epidemiology Flashcards
Glaucoma: definition
is a group of diseases; defined by:
- optic neuropathy
- remodeling of the optic nerve head cognitive tissues
- loss of neural tissue
- distinctive patterns of visual dysfunction.
when we talk about glaucoma we mostly talking about ……… glaucoma
POAG
Glaucoma: Natural history 5
- Glaucoma(POAG)isnotafastmovingdisease
- Thereisawiderangeofnormalandborderlineclinicalpresentations making correct detection and classification difficult
- Cross-sectionalclassification–verychallenging
- Sensitivity/Specificity(prevalence)
- Longitudinalchangeinclinicalfindings(Progression)isanimportantkeyto clinical management (incidence)
sensitivity
is the number of correct cases of disease that you were able to detect
specificity
is the number of correct normal individuals that were called as normals
Correct Classification (2)
true positive
true negative
Aqueous Humor Flow
aqueous humor is produced in the posterior chamber by the ciliary body. It then flows between the anterior surface of the lens and the posterior surface of the iris before reaching the anterior chamber. Aqueous fluid then circulates within the anterior chamber before returning to vascular circulation via the trabecular meshwork, Schlemm’s canal, and the finally the episcleral veins.
when the pupil is constricted the angle is ….
open
The pupil is mid-dilated, the iris is bowed anteriorly and the angle is
narrowed
The pupil is mid-dilated, the iris is bowed anteriorly and the angle is
reduced because the iris has a relatively flatter configuration
Classifcation of glaucoma (2)
- open angle
2. Closed angle
types of Open Angle glaucoma (6)
- POAG
- NTG
- JOAG
- OHT
- GLAUCOMA Suspect
- Secondary open angle
classification of Closed angle Glaucoma (5)
- Primary angle closure (PACG)
- primary angle closure/suspect (PAC/PACS)
- Chronic angle closure
- Secondary angle closure
- secondary angle closure without pupillary block
primary glaucoma
there is no other known cause
secondary glaucoma
there is an identifiable cause
Classification based on angle status is an important…..
therapeutic distinction
age dependent class-action
- ≤ 3 years (congenital) cornea normally stops growing at this age
- 435 adult (the majority)