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4-14
4.1.8 SRK/T Double K
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This formula is for POST LASIK.
1. Implanted IOL power (D) for emmentropization
2. Implanted IOL power (D) for ametropia
post
post
amet
rCYVREFYCL
rLXVREFXna
P
1001.011
1001.01000
3. Predicted refractive power after surgery (D)
postpost
iol
rCYVCLPrLXVna
CLYPXna
REF
111001.01
111000
Where:
X = na•r
post
– L1 (nc – 1)
Y = na•r
post
– C1 (nc – 1)
L1 : Visual axial length (mm)
= L + (0.65696 – 0.02029L)
L : Axial length (mm)
C1 : Estimated anterior chamber depth after surgery (mm)
= H + Ofst.
Ofst: Calculated distance from the iris surface to the optical
surface of the implanted IOL (including corneal thickness)
(mm)
= ACD const – 3.336
= (0.62467A – 68.747) – 3.336
H : Height of cornea dome (mm)
W : Calculated corneal diameter (mm)
= -5.41 + 0.58412LC + 0.098K
LC : Corrected axial length (mm)
L≦24.2 → LC = L
L > 24.2 → LC = –3.446 + 1.716L – 0.0237L
2
A : A-Constant