CONFRONTATION TEST & AMSLER GRID What Is A

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CONFRONTATION TEST & What is a “visual field” and why does AMSLER GRID it matter? Definition: • Visual field: The entire area that can be seen when eye is looking straight ahead @ fixed point Why does it matter? • If a person is experiencing a “shrinking” visual field or a “distorted” visual field, they have a problem. We want to help them before the problem robs them of any more visual loss. Instructor: Michael Patrick Coleman, COT & ABOC

Peripheral vs. Central fields which test does what? Peripheral vs. Central fields–which test does what? (cont.) • A normal visual field extends out as far as: * A physiologic – 100° temporally scotoma (a blind – 60° nasally spot) exists 15° – 60° superiorly temporally in VF; it – 70° inferiorly is due to the optic nerve (nasal retina) * The average blind spot is 7.5° in diameter & vertically centered 1.5° below the horizontal meridian

Peripheral vs. Central fields–which test does what? (cont.) Confrontation Field Test IN A NUTSHELL: 1. The examiner & Pt face each other, eye level 2. Examiner asks Pt to look into his/her open eye 3. Examiner presents one or two fingers in Pt’s peripheral Visual Field (VF) 4. Pt responds when he/she can see the target 5. All four “quadrants” of an eye are tested (ST, IT, SN, & IN) 6. Once done w/one eye, test is repeated for the other eye

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Confrontation Field Test (cont.) Confrontation Field Test (cont.) • Test distance? • Recording the results? – ARMS LENGTH DISTANCE (about 24 inches) – WNL (within normal limits) if Pt results are • Instructions to patient? comparable to yours – “Look @ my open eye ONLY” – ONL (outside normal limits) if Pt results are – “Tell me WHEN you see my fingers and HOW MANY I ‘worse’ than your own perceptions am holding up” • If ONL, describe problem; For EXAMPLE: • Comparing the patient’s perception to the – “OD constricted in ST and IT fields” examiner’s perceptions? – You (the examiner) are the “NORM”; if Pt sees your – “OU constricted in all quadrants” fingers when YOU see your fingers, they are “WNL”; if you have to keep moving closer to central fixation before Pt responds, they are “ONL”

Amsler Grid Test ** Amsler Grid Test (cont.) • Amsler Grid invented by Dr. Marc Amsler (Swiss • Test chart ophthalmologist) • Recording chart • The AMSLER GRID “TEST” is a booklet with six (6) • Additional charts different charts in it • Administering the test • Purpose is to ASSESS THE MACULAR AREA, so it is – Test distance most commonly used to check patients with – Degree of field measured Macular Degeneration (wet or dry) – Questions to ask & in what order – Recording the results

Amsler Grid: Test Chart Amsler Grid: Recording Chart

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Amsler Grid: Additional Charts Amsler Grid: Additional Charts (cont.) Also available are charts with… Red lines on black background? Helpful for: • Blue lines on a yellow background • Optic nerve issues • Blue lines on a red background • Chiasm disorders • Toxic amblyopia • on a red background • Hydroxychloroquine White lines ocular toxicity • When would you use them? – Whenever your doctor SAYS to use them!

Amsler Grid: Administering the Test Amsler Grid: Administering the Test (cont.) • Test distance = 30cm (or 12 inches) • Another way to “prove” that • Pt wears their NEAR VISION CORRECTION the AMSLER GRID only tests out to 10 degrees is this… – BiFocal or PAL? Have Pt hold glasses up so they can look at GRID through the near correction – Each square of the grid • Degree of field measured = 10 degrees measures 5mm – Have you ever read that it tests “20 degrees”? That is – When the Amsler Grid is WRONG! held 30cm from eye… – We measure Visual Field from how many degrees we – …each square “subtends” are from the fixation point; the AMSLER GRID only tests 1 degree on the retina out to 10 degrees from the center of fixation – Let’s count the ‘squares’, – (If it tested out to “20 degrees”, as claimed, the ‘physiological blind spot’ would be detected!) shall we…

Amsler Grid: Administering the Test (cont.) Amsler Grid: Administering the Test (cont.) Questions to ask & in what order 1. “While looking at the center dot, can you see the FOUR CORNERS and FOUR SIDES of the grid?” 2. “While looking at the center dot, can you see there are lines going UP & DOWN and SIDE TO SIDE in the chart?” 3. “Are the lines straight & clear, or do you see any • A Pt indicating the chart looks like this most likely WAVINESS, DISTORTION, or MISSING AREAS” has Macular Degeneration • Distortion of the vision is called “Metamorphopsia” • It’s caused by the cones of the retina being spread apart one place & squeezed together in others

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Amsler Grid: Administering the Test (cont.) Recording the results • If patient saw the chart fine (no problems) you can record “WNL” in the medical record • If there were problems, You should have the patient draw any abnormalities found. Make a note on the grid paper of the: – Pt’s name, date & which eye the chart represents – The Amsler Grid the pt marked on should be placed in Pt’s chart – Use a separate Amsler Grid for each eye