Calculation of iris-claw IOL power for correction of late in-the-bag IOL complex dislocation

Aetiology and Management of IOL Dislocations

Early (< 3 months) intraocular lens (IOL) dislocation occurs due to insufficient fixation in the capsular bag, while late dislocation (≥ 3 months) is due to increasing insufficiency of the zonular apparatus. Iris-fixated IOL (IFIOL) and suture- or sutureless-fixated scleral IOL (SFIOL) are currently the most commonly used methods when IOL exchange is indicated. Different methods of scleral fixation with or without sutures have been described. The most important techniques are summarised in this paper. IFIOL and SFIOL allow comparable visual outcomes but differ in their risk profile. The decision of which method to use should be made case by case and in accordance with the surgeon's preference.

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.

RETROPUPILLARY IRIS-CLAW INTRAOCULAR LENS AND PARS PLANA VITRECTOMY IN APHAKIA MANAGEMENT: A National Multicenter Audit

PURPOSE

To evaluate the outcomes and safety of retropupillary iris-claw intraocular lens implantation and associated pars plana vitrectomy.

METHODS

Multicenter, national audit of 325 eyes (325 patients). Demographics, surgical details, and complications are described. Visual acuity, intraocular pressure, and central retinal thickness assessed by optical coherence tomography were collected at 1, 3, 6, and 12 months after surgery. Kaplan-Meier curves were created to assess the cumulative probability of postoperative visual acuity and intraocular pressure levels, macular edema development, and corneal decompensation.

RESULTS

The cumulative probability of the final visual acuity ≤0.3 logarithm of the minimum angle of resolution (≥20/40 Snellen) was 75.6% at 12-month follow-up. The probability of intraocular pressure >21, ≥25, and ≥30 mmHg was 48.1%, 33.1%, and 19.0%, and the probability of intraocular pressure-lowering drops was 50.9% at 12 months. Glaucoma surgery was required in 4.3% of the eyes (14/325). The cumulative probability of macular edema was 20.5% at 12 months and was greater in complicated cataract surgery than in intraocular lens-luxation eyes (26% vs. 16.7%, P = 0.04). Corneal transplantation was required in 2.8% of the eyes (9/325).

CONCLUSION

This study on 325 eyes with aphakia or intraocular lens dislocation managed with the retropupillary iris-claw intraocular lens technique provides clinical outcomes in a real-world scenario, reporting relevant data for patient counseling and preoperative discussions.

Late in-the-bag intraocular lens dislocation

This review aimed to evaluate the cumulative incidence, patient characteristics, predisposing conditions, and treatment outcomes for late in-the-bag intraocular lens (IOL) dislocation. Literature searches in PubMed (MEDLINE), Embase, and Cochrane Library Central database identified 1 randomized clinical trial, 1 prospective case series, 2 prospective cohort studies, and 36 retrospective studies of this condition, which showed that the cumulative incidence was 0.5% to 3%, it occurred on average 6 to 12 years after cataract surgery, and mean patient age was 65 to 85 years. Pseudoexfoliation syndrome, myopia, and previous vitreoretinal surgery were the most common predisposing conditions. Studies indicated that IOL repositioning and IOL exchange provided similar visual outcomes and were equally safe. The long-term visual outcome seemed satisfactory. However, the quality of evidence regarding treatment was in general quite low. More studies of late in-the-bag IOL dislocation are needed, and in particular, different surgical techniques should be included in high-quality clinical trials.