Ratinoscopy calculation

Retinoscopy Procedure completed after do retinoscopy calculation

1. RATINOSCOPY
calculation
BY SUJIT KUMAR
saraswati-eye-care.business.site

2. RATINOSCOPE
CONVERGING
5 CMS 10 CMS 50 CMS 100 CMS
66 cms
•1 D MYOPIA 100 CMS
•1.5 D MYOPIA 66 CMS
•2 D MYOPIA 50 CMS
•20 D MYOPIA 5 CMS

3. EXAMPLE DISTASNCE ATROPINE
+6.00DS +5.00DS +4.00DS
DISTANCE SUBTRACTION
•1 mt=1 D
•2/3 mt=1.50 D
CYCLOPLEGIC
•ATROPINE = -1.00 D
•HAMATROPINE = -0.50 D
•CYCLOPENTOLATE = -0.75 D

4. Few Algebraic rules for signs of Cylinders
•(-)(-)=(+)
•(-)(+)=(+)
•-6.00-4.00=-10.00
•-6.00+4.00=-10.00

5. Some Important steps
•While doing retinoscopy,weneed to substractthe working distance or
cyloplegicDrug value from the Horizontal and Verticlemeridian.
•Then we assume the smallest power as the spherical value.
•Then the assume value as spherical value need to the substractedfrom the
other value use

6. “
”
-2.00(180 axis)
-3.00
(90 axis)
-2.00-(+1.00) = -2.00-1.00 = -3.00 -3.00180 axis
-3.00-(+1.00) = -3.00-1.00 = -4.00 -4.00
= -3.00 90 axis
= -4.00-(-3.00)=-4.00+3.00 = -1.00
Spectalenumber = -3.00 D sph. / -1.00 D cyl*90

7. “
”
+2.00(180 axis)
+4.00
(90 axis)
+2.00-(+1.00) = +2.00-1.00 = +1.00 +1.00180 axis
+4.00-(+1.00) = +4.00-1.00 = +3.00 +3.00
= +1.00 90 axis
= +3.00-(-1.00)=-+3.00-1.00 = +2.00
Spectalenumber = +1.00 D sph. / +2.00 D cyl*90

8. “
”
-2.00(180 axis)
+5.00
(90 axis)
-2.00-(+1.00) = -2.00-1.00 = -3.00 -3.00180 axis
+5.00-(+1.00) = +5.00-1.00 = +4.00 +4.00
= -3.00 90 axis
= -4.00-(-3.00)=-4.00+3.00 = +7.00
Spectalenumber = -3.00 D sph. / +7.00 D cyl*90

9. “
”
+2.00(180 axis)
-3.00
(90 axis)
+2.00-(+1.00) = +2.00-1.00 = +1.00 -3.00180 axis
-3.00-(+1.00) = -3.00-1.00 = -4.00 -4.00
= +1.00 90 axis
= -4.00-(+1.00)=-4.00-1.00 = -5.00
Spectalenumber = +1.00 D sph. / -5.00 D cyl*90

10. “
”
-2.00*90(Verticle)/-1.00*180(Horizontal)/66cm(WD)
-2.00*90(Verticle)/-3.00*180(Horizontal)/50cm(WD)
+3.00*90(Verticle)/+1.00*180(Horizontal)/66cm(WD)
-5.00*90(Verticle)/-4.00*180(Horizontal)/50cm(WD)
+4.00*90(Verticle)/-3.00*180(Horizontal)/50cm(WD)
-4.00*90(Verticle)/+5.00*180(Horizontal)/66cm(WD)
QUESTION
POWER -(WORKING DISTANCE )= FINAL VALUE
Mean POWER –(SPHERICAL POWER) = FINAL CYLINDER POWER