Dry Eye & Glaucoma Management Flashcards
(10 cards)
Define dry eye
multifactorial disease of ocular surface with loss of tear film homeostasis and ocular symptoms
Describe the structure and function of the tear film
protects/lubricates the eye reducing risk of infection and washing away foreign particles
lipid (meibomian) reduces evaporation/maintains smooth optica surface
aq (lacrimal) has nutrients/EGFs/Proteins for epithelial hydration/oxygenation
mucous (Conj. GCs) enhances stability to cornea
Describe the ideal eye drop properties
kind to ocular surface prolonging TF stability, balances electrolytes with no preservatives
protection from desiccation/hyperosmolarity with viscoelasticity/potassium
State the (non)+modifiable risk factors for dry eye
Non-modifiable: age, females, asian, MGD, Sjogren’s
Modifiable: CL use, computers, environment, medication
Explain the dry eye cycle of doom
TF instability due to excessive surface evaporation, increased TF osmolarity damges surface cells causing inflammation
causes loss of microvilli glycocalyx/GCs to destabilise TF
What are the main factors for dry eye?
Preservatives, allergies
Bleph, CL wear, MGD
unstable lipid layer, low lacrimal flow, dry environment
What are the risk factors for glaucoma?
asymptomatic vision loss
IOP>21mmHg
Family history, afro-caribbean
Systemic OHT, CVD, migraines
previous ocular disease/steroid use
Describe the primary/secondary causes of OAG
Primary: high IOP (POAG), normal IOP (NTG): progressive nerve head damage (vasc. change)
Secondary: post-op/trauma, IOHaemorrhage/Tumour, RetDet, Uveitis
Describe the sites for aq production/outflow
Produced in ciliary epithelial cells and drainage through trabecular meshwork/Schlemm’s canal (90%), sclera (10%)
What are the risks of using B-blockers at night?
exacerbate nocturnal bradycardia
BP dips
impaired ONH perfusion
