Rhexis-fixated intraocular lens
Capsule-fixated lens achieves stable rotation and centration in international trial
Gerd Auffarth MD
The rhexis-fixated FEMTIS (Oculentis) intraocular lens achieved very good visual acuity and excellent centration and rotational stability in an international multi-centre study, reports Gerd Auffarth MD, University Eye Clinic of Heidelberg, Heidelberg, Germany.
“Compared to historical data, the FEMTIS IOL was superior to the conventional in-the-bag implanted IOLs,” Dr Auffarth told the 36th Congress of the ESCRS in Vienna, Austria.
The study took place in eight clinics in Germany, the UK, Spain and Andorra and involved 360 eyes with cataract and expected postoperative corneal astigmatism of under -1.00D. All underwent implantation of a monofocal FEMTIS IOL following cataract extraction surgery performed with femtosecond laser-assisted capsulotomy.
The FEMTIS IOL Foldable one-piece IOL is composed of Hydrosmart, a UV absorbing co-polymer consisting of acrylates with a hydrophobic surface. The lens has a biconvex optic with an aspheric posterior surface. It has a modified plate haptic design with four additional haptics for rhexis-fixation.
The mean logMAR best-corrected distance visual acuity improved from 0.25 preoperatively to 0.00 at six-to-eight weeks, 0.00 at six months and -0.04 at 12 months postoperatively. In terms of refractive predictability, Dr Auffarth noted that patients ended up slightly hyperopic on average, with a mean spherical equivalent of +0.35D at 12 months. However, 85% were within 0.75D of emmetropia and 68% were within 0.5D and 41% were within 0.25D. The A constant of the IOL has since been adjusted to improve accuracy.
The FEMTIS study group assessed the centration, tilt and rotational stability using images they obtained with microscope, slit lamp and Scheimpflug camera (Pentacam, Oculus). They analysed the data using a dedicated analysis program developed by Heidelberg Institute of Applied Mathematics.
Their assessment showed that the average IOL-rotation was 0.78° at 12 months postoperatively, compared to values ranging from 2.7° to 5.3° in historical series. The mean IOL decentration was 0.07mm at 12 months postoperatively, compared to values ranging from 0.19mm to 0.23mm in historical series. In addition, the mean tilt at 12 months was 0.45° compared to tilt of 2.0° to 3.0°. Regarding posterior capsule opacification, the mean PCO grade was 0.7% at six months postoperatively and 1.1% at 12 months postoperatively.
“The rhexis-fixated FEMTIS IOL shows very good results regarding the uncorrected and best-corrected distance visual acuity and excellent rotational as well as centration behaviour,” Dr Auffarth concluded.
Gerd Auffarth: Gerd.Auffarth@med.uni-heidelberg.de