.
Combination pharmaceutical treatments for SAC and PAC
...
and ...
- S...
- one to two drops a day to avoid ...
.
...
and ...
- olopatadine S...
and ketotifen S...
- first line therapy for AC. Dual effect is better since one drug with two actions and far fewer ...
.
...
and ...
/...
or ...
to aggressively treat inflammation, and while ...
, the other drug kicks in.
Combination pharmaceutical treatments for SAC and PAC
Topical vasoconstrictors
and antihistamines
- S3
- one to two drops a day to avoid rebound redness
.
Topical antihistamines
and mast cell stabilisers
- olopatadine S4
and Ketotifen S3
- first line therapy for AC. Dual effect is better since one drug with two actions and far fewer side effects
.
Topical steroid
and MCS
/AH
or NSAID
to aggressively treat inflammation, and while steroid is tapering
, the other drug kicks in.
Single pharmaceutical treatments for SAC and PAC
...
- levocabastine HCL - available as eyedrop or nasal spray, S...
...
- phenylephrine HCl, naphazoline HCl, and tetrahydrozoline, S...
. Chronic use can result in ...
, ...
, and/or ...
as they downregulate the receptors over time and become less effective.
...
- sodium cromoglycate - available as eyedrop, S...
.
...
- ketorolac and diclofenac - S...
...
- used to reduce itch an inflammation
Single pharmaceutical treatments for SAC and PAC
Topical antihistamines
- levocabastine HCL - available as eyedrop or nasal spray, S3
Topical vasoconstrictors
- phenylephrine HCl, naphazoline HCl, and tetrahydrozoline, S3
. Chronic use can result in follicular reactions
, contact dermatitis
, and/or rebound redness
as they downregulate the receptors over time and become less effective.
Topical mast cell stabilisers
- sodium cromoglycate - available as eyedrop, S3
.
Topical NSAIDs
- ketorolac and diclofenac - S4
Topical steroids
- used to reduce itch an inflammation
Oral antihistamines for SAC and PAC
Can work for ocular conditions but ...
? Targets ...
receptors but is body wide and therefore has ...
side-effects.
Topical antihistamines are more ...
, with less ...
and higher ...
whereas oral antihistamines are best used for ...
or ...
.
Oral antihistamines for SAC and PAC
Can work for ocular conditions but are they safe
? Targets H1
receptors but is body wide and therefore has body wide
side-effects.
Topical antihistamines are more rapid
, with less side effects
and higher efficacy
whereas oral antihistamines are best used for non-ocular
or multisystem disease
.
Vernal Keratoconjunctivitis (1)
Defined as ...
conjunctivitis
Symptoms include: intense ...
/...
, ...
, ...
, ...
, ...
, ...
, ...
, ...
Vernal Keratoconjunctivitis (1)
Defined as recurrent, bilateral, self-limiting
conjunctivitis
Symptoms include: intense itching
/burning
, watering
, photophobia
, foreign body sensation
, puffy lids
, mucoid discharge
, blurred vision
, eye rubbing
Vernal Keratoconjunctivitis (2)
Conjunctival signs
* Worse in ...
/...
* ...
and affects ...
more
* Most commonly manifests between ...
and ...
years and runs its course by ...
* Can develop into ...
* Most suffers are ...
* Usually affects ...
conjunctiva and may involve ...
; two forms can coexist
* Conjunctival ...
and ...
* Large palpebral ...
* Discharge is ...
* ...
Vernal Keratoconjunctivitis (2)
Conjunctival signs
* Worse in spring
/early summer
* bilateral
and affects men
more
* Most commonly manifests between 5
and 25
years and runs its course by early adulthood
* Can develop into atopic keratoconjunctivitis
* Most suffers are atopic
* Usually affects superior tarsal
conjunctiva and may involve limbal area
; two forms can coexist
* Conjunctival hyperaemia
and chemosis
* Large palpebral papillae
* Discharge is stringy mucous
* ptosis
Vernal Keratoconjunctivitis (3)
Corneal signs
* ...
* ...
* ...
* ...
Limbal signs
* ...
with ...
(...
)
* ...
(...
) - occurs when ...
Differential diagnosis: ...
and ...
Assessment via ...
, ...
, ...
, and ...
Vernal Keratoconjunctivitis (3)
Corneal signs
* SPK
* shield ulcers
* subepithelial scarring
* eosinophilic plaques
Limbal signs
* limbitis
with limbal papillae
(Horner-Trantas' dots
)
* psuedogerontoxon
(cupids bow
) - occurs when Horner-Trantas' dots retract
Differential diagnosis: AKC
and GPC
Assessment via history
, slit lamp
, flourescein
, and lid eversion
Pathophysiology of VKC
- Type
...
sensitivity -
...
lymphocytes mediate...
production of IgE and mediate...
and...
of mast cells and eosinophils - Over production of
...
and...
receptors in conjunctiva may explain...
- Hypersensitivity to
...
,...
, and/or...
may have a role - Probably
...
component
Pathophysiology of VKC
- Type
I
sensitivity -
Th2
lymphocytes mediatehypo
production of IgE and mediatedifferentiation
andactivation
of mast cells and eosinophils - Over production of
estrogen
andprogesterone
receptors in conjunctiva may explainimprovement with onset of puberty
- Hypersensitivity to
wind
,dust
, and/orsun
may have a role - Probably
genetic
component
Treatment for VKC
Same as for other ACs except ...
. If we know the triggers, we can ...
.
Treatment for VKC
Same as for other ACs except need to be more aggressive to save the corneal tissue
. If we know the triggers, we can prophylactically treat it to avoid flare ups
.
Shield ulcers
Break in epithelium due to ...
. Mechanical hypothesis: ...
Toxin hypothesis: ...
is ...
and inhibits ...
.
Shield ulcers
Break in epithelium due to SPK
. Mechanical hypothesis: giant papillae on upper tarsal conjunctiva causes corneal abrasion
. Toxin hypothesis: eosinophil granule
is cytotoxic
and inhibits healing of corneal epithelium
.
VKC follow-up
If there is a shield ulcer, every ...
-...
days.
During exacerbations, every ...
.
Between exacerbations, ...
.
If no resolution of shield ulcer, refer for ...
.
VKC follow-up
If there is a shield ulcer, every 1
-3
days.
During exacerbations, every few weeks
.
Between exacerbations, less frequently
.
If no resolution of shield ulcer, refer for superficial keratectomy
.
Atopic Keratoconjunctivitis (1)
Similar to VKC but ...
.
Signs:
* Type ...
sensitivity
* ...
and ...
, affecting ...
* Onset is ...
and ...
* ...
with associated ...
* Prone to chronic ...
and ...
* Skin has ...
* Discharge is ...
* Eyelids are ...
and ...
with ...
* Conjunctiva have ...
, ...
, and ...
* Cornea has ...
, ...
, and ...
which tend to ...
Atopic Keratoconjunctivitis (1)
Similar to VKC but year round
.
Signs:
* Type I
sensitivity
* uncommon
and bilateral
, affecting both sexes equally
* Onset is early adulthood
and stays year round
* atopic
with associated allergic skin disease
* Prone to chronic staph blepharitis
and HSV disease
* Skin has atopic dermatitis
* Discharge is stringy mucous
* Eyelids are thickened
and crusty
with ptosis
* Conjunctiva have papillary hypertrophy
, fibrosis
, and scarring
* Cornea has SPK
, shield ulcers
, and Horner-Trantas' dots
which tend to blend together
Atopic Keratoconjunctivitis (2)
Differential diagnosis: ...
and ...
Assessment: ...
, ...
, ...
, ...
, ...
, ...
, ...
, ...
, and ...
Treatment: ...
, ...
, ...
as per VKC, avoid ...
Atopic Keratoconjunctivitis (2)
Differential diagnosis: VKC
and GPC
Assessment: history
, slit lamp
, fluorescein
, eyelid eversion
, eyelid margins
, lens
, corneal topography
, DFE
, and skin
Treatment: allergen avoidance
, flushing of conjunctiva
, pharmaceutical treatment
as per VKC, avoid eye rubbing
Aggressive topical steroid therapy for VKC and AKC
It’s a ...
, how compromised is the cornea?
Long term use of topical steroids can lead to ...
, ...
, and ...
.
Aggressive topical steroid therapy for VKC and AKC
It’s a risk-benefit analysis
, how compromised is the cornea?
Long term use of topical steroids can lead to elevated IOP
, cataracts
, and increased susceptibility to infections
.