Tu. Bartke et al., Reliability of intraocular lens power calculation after cataract surgery in patients with relative anterior microphthalmos, GR ARCH CL, 238(2), 2000, pp. 138-142
Citations number
26
Categorie Soggetti
Optalmology
Journal title
GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
Background: Patients with relative anterior microphthalmus (RAM) are charac
terized by special anatomical features (corneal diameters <11 mm, anterior
chamber depth <2 mm and normal axial length) that sometimes make intraocula
r lens (IOL) power calculation difficult. Patients and methods: Seventy-fiv
e patients aged 75.6+/-10.3 years with RAM were evaluated for preoperative
target refraction and postoperative refraction after cataract surgery. We u
sed biometric formulas as modified by Haigis for IOL power calculation. Res
ults: The average IOL power implanted was 25.2+/-2.8 dptr (one-piece all-PM
MA IOL; range 19-31 dptr). The preoperatively calculated target refraction
was -0.71+/-1.43 dptr (range 4.3 to +2.2 dptr). The average postoperative s
pherical equivalent was -0.41+/-1.50 dptr (range -5.5 to +6.0 dptr). The me
an difference between target and end refraction was -0.30+/-1.54 dptr Fifty
-seven percent of cases did not differ by more than 1 dptr from target refr
action, 81.3% by not more than 2 dptr, and 94.7% by not more than 3 dptr; o
nly 5.3% of cases deviated by more than 3 dptr. There was no correlation of
the amount of deviation between target and postoperative refraction with a
xial length, corneal diameter and anterior chamber depth. There was, howeve
r, a significant correlation between target refraction and amount of deviat
ion of spherical equivalent. The largest differences were found with target
refractions greater than +2 dptr. Conclusions: In spite of the special ana
tomical conditions in patients with RAM the biometric formulas as modified
by Haigis produced reliable IOL power calculations. The best accuracy was a
chieved when aiming at a target refraction in the range of +/-2 dptr.