3- Dry eye disease Flashcards
What is the first sign of Dry Eye Disease (DED)?
Formation of dry spots on the tear film.
Leads to epithelial cell loss and initiation of the vicious cycle of tear hyperosmolarity and inflammation.
How can we differentiate between EDE and ADDE using symptoms?
time of day differences
EDE: Symptoms worse in the morning.
ADDE: Symptoms worsen throughout the day.
However, there may be little correlation between signs and symptoms.
What lifestyle factors should be assessed in patients with DED?
(5)
SAWAS
Screen use duration
Air-conditioned or dry environments
Windy or dusty conditions
Alcohol and water intake
Smoking
What are the common symptoms of DED?
G,E,P
Gritty eyes
Epiphora (excess tearing)
Photophobia
What are the key tests for diagnosing DED?
T, S,T,C
Tear break-up time (TBUT): <10 seconds indicates DED.
Schirmer’s test: Measures tear production; normal in EDE, low in ADDE.
Tear osmolarity: >308 mOsm/L or asymmetry >8 between eyes is diagnostic.
Corneal stains: Fluorescein and lissamine green show epithelial damage.
How do symptoms differ between EDE and ADDE?
EDE: Worse in the morning.
ADDE: Worsens throughout the day.
What are the typical causes of EDE?
M,A,C,P
Meibomian gland dysfunction (MGD)
Anterior blepharitis
Contact lens wear
Psoriasis
What are the typical causes of ADDE? (6)
S, R, S-J, R, T, S
Sjögren’s Syndrome
Rheumatoid arthritis
Stevens-Johnson Syndrome
Refractive surgery
Trigeminal nerve injury
Systemic lupus erythematosus
How can slit lamp examination be used to differentiate EDE from ADDE?
EDE: Issues with the lipid layer (e.g., meibomian gland dysfunction).
ADDE: Lack of aqueous secretion (e.g., reduced Schirmer’s test result).
What is tear break-up time (TBUT)?
The time taken for the tear film to break after blinking. A TBUT of <10 seconds indicates DED.
How is Schirmer’s test performed?
where and result
A strip of filter paper is placed in the lower fornix for 5 minutes.
A result of <10 mm of wetting indicates reduced tear production.
What is considered a diagnostic tear osmolarity value for DED?
Tear osmolarity >308 mOsm/L or asymmetry >8 mOsm/L between eyes.
What role do corneal stains like fluorescein play in DED diagnosis?
They highlight areas of corneal damage and help assess the extent of epithelial cell loss.
What is lid wiper epitheliopathy (LWE), and why is it significant?
An inflammatory condition where the lid margin becomes rough, impacting tear film quality and causing irritation.
lid wiper is the area where the upper eyelid’s marginal conjunctiva meet
Symptoms- Staining, foreign body sensation, burning or discomfort and blurred vision:
What is the primary pharmacological treatment for DED?
Artificial tears are the most common initial treatment.
List types of artificial tear formulations in increasing viscosity (5)
H, C, S, C, T
Hypromellose
Carbomers
Sodium Hyaluronate (Hyaluronic Acid)
Carmellose
Trehalose
What are the limitations of viscous artificial tears?
They can blur vision and are less suitable for regular daytime use.
What additional treatments can be used if artificial tears are insufficient?
Steroids to reduce inflammation.
Ciclosporin or autologous serum eye drops for severe cases.
What is the role of punctal plugs in ADDE treatment?
They block tear drainage to increase tear retention to the ocular surface
Which lifestyle factors are the first step in non-pharmacological management of DED?
Identifying and modifying lifestyle factors like smoking, screen time, and dry environments.
What is the purpose of warm compresses in DED treatment?
To improve meibomian gland function and comfort in EDE.
How does lid hygiene help with EDE?
CMI
Cleans the lid margin
Manages meibomian gland dysfunction
Improves lipid layer quality
What tools are used for lid hygiene in EDE (3)
L,E,R
Lid wipes
Electronic brushes
Red light therapy
What are the most common symptoms of DED? (3)
G,L,E
Gritty eyes
Light sensitivity
Epiphora (watery eye)
What causes epiphora in DED
Reflex tearing due to irritation or tear film instability.
What is the vicious cycle in DED related to tear hyperosmolarity
Tear hyperosmolarity activates inflammatory proteins.
Inflammatory mediators damage the glycocalyx layer.
Loss of glycocalyx mucins causes epithelial cell apoptosis and goblet cell loss.
Reduced wetting and tear film stability perpetuate tear hyperosmolarity.
Why might there be a lack of correlation between DED symptoms and signs?
Patients can have significant signs of DED without noticeable symptoms.
Patients can have no significant signs with noticeable symptoms.
Why is near work associated with DED
Near work reduces blink rate, leading to tear film instability and evaporation.
What are the goals of DED treatment
To break the vicious cycle and restore ocular surface homeostasis.
How can questionnaires like OSDI help in DED management? (3)
-Assist in diagnosing DED
-Monitoring disease progression
-Assessing treatment effectiveness.
What is dry eye disease
A multifactorial disease of the ocular surface characterized by loss of tear film homeostasis and ocular symptoms.
Key factors:
Tear film instability and hyperosmolarity
Inflammation and damage
Neurosensory abnormalities
What are the two main types of DED
**Evaporative Dry Eye (EDE): **Affects the lipid layer, leading to tear evaporation.
Aqueous Deficient Dry Eye (ADDE): Reduced production of the aqueous layer of the tear film.
What are the three layers or the tear film
L,A,M
Lipid layer: Reduces evaporation (produced by meibomian glands).
Aqueous layer: Provides moisture.
Mucin layer: Increases wettability and spreads tears across the eye surface.
What are reflex tears, and how are they related to DED?
Reflex tears are produced in response to irritation.
Unstable tear film in DED can trigger reflex tear production, leading to epiphora (excess tearing).
What research findings are important for DED
Increased understanding of DED complexity and prevalence (Barabino, 2021).
DEWS reports (2007, 2017, 2023) have expanded classification and management strategies.
COVID-19 pandemic increased risks due to lifestyle changes (Stapleton et al., 2023).
How is the tear film regulated in DED
Quality of the tear film is under active regulation.
Damage to the cornea disrupts tear film homeostasis.
Symptoms are required to diagnose DED; no symptoms mean no DED.
What is tear hyperosmolarity and why is it significant in DED
Tear hyperosmolarity is an increased concentration of salts in the tear film.
Activates inflammatory proteins- recruiting other inflammatory mediators- damages the glycocalyx layer- leadsto epithelial cell apoptosis - loss of goblet cells.
What is the glycocalyx layer, and what is its role in the eye?
what happens if glycocalyx layer is lost
A rich interface between the corneal epithelium and tear film, strongly associated with the mucin layer.
Maintains corneal “wetting” and tear film stability.
Loss of glycocalyx causes corneal cell death (acocolyx) and reduced goblet cells.
What are the core drivers of Dry Eye Disease (DED) according to DEWS 2?
Tear H and F
Tear hyperosmolarity
Tear film instability
regardless of the sub-type.
How does the loss of glycocalyx layer contribute to DED symptoms
Reduces corneal wetting- Leads to corneal staining and shorter (TBUT)- Contributes to instability of the tear film.
What happens to goblet cells in DED
Goblet cells in the conjunctiva are lost due to inflammatory damage and glycocalyx disruption, reducing mucin production and tear film stability.
What study highlights the role of glycocalyx loss in DED symptoms?
Uchino (2018): Loss of glycocalyx mucins likely accounts for corneal staining and reduced corneal wetting, contributing to tear instability.
How is DED affected by blink rate and near work?
Blink rate decreases during near work, worsening tear film instability and DED symptoms.
What is the role of artificial tears in DED treatment
Artificial tears help restore tear film stability.
Hyaluronic acid is effective across severities (optimal concentration: 0.1–0.4%).
Different viscosities available (e.g., Hypromellose, Carbomers, Sodium Hyaluronate).
What treatments are available for severe or unresponsive DED?
Steroids to reduce inflammation.
Ciclosporin or autologous serum eye drops (requires referral).
For ADDE: Punctal plugs to increase tear retention.
How is evaporative dry eye treated
LWR
Address meibomian gland dysfunction using:
Lid hygiene (e.g., wipes, electronic brush).
Warm compresses
Red light therapy
What tools are available for monitoring DED?
Questionnaires like the Ocular Surface Disease Index (OSDI).
Available online at: http://eyecalc.org/osdi/.
What is the first-line treatment for DED?
Non-pharmacological strategies like lifestyle modifications (hydration, screen time reduction, avoiding dust).
What are some commonly used artificial tears?
H,C,SH,T
Hypromellose, carbomers, sodium hyaluronate, and trehalose.
What is the goal when prescribing artificial tears?
A balance of….
Balance viscosity for comfort and visual quality.
Name a pharmacological option for persistent DED cases.
Steroid eye drops to reduce inflammation.
What is the role of punctal plugs in DED management?
To increase tear reservoir in aqueous deficiency cases.
