Higa: Dry Eye 1 Flashcards
What are the functions of the eyelids?
- cover/protect globe
- Move tears medially
- spread tears
- Contains glands
Which muscle: Causes negative pressue to help drain tears w/ a blink
Muscle of horner
Which muscle: found within eyelid, keeps the eyelid on the globe
Muscle of Riolan
WIT: Loss of muscle tone, can lead chronic epiphora
Ectropion
WIT: due to involutional entropion or an inward turning of lashes, can lead to FBS
Trichiasis
Rubbery tarsus and loose upper lids, often seen in obese men and associated with sleep apnea; can result in mechanical GPC
Floppy eyelid syndrome
Accessory glands of wolfring & Krause produce?
Aqueous
WIT: Preservatives in ophthalmic drugs/sons can cause breaks in epithelial tight junctions resulting in PEE
Toxic Keratitis
WIT: Loss of corneal sensory innervation that results in lack of corneal healing and symptoms
Neurotrophic Keratitis
What 5 things do the tears contain?
- Water
- Electrolytes
- Lysozyme
- Lactoferrin
- Immunoglobulins
WIT: Acute infection of the meibomian glands
Internal hordeolum
WIT: Infection of sebaceous gland (zeiss or moll)
External hordeolum
Meibum is thought to be caused by what?
Testosterone and Progesterone
What are the functions of the tear film?
- Lubricant
- Traps Debris/Removes Epithelial cells
- Oxygen for cornea
- Smooth refractive surface
- Antibacterial properties
- Maintain corneal hydration
- Growth factors
What is the average osmolarity of the tear film? ph? thickness?
300mOsm
6.2-8.2
2-5.5um
What % of tears pass through lacrimal drainage?
75%
What is the length of the ampulla, canaliculus, lacrimal sac & nasolacrimal canal?
2mm
8mm
10mm
12mm
A positive Jones 1 test means what?
- the drainage system is open/patent
A positive Jones 2 test means what?
- dye is now present
There was a blockage, but dilation and irrigation removed it
What does a negative Jones 2 test mean?
Regurgitation from superior/inferior puncta… obstruction
Receptors sense feeling/abnormality and send signal via what nuclei?
- Nuclei of V
2. Superior Salvitory Nucleus
WIT: Pain that arises from actual damage to tissue & is due to the activation of nociceptors.
Nociceptive pain
WIT: Pain caused by a lesion or disease of the somatosensory nervous system; Pain without biologic value
Neuropathic pain
What are the 3 types of corneal sensory neurons?
- Polymodal nociceptors
- Specific mechano-nociceptors
- Cold thermoreceptor neurons
WIT: Respond to chemical, thermal and mechanical insult; sensitized by inflammation
Polymodal nociceptors
WIT: Responds only to mechanical injury
Specific mechano-nociceptors
WIT: Increase or decrease of firing due to heat/cold of ocular surface; sensitive to changes in tear osmolarity
Cold thermoreceptor neurons
What is the most important neuron in DED?
Cold thermoreceptor neurons.
What are the new components of DEWS 1 compared to DEWS 2?
- Loss of homeostasis
2. Neurosensory abnormalities
What are the 2 components of Non-Sjogrens/K.sicca ?
- Aging
2. Low Androgens
What is found to be decreased in ppl over 80?
Lactoferrin & Lysozyme
High levels of what androgen is a risk factor for DED? This is found in post-menopausal women
high levels of estrogen
Sjogren’s is an autoimmune attack on what? What infiltrates them?
Lacrimal and Salivary glands
- infiltration of T & B lymphocytes
What auto-antigens are expressed in Sjogrens?
Ro & La
What are the 3 characteristics of primary sjogren’s?
- Reduced salivary production
- Reduced tear production
- Presence of autoantibodies (ro & la)
What is secondary sjogrens?
Primary sjo + autoimmune disease (RA, SLE, PA, Wegner’s)
What are the factors leading to ADDE?
- Non-Sjo/K.sicca
- Sjogrens
- Lacrimal Obstruction
- Inflam. Lacrimal infiltration
- Systemic Drugs
Trachoma causes what 3 things?
- Tarsal and conjunctival scarring
2 Trichiasis - Cicatricial MG obstruction
WIT: Mucocutaneous disorder characterized by blistering of skin/mucous membranes
Cicatricial Pemphigoid
WIT: Acute, self-limiting mucocutaneous disorder usually caused by drugs, infection or malignancy
Erythema multiforme
What are the 4 types of lacrimal obstruction?
- Trachoma
- Cicatricial Pemphigoid
- Erythema Multiforme
- Chemical/Thermal Burns
What are the 4 things that can cause inflammatory lacrimal infiltration/damage?
- Sarcoidosis
- Lymphoma
- AIDs
- Graft vs. Host Disease
WIT: May present initially as dacryoadenitis; infiltration of lacrimal gland by sarcoid granulomata?
Sarcoidosis
Sjogren’s patients are at an increased risk of developing what disease?
Lymphoma
What 4 categories of systemic drugs can cause ADDE?
- Anticholinergics
- Adrenergic Agonist
- Diuretics
- Anti-hypertensive
What 3 things can cause a reflex sensory block for making aqueous/tears?
- Infective (HSV)
- Corneal Surgery
- Neutrophic Keratitis
- Diabetes
- CL wear
The severing of what 2 corneal nerves can cause sensory denervation?
LPCN & SPCN
Neurotrophic Keratitis is due to what type of injury?
CN V nerve or ganglion injury
What are the intrinsic causes of EDE?
- MGD
- Disorders of Lid
- Low Blink Rate
Increased ocular surface exposure leads to an increase in evaporatation and resultant ___ ____?
Tear hyperosmolarity
What are some disorders leading to increased ocular surface exposure?
- High myopia
- Exophthalmos
- Nocturnal lagophthalmos
Low blink rate is found in what disease?
Parkinson
What are the extrinsic causes of EDE?
Environments with increased air flow or low humidity
- increases tear osmolarity
What additional factors can lead to tear film instability?
- Vitamin A def.
- Topical drugs/preservatives
- Allergic Conjunctivitis
- Anterior Blepharitis
Why does Vit A. deficiency cause DED?
Vitamin A is needed for the development of goblet cells and expression of the glycocalyx mucin
What is a Bitot’s spot?
Build up of keratin on the conjunctiva due to Vitamin A deficiency
