Module 3: Supplementary Testing

Question 1

• sensitivity of px visual field
• checking photoreceptors (cones/rods)
• requires dim room lighting
  -each point = spot on retina/mapped out

Answer 1

Visual field testing

Question 2

• highest point = fovea
• decreases into periphery
• less sensitive with age (decrease superior)

Answer 2

Hill of vision

Question 3

-blind spot
-15 degree line of sight (ONH)

Answer 3

Scotoma

Question 4

-Confrontation
-Tangent
-Automated

Answer 4

Types of Visual Fields

Question 5

-general idea
-gross indication of sensitivity of each 1/4 section
-compare px to examiner

Answer 5

Confrontation VF

Question 6

-not routinely used
-central 30 degrees
-using black felt forms
-brings forward various size white targets
-maps blind spot(scotoma)

Answer 6

Tangent Screen VF

Question 7

• most commonly used
  -uses static perimetry method
  -testing central 60 degrees (30 in all directions)
  -starts bright until not visible
• target spot brightness = retinal sensitivity
  -high value = very dim can be seen
  -low value = bright light required to see

Answer 7

Automated VF

Question 8

-90 temporally
-60 nasally
-70 inferiorly

Answer 8

Normal field of vision

Question 9

-must be shorter than latency time for voluntary eye movement
-px looks at target= disspear on them

Answer 9

Stimulous Duration

Question 10

-top of hill must be monitored
- HVF plot/measure blind spot, if px clicks when lit then incorrect positioning

Answer 10

Fixation monitoring

Question 11

-dimmest target seen
-starts with 4dB brighter than expected
-descreases by 4dB when target seen
-increases by 2dB if px not responding
-50% of time target seen= threshold
- central threshold= glaucoma
-suprathreshold = general screening

Answer 11

Threshhold VF

Question 12

-target moves/changes sizes &brightness
-for px who cant focus (kids/disabilities)
-confrantion/tangent/goldman

Answer 12

Kinetic Perimetry

Question 13

-px covers one eye
-examiner moves hand around
-px signals
- px uncorrected/no glasses
-1 meter distance
-1,2 or 4 fingers at 45-90 degrees
-compare with examiners results

Answer 13

Kinetic Confrontation

Question 14

-using wall/poster
-not commonly used
- but more accurate than confrontation
-maps central 30 and scotoma
- stare at target while bringing target inwards

Answer 14

Kinetic Tangent

Question 15

• most common
• 33cm from cornea

Answer 15

Kinetic Goldman

Question 16

• target doesn’t move/stationary
  -starts dim, increases until seen
• size doesn’t change
  -detects scotomas (blind spots)
  -automated

Answer 16

Static Perimetry

Question 17

• false positive (clicking at nothing) 33% or 3/10
  -False negative(not clicking when seen) 33%
  -both mean unreliable test results

Answer 17

Automated VF errors

Question 18

-20 degrees consisting of 17-19 sections
-early detection of glaucoma,retina,neurological
-glasses optional
-screening type = 45 sec-2 mins
-threshold= 4-5 mins
-series low spatial frequecy gratings
-stimulates ganglionic cells (neurons) in retina/ detects early glaucoma before others

Answer 18

Frequency Doubling Technology (FDT)

Question 19

-photokeratoscopy/videokeratography
-corneal surface not spherical
-measures thousands points entire surface
-creates 3D image
- screens before OMD referrals
- diagnose keratoconus
-pre-post op for PRK/Lasik
-specialty contact lens fittings

Answer 19

Corneal Topography

Question 20

-measures corneal thickness
-device is ultrasonic measured in microns ym (AVG 540ym)
-monitors keratoconus
- detects corneal edema
-pre/post Lasik
-glaucoma because thinner central cornea

Answer 20

Pachymetry

Question 21

-creates baseline for conditions/diseases
-typical range= 15-60 degrees
-requires 2mm pupil size
-optomap doesn’t have pupil size requirements
- autofluorescense detects chemical tissue changes
-wait 5-10 mins for VA

Answer 21

Fundus Photography

Question 22

-ultra-wide field (opthalmoscope)
-scanning laser (green/red wavelength)
-200 degree view without DFE (82%)
-sees through cataracts/corneal opacities/vitreous hemorrhages
-green laser = superficial
-red laser = deep layers

Answer 22

OPTOMAP

Question 23

-non-invasive
-waves of energy
-images retina + ONH
- several directions= 3D image
1) Heidelberg Retinal Tomograph (HRT)
2) Optical Coherence Tomograph (OCT)

Answer 23

Tomography

Question 24

• depth of anterior chamber/corneal thickness
  -see 10 retinal layers/thickness
  -cross-sections of pathologies
  -glaucoma (ant. chamber/cup shape/disc/RNFL)

Answer 24

Tomography benefits