Position-dependent accommodative shift of retropupillary fixated iris-claw lenses

Optical Coherence Tomography Position Analysis of Retropupillary Iris-Fixated Intraocular Lens in Iris Tissue

Purpose

The aim of this study was to evaluate a micrometer-accurate analysis of the retropupillary Verisyse® intraocular lens (IOL) (Ophtec, Groningen NL; Santa Ana, USA) enclavation in the iris tissue.

Methods

A retrospective consecutive case series was conducted at the Department of Ophthalmology, University Hospital Mainz. Patients with an optical coherence tomography (Spectralis®, Heidelberg Engineering®; Heidelberg, Germany) examination after retropupillary Verisyse® IOL implantation were included retrospectively. The enclavation geometry was measured using the Eye-Explorer® from Heidelberg Engineering® (Heidelberg, Germany). Seventeen measuring positions were determined nasally and temporally at the corresponding enclavation points.

Results

72 eyes of 67 patients after implantation of a retropupillary Verisyse® IOL were analyzed. The average age was 68 ± 17.2 years (63% female; 38% male). The analysis of the position of the Verisyse® IOL showed highly homogeneous data in all measured points. The depth of the anterior chamber showed a positive correlation with width of the posterior deflection of the iris tissue behind the enclavation (Pearson r: 0.321, p=0.041). The offset of the haptics showed greater deviations, and the lens diopter implanted was higher (r = 0.337, p=0.007).

Conclusion

This is the first study that analysis the exact enclavation of retropupillary implanted Verisyse® IOL. It provides new information about the intrastromal course of the haptics in the iris tissue. It could be shown that the haptics do not run parallel in the iris tissue, but are anchored in the iris tissue with an average offset of 95 µm. This rebuts previous assumptions about the intrastromal course and provides new information.

Implantation of retropupillary iris-claw lenses: A review on surgical management and outcomes

Iris-claw lenses have gained increasing popularity over the last years and are by many surgeons regarded as viable options in eyes with insufficient capsular or zonular support. The iris-claw lens has two haptics with fine fissures for folding (enclavating) the mid-peripheral part of the iris stroma and can either be placed in front of or posterior to the iris. In particular, the retropupillary implantation has been increasingly chosen probably due to having an anatomical position similar to that of the crystalline lens. The present review is based on a literature review and also on the authors' clinical experience with this lens, and it focuses on surgical techniques and outcomes especially related to the characteristics of this lens, having haptics with claws that fixate the lens to the posterior iris. Implanting retropupillary iris-claw lenses has a relatively short learning curve, and there are only few complications reported during surgery. Retropupillary iris-claw lenses have demonstrated generally favourable efficiency and safety. However, the outcomes are probably more influenced by the reason for surgery and eye comorbidity than the lens itself. Albeit seldom reported, the postoperative complications have mostly been related to atrophy of the iris at the site of the haptics, or IOL decentration or disenclavation of one of the haptics. To date, however, there are few randomized clinical trials comparing this lens to other lens alternatives in eyes exhibiting insufficient capsular or zonular support for placing the lens in the ciliary sulcus. In the future, prospective studies with large samples should be performed to gain insights into the long-term safety of retropupillary placed iris-claw lenses, and for comparisons with the various other techniques of lens fixation.

Long-term surgical outcomes of primary retropupillary iris claw intraocular lens implantation for the treatment of intraocular lens dislocation

We aimed to investigate the efficacy and safety of primary retropupillary iris claw intraocular lens (R-IOL) implantation in patients with complete intraocular lens (IOL) dislocation. In this single-center retrospective case series, we reviewed the medical records of patients who underwent R-IOL implantation surgery with pars plana vitrectomy for the treatment of IOL dislocation between September 2014 and July 2019. The primary outcome was change in visual acuity (VA) up to 24 months postoperatively. The secondary outcomes included changes in intraocular pressure (IOP), refractive errors, and endothelial cell count (ECC) over the same period. Data of 103 eyes (98 patients) were analyzed. The mean uncorrected VA was significantly improved at one month postoperatively (− 0.69 logMAR, P < 0.001), compared to the preoperative value. IOP (− 2.3 mmHg, P = 0.008) and ECC (− 333.4 cells/mm², P = 0.027) significantly decreased one month post-surgery and remained stable thereafter. Postoperative mean spherical equivalents were similar to the prediction error throughout the follow-up period. IOP elevation (n = 8, 7.8%), cystoid macular edema (n = 4, 3.9%), and dislocation of the R-IOL (n = 10, 9.7%) were managed successfully. Overall, primary R-IOL implantation with pars plana vitrectomy is effective and safe for correcting IOL dislocation due to various causes.

[Long term postural myopic shift assessment after posterior iris-claw aphakic intraocular lens implantation]

PURPOSE

Posterior chamber iris-claw intraocular lens (IOL) is often used in aphakic eyes with inadequate capsular support. Postoperatively, patients may describe better capabilities for near reading in a face-down position. The goal was to evaluate the indications, visual outcomes and complications of this IOL and to compare postoperative spherical equivalent between the prone and the face-down position.

MATERIALS AND METHODS

Retrospective single-center case series of 31 eyes of 28 patients who underwent surgery between 2007 and 2016. Visual outcomes, early and late complications were analyzed. The refractive measurements were also assessed using a portable refractometer in prone and face-down position for each patient. The spherical equivalents were then compared.

RESULTS

The mean follow up was 29 months (3-73). The final mean corrected visual acuity (0.17±0.5 SD LogMar) was significantly better than preoperatively (0.5±0.50 SD LogMar) (P<0.05). Postoperative refractive error was within±2 diopters of emmetropia in 95 % of patients. The mean spherical equivalents in prone and face down position were different (P<0.05),-0.44 diopters (-4;+2.75) and-1.38 diopters (-5.25; 1) respectively. A mean myopic shift of-0.95 diopters (-5.25; 1.00) was observed in face down position. Cystoïd macular edema (6 %) and IOL disenclavation (9.6 %) were the main complications.

DISCUSSION

A posterior iris-claw intraocular lens appears to be an effective and relatively safe IOL to treat aphakia with poor capsular support. When the patient's head is bent forward, a mean myopic shift of 1 diopter is observed. This may support the idea that this IOL could be considered as an accommodative implant. Anterior movement of the iris-IOL complex due to gravity may be responsible for this myopic shift.

Observation of anterior chamber volume after cataract surgery with swept-source optical coherence tomography

PURPOSE

To investigate the changes in the anterior chamber volume (ACV) with swept-source optical coherence tomography (SS-OCT) after cataract surgery and the factors that influence these ACV changes.

METHODS

This was a prospective cohort study. Fifty-one patients who underwent cataract surgery were enrolled. Their ACV, anterior chamber depth, and angle widths were measured with SS-OCT before and 1 day, 1 week, and 1 month after surgery. The associations between the changes in ACV and posterior vitreous detachment (PVD) and axial length (AXL) were determined.

RESULTS

Compared with the preoperative volume, ACV increased significantly at all three time points after surgery (all p < 0.001). ACV was greater at 1 week after surgery than at 1 day after surgery (p < 0.001). Both AXL and the presence of PVD were significantly associated with the change in ACV at 1 day after surgery (p = 0.005). However, neither PVD nor AXL affected the change in ACV between 1 day and 1 week after surgery.

CONCLUSIONS

ACV stabilized in the first week after cataract surgery. The absorption of irrigation fluid and balanced salt solution in the vitreous cavity contributed to the change in ACV 1 week after surgery. Eyes with longer AXL and PVD tended to show less change in ACV at 1 day after surgery.

[Aphakic Artisan/Verisyse IOLs as retropupillary implants : Video article]

The retropupillary implantation of an iris claw intraocular lens (IOL) is an uncomplicated and fast technique for rehabilitation of aphakic eyes without any capsular structures and is presented in a video in the online version of this article. A complete anterior pars plana vitrectomy as shown in our case or an extensive preceding anterior vitrectomy as well as an intact iris are prerequisites. Special instruments for the implantation and fixation of the IOL are available to optimize the operative procedure. In addition to a rapid operating time the advantages of a trained surgeon are low complications rates and fast rehabilitation. For eyes with a defective iris diaphragm, ischemic vitreoretinopathy and uveitis, other implantation techniques should be selected.

[Retropupillary iris claw intraocular lens implantation technique for aphakia]

BACKGROUND

Overview of the retropupillary implantation of iris claw intraocular lenses (Artisan®,Ophtec, Groningen, Niederlande and Verisyse(TM),AMO, Santa Ana CA).

MATERIAL AND METHODS

A literature search and review of implantation techniques, patient selection, potential complications and management strategies.

RESULTS

This approach has the advantage of a simple implantation technique, an anatomically correct implantation site (as compared to endocapsular implantation) and a relatively low complication rate. An intact iris is, however, a prerequisite for this technique. Ischemic vitreoretinopathies, such as diabetes or vascular occlusive entities, as well as uveitis might be considered as contraindications.

CONCLUSIONS

The retropupillary implantation of iris claw intraocular lenses is an interesting and especially time-effective rehabilitation technique for aphakia.

Using a slit lamp-mounted digital high-speed camera for dynamic observation of phakic lenses during eye movements: a pilot study

Purpose

To evaluate a digital high-speed camera combined with digital morphometry software for dynamic measurements of phakic intraocular lens movements to observe kinetic influences, particularly in fast direction changes and at lateral end points.

Materials and methods

A high-speed camera taking 300 frames per second observed movements of eight iris-claw intraocular lenses and two angle-supported intraocular lenses. Standardized saccades were performed by the patients to trigger mass inertia with lens position changes. Freeze images with maximum deviation were used for digital software-based morphometry analysis with ImageJ.

Results

Two eyes from each of five patients (median age 32 years, range 28–45 years) without findings other than refractive errors were included. The high-speed images showed sufficient usability for further morphometric processing. In the primary eye position, the median decentrations downward and in a lateral direction were −0.32 mm (range −0.69 to 0.024) and 0.175 mm (range −0.37 to 0.45), respectively. Despite the small sample size of asymptomatic patients, we found a considerable amount of lens dislocation. The median distance amplitude during eye movements was 0.158 mm (range 0.02–0.84). There was a slight positive correlation (r=0.39, P<0.001) between the grade of deviation in the primary position and the distance increase triggered by movements.

Conclusion

With the use of a slit lamp-mounted high-speed camera system and morphometry software, observation and objective measurements of iris-claw intraocular lenses and angle-supported intraocular lenses movements seem to be possible. Slight decentration in the primary position might be an indicator of increased lens mobility during kinetic stress during eye movements. Long-term assessment by high-speed analysis with higher case numbers has to clarify the relationship between progressing motility and endothelial cell damage.