Lect 1 Flashcards
(32 cards)
Ocular Surface Diease
Dry eye disease and blepharitis
Main components of ocular surface
Eyelids, conjunctiva, tear film, cornea
Eyelid
Skin, muscles, tarsal plate (fibrous and elastic tissue), meibomian glands, and principal accessory lacrimal glands
Principal accessory lacrimal glands
Glands of: Zeiss, Moll, Krause and Wolfring, Manz and Henle
Glands of Krause and Wolfring function
Secrete aqueous layer of tear film
Glands of Manz and Henle function
Secrete mucous layer of tear film
Glands of Zeis function
Sebaceous
Glands of Mol function
Sweat
Eyelid function
Protection of corneal and conjunctival surface. From infection, foreign bodies, and light.
Blinking process is important for…
Tear film by supporting: meibum/lipids secretion, spreading uniform tear film, and drainage of the tears.
Types of blinking
Voluntary, spontaneous, and reflex
Blinking phases
Closing/occulsion: gland compression, excretion of glands, drainage of old tears through lacrimal puncta, and closing of lacrimal puncta.
Opening: homogenous spreading of new tears and lacrimal puncta opening.
Tear film function
Protects from infection and hydrates cornea and conjunctiva.
Provides O2 to reach cornea.
70% of eye’s refractive power through the cornea and polishes its surfaces.
Tear film layers
Lipid layer (meibomian glands) Aqueous layer (lacrimal glands) Mucin layer (epithelial cells)
Corneal layers
Epithelium, Bowman’s layer, Stroma, Descemet’s memebrane, Endothelium.
Conjunctiva function
Produces mucous layer through goblet cells. Protects the cornea and interior of the eye from the external environment. Allows independent movement of the eye and eyelids.
Cornea function
Refracts incoming light, helps shield eye from foreign bodies, and serves as a filter, screening UV wavelengths in sunlight
Dry eye risk factors
Asians, Females, Menopause, Certain meds, Systemic autoimmune and inflammatory disease, long term glaucoma meds, CL wear, Eye surgeries, Life style (smoke, low humidity, prolonged comp, dec essential fatty acids).
Dry eye symptoms
Burning, Itching, Redness, Soreness, Dryness, FBS, Grit/sand sensation, CL intolerance, Fluctuating or transicent blurred vision, photophobia
Dry eye lifestyle modifications
Avoid allergens, Humidify environment, Quit smoking, Limit screens: Reduces blink rate and increased evaporative tear loss. Lower display terminals to decrease inter palpebral aperture. Frequent breaks and A.T.s
Dry Eye Therapeutic Management
Lifestyle changes, dietary mods, eyelid hygiene, eye lubricants, anti inflammatory eye drops: steroids, non steroids, antibiotics and/or cyclosproine A. Punctual plugs (retain moisture on ocular surface). Treatment of other coexisting conditions.
Artificial Tears benefits
Inc volume of tears, moist and lubrication of ocular surface, stabilizing tear film, formation of functional film and preserving visual function.
Prefer properties of A.T.
Very high tolerance, high affinity for the ocular surface, prolonged contact time, acceptable viscosity, appropriate osmolarity, non preservative.
Blepharitis
Chronic inflammation of the eyelids.