Tomey AL-2000, Operator'S Manual

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AL-2000 Biometer & Pachymeter
85
9 9..1 1 IIO OL L C Ca allccu ulla attiio on n F Fo orrm mu ulla ae e
cc.. P Pe errsso on na all S SF F
Where:
na: Refractive index of aqueous and vitreous = 1.336
nc: Refractive index of cornea = 4.0/3.0
L: Measured axial length (mm)
r: Average corneal radius of curvature (mm) = 337.5/K
K: Average corneal refractive power = (K1 + K2)/2 (D)
V: Vertex distance (mm) = 12
P: Power of IOL implant (D)
L2: Modified axial length (mm) = L + 0.2 (mm)
S: Spherical index (D)
C: Cylindrical index (D)
AREF: Postoperative refraction <equivalent to the spherical index (D)>
= S + C/2
C2: Anatomical anterior chamber depth (mm) (distance between corneal
apex and iris surface) (mm)
if r < 7 mm, then R
ag
= 7 mm
if r > 7 mm, then R
ag
= r
AG = 12.5L/23.45 (if AG > 13.5 mm, then AG = 13.5 mm)
d d.. C Co orrrre essp po on nd diin ng g S SF F
Where:
A: A-constant