gonioscopy 3 mirror

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what are you examining with gonio?: the anterior chamber
The ant. chamber angle is the filter and exit point for what?: aqueous humor
what physiological process affects the risk for glaucoma? What is the state of the angle which causes concern?: dilation, the narrowness of the angle.
Would you perform gonio after noticing a small angle when doing the Van Herrick technique?: of course!
Would you do gonio if the patient has a history of angle closure?: yes
Would you do gonio to rule out ischemic NVI? What could you rule out?: yes, rule out uncontrolled diabetes and vein occlusion
Would you do gonio to assess a peripheral anterior synechia?: yes
Name 5 others reasons to perform gonio.: 1-suspect glaucoma
2- evidence of NVI
3- evidence of neoplasms in AC or on iris behind limbus
4- evidence of inflammation or trauma
5- evidence of degenerative conditions of the anterior segment.
What structure of the eye prevents you from seeing the angle with just using the slit lamp?: the opaque white nature of the limbal cornea.
What quantifies the anterior chamber angle?: anatomical zone b/t the iris root and descemet's membrane.
What is the critical angle of total reflection dependent on?: the refractive indices on either side of the interface.
How does the design of the gonio lens enable you to view the angle. (long answer): the gonio lens involves placing a concave surface against the cornea-- this eliminates the cornea as a refracting surface. The obliquely inclined mirrors allow observation of the anterior chamber structures.
What amazing and super talented man designed the gonio lens we use today?: Goldmann
any small difference in curvature b/t the lens and the cornea is minimized by a ______ b/t the 2 surfaces.: fluid
What distinguishes the various gonio lenses?: the diameter of their contact surface.
Small gonio lenses have a diameter of___? Large is____?: <10 mm, >13 mm
What do large lenses require?: require an interface solution (used to mask the air/cornea interface difference)
(Large=Liquid)
What is the name of the 3-mirror?: Goldmann
What are 3 names of 4-mirror lenses?: 1- Posner
2- Zeiss
3- Sussman
What is the name of a single high plus lens?: Koeppe
Describe a direct lens system.: this uses a high convex lens to view the AC. (no mirrors)
Describe an indirect lens system.: this uses mirrors + a slit lamp for AC evaluation.
Goldmann contains 3 ______mirrors and is thus a(n) ________ system?: internal mirrors, indirect
A D-shaped mirror is used to view the______?: AC angle
The trapezoid mirror is used to view the _____?: mid-peripheral retina
The cylindrical mirror is used to view the ____?: ora seratta
Goldmann 3-mirror requires the use of____?: a viscous gel
How many of the 3 mirrors is used to evaluated the angle?: only 1
The center lens may be used to get a _____ view of the post. pole.: magnified
Does the Koeppe gonio lens have mirrors?: No!!
The Koeppe is a ____ view of the angle?: direct
How many diopters is the koeppe gonio lens?: 50D
Compare the mag of the koeppe to the mag of ziess and goldmann.: The koeppe gives a Lower mag.(~1/2) As a result the field of view is doubled and has less distortion.
When using the koeppe, do you need a slit lamp?: No, patient lies down, face up.
Does the koeppe lens require a viscous solution?: yes
When using the koeppe lens the clincian views the angle _____ of where he is located.: opposite
What are 2 gonio lens that require a viscous solution?: 1-goldmann
2-koeppe
(any lens that has a large corneal contact area)
What are 2 choices of viscous solutions?: 1- goniosol
2- celluvisc
what is an advantage of using goniosol? a disadvantage?: advantage= better view, less bubble formation
disadvantage= allergic RXN to the preservative BAK
What is an advantage of using celluvisc? disadvantage?: advantage= less corneal disruption
disadvantage= greater frequency of bubble formation.
What are the needed supplies when performing goldmann 3-mirror? (5): 1- lens
2- soap, water, saline, and 2% glutaraldehyde
3-anesthetic
4-methylcellulose sol'n
5-slit lamp
What will you use to numb the patient while doing gonio?: 0.5% proparacaine
what mag do you use for goldmann gonio?: 16X
What size beam for goldmann gonio? ______wide and ____ tall?: wide parallelopiped, ~4mm wide, and maximum height.
What angle should your light housing be when doing goldmann gonio?: 0 degrees
What solution do you use to soak the gonio lens?: 2% glutaraldehyde
The D-shaped mirror will be located ______ when on the eye.: superiorly
The angle is viewed ____ from the mirror.: 180 degrees
If the mirror is at the 12:00 position, the angle viewed is at _____?: 6:00
With the gonio lens in place, in which direction will you push the slit lamp(in, or out?) to bring the structures into focus?: push in towards the patient.
You must _____ the lens to view all of the angles.: rotate
The light beam must be ______ to the flat surface of the "D".: perpendicular
To view lateral angles, the slit beam should be rotated to the ______ position.: horizontal
T or F: It is best to forcefully pull the lens off of the cornea when you are done.: False--this will cause corneal trauma!
T or F: There is no need to perform a parallelopiped scan of the cornea after gonio.: False! You must do this, and you may need to use a FL strip.
What has happened if you see stippling over the entire cornea when you are scanning?: Patient had a reaction to goniosol
What has happened if you see patchy puntate staining?: patient RXN to proparacaine.
Describe the procedure for cleaning the gonio lens.: 1- 2% glutaraldehyde soak for 20 minutes
2- sterile saline rinse
3- dry with a lint free tissue or cotton towel
4- replace in lens container
What is the best choice for performing gonio if you have to take fundus photos?: use celluvisc (instead of goniosol), this will prevent the possibility of corneal rxns. Better yet, use a 4 mirror lens (b/c it does not require a solution)
To get deeper into the angle, have the patient _____?: look toward the mirror slightly.
T or F: Always check IOP BEFORE gonio.: true
What are the 3 things a clinician needs to examine when doing gonio?: 1- the openness of the angle
2- are the structures healthy?
3- anything unusual?
What is the last iris roll?: Fuchs roll
What is the most posterior AC angle structure?: the CBB ( ciliary body band )
What color is the CBB?: grayish brown-white
What does the CBB play a role in?: aqueous production
The CBB is broader ___ and ____?: inferiorly, temporally
What structure comes after the CBB?: the SS (scleral spur)
What color is the SS?: thin whitish band
What does the SS represent?: the continuation of the sclera into the anterior chamber
where is the SS?: b/t the ciliary body and the TM
What structure comes after the SS?: The TM!
The TM is like a ____? What does it do?: sieve, it drains the aqueous from the anterior chamber.
What color is the TM? What might you see in here?: translucent gray. pigment
Where will most of the pigment be within the TM? why?: the posterior portion, b/c it is the filtering point
T or F: darker eyes will have more pigment in the TM than lighter eyes.: true

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