oftalmo second test Flashcards
what is glaucoma
various processes in which a intraocular pressure is higher than what the eye can tolerate affecting the optic nerve which is showsn as a CV defect
increases with age
pathway of aqueous humor
Aqueous humor flows from the ciliary processes into the posterior chamber, bounded posteriorly by the lens and the zonules of Zinn and anteriorly by the iris. It then flows through the pupil of the iris into the anterior chamber, bounded posteriorly by the iris and anteriorly by the cornea. From here the trabecular meshwork drains aqueous humor via Schlemm’s canal into scleral plexuses and general blood circulation.
angular structures
Schwalbe line schlemm channel scleral espolon ciliary body iridian processes
incidence of glaucoma depends on
increases with age
where is aqeous humor produced
in ciliary processes in posterior camer
then go through pupil to anterior camer and evacuate at irido corneal angle through trabeculum, schleemm chanal, and episcleral venous system
average intraocular pressure
20mmhg (varies per person)
if you have no angular structures
closed angle
1-2 anglular structures
thin
all angular structures
open angle
drainage of aqeous humor
trabecular malla is where aqeous humor exist
formed by 3 portions
3 portions of malla trabecular
uveal trama - most internal which extends to Schwalbe line
corneoscleral trama - medial and widest extends from espolon of sclera to Schwalbe line
endothelial trama - exterior that untes corneo-scleral trama with schlemm canal
this is where anti-glaucoma meds work
tx if you have IOP > 30mmhg
cant put just anti-glauc drops
need VO
b/c corneal edema is produced prevents liquid from correctly penetrating
*Anteriormente se llegaron a usar Mióticos, porque si cierras un poco más el iris fluye mejor el humor acuoso a cámara anterior.
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Factors that increase IOP
increase in hematic V
increase in BF in ciliar body
beta-agonists
pretrabecular block (sinequias, neovesssels)
trabecular block
post-trabecular block
increase in venous pressure (carotid-cavernouse fistula)
how to dx a fistula
*Le tomas la presión intraocular sentado y acostado si aumenta 3mmHg es diagnóstico de fistula (Junto con la clínica
factors that decrease IOP
Pilocarpina: Parasimpaticomimético Análogos de prostaglandinas Trabeculectomía Trabeculoplastía Destrucción del cuerpo ciliar
Classification of glaucoma
depending on alteration in drainage (open/closed)
depending on associated factors with increased IOP (primary , secondary)
depending on age (congenital, infantile, juvenile, adult)
most common glaucoma
primary, open angle
cx of primary glaucoma
El aumento de la presión intraocular no se asocia a otro trastorno ocular. Asociado a miopatía alta, diabetes mellitus y antecedentes familiares.
only glaucoma that causes crisis
closed angle
other are asymptomatic
perfusion pressure of capilaaries of head of optic nerve is
27 plus or minus 3 mmHg
mild increases in IOP produce difficulty in nutrition
pathogenesis of glaucoma
Hay atrofia de las células de sostén y fibras nerviosas, lo cual ocasiona aumento en la excavación del disco.
Mientras más profundo, mas es la excavación, mientras más grande es la excavación, mayor es el glaucoma.
- Mientras más morenito es uno, más tiende a ser grande la excavación.
- La excavación se mide en relación con la fóvea total. Si la excavación ocupa el 100% entonces es una atrofia óptica.
dx glaucoma criteria
must have 2/3 criteria
alteration in sxcavation of II
alteration in IOP
alteration in visual field
hereditary cx of congenital glaucoma
incomplete penetrance
AR