Soi bóng đồng tử từ lý thuyết đến thực hành - Loose-lens Retinoscopy
Three Steps to Retinoscopy
1. Start with WITH motion
You need to the retina reflection to be “with” in all directions. If you see “against” motion in the beginning, you might need to hold up a -2.00, -4.00, or even a -10.00 lens in front of the eyes to get that “with” motion. Only then can you proceed without getting confused!!!
You need to the retina reflection to be “with” in all directions. If you see “against” motion in the beginning, you might need to hold up a -2.00, -4.00, or even a -10.00 lens in front of the eyes to get that “with” motion. Only then can you proceed without getting confused!!!
2. ADD power to neutralize reflex
Slowly add more power (plus power) until you neutralize the red-reflex. If you see “against” motion, you’ve gone too far. If the patient has astigmatism, you may get different powers for each axis … don’t worry. Just set the lenses aside so you can calculate the prescription later. Remember: the sphere power is your first lens, the cylinder power is the difference between the lenses. The axis is the angle your light beam ends up at (see example below)
Slowly add more power (plus power) until you neutralize the red-reflex. If you see “against” motion, you’ve gone too far. If the patient has astigmatism, you may get different powers for each axis … don’t worry. Just set the lenses aside so you can calculate the prescription later. Remember: the sphere power is your first lens, the cylinder power is the difference between the lenses. The axis is the angle your light beam ends up at (see example below)
3. SUBTRACT working distance at end
The last step is to subtract -1.50 from the sphere.
The last step is to subtract -1.50 from the sphere.
Soi bóng đồng tử từ lý thuyết đến thực hành - Loose-lens Retinoscopy
Reviewed by Thamkhaoyhoc
on
tháng 7 30, 2018
Rating:
Reviewed by Thamkhaoyhoc
on
tháng 7 30, 2018
Rating:
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