In vivo comparison of implantation behavior and laboratory analysis of two preloaded intraocular lens injectors

PURPOSE

We evaluated implantation behavior and injector damage of two different IOL injector systems, the Multisert and the AutonoMe.

DESIGN

Prospective, randomized, comparative study with laboratory investigation.

METHODS

We examined used injectors from 48 bilateral cataract cases and assessed video recordings of each Implantation. All eyes were intraindividually randomized for treatment with one of the two IOL injectors. Implantation videos were reviewed for inadvertent events and the time for different implantation steps was determined. The injector nozzle tips were examined using light and scanning electron microscopy (SEM). Damage was graded using the Heidelberg Score for IOL injector damage (HeiScore). Three months postoperatively, IOLs were assessed for material changes.

RESULTS

Implantation was without critical events in 96 of 96 eyes. Mean implantation time was 41.90 ± 7.11 s with the Multisert and 52.22 ± 12.06 s with the AutonoMe. In the AutonoMe group, we observed 4 eyes (8.3%) with a failed docking attempt, 28 eyes (58.3%) with a haptic adherence, one case (2.1%) of straight leading haptic and 2 cases (4.2%) of intrawound IOL manipulation. There were no events observed in the Multisert group. The mean HeiScore values were 0.87 ± 0.61 and 3.68 ± 0.47 for the AutonoMe and Multisert. 3 months postoperatively, IOL material changes were absent.

CONCLUSIONS

Both injectors allowed safe and controlled implantation. Using Multisert, implantation behavior was more consistent. The injectors showed different damage profiles with a higher damage score for the Multisert.The study is registered at the German Clinical Trials Register (Deutsches Register Klinischer Studien; reference number: DRKS00007837).

Material Analysis of Explanted Calcified Silicone Intraocular Lenses in Association with Asteroid Hyalosis

INTRODUCTION

The aim of this study was to analyze posterior surface opacification in explanted silicone intraocular lenses (IOLs) with clinicopathologic correlation to asteroid hyalosis.

METHODS

In a laboratory setup, 12 explanted silicone IOLs underwent laboratory analyses, including light microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy for elemental composition (EDX). Relevant clinical data were obtained for each case, including gender, age at IOL implantation, dates of implantation and explantation, as well as history of neodymium-dopped yttrium aluminum garnet (Nd:YAG) laser treatments or other opacification removal attempts. High-resolution optical coherence tomography (OCT) images were obtained in vitro with an anterior segment OCT device (Anterion, Heidelberg Engineering, Heidelberg, Germany).

RESULTS

Calcification located at the posterior optic surface of each lens was identified through SEM and EDX analyses, revealing deposits composed of hydroxyapatite. In all cases, IOL polishing using Nd:YAG laser had been attempted prior to IOL exchange. The clinical functional data showed that this type of IOL opacity led to increase in straylight and subjective symptoms of glare.

CONCLUSIONS

Silicone IOLs can develop posterior surface calcification in eyes with asteroid hyalosis. There are mechanical techniques of cleaning the IOL surface but in many cases, IOL explantation is the only sustainable way to reduce the patients' straylight levels and glare symptoms. Due to the risk of posterior surface calcification, silicone IOL implantation should be avoided in eyes with asteroid hyalosis.

Influence of Subclinical Corneal Edema on Contrast Sensitivity in Fuchs Endothelial Corneal Dystrophy

PURPOSE

The aim of this study was to compare visual function, with a focus on contrast sensitivity, between patients with Fuchs endothelial corneal dystrophy (FECD) with and without subclinical corneal edema.

METHODS

In this cross-sectional, observational, single-center study, 46 pseudophakic eyes of 31 patients with FECD were divided into 2 groups depending on the presence of subclinical corneal edema. All eyes presented with a Krachmer grade of 5 and no clinical corneal edema. The criteria for subclinical corneal edema were loss of regular isopachs, displacement of the thinnest point, and focal posterior surface depression in Scheimpflug tomography. If more than 1 criterion was present, subclinical corneal edema was diagnosed. The corrected distance visual acuity, contrast sensitivity (Pelli-Robson chart and CSV-1000 test with optional glare), and straylight were measured. The differences between both groups were analyzed using clustered Wilcoxon rank-sum tests.

RESULTS

The corrected distance visual acuity and the contrast sensitivity, measured with a Pelli-Robson chart, were significantly inferior in eyes with subclinical corneal edema compared with eyes without subclinical edema ( P < 0.05). At all spatial frequencies, eyes with subclinical edema demonstrated lower contrast sensitivity with a statistically significantly reduction in total contrast sensitivity when tested with ( P = 0.005) and without ( P = 0.002) glare. The straylight did not significantly differ between both groups ( P > 0.05).

CONCLUSIONS

The corrected distance visual acuity and contrast sensitivity were significantly reduced in FECD eyes with subclinical corneal edema compared with those with no subclinical edema. This decrease in visual quality may be considered when evaluating the need for surgical intervention at earlier stages of FECD.

Enlargement of main corneal incision: clinical intraindividual comparison of two preloaded intraocular lens injectors

PURPOSE

To compare the enlargement of the clear corneal incision from IOL implantation with 2 different intraocular lens (IOL) injectors: the AutonoMe preloaded with the Clareon IOL and the Multisert preloaded with the Vivinex IOL.

SETTING

The David J. Apple Center for Vision Research, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.

DESIGN

Prospective randomized clinical comparative study.

METHODS

96 eyes of 48 patients with cataract were intraindividually randomized to treatment with 1 of the 2 injectors. For Multisert eyes, the insert shield (IS) was used in the advanced position in 23 eyes. The initial incision was 2.2 mm, and intraoperative measurements of the incision size were made before and after IOL injection. 3 months postoperatively, keratometry and uncorrected (UDVA) and corrected (CDVA) distance visual acuities were assessed.

RESULTS

Results are reported for 96 eyes of 48 patients. The mean incision enlargement was 0.213 ± 0.068 mm in the Multisert with the IS group, 0.265 ± 0.055 mm in the fellow eyes (AutonoMe) ( P < .05), 0.272 ± 0.060 mm in Multisert eyes treated without the IS, and 0.296 ± 0.066 mm for the fellow eyes (AutonoMe) ( P > .05). The mean absolute surgically induced astigmatism was 0.42 ± 0.23 diopters (D), 0.50 ± 0.25 D, and 0.44 ± 0.18 D in the Multisert with the IS, Multisert without the IS, and AutonoMe group, respectively ( P > .05). The UDVA and CDVA were comparable in all groups.

CONCLUSIONS

The Multisert was associated with less wound enlargement than the AutonoMe. All groups had comparable functional outcomes. Therefore, the observed difference in incision enlargement may be of limited clinical relevance.