Tomey UD-600, Руководство оператора

Страница: 204 / 262

4-12
3. Personal A-Constant
Where,
a1: 0.4
a2: 0.1
RC: Average corneal curvature (mm)
ACD: Anterior chamber depth (mm)
L:
Axial length (mm)
P: Implanted IOL power (D)
na: Aqueous and vitreous body refractive indexes
nc: Corneal refractive index =1.3315
DC: Average corneal refractive power (D)
AREF:Post surgery refractive power (D)
V:
Vertex distance (mm) = 12
d-a1·ACD-a2·L+72.434
A = ——————————— (ACD
g
0)
0.62467
d-L(a2+0.139·a1)+0.241·al+72.434
A = ———————————————
0.62467 (ACD = 0)
P(L·z+1000na) - P
2
(L·z + 1000na)
2
- 4P·z(1000L·na·z + 1000L·na·P - 1000
2
·na
2
)
d = —————————————————————————————————
2P·z
AREF
Z = DC + ———————
AREF·V
1 - ————
1000
1000(nc - 1)
DC= —————
r
4.3 IOL power calculation