Tomey UD-600, Operator'S Manual

Page: 201 / 262

4-9
4.3 IOL power calculation
4.3.4 Hoffer Q
1. Implanted IOL power (D)
Where,
2. Post surgery expected refractive power with spectacles (D)
Where,
C=X+Y
X=C1+0.3(L-23.5) + (tan K)
2
Y=0.1M(23.5-L) 2 tan{0.1(G-L) 2 }-0.99166
L 23
→
M=+1, G=28
L > 23
→
M=-1, G=23.5
L > 31
→
L=31
L < 18.5
→
L=18.5
where,
P:
Implanted IOL power (D)
L: Axial length (mm)
C1: Personal ACD (mm)
K: Average corneal refractive power (D)
=(K1+K2)/2
Rx: Post surgery expected refractive power with spectacles
(D)
Rx
R = —————
1-0.012Rx
1336 1.336
P = ————— - ———————
L - C-0.05
1.336 C+0.05
——— - ———
K+R 1000
R
Rx = —————
1+0.012R
1.336
R = ——————————— - K
1.336 C+0.05
————— + ———
1000
1336
———— - P
L-C-0.05