Gonioscopy II Flashcards
What type of image is produced with a direct view (Koeppe lens) and an indirect view (Mirror)?
- Direct: Virtual, upright, magnified
- Indirect: Virtual, unmagnified
Which is not an advantage in using Indirect?
A. Vary magnification with slit lamp B. Requires Gonio fluid C. Bright illumination allows for small detail detection D. Easy Implementation E. Can use Laser treatment
B. Requires Gonio fluid
What are five disadvantages of Indirect?
Patient, Field of View, Gonio Fluid?, Corneal Folds?, Pressure?
- Patient discomfort
- Small Field of View and poor lateral view
- Requires gonio fluid
- Artifacts and corneal fold may distort view
- Pressure from lens may produce angle opening or narrowing
How often does a 1-mirror and 2-mirror need to be rotated to view entire angle?
1-mirror: 4x
2-mirror: 90 degrees (1x)
What are some advantages of 1-2 mirror lenses?
Size, Weight, MIrror position
- Smaller lens
- Lighter lens
- Mirror closer to center of lens, easier to see angle recess over iris
What are four advantages of a 4-mirror gonio?
Rotations, Tear layer, Radius of curvature, Is it quick?
- no lens rotation needed
- tear layer acts and interface medium
- smaller radius of curvature, more useful for indentation
- Useful quick angle assessment
What are five disadvantages of a 4-mirror gonio?
Patient, Practice, Distortion of angle, Corneal Folds, Peripheral abilities?
- Requires patient cooperation
- Requires steady hand and practice
- Distortion of normal angle possible
- Corneal folds easily induced
- No peripheral retinal examination abilities
What are two advantages of a 3-mirror gonio?
Gonioscopic solution, Angle structure
- Gonioscopic solution helps maintain stability
- Angle structures are less crowded and easier to differentiate
What does the central, trapezoid, rectangle and thumbnail mirror view in the eye?
(Posterior, Equatorial, Ora)
- Central: posterior pole
- Trapezoid: equatorial region
- Rectangular: peripheral fundus anterior to equatorial region
- Thumbnail: Angle and ora serrata
Which mirror would you use to view the equatorial region?
A. Central
B. Trapezoid
C. Rectangular
D. Thumbnail
B. Trapezoid
Which mirror would you use to view the peripheral fundus anterior to the equatorial region?
A. Central
B. Trapezoid
C. Rectangular
D. Thumbnail
C. Rectangular
Which mirror would you use to view the posterior pole?
A. Central
B. Trapezoid
C. Rectangular
D. Thumbnail
A. Central
Which mirror would you use to view the angle and ora serrata?
A. Central
B. Trapezoid
C. Rectangular
D. Thumbnail
D. Thumbnail
