What is gonioscopy?
procedure to view the anterior eye using a gonioscope
What can you see with gonio when dilated/not dilated?
anterior chamber angle without dilation
peripheral fundus when dilated
What are the reasons to evaluate the anterior angle chamber?
determination of likelihood of angle closure
examination of abnormal structures in angle
Pigment dispersion syndrome
What are the contraindications for gonio?
Corneal abrasions or ocular trauma
Lacerated or perforated globe
Following ocular surgery including cataract surgery
Recurrent corneal erosion syndrome
Anterior uveitis-iritis including patients with known recurrent attacks
What are the 6 layers visible with the anterior angle?
LICKING TOILETS SHALL CAUSE ILLNESS
What are the characterisitics of schwalbe's line?
fine white line- not always visible
indicates termination of descemet's membrane
line becomes pigmented with age
what is psuedoexfoliation?
accumulation of granular amyloid-like fibres found in schwalbe's line
What are the characteristics of the trabecular meshwork?
contains 2 distinct bands- non pigmented anterior line, pigmented posterior line
What are the characteristics of schlemm's canal?
only seen if contains blood
What are the characteristics of the scleral spur?
defined light coloured band
point of attachment of ciliary body to sclera
What are the characteristics of the ciliary body band?
darker brown/grey uniform colour
if visible- angle is very wide
What is the characteristic of the image in gonio?
inverted but NOT reversed
Why is the goldmann lens gonio limited?
needs coupling fluids
What are the advantages of using a goldmann?
Gonioscopic angle evaluations
Direct posterior pole examination through contact
Peripheral retinal examinations extending to ora if good dilation
What are the disadvantages of using a goldmann?
only 1 view of the angle at a time
need to rotate for view
scary for px
Zeiss type advantages?
360 view without rotation
no coupling fluids needed
allows indentation gonio
less imposing for px
Zeiss type disadvantages?
view less mag and sharp
What is the Schaffer classification of anterior chamber angles?
0/0/iridocorneal contact present, apex of corneal wedge not present
1/10/schwalbe line present
2/20/only trabeculum present
3/25-35/scleral spur present
4/35-45/ciliary body easily visible
What is the modified Schaffer classification of anterior chamber angles?
narrow angle/<10/less than 1/3 of trabecular seen
intermediate/10-20/entire trab seen
wide/>20/ciliary body present
How can you tell that the angle is acutally closed?
if beam from iris and posterior cornea are coincident