Glaucoma And Dry Eye Disease Flashcards
TorF: glaucoma can potentially induce reversible damage to the retina if untreated, or inadequately treated
FALSE. It can potentially induce irreversible damage to the retina if untreated, or inadequately treated
Conventional Pathway:
exit/outflow through the trabecular meshwork (TM) ⇨
Schlemm’s Canal
Unconventional Pathway:
Most common is the uveoscleral pathway: outflow through base of ciliary
muscle ⇨ uvea ⇨ sclera
In a healthy person normal IOP is
~15 mm Hg
IOP ranges from
Range 11 – 21 mm Hg
Most common pathology of glaucoma is:
increased resistance to outflow
e.g., dysfunction of the trabecular meshwork
Acute Angle-Closure Glaucoma:
Primary and secondary
Primary AAG:
closure of a pre-existing narrow anterior chamber angle
Associated shallow anterior chamber (linked with far sightedness, small eye, enlargement of lens with age, inheritance)
Closure of angle is precipitated by
Pupillary dilation
Secondary AAG
May occur in anterior uveitis
With dislocation of lens
TorF: secondary AAG does not require a pre-existing narrow angle
True
Chronic glaucoma is characterized by ___________ of the optic disk with loss of vision
gradual progressive excavation (cupping)
In chronic Open-angle glaucoma (primary or secondary), IOP is _________ due to __________ drainage of AH through the trabecular
meshwork
In chronic Open-angle glaucoma (primary or secondary), IOP is
ELEVATED due to REDUCED drainage of AH through the trabecular
meshwork
TorF: Primary (chronic) open-angle glaucoma is usually bilateral
True
Secondary open-angle glaucoma may result from ocular disease
such as
pigment dispersion, uveitis, trauma or corticosteroid therapy
this appears as a red donut:
Retinal nerve fibers converge at the optic disc which forms the optic nerve
On dilated eye exam, this appears as the white center of the donut
The center of the optic disc, optic cup, which is devoid of nerve fibers
The _______ collapses under elevated IOP, pinching blood vessels and nerve fibers
Lamina cribosa
A major pharmacological strategy employed in treating glaucoma is focused on lowering IOP via:
Decreasing AH production from the ciliary processes
Increasing AH outflow from conventional or uveoscleral pathways or remodeling of the trabecular meshwork cytoskeleton)
What is the MOA of prostaglandin analogs?
Binds to prostaglandin FP receptors to cause an increase in AH outflow ‘ from the uveoscleral pathway via:
Relaxation of ciliary smooth muscles
Cytoskeletal alteration leading to change in shape of cells
Remodeling of extracellular matrix of the uveoscleral pathway by
increasing matrix metalloproteinases
Ocular side effects of latanoprost:
blurred vision
conjunctival hyperemia
foreign body sensation
itching
Increase ocular pigmentation (e.g., iris, eyelid and eyelashes)
photophobia
Latanoprost is used for the treatment of:
open-angle glaucoma and
ocular HTN
LATANOPROSTENE BUNOD
A nitric oxide (NO)-donating prostaglandin F2α analog
What is the MOA of lantanoprostene bunod ?
Dual mechanism of action:
*Increasing AH outflow from uveoscleral pathway
- Increasing AH outflow from trabecular meshwork pathway
mediated by NO (lantanoprost does not have this MOA)
What is the MOA of BETA-ADRENOCEPTOR BLOCKERS
Lower production of AH from the ciliary epithelial cells of the ciliary processes leading to decreased inflow into the posterior chamber.
Ocular side effects of timolol include:
irritation, photophobia, eyelid
erythema, epiphora (Excessive watering of the eye)
Systemic side effects of timolol are:
Systemic side effects include bradycardia, arrhythmias,
hypotension, bronchospasm and heart failure
TorF: Timolol is used for the treatment of open-angle glaucoma
True
TorF: BETAXOLOL is a cardioselective B1 blocker
True
BETAXOLOL can be used for:
open-angle glaucoma
and
ocular hypertension
MOA of a2 agonist:
- Leads to an INCREASE in both intracellular and aqueous humor CAMP levels and INCREASE in AH outflow facility
- Leads to VASOCONSTRICTION and REDUCED AH production
Brimonidine is used:
Used in the treatment of open-angle glaucoma and ocular
hypertension
PARASYMPATHOMIMETICS Acts by increasing AH outflow via two mechanisms:
*Activation of muscarinic receptors in scleral spur and the ciliary
muscle to cause contraction leading to an increase in aqueous
humor outflow
*Activation of muscarinic receptors in the iris to cause
contraction (miosis) which can relief the narrowing of the
anterior chamber angle
___________ is a cholinesterase inhibitor which acts by increasing
the concentration of acetylcholine at muscarinic receptor sites
Ecothiophate
PILOCARPINE is used in the tx of:
open-angle glaucoma
ECOTHIOPHATE is used in the tx of
reduction of elevated intraocular presssure
CARBONIC ANHYDRASE INHIBITORS MOA:
- Acts by inhibiting carbonic anhydrase isoenzymes present in the ciliary processes leading to a REDUCTION of bicarbonate and AH SECRETION.
AND
- A decrease in AH secretion will cause a decrease in AH
inflow into the posterior chamber.
ACETAZOLAMIDE is used in the tx of:
adjunct in open-angle glaucoma
Inhibition of rho kinase reduces intraocular pressure via:
- lowering of outflow resistance in the trabecular meshwork leading to enhanced outflow of AH from the eye
- Decreasing AH production
- Decreasing episcleral venous pressure
NETARSURDIL is used in the tx of:
open-angle glaucoma and ocular hypertension
What is the function of the tears?
Makes cornea a smooth optical surface by covering minor surface
epithelial irregularities
Moisten and protect corneal and conjunctival epithelium
Inhibit the growth of microorganisms by mechanical flushing and antimicrobial action
Provide nutrition for the cornea
Maintain ocular tissues; support wound healing
The outermost lipid layer:
Seal the tear film and prevent evaporation of aqueous layer
The middle aqueous layer:
Produced by lacrimal glands and accessory glands
Contains water-soluble substances: electrolytes; proteins; immunoglobulins; nutrients
Lubricate eye, prevent infection, flush particles from eye, nourish cornea
Dry Eye Disease Definition:
Dry eye is a multifactorial disease of the ocular surface characterized by:
*a loss of homeostasis of the tear film, and accompanied
by ocular symptoms, in which tear film instability and
hyperosmolarity, ocular surface inflammation and damage,and neurosensory abnormalities play etiological roles.
What is the most common cause of evaporative dry eye?
Meibomian Gland Dysfunction
Artificial tear substitutes are _______ or __________ solutions composed of electrolytes, surfactants, preservatives, and some viscosity-increasing agent that prolongs the residence time in the cul-de-sac and precorneal tear film.
hypotonic or isotonic
MOA of ANTI-INFLAMMATORY IMMUNOMODULATORS
A calcineurin inhibitor that exerts immunomodulatory action by blocking T cell infiltration, activation and subsequent release of inflammatory cytokines and chemokines (IL-1β, TNF-α, IL-6, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1)
Cyclosporine A also inhibits p38 and JNK activation that leads to IL-2 production. Reduced IL-2 levels further blocks the function of effector T cells
PHARMACOLOGICAL ACTIONS of CYCLOSPORINE A
Increases tear production in patients with dry eye
disease that are refractory to conservative treatments
such as ocular lubricants
Protects human conjunctival epithelial cells via its
antiapoptotic actions
Improves conjunctival goblet cell density and corneal
surfact integrity via its immunomodulatory actions
CYCLOSPORINE A is used in the tx of:
*Ocular side effects include instillation site pain,
conjunctival hyperemia, blepharitis, eye irritation
*Systemic side effects include urinary tract infection,
headache
*Used to increase tear production in adults with keratoconjunctivitis sicca (dry eye)
Lifitegrast _____ T cell migration, activation and release of proinflammatory cytokines
Inhibit
LIFITEGRAST is used for the tx of:
Used for the treatment of signs and symptoms of dry eye disease
This drug is a corticosteroid that reduces the inflammatory processes associated with dry eye disease
LOTEPREDNOL
