Gonio 2 Flashcards
anterior curve of goniolens is such that the critical angle is not reached
direct gonio (koeppe) truer appreciation of the angle depth can be used on sedated patients
In indirect gonio the image is
mirror image of the opposite angle
ojects anterior-> periphery
objects posterior - centraly
no change in lateral orientation
what causes suction effect on goldmann gonioscopy
the solution and the steep BC of the lens
most common angle of gonio mirrors
62 degrees
greater distance of gonio lens results in more
tangential view across iris
tilting a gonio lens will change
angulation and brings mirror closer to the corneal apex (less tangential)
what can allow you to view over convex iris during gonio
tilting the lens
Indentation gonioscopy can be done with a Zeiss gonio lens because
it has a small diameter and its possible to indent the cornea and open an angle that is appositionally closed
ability to manipulate the peripheral iris can be helpful in
differentiating appositional vs synechial closure
indentation fails to open= synechial closure
since goldmann gonio lens is steeper than the cornea (smaller base curve)
solution is used, suction occurs
goldmanns gonio is a ___ mirror design, with diameter __ than corneal and ___ than the cornea.
3 mirror
greater diameter than cornea
steeper than cornea
Zeiss is a __ mirror design. With handle (Posner) or without(Sussman). Diameter is ___ than the cornea, BC is ___ compared to the cornea.
4 mirror
smaller diameter than the cornea
same BC as the cornea
insertion of Zeiss gonio lens requires patient to look
in primary gaze
insertion of golmanns gonio requires patient to look
up, lens is inserted in inferior fornix and then tilted on the globe
when performing gonio it is important that the light
does not enter the pupil
to examine 4 quadrants with Zeiss you ___. and with Goldman’s you___.
zeiss-> shift view from mirror to mirror
goldmanns-> rotate the lens
during gonio you have to identify the most __ visible angle structure
posterior
which quadrant is usually the deepest during gonio
inferior is deepest and superior is shallowest
corneal wedge is used to identify
SL
Removing lenses during gonio. For Zeiss ___. For Goldmanns ___.
zeiss-> simply lifting lens
goldmans-> use second hand to break seal, press through inferior lid at edge of lens
___ is the visual landmark with maximum angle orientation
scleral spur
if not located assume abnormal angle
outflow anterior to the spur is ___ and uveoscleral outflow is ___.
- trabecular
- posterior
for rapid orientation during gonio first look for the
scleral spur
look for ____ in the pupillary border during gonio
blood vessels, iris cysts , dandruff like particles
iris can insert anywhere between
CB and the cornea
3 things to check in peripheral iris during gonio
where iris inserts, configuration , angular approach
the geometric ACA is formed by
angle formed by a tangent drawn at the level of the trabecular meshwork and the peripheral iris face
CB difference between myopes and hyperopes
narrow in hyperopes
wider in myopes
when is the ciliary band not seen
if the iris insert directly into the scleral spur
in angle recession you can usually see
a very wide and sometimes irregular ciliary body band
most notable landmark
scleral spur
inability to locate ss suggest
the angle may be closed (appears as a white circumferential band)
if unable to identify spur you can try to locate schwalbes by
performaing corneal wedge
note degree of Trabecular pigmentation with
scale of 0-4+
unusually heavy or asymmetric pigmentation may suggest an abnormality
pigmented TM is located ___ to sclemms
directly adjacent to schlemms
non pigmented is anterior to schlemms
anterior limit of the TM
scwalbes line
identifiable where the anterior and posterior limits of the corneal wedge meet
corneal wedge
pigment deposition along schwalbes line often seen in pigment dispersion syndrome
sampaolesi line
congenital prominence of schwalbes
posterior embryotoxon
peripheral chamber depth is measured
with van herick
in the vicinity if the limbus
central chamber depth is measured
in the vicinity if the corneal apex
in most eyes, a shallow central chamber will predict
a narrow peripheral chamber
Plateau iris syndrome : abnormal anatomic configuration of iris resulting ___ central chamber and ___ peripheral chamber
deep central chamber
shallow peripheral chamber
(when the pupil is dilated it may close angle despite patent iridotomy)
ACG is possible if iris plateau is
at or above TM
shallow anterior chamber depth is ____ to develop ACG
necessary but not sufficient
traditional definition of an occludable angle
inability to visualize the pigmented meshwork in 2 quadrants without indentation
abnormality where chamber is deep centrally but narrow peripherally
plateau iris
pupil block is
resistance to aqueous flow through the pupil causes it to accumulate in the posterior chamber
iris cyst can cause
uneven narrowing of the angle by displacing the iris anteriorly
