Cracked cartridges during foldable intraocular lens implantation

Evaluation of Nozzle Tip Damage in Intraocular Lens Injectors with V-Shaped Notch

INTRODUCTION

Damage to the nozzle tips of intraocular lens (IOL) injectors has been associated with various adverse events and even IOL surface abnormalities after IOL implantation. In this study, nozzle tip damage of three different injector models with v-notched nozzle tips was systematically evaluated using our self-developed system - the Heidelberg Score for IOL injector damage.

METHODS

Nozzle tip damage was categorized into 6 grades: no damage (grade 0), slight scratches (1), deep scratches (2), extensions (3), cracks (4), and bursts (5). Each grade was assigned to a score of 0-5. In each IOL injector group, all IOLs were divided into 2 subgroups based on IOL power: +15 to +21D group and +21 to +26D group. The total scores for each group were the sum of scores for all injectors in this group. Further analysis was performed on the nozzle tip configuration and parameters in each injector model.

RESULTS

The median (Q1-Q3) for each injector group in group +15 to +21D was 1.5 (1-2) for Avansee, 4 (3-4) for iSert, and 4 (3-4) for multiSert. A statistically significant difference was found between Avansee and iSert (p < 0.001) as well as between Avansee and multiSert (p < 0.01) in terms of median scores. The median (Q1-Q3) for each injector group in group +21 to +26D was 1.5 (1-2) for Avansee, 4 (4-4) for iSert, and 3 (3-3.75) for multiSert. A statistically significant difference was found between Avansee and iSert in terms of median scores (p < 0.001). The outer cross-sectional diameters were 1.80 and 1.78 mm for Avansee, 1.70 and 1.69 mm for iSert, and 1.69 and 1.68 mm for multiSert. The radii of each notch-based circle were 0.21 mm (Avansee), 0.09 (iSert), and 0.06 (multiSert), respectively. The tip angles for three injector models were 48° (Avansee), 46° (iSert), and 37° (multiSert).

CONCLUSIONS

Avansee showed the least nozzle tip damage of all three groups. Compared with our earlier study using preloaded injectors with intact endpieces, all the injector groups with v-notched nozzle tips had more damage to the nozzle tip. It was found that the closer the notch of the nozzle tip was to the letter "V," the more damaged the nozzle tip was after IOL implantation.

Evaluation of preloaded intraocular lens injection systems: Ex vivo study

PURPOSE

To compare preloaded intraocular lens (IOL) injection systems.

SETTING

Sussex Eye Hospital, Brighton, United Kingdom.

DESIGN

Experimental study.

METHODS

In 30 porcine eyes, 5 preloaded +22.0 diopters IOLs were implanted from each of the following preloaded IOL systems: Ultrasert (U), iTec (iT), Eyecee (E), iSert (iS), Rayone (R), and CT Lucia (CT). External and internal wound size was measured. Nozzle damage was assessed using digital photography. The ease of opening the pack, ophthalmic viscosurgical device (OVD) injection, advancing into the nozzle, nozzle insertion, and IOL delivery was scored on a 4-point Likert scale, and the time was recorded.

RESULTS

The iT, E, and iS injectors with acute angled bevels and shorter nozzle tips showed more damage after implantation. The fastest with regard to opening the pack and nozzle insertion was U, OVD injection and advancing into the nozzle was E, and IOL delivery was R. The maximum postimplantation wound stretch was 20% with the CT (mean 2.64 mm ± 0.1 [SD]), and the least was 11.8% with the iT (mean 2.46 ± 0.1 mm). Both the U and R scored 4 (very easy) for all parameters measured; the E, iS, iT, and CT scored 4 or less in some parameters with decreasing scores, respectively.

CONCLUSIONS

The models, design, and injection systems varied with each brand; however, the longer and more parallel the nozzle and less acute the angle of the bevel tip, the lesser the stress with less nozzle damage after surgery. All preloaded systems varied in the ease-of-use and time for surgical steps, and all lead to postoperative wound stretch.

Linear deposits on the surfaces of intraocular lenses implanted through a hexagonal cartridge which mimic scratches/cracks on the lenses

AIM

To describe unique linear deposits on the surface of posterior chamber intraocular lenses (IOLs) occurring after implantation through a hexagonal cartridge.

METHODS

Five ACR6D SE IOLs (Corneal Laboratories, Pringy, France) were injected/implanted through hexagonal cartridges. Two of these were injected into a petri dish and the remaining three were inserted into the evacuated capsular bag of cadaver eyes. In addition, three other ACR6D SE IOLs were injected into a petri dish through round cartridges. The latter served as controls.

RESULTS

All lenses that were injected/implanted through the hexagonal cartridges demonstrated linear deposits on the posterior surface of the IOL optic component. The IOLs that were injected through the round cartridges had no deposits. All the hexagonal cartridges showed signs of internal cracking. None of the round cartridges were cracked.

CONCLUSION

Implantation of at least one IOL model, the ACR6D SE IOL, through a hexagonal cartridge can result in linear deposits on the posterior optical surface of the IOL. The shape of the cartridge appears to be a significant factor in causing the depositions.

Spontaneous disinsertion of a haptic from a 3-piece acrylic foldable intraocular lens after surgery

A 49-year-old man with cataracts had uneventful phacoemulsification, continuous curvilinear capsulorhexis, and implantation of an MA30BA acrylic foldable intraocular lens (IOL) in the bag. One week later, 1 haptic spontaneously dropped off and the optic dislocated into the anterior chamber. The IOL was surgically removed and replaced with a new acrylic foldable IOL. Examination of the explanted IOL revealed that the loop hole was not created in the middle of the side face, leading to in vivo detachment of the haptic postoperatively.

Effect of folding on the multifocal silicone intraocular lens: scanning electron microscopic study

PURPOSE

To evaluate whether the surface of the refractive zonal multifocal silicone intraocular lens (IOL) is altered by different folding and implantation instruments and is more sensitive to manipulation during folding than the surface of a monofocal IOL.

SETTING

Department of Ophthalmology, University Hospital, Kiel, Germany.

METHODS

Evaluated were the refractive multifocal silicone IOL (SA-40N, Array) and an otherwise identical monofocal IOL (SI-40NB) from the same manufacturer (Allergan Inc.). Different folding devices (folding blocks, folding and implantation forceps, and an injector system) were used. The IOLs were kept folded for 60 seconds; 24 hours later, scanning electron microscopy (SEM) was performed. In addition, the cartridges of the injector system were examined by SEM.

RESULTS

Overall, regardless of the folding and implantation instruments used, both the multifocal and monofocal IOLs had discrete surface alterations. The cartridges of the injector system had a rough surface at the tip, while the proximal portion appeared smooth.

CONCLUSION

There were no signs of lesions particularly affecting the surface of multifocal IOLs.

Cartridge cracks during foldable intraocular lens insertion

PURPOSE

To assess the incidence of cartridge cracks during foldable intraocular lens (IOL) insertion and to determine factors that play a role in the development of these cracks.

SETTING

Leesburg Regional Ambulatory Surgical Care Center, Leesburg, Florida, USA.

METHODS

Small incision cataract surgery was performed in 350 consecutive cases. A foldable silicone IOL (Allergan Medical Optics SI-40) was inserted in all cases using the Unfolder cartridge and 3 viscoelastic agents: sodium hyaluronate (Healon, Vitrax) and sodium chondroitin sulfate-sodium hyaluronate (Viscoat).

RESULTS

Cartridge cracks occurred in 52 eyes (14.86%). Almost all cracks (98.1%) occurred in cases in which Healon was used to load the IOL. In each case of a cracked cartridge, there was evidence of the plunger overriding the optic edge.

CONCLUSIONS

We recommend the use of chondroitin-based viscoelastic agents to load the SI-40 foldable IOL to minimize the risk of cartridge cracks. Modifications in the design of the IOL inserter may eliminate the problem of cartridge cracks.

Bisecting a foldable acrylic intraocular lens for explantation

We describe a method of explanting an implanted foldable acrylic intraocular lens (IOL) through a small incision at the time of primary implantation without enlarging the original small incision. This method of bisecting foldable IOLs in the anterior chamber is safe and preserves the advantages of the original small incision.