Clinical and Histopathologic Evaluation of Six Human Eyes Implanted with the Bag-in-the-Lens

The importance of the epithelial fibre cell interface to lens regeneration in an in vivo rat model and in a human bag-in-the-lens (BiL) sample

Human lens regeneration and the Bag-in-the-Lens (BIL) surgical treatment for cataract both depend upon lens capsule closure for their success. Our studies suggest that the first three days after surgery are critical to their long-term outcomes. Using a rat model of lens regeneration, we evidenced lens epithelial cell (LEC) proliferation increased some 50 fold in the first day before rapidly declining to rates observed in the germinative zone of the contra-lateral, un-operated lens. Cell multi-layering at the lens equator occurred on days 1 and 2, but then reorganised into two discrete layers by day 3. E- and N-cadherin expression preceded cell polarity being re-established during the first week. Aquaporin 0 (AQP0) was first detected in the elongated cells at the lens equator at day 7. Cells at the capsulotomy site, however, behaved very differently expressing the epithelial mesenchymal transition (EMT) markers fibronectin and alpha-smooth muscle actin (SMA) from day 3 onwards. The physical interaction between the apical surfaces of the anterior and posterior LECs from day 3 after surgery preceded cell elongation. In the human BIL sample fibre cell formation was confirmed by both histological and proteome analyses, but the cellular response is less ordered and variable culminating in Soemmerring's ring (SR) formation and sometimes Elschnig's pearls. This we evidence for lenses from a single patient. No bow region or recognisable epithelial-fibre cell interface (EFI) was evident and consequently the fibre cells were disorganised. We conclude that lens cells require spatial and cellular cues to initiate, sustain and produce an optically functional tissue in addition to capsule integrity and the EFI.

Intraocular Bag-in-the-Lens Exchange: Indications, Outcomes and Complications

PURPOSE

To report the indications, outcomes, and complications regarding the Bag-in-the-lens (BIL) intraocular lens (IOL) exchanges over a period of 13 years in a tertiary ophthalmologic centre.

SETTING

Department of Ophthalmology of the University Hospital of Antwerp (UZA).

DESIGN

Observational retrospective study.

PATIENTS AND METHODS

Between 2003 and 2020, 12 176 patients were operated using the BIL technique. We included adult patients who underwent an intraocular BIL exchange and recorded the demographics, indications, outcomes, and complications.

RESULTS

Fifty-nine eyes of 59 patients who underwent a BIL exchange between 2007 and 2020 were included (0.48%). The mean age was 61.15 ±13.53 years. The mean time between primary surgery and IOL exchange was 25.73 ± 41.88 months. The main indication for explantation was refractive surprise mostly related to the patients' risk factors e.g. preoperative corneal and refractive surgery. The mean preoperative uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were 0.36 ± 0.24 and 0.79 ± 0.24 respectively. The postoperative 1 month-UDVA and CDVA were 0.66 ± 0.28 and 0.86 ± 0.19 respectively. The improvement in UDVA was statistically significant (<0.0001). The most common peroperative complication was damage to the anterior hyaloid in 9 eyes (15%), which did not prohibit reimplantation of a secondary BIL.

CONCLUSIONS

BIL to BIL exchange is an viable and successful technique that provides good refractive results with few, manageable complications. Because of the tertiary profile of our centre with referral of complex cases, BIL was our preferred IOL in patients at risk of postoperative refractive surprise.

Intraocular Lenses: Overview of Designs, Materials, and Pathophysiologic Features

This article provides an overview of intraocular lenses (IOLs) currently used in cataract surgery. Aspects presented include design features related to IOL construction and sites of fixation; optic, filter, and haptic materials; as well as pathophysiologic features of uveal biocompatibility, capsular biocompatibility, and postoperative IOL opacification. This overview also includes supplementary (add-on; piggyback) lenses implanted in eyes that are already pseudophakic and considerations on IOLs used in the pediatric population. Different IOLs are made available to surgeons each year, including lenses with increasingly complex design characteristics owing to advancements in manufacturing and surgical techniques.

[Combined vitrectomy-lensectomy surgery with bag-in-the-lens or lens in the bag implantation: comparison of final visual acuity]

INTRODUCTION

Combined vitrectomy-lensectomy surgery is a safe and effective procedure. Nevertheless, it is frequently complicated by posterior capsule opacification and the formation of posterior synechiae. These complications can be avoided by placing a "bag in the lens" (BIL) implant. The objective of this study is to compare the visual acuity gain (VA) after combined vitrectomy-lensectomy surgery between a group implanted with the BIL technique and a group with implantation in the bag (LIB).

MATERIAL AND METHODS

We included in the study all vitrectomy-lensectomy procedures for epiretinal membrane and vitreomacular traction performed between May 2013 and July 2016 at the Hospital and University Center of Caen. We compared the VA gain between the BIL group and the LIB group six months after surgery.

RESULTS

A total of 33 patients were included in the study, consisting of 28 eyes in the BIL group and 8 eyes in the LIB group. The mean VA gain in the BIL group was -0.52 LogMAR (P<0.0001) and -0.56 LogMAR (P=0.0047) for the LIB group. The difference between the two groups was not significant (P=0.74).

CONCLUSION

The use of the BIL technique during vitrectomy-lensectomy allows visual recovery as good as implantation within the capsular bag. In addition, this implant has the advantage of significantly reducing the occurrence of posterior synechiae and preventing anterior and posterior capsular proliferation.

Bag-in-the-lens implantation helps avoid posterior synechiae of the iris after phacovitrectomy

PURPOSE

To compare the rate of posterior synechiae of the iris (PSI) occurrence after phacovitrectomy between a group with lens-in-the-bag (LIB) implantation, that is, implantation in the capsular bag, and a group with bag-in-the-lens (BIL) implantation.

SETTING

CHU de Caen, Department of Ophthalmology, Caen, France.

DESIGN

Comparative retrospective study.

METHODS

One hundred consecutive cases of phacovitrectomies conducted between May 2013 and July 2016 were included. A retrospective analysis of the occurrence rate of PSI in the LIB group and in the BIL group was performed, using multivariate analysis including multiple risk factors such as preoperative synechiae, proliferative diabetic retinopathy, use of 20-gauge vitrectomy, use of gas or silicone tamponade, and use of endophotocoagulation.

RESULTS

One hundred eyes of 92 patients were included in this study (55 eyes in the LIB group and 45 in the BIL group). The occurrence of PSI was significantly lower in the BIL group with 1 case (2%) versus 22 cases (40%) in the LIB group (P < .001). Among the risk factors studied, preoperative synechiae and the use of retinal endophotocoagulation were almost significantly associated with the occurrence of PSI (P = .068 and P = .087, respectively). In the LIB group, these PSI led to 1 case of acute elevation of intraocular pressure by pupillary seclusion and the use of laser iridotomy in 8 cases.

CONCLUSION

The use of BIL rather than LIB implantation in phacovitrectomy practically eliminates PSI.

The roles of αV integrins in lens EMT and posterior capsular opacification

Posterior capsular opacification (PCO) is the major complication arising after cataract treatment. PCO occurs when the lens epithelial cells remaining following surgery (LCs) undergo a wound healing response producing a mixture of α-smooth muscle actin (α-SMA)-expressing myofibroblasts and lens fibre cells, which impair vision. Prior investigations have proposed that integrins play a central role in PCO and we found that, in a mouse fibre cell removal model of cataract surgery, expression of αV integrin and its interacting β-subunits β1, β5, β6, β8 are up-regulated concomitant with α-SMA in LCs following surgery. To test the hypothesis that αV integrins are functionally important in PCO pathogenesis, we created mice lacking the αV integrin subunit in all lens cells. Adult lenses lacking αV integrins are transparent and show no apparent morphological abnormalities when compared with control lenses. However, following surgical fibre cell removal, the LCs in control eyes increased cell proliferation, and up-regulated the expression of α-SMA, β1-integrin, fibronectin, tenascin-C and transforming growth factor beta (TGF-β)-induced protein within 48 hrs, while LCs lacking αV integrins exhibited much less cell proliferation and little to no up-regulation of any of the fibrotic markers tested. This effect appears to result from the known roles of αV integrins in latent TGF-β activation as αV integrin null lenses do not exhibit detectable SMAD-3 phosphorylation after surgery, while this occurs robustly in control lenses, consistent with the known roles for TGF-β in fibrotic PCO. These data suggest that therapeutics antagonizing αV integrin function could be used to prevent fibrotic PCO following cataract surgery.

[Chronic angle-closure glaucoma in a pseudophakic eye with Soemmering's ring and plateau iris: case report]

We present a case of a pseudophakic woman with chronic angle-closure glaucoma. She had undergone uncomplicated bilateral phacoemulsification in 1994 with 21-diopter implants in the capsular bag. Fourteen years later, the right eye developed progressive angle closure with ocular hypertension, disc cupping and visual field defect. We observed a shallow anterior chamber, myopic shift, and closed angle, not openable on indentation gonioscopy. UBM revealed anteroposition of the ciliary body and a Soemmering's ring, with both appearing to contribute to the angle closure. After two incomplete iridotomies and one complete but blocked by the Soemmering's ring, a final UBM-guided iridotomy afforded a partial reopening of the angle, and satisfactory IOP control. The appearance and development of a Soemmering's ring after phacoemulsification are not always appreciated. It is common but usually asymptomatic. However, in some cases, when it is thick and/or located anteriorly, in the case of an anteroposition of the ciliary body (as in our case), it seems to cause direct pressure on the iris and pupillary block. Angle-closure glaucoma in pseudophakic eyes remains uncommon, the use of UBM is recommended, the role of a Soemmering's ring should be investigated, iridotomies must often be repeated, and long-term monitoring of pseudophakic patients remains necessary.

A randomized intraindividual comparison of the accommodative performance of the bag-in-the-lens intraocular lens in presbyopic eyes

PURPOSE

To compare the accommodative performance of the Morcher BioComFold Type 89A bag-in-the-lens intraocular lens (IOL) with a conventional in-the-bag control IOL in presbyopic eyes.

DESIGN

Prospective, randomized clinical trial with intraindividual comparison.

METHODS

SETTING

Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom.

STUDY POPULATION

Fifty-two eyes of 26 patients with bilateral age-related cataracts.

INTERVENTION

Phacoemulsification cataract extraction with implantation of a bag-in-the-Lens and a control IOL, the Alcon AcrySof SA60AT (Alcon Laboratories, Fort Worth, Texas, USA), randomized to either eye.

MAIN OUTCOME MEASURES

Axial IOL shift stimulated by physiologic (near visual effort) and pharmacologic (pilocarpine and cyclopentolate) accommodative stimulation was measured objectively with partial coherence interferometry. Other outcome measures were objective and subjective accommodation, logarithm of the minimal angle of resolution distance-corrected near visual acuity, and defocus curves.

RESULTS

Three months after surgery, axial IOL shift stimulated by near visual effort measured -5.9 ± 10.3 μm in bag-in-the-lens eyes versus -8.4 ± 12.8 μm in control eyes (P = .37), that stimulated by pilocarpine measured 20.2 ± 165.6 μm versus 50.4 ± 164.4 μm (P = .36), and that stimulated by cyclopentolate measured -65.8 ± 64.3 μm versus -54.0 ± 37.5 μm (P = .34), respectively (n = 25). Objective accommodation measured 0.03 ± 0.18 diopters (D) in bag-in-the-lens eyes versus 0.08 ± 0.21 D in control eyes (P = .40), whereas subjective accommodation measured 2.48 ± 0.72 D versus 2.45 ± 0.80 D (P = .75), respectively. Distance-corrected near visual acuity and defocus curves showed no difference between IOLs.

CONCLUSIONS

The bag-in-the-lens IOL demonstrated negligible axial shift and objective accommodation with physiologic near visual stimulation. The IOL shift demonstrated with pilocarpine also was clinically insignificant. The bag-in-the-lens IOL showed no accommodative or near visual advantage over a conventional in-the-bag IOL, despite its unique capsular fixation method. This provides further evidence that the focus-shift principle fails to produce clinically significant IOL movement.