Klinische Ergebnisse unter besonderer Berücksichtigung von Dezentrierung und Verkippung der asphärischen Intraokularlinse FY-60AD

Impact of intraocular lens displacement on the fixation axis

To investigate the impact of intraocular lens (IOL) decentration ≤±1  mm and IOL tilt ≤±10° on the fixation axis and spherical equivalent refraction (SE), 50 pseudo-phakic eyes were simulated using numerical ray-tracing. We computed the position of the object point whose image ends up at the virtual fovea for each scenario and estimated the corresponding change of fixation axis and SE. The eye turned opposite to the direction of IOL decentration or tilt to compensate for the associated prismatic effect (angle <1.2°). Decentration of the aspheric IOL resulted in a hyperopic shift (<0.57 D), and tilt in a myopic shift (<0.77 D).

Outcome of a New Acrylic Intraocular Lens Implantation in Pediatric Cataract

PURPOSE

To study the outcome of Hoya Clear Preloaded intraocular lens (IOL) (PC 60AD, AF Series; Hoya, Tokyo, Japan) implantation in children.

METHODS

Children who underwent phacoaspiration with primary posterior capsulotomy, anterior vitrectomy, and primary IOL implantation through a 2.8-mm incision were observed prospectively. In all cases, attempts were made to implant the IOL into the capsular bag. Parameters noted were ease of implantation, synechiae formation, IOL deposits, decentration of IOL, visual axis obscuration, haptic compression, and ovalling of the rhexis. Intraoperative complications related to the IOL were also recorded.

RESULTS

This series comprised 58 eyes of 38 patients with congenital/developmental cataract who underwent implantation of the Hoya IOL. Mean age of the patients was 3.27 ± 2.69 years (range: 3 months to 8 years) and mean follow-up was 24.5 ± 9.13 months. Visual axis obscuration occurred in 4 eyes, posterior synechiae in 5 eyes, IOL deposits in 6 eyes, haptic compression in 3 eyes, and IOL decentration in 1 eye.

CONCLUSIONS

The data suggest that implantation of the Hoya IOL is a safe option in children undergoing cataract surgery.

[Investigation of the theoretical image quality of aspheric intraocular lenses by decentration. Hoya AF-1 iMics1 und Zeiss ASPHINA(TM) (Invent ZO)]

BACKGROUND

The image quality of aberration correcting aspherical intraocular lenses (IOLs) depends on the centration in the eye. Aberration correcting IOLs of the second generation are claimed to be more robust to decentration. In this study the image quality of such IOLs was analyzed with decentration values of up to 1 mm.

MATERIALS AND METHODS

In this study two aberration correction IOLs of the second generation were compared in a model eye. The IOLs were decentered for two pupil diameters (3.0 and 4.5 mm) in a range of ± 1 mm relative to the line of sight in 50 µm steps and the modulation transfer function was calculated. The results were compared for different spatial frequencies and visual acuities.

RESULTS

The analyzed IOLs are superior to the spherical IOL in a decentration range from -0.45 mm to 0.60 mm (30 CPD, cycles per degree) for both pupil diameters. Especially for the greater pupil diameter the lenses show tolerance of image quality to lens decentration.

CONCLUSIONS

Both IOLs show only a slight decrease in image quality with decentration and the range of tolerable decentration is increased compared to aspherical IOLs of the first generation.