New toric IOL corrects high corneal
astigmatism after cataract surgery, Austrian study reveals
Stefanie Petrou-Binder MD
from recent Austrian study show that a new foldable, toric IOL with
z-haptics can correct high corneal astigmatism and produce a good
visual outcome, Irene Dejaco-Ruhswurm MD told the annual meeting
of the German Society of Ophthalmology.
She and her team at the University Clinic for Ophthalmology and
Optometry, Vienna, Austria implanted individually crafted toric
silicone IOLs (MicroSil 6116 TU, Schmidt) in 14 eyes of nine patients.
Four of the patients had previously undergone keratoplasty.
“The implantation of toric IOLs to reduce pre-existing corneal
astigmatism may improve visual acuity after cataract surgery. But
the correction of high corneal astigmatism, for example after keratoplasty,
was limited until now,” she said.
The MicroSil 6116 lens is a three piece foldable silicon IOL with
z-haptics. The diagonal length is 11.6 mm and the optical diameter
The cataract surgery was standard in all cases. Eleven of the patients
had a sclerocorneal incision, and the remaining three had a clear
corneal incision. The surgeon implanted the toric IOL through the
3.2 mm incision with a pair of tweezers recommended by the manufacturer,
or alternately with a micro-injector.
While the insertion of the lens with tweezers required more experienced
surgical skill, IOL injection using a micro-injector was more easily
The investigators evaluated visual acuity with and without the best
spherical and the best corrected visual acuity at one week, and
one, three, six, and 12 months postoperatively. They also measured
the refraction, corneal astigmatism and postoperative rotation of
the IOL. All patients had a minimal follow-up of six months.
Dr Dejaco-Ruhswurm calculated the cylindrical power of the lens
individually for each patient, depending on the degree of keratometric
astigmatism. Schmidt, which produces the lens, manufactures lenses
with cylindrical power of up to 12 D.
The mean preoperative keratometric astigmatism was 5.28 D (±
3.53 D) and the mean preoperative refractive astigmatism 3.73 D
(± 1.52 D). Four of the patients underwent PK. The mean cylindrical
power of the implanted IOLs was 5.50 D (± 2.74 D.)
The refractive astigmatism was reduced to +0.68 D (± 0.75
D) following surgery. The mean amount of postoperative keratometric
astigmatism was +4.62 D (± 3.32 D).
Visual acuity without correction was 0.55. With spherical correction,
it registered 0.7 and BCVA acuity was 0.8. The researchers observed
no significant IOL rotation in nine patients followed for six months
At the XX ESCRS Congress in Nice in September last year, Dr Sven
Kulus and colleagues from the Klinik Dardenne in Germany reported
that the MS 6116 performed well in six eyes with high astigmatism
following keratoplasty. Post-PK keratoplasty astigmatism was reduced
from a mean of 7.5 D to 2.4 D following IOL implantation.
Irene Dejaco-Ruhswurm MD
Vienna University Eye Clinic, Austria