Sclera and Uvea Flashcards
(28 cards)
Three components of the uveal tract
Iris, Choroid, Ciliary Body
Granulomatous vs Nongranulomatous Uveitis
non-Granulomatous: acute onset, marked pain and photophobia, moderate blurred vision, marked circumcorneal flush, small white keratic ppts, small and irreg pupils, sometimes post. synechiae, no iris nodules, anterior site, acute course, common recurrence
granulomatous: insidious onset, no or minimal pain, slight photophobia, marked blurred vision, slight circumcorneal flash, large gray (“mutton fat”) keratic ppts, small and irregular (variable), sometimes post. synechiae, ant, post or panuveitis, chronic course, sometimes recurs
Two conditions classified as anterior uveitis
Iritis, iridocyclitis
Uveitis can be classified based on three (3) categories. Enumerate and provide the subcategories.
a) Anatomical or Clinical - anterior, intermediate, posterior, diffuse
b) Pathological - granulomatous, non-granulomatous
c) Etiology - infectious, non-infectious, and malignancy
Part of the uveal tract that is responsible for aqueous production.
Ciliary body
Iris muscle that contracts in response to parasympathetic stimulation
Sphincter
Anterior extension of the ciliary body
Iris
Layers of the iris
Stroma - chromatophores; sphincter and dilator muscles
Iris Pigmented Epithelium (IPE) - anterior extension of neuroretina and RPE
Function of the iris
Regulate pupil size
Extent of the ciliary body
From ant end of choroid to the root of the iris
Part of the ciliary body involved in aqueous humor production:
a) pars plana
b) pars plicata
pars plicata
Why is backflow of the aqueous humor impossible?
Posteriorly, the solid, gel-like vitreous humor is present. Vitreous is immiscible with aqueous.
Trace the pathway of the aqueous humor.
Lens and iris to pupil to iridocorneal angle (trabecular meshwork)
T or F: Angle is only found in the periphery
True
Where does the aqueous humor drain?
trabecular meshwork
True about the pars plana, except:
a) located 3.5 mm away from the limbus
b) flattened, located posteriorly
c) it is where ciliary processes arise from
d) it is devoid of any important stuctures
C - ciliary processes arise from pars plicata
pars plana - entry point for surgical procedures because it is devoid of important structures
Which ciliary muscle inserts into the trabecular meshwork?
Longitudinal
Two main functions of the ciliary body
- acts in accommodation due to the circular muscles that contracts and relaxes the zonules
- secretion of aqueoua humor
True about accommodation:
a) when looking at a distance, the ciliary muscle relaxes, zonules contract and the lens thickens
b) when looking near, ciliary muscles relax, zonules relax and the lens narrows
c) when looking far, ciliary muscles relax, zonules contract and the lens narrows
d) when looking near, ciliary muscle contracts, zonules relax, and the lens narrows
C
Looking far or at a distance, ciliary muscle relaxes, zonules contract, and lens narrows
Looking near, ciliary muscle contracts, zonules relax and lens thickens
True about the sclera:
a) It is the fibrous outer protective coating of the eye, consisting almost entirely of collagen
b) It is dense and white, continuous with the cornea anteriorly and the dural sheath of the optic nerve posteriorly
c) Outer surface of the anterior sclera is covered by a thin layer of fine elastic tissue called episclera
d) The brown pigment layer on the inner surface of the sclera is called lamina fusca and forms the outer layer of the suprachoroidal space
e) AOTA
E
T or F: The sclera is about 0.3 mm at the insertion of the recti muscles and 0.6 mm thick elsewhere
True
Nerve supply of the sclera
ciliary nerves
Blood supply and nerve supply to the iris and ciliary body
BS - major circle of iris
NS - ciliary nerves
Pupillary size is principally determined by a balance between constriction due to ________ activity transmitted via CN III and dilation due to _______ activity.
parasympathetic; sympathetic
