Lens epithelial cells in an in vitro capsular bag model: Lens-in-the-bag versus bag-in-the-lens technique

Safety of the bag-in-the-lens implantation regarding the development of clinically significant pseudophakic cystoid macular edema: A retrospective case series study

PURPOSE

To determine the incidence of clinically significant pseudophakic cystoid macular edema (CSPME) after phacoemulsification using the 'bag-in-the-lens' lens (BIL) implantation technique and to examine the influence of associated risk factors for clinically significant pseudophakic macular edema (CSPME), both ocular and systemic.

METHODS

This retrospective study included 2419 first-operated eyes of 2419 adults who underwent phacoemulsification cataract surgery using the BIL implantation technique between January 2013 and December 2018 in the Antwerp University Hospital, Belgium. The significance of several risk factors (age, gender, previous history, intra- and postoperative complications) was examined by extraction of electronic medical files.

RESULTS

The 3-month incidence of CSPME in the subgroup without risk factors was 0.00% (95% CI: 0.00 -NA). The 3-month incidence of CSPME in the subgroup with risk factors was 0.57% (95% CI 0.22-1.29%). The 3-month incidence of CSPME in the total population of 2419 patients was 0.29% (95% CI: 0.11-0.65%). The risk factors most significantly associated with CSPME included renal insufficiency (hazard ration [HR]: 5.42; 95% CI: 1.69-17.44; P = .014), exudative age-related macular degeneration (HR: 74.50, 95% CI: 25.75-215.6; P < .001) and retinal vein occlusion (HR: 22.48, 95% CI: 4.55-111.02; P = .005).

CONCLUSIONS

In the absence of risk factors, the incidence of CSPME was zero. We can conclude that Primary Posterior Continuous Curvilinear Capsulorhexis (PPCCC) does not increase the risk for CSPME. Non-inferiority of the BIL implantation regarding the development of CSPME, relative to the traditional 'lens-in-the-bag' (LIB) implantation, confirms that BIL is a safe surgical technique. This study also illustrates a previously undescribed risk factor for developing CSPME, namely renal insufficiency.

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.

Incidence of rhegmatogenous retinal detachment after bag-in-the-lens IOL implantation: extended follow-up in a larger cohort of patients

PURPOSE

To report the incidence of rhegmatogenous retinal detachment (RRD) and associated risk factors after cataract surgery using the bag-in-the-lens (BIL) intraocular lens (IOL) implantation technique.

SETTING

Department of Ophthalmology, Antwerp University Hospital, Belgium.

DESIGN

Prospective cohort study.

METHODS

All consecutive BIL IOL surgeries performed between January 2001 and December 2010 were included, with the exclusion of combined procedures and IOL exchanges. The incidence of RRD was reported first in the total cohort, then in a subgroup of patients with 1 year to 5 years of follow-up, and finally in the group remaining after exclusion of all risk factors, except gender. Risk factors associated with RRD were examined using multiple Cox regression analysis with a random intercept.

RESULTS

Rhegmatogenous RD was diagnosed in 36 eyes (1.06%) of 3385 BIL cases, with a mean follow-up of 48.28 ± 40.05 months (range 0 to 195 months). The 2-year cumulative RRD incidence rate was 0.66% (17 cases in 1024 eyes; 0.00% in patients without risk factors). The 5-year cumulative RRD incidence rate was 1.17% (26 cases in 931 eyes; 0.15% without risk factors). Five risk factors were confirmed: male sex, age less than 60 years at the time of surgery, axial length 25.0 mm or greater, a history of contralateral RD, and intraoperative surgical complications.

CONCLUSIONS

The incidence of RRD after BIL IOL implantation is comparable with that of lens-in-the-bag (LIB) implantation. This larger study provided a longer follow-up and suggested that RRD incidence is even lower than that previously reported. This study also confirmed intraoperative surgical complications as an additional risk factor for RRD development, as already described with LIB implantation.

Clinically significant pseudophakic cystoid macular edema after bag-in-the-lens implantation

PURPOSE

To determine the incidence of clinically significant pseudophakic cystoid macular edema (CSPME) after phacoemulsification using the bag-in-the-lens intraocular lens (BIL IOL) implantation technique and to examine the influence of associated risk factors, both ocular and systemic.

SETTING

Monocentric, Antwerp University Hospital, Belgium.

DESIGN

Retrospective.

METHODS

This study included 1 077 first-operated eyes of 1 077 adults who underwent phaco-emulsification cataract surgery using the BIL IOL implantation technique between January 2013 and December 2015.

RESULTS

The 3-month incidence of CSPME in the subgroup without risk factors was 0% (95% CI, 0.0-0.0). The 3-month incidence of CSPME in the subgroup with risk factors was 2.8% (95% CI, 1.3-4.3). The 3-month incidence of CSPME in the total group of 1077 patients was 1.4% (95% CI, 0.6-2.1). The risk factors most significantly associated with CSPME included diabetes (hazard ratio [HR]: 5.37; 95% CI, 1.5-19.3; P = .019), exudative age-related macular degeneration (HR: 121; 95% CI, 36.1-409; P < .001), and macular traction (HR: 6.47; 95% CI, 1.9-22.1; P < .009).

CONCLUSIONS

The incidence of CSPME was zero in eyes without risk factors. The incidence was consistent with previous reports in the literature regarding the lens-in-the-bag IOL implantation technique in eyes with risk factors. This indicates that the BIL IOL implantation technique is a safe procedure and does not confer a higher risk for developing cystoid macular edema after cataract surgery compared with the lens-in-the-bag IOL implantation technique, despite the requirement of a primary posterior continuous curvilinear capsulorhexis.

Comparison of visual acuity and complications between primary IOL implantation and aphakia in patients with congenital cataract younger than 2 years: a meta-analysis

To analyze the visual acuity and complications between primary intraocular lens (IOL) implantation and contact lens wearing, this literature search was performed with data on patients with congenital cataract younger than 2 years published in March 2019. Seven identified studies enrolling 675 eyes were selected for analysis. Patients with primary IOL implantation owned better visual acuity than those with aphakia who wore the contact lens (weighted mean difference = 0.161; 95% CI, 0.108-0.214). For visual axis opacification (VAO), primary IOL implantation increases the incidence of VAO compared with contact lens wearing (relative risk = 0.23; 95% CI, 0.13-0.42). No statistically significant difference was found between the 2 groups about the prevalence of glaucoma and strabismus. Primary IOL implantation achieved better visual outcomes after cataract extraction in patients younger than 2 years. In addition, no higher risk for complications among primary IOL implantation compared with contact lens wearing was noted. Therefore, implanting a primary IOL during congenital cataract surgery is a better therapy for children younger than 2 years than wearing a contact lens.

[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.

Incidence of rhegmatogenous retinal detachment after bag-in-the-lens intraocular lens implantation

PURPOSE

To determine the incidence of rhegmatogenous retinal detachment (RRD) and associated risk factors after phacoemulsification and bag-in-the-lens intraocular lens (IOL) implantation.

SETTING

Antwerp University Hospital, Department of Ophthalmology, Antwerp, Belgium.

DESIGN

Prospective cohort study.

METHODS

All consecutive bag-in-the-lens IOL implantations performed between January 2001 and December 2007 were included, with the exception of combined procedures and IOL exchanges. The retinal detachment (RD) incidence was studied in the total cohort, in a subgroup of patients with 1 to 5 years of follow-up, and finally in the group remaining after exclusion of all risk factors except gender.

RESULTS

RD after bag-in-the-lens IOL implantation in 1323 eyes with an average follow-up of 44.75 months (range 0 to 152 months) was found in 19 eyes (1.44%). The 1-year RD incidence was 0.49% (5 RD cases in 1024 eyes) (0.00% in patients without risk factors). The 2-year cumulative RD incidence was 0.84% (9 RD cases in 931 eyes; 0.15% without risk factors). Four clinically significant risk factors were confirmed: male gender, young age at time of surgery (<60 years), axial myopia (axial length ≥25 mm), and history of contralateral RD in the total cohort.

CONCLUSION

The RRD incidence following bag-in-the-lens IOL implantation was comparable to that seen after lens-in-the-bag (LIB) implantation. The wide variation in study design in the literature precludes direct comparison, so there is a need for standardization in evaluating RRD incidence after cataract surgery. Future prospective studies should consider patients with and without risk factors (except gender) separately.

FINANCIAL DISCLOSURE

Prof. dr. M.J. Tassignon has intellectual property rights to the bag-in-the-lens intraocular lens (U.S. patent 6 027 531; EU patent 009406794; PCT/120268), which is licensed to Morcher GmbH, Stuttgart, Germany.

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.