Bag-in-the-lens implantation of intraocular lenses

The prevalence of visual axis opacification in the Swedish Pediatric Cataract Register

PURPOSE

To report on the occurrence of postoperative visual axis opacification (VAO) in children younger than 5 years of age operated for cataract in Sweden, and to analyse correlations with age at surgery and surgical method.

METHODS

Data were derived from the Swedish Pediatric Cataract Register (PECARE). All children operated on between 1 January 2007 and 31 December 2020 were included. Follow-ups at 1, 2 and 5 years of age were analysed.

RESULTS

Cataract surgery were performed on 770 eyes belonging to 549 children (n = 282 boys, 51.4%); 327/770 (42.5%) of the children underwent surgery before 3 months of age and 216/770 (28%) before 6 weeks of age. Data on 881 follow-up visits were registered. At the follow up-visits at 1, 2 and 5 years of age, VAO was present in 154/349 (44.1%), 41/323 (12.7%) and 25/208 (12%). The majority of the children with VAO underwent cataract surgery before age 6 months, with a predominance before age 2 months. Primary IOL was implanted in 601/770 (78%) of eyes; 40.8% had an acrylic one-piece lens, 31.8% had a bag-in-the-lens IOL, 21.9% were aphakic and 5.2% had an acrylic three-piece lens. Implantation of a bag-in-the-lens IOL was related to a significantly lower occurrence of VAO compared to other types of IOL, including aphakia (p < 0.0002).

CONCLUSION

Our results are in accordance with the literature. Primary bag-in-the-lens IOL implantation before 2 years of age seems adequate and safe, with a low occurrence of VAO, and can thus be continued as routine in Sweden.

Optic Capture Without Anterior Vitrectomy in Pediatric Cataract Surgery

PURPOSE

To compare outcomes of 2 surgical techniques in children undergoing cataract surgery with intraocular lens (IOL) implantation: optic capture of IOL without anterior vitrectomy (AV) or in-the-bag IOL with AV.

DESIGN

Prospective randomized controlled trial.

METHODS

Patients were randomized to 2 groups: optic capture without AV (group 1) or in-the-bag implantation with AV (group 2). The following variables were compared: visual axis opacification (VAO), inflammatory deposits on IOL surface, anteroposterior synechia, IOL tilt and decentration, lenticular astigmatism, refractive prediction error, and posterior segment complications.

RESULTS

Fifty-one eyes of 37 children were investigated with a mean follow-up of 20.1±8.5 months. Group 1 and group 2 had mean ages of 59.2±32.6 and 46.5±21.9 months, respectively (P = .104). Three eyes in group 1 and 2 eyes in group 2 developed VAO (P = .656). Two eyes in group 1 and 5 eyes in group 2 developed anteroposterior synechia (P = .291). Six eyes in group 1 and 11 eyes in group 2 had inflammatory deposits on the IOL (P = .233). Both groups had similar IOL tilt and decentralization (for all meridians, P > .05). The absolute refractive prediction error was 0.55±0.34 diopter (D) and 0.53±0.3 D, respectively (P = .294). Each group had 1 eye with intraocular hypertension (P = .932).

CONCLUSION

The optic capture method was similar to the conventional technique in the quantitative evaluation of comprehensive data such as visual axis opacification, inflammatory sequelae, refractive outcomes, and IOL stability. The optic capture technique is an appealing option for pediatric cataract surgery because it eliminates the requirement for vitrectomy.

Bag-in-the-lens intraocular lens implantation before 12 weeks of age in congenital cataract

PURPOSE

The aim of this study was to evaluate the intra- and postoperative complications, especially the risk of visual axis opacification (VAO), following the implantation of the bag-in-the-lens (BIL) intraocular lens (IOL) in infants with congenital cataract operated on before 12 weeks of age.

METHODS

Infants operated on before 12 weeks of age between June 2020 and June 2021 with a follow-up longer than 1 year were included in the present retrospective study. This was a first-experience cohort of an experienced paediatric cataract surgeon with this type of lens.

RESULTS

Nine infants (13 eyes) with a median age at surgery of 28 days (range, 21-49 days) were included. The median follow-up time was 21.6 months (range, 12.2-23.4 months). The lens was correctly implanted with the anterior and posterior capsulorhexis edges placed into the interhaptic groove of the BIL IOL in seven of 13 eyes; none of these eyes developed VAO. In the remaining six eyes, the IOL was only fixated to the anterior capsulorhexis edge, and in these cases, an anatomical anomaly of the posterior capsule and/or anterior vitreolenticular interface dysgenesis were observed. These six eyes developed VAO. One eye had a partial iris capture in the early postoperative phase. Otherwise, the IOL remained well centred and stable in all eyes. Anterior vitrectomy was necessary in seven eyes due to vitreous prolapse. One patient with unilateral cataract was diagnosed with bilateral primary congenital glaucoma at 4 months of age.

CONCLUSION

Implantation of the BIL IOL is safe even in the youngest age group less than 12 weeks of age. Although being a first-experience cohort, the BIL technique is shown to reduce the risk of VAO and the number of surgical procedures.

The lens epithelium as a major determinant in the development, maintenance, and regeneration of the crystalline lens

The crystalline lens is a transparent and refractive biconvex structure formed by lens epithelial cells (LECs) and lens fibers. Lens opacity, also known as cataracts, is the leading cause of blindness in the world. LECs are the principal cells of lens throughout human life, exhibiting different physiological properties and functions. During the embryonic stage, LECs proliferate and differentiate into lens fibers, which form the crystalline lens. Genetics and environment are vital factors that influence normal lens development. During maturation, LECs help maintain lens homeostasis through material transport, synthesis and metabolism as well as mitosis and proliferation. If disturbed, this will result in loss of lens transparency. After cataract surgery, the repair potential of LECs is activated and the structure and transparency of the regenerative tissue depends on postoperative microenvironment. This review summarizes recent research advances on the role of LECs in lens development, homeostasis, and regeneration, with a particular focus on the role of cholesterol synthesis (eg., lanosterol synthase) in lens development and homeostasis maintenance, and how the regenerative potential of LECs can be harnessed to develop surgical strategies and improve the outcomes of cataract surgery (Fig. 1). These new insights suggest that LECs are a major determinant of the physiological and pathological state of the lens. Further studies on their molecular biology will offer possibility to explore new approaches for cataract prevention and treatment.

Pediatric cataract surgery: Rate of secondary visual axis opacification depending on intraocular lens type

PURPOSE

To assess the time course of secondary visual axis opacification (VAO) that led to additional surgery after primary intraocular lens (IOL) implantation in children and to describe further surgical outcomes. Comparison of different lens types.

DESIGN

Single center, retrospective analysis of children aged 1-14 years who underwent cataract surgery with primary IOL implantation. The surgical technique was either in-bag IOL placement with primary posterior capsulotomy and anterior vitrectomy or bag-in-lens IOL placement. We excluded eyes with visually significant ocular comorbidities.

SUBJECTS

Total of 135 eyes of 95 children. Of these, 64 had received an acrylic three-piece IOL, 51 an acrylic single-piece IOL, and 20 an acrylic single-piece bag-in-lens IOL. The median ages at surgery were 53 months (IQR 35-75), 52 months (27-65), and 60 months (40-84) in the 3-piece, 1-piece, and bag-in-lens group, respectively.

METHODS

Analysis of medical records. We used the Kaplan-Meier method and a cox proportional hazards model with pre-defined adjustments for age at surgery, year of surgery, and socioeconomic deprivation (GISD score by postal code) to analyze VAO-free survival by lens type. Patients were invited to attend a clinical visit to achieve longer follow-ups.

MAIN OUTCOME MEASURES

The rate of survival without VAO that required clearing of the visual axis after cataract surgery with primary IOL implantation. Any other surgical complications.

RESULTS

The overall median follow-up was 19 months (IQR 3-58). There were 13 cases of VAO, occurring at a median of 10 months (IQR 10-12) after surgery. Of these, 1 eye had a 3-piece in-bag IOL, 10 eyes had 1-piece in-bag IOLs, and 2 eyes had bag-in-lens IOLs. The adjusted hazard ratio was 32.8 (95% CI: 3.3-327, p=0.003) for 1-piece acrylic IOLs and 19.6 (1.22-316, p=0.036) for bag-in-lens IOLs, compared to 3-piece acrylic in-bag IOLs. Two eyes with bag-in-lens surgery (10%) had an iris capture. There was one case of endophthalmitis. We found no cases of postoperative retinal detachment or new glaucoma.

CONCLUSIONS

Children with secondary visual axis opacification that required a procedure to clear the visual axis generally presented within fifteen months. Opacification rates were lowest when a 3-piece acrylic IOL was used.

Bag-in-the-lens intraocular lens in paediatric cataract surgery: intraoperative and postoperative outcomes

PURPOSE

To report intra- and postoperative surgical outcome using the bag-in-the-lens (BIL) technique in paediatric cataract surgery.

METHODS

In a retrospective case series, we studied the outcomes of children aged <12 years operated for cataract with the bag-in-the-lens intraocular lens (IOL), with a minimum of 6 months of follow-up.

RESULTS

Since 2013, 50 eyes in 30 patients <12 years (20 bilateral and 10 unilateral) have been operated at our department with the BIL technique, with a median follow-up time of 33.5 months (range 6-77). Median age at surgery was 49.5 months (4-139). In one case, the IOL luxated through the capsulorhexes to the vitreous, but could be secured and repositioned as planned without further difficulties. Anterior vitrectomy was necessary in one case due to prolapse of vitreous to the anterior chamber during surgery. No other intraoperative complications occurred. Visual axis opacification (VAO) developed in four eyes (8%). So far, only one of these has needed a reoperation with clearing of the secondary cataract. A complete absence of VAO was thus seen throughout the study period in 92%. In two eyes, postoperative iris capture occurred. In both cases, surgical repositioning of the iris was needed. No eyes developed secondary glaucoma during the study period.

CONCLUSION

The BIL technique seems to be a safe surgical procedure in paediatric cataract, with significantly less complications and need for additional surgery compared with the conventional lens-in-the-bag technique.

Post-operative outcomes in canine eyes receiving a rhexis-fixated prosthetic intra-ocular lens: 30 cases (2014-2020)

OBJECTIVES

To report the outcomes following the insertion of a rhexis-fixated prosthetic intraocular lens (IOL) in dogs undergoing lens removal.

MATERIALS AND METHODS

The results are from 30 eyes of 28 dogs, undergoing lendectomy, in which the lens capsule could not accommodate a conventional prosthetic endo-capsular IOL. The reported cases had sustained either spontaneous or traumatic lens capsule rupture, or accidental intra-operative iatrogenic lens capsule disruption, or had required a planned, large, anterior or posterior continuous curvilinear capsulorhexis, all of which precluded insertion of a prosthetic IOL within the lens capsule. An acrylic IOL (XVET; Medicontur) was modified and positioned across the anterior and/or posterior capsulorhexes.

RESULTS

Other than haptic luxation in three cases, no complications were seen that were directly attributable to the rhexis-fixated lens. Over a follow-up period from three to 76 months (mean 20.7 months) 26/30 eyes remained visual. Blindness developed in three eyes due to retinal detachment and one eye was enucleated due to regrowth of a ciliary body adenoma.

CLINICAL SIGNIFICANCE

Rhexis fixation provided an alternative method to implant a prosthetic IOL when the lens capsule was unable to accommodate a conventional endo-capsular IOL.

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.

Effect of Nd: YAG laser capsulotomy on the risk of retinal detachment after cataract surgery: A systematic review and meta-analysis

ABSTRACT

We aimed to evaluate the impact of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy on the incidence of pseudophakic retinal detachment (RD). The PubMed and Embase databases were searched for meta-analysis. Subgroup analyses were conducted according to study location, number of cases, mean follow-up time, and cataract procedure. The final analysis included 11 studies with 309 cases of RD in 65,117 eyes undergoing cataract surgery. Among them, 8,232 eyes underwent Nd:YAG capsulotomy. Our analysis demonstrated an increased risk of RD with Nd:YAG laser capsulotomy (RR=1.57; 95%CI, 1.17-2.12; P=0.003; HR=1.64; 95%CI, 1.03-2.62; P=0.04). Subgroup analysis suggested somewhat stronger associations in Asian (RR=4.54; 95%CI, 2.20-9.38; P<0.0001) than in non-Asian populations (America, P=0.12; Europe and others, P=0.21), and with extracapsular cataract extraction (RR=2.97; 95%CI, 1.83-4.83; P<0.0001) than with phacoemulsification (P=0.95). To conclude, Nd:YAG laser capsulotomy may be associated with an increased risk of pseudophakic RD.

Precision of bag-in-the-lens intraocular lens power calculation in different age groups of pediatric cataract patients: Report of the Giessen Pediatric Cataract Study Group

PURPOSE

To evaluate the precision of bag-in-the-lens intraocular lens (BIL IOL) power calculation in different age groups of pediatric cataract patients.

SETTINGS

Department of Ophthalmology, Justus-Liebig-University Giessen, University Hospital Giessen and Marburg GmbH, Campus Giessen, Giessen, Germany.

DESIGN

Retrospective nonrandomized consecutive case series.

METHODS

Pediatric patients diagnosed with cataract and operated with BIL IOL implantation were divided into 4 age groups: Group 1 (0 to 3 months), Group 2 (>3 months, <12 months), Group 3 (12 to 36 months), and Group 4 (>36 months to 17 years). BIL IOL power was calculated with the SRK/T formula. The prediction error (PE) was defined as the absolute difference between the preoperative selected target and postoperative achieved refraction. The impact of age at the time of surgery, axial length (AL), keratometry, and corneal astigmatism on PE was analyzed.

RESULTS

The study comprised 87 eyes of 56 pediatric patients. The mean and median PEs for the entire group were 1.79 diopters (D) and 1.23 D, respectively. The mean PE in each age group was: 3.43 D in Group 1, 2.14 D in Group 2, 1.60 D in Group 3, and 1.33 D in Group 4. The mean PE in eyes with ALs shorter than 20 mm was 2.67 D, and 1.44 D in eyes with an AL of 20 mm or longer. The mean PE in eyes with corneal radii less than 7.3 mm was 2.45 D, and 1.66 D in eyes with corneal radii of 7.3 mm or more. In the age and AL subgroups, the PE differences were statistically significant (P < .05).

CONCLUSIONS

The PE was larger in the youngest study group, and it decreased gradually with age and in eyes with ALs shorter than 20 mm. The PE has to be considered during BIL IOL power calculation in children.

[Primary posterior capsulorhexis in difficult situations]

Primary opening of the posterior capsule (primary continuous curvilinear capsulorhexis, PCCC) during cataract surgery is a safe and efficient procedure to prevent formation of an aftercataract. When combined with buttonholing of the optic in the posterior capsule opening no unintended rotation of a toric intraocular lens (IOL) can occur postoperatively. This article shows that PCCC can be safely performed even in difficult situations.

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.

[New intraocular lens designs for femtosecond laser-assisted cataract operations : Chances and benefits]

BACKGROUND

The perfection and high reproducibility of capsulotomy in femtosecond laser-assisted cataract surgery (FLACS) lead to the possibility of new intraocular lens (IOL) designs for capsulotomy fixed implantation.

ISSUE

Which different designs have so far been presented for which problems in capsulotomy fixation?

MATERIAL AND METHOD

An evaluation of the literature and conference data was carried out.

RESULTS

Currently four different types of femtolenses for capsulotomy fixation are described in the literature or are commercially available. The first described was the lens in the bag or Tassignon IOL, which was developed for secondary cataract prevention, the second was the Masket IOL for reduction of negative dysphotopsia and third the 90F designed by Dick. All three types are or will be produced by Morcher. The fourth lens is the Femtis from Oculentis. All lenses are characterized by a high level of safety during implantation, The Tassignon lens leads to reduction of secondary cataract, especially in juvenile cataract because of the additional posterior capsulotomy. In studies the Masket IOL could show a decrease of negative dysphotopsia. In comparison to standard lenses, the 90F and Femtis in particular showed better results with respect to tilt, rotation and decentration.

CONCLUSION

The new IOL designs for capsulotomy fixation show a safe implantation procedure and indications for a very stable position in the capsular sac. Further studies must be carried out to confirm the possible advantages in comparison to standard IOL with respect to postoperative results for refraction, tilt, rotation and decentration and possible induction of aberrations.

Comparison of the Accuracy of IOL Power Calculation Formulas for Pediatric Eyes in Children of Different Ages

Purpose

This study aims to compare the accuracy of five intraocular lens (IOL) power calculation formulas (SRK/T, Hoffer Q, Holladay 1, Haigis, and Holladay 2) for pediatric eyes in children of different ages.

Methods

In this prospective study, patients who received cataract surgery and IOL implantation in the capsular bag were enrolled. We compared the calculation accuracy of 5 formulas at 1 month postoperatively and performed subgroup analysis with the patients divided into three groups according to their ages at the time of surgery as follows: group 1 (age ≤ 2 years, 35 eyes), group 2 (2 years < age < 5 years, 38 eyes), and group 3 (age > 5 years, 29 eyes).

Results

75 patients (102 eyes) were enrolled in this study. The Haigis formula got the smallest PE among all formulas in all three groups. With regard to APE, there were no statistical differences among the formulas except group 2, with the SRK/T formula a little smaller, the Holladay 2 formula a little larger in group 1, and the Haigis formula a little smaller in group 3. In group 2, the Haigis formula had the lowest APE (0.87 ± 0.61 D), while the Holladay 2 formula had the largest (1.71 ± 1.20 D, p < 0.001), followed by the Holladay 1 formula (1.51 ± 1.07 D, p=0.002). On comparing the percentage of APE within 0.5 D and 1.0 D obtained with 5 formulas in each group, there were no statistical differences. The SRK/T formula and the Holladay 1 formula showed the highest percentage (40.00% and 60.00%) in group 1. While the Haigis formula got the highest percentage in less than 0.5 D (34.21%) and less than 1 D (60.53%) in group 2. In group 3, the Holladay 2 formula and the Haigis formula got the highest percentage less than 0.5 D (58.62%) and less than 1 D (79.31%). The multiple linear regression indicated that the age at the time of surgery was a significant factor affecting the accuracy of APE; after removing the age, AL was the only factor that affected the accuracy of APE.

Conclusion

The SRK/T and the Holladay 1 formulas were relatively accurate in patients younger than 2 years old, while the Haigis formula performed better in patients older than 2.

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.

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.

Femtosecond laser-assisted cataract surgery: A review

PURPOSE

Review scientific literature concerning femtosecond laser-assisted cataract surgery.

METHODS

Following databases were searched: CENTRAL (Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 2 of 12, June 2019), Ovid MEDLINE^® without Revisions (1996 to June 2019), Ovid MEDLINE^® (1946 to June 2019), Ovid MEDLINE^® Daily Update June 2019, MEDLINE and MEDLINE Non-Indexed Items, Embase (1980-2019), Embase (1974 to June 2019), Ovid MEDLINE^® and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1946 to June 2019), Web of Science (all years), the metaRegister of Controlled Trials ( www.controlled-trials.com ), ClinicalTrials.gov ( www.clinicaltrial.gov ) and World Health Organization International Clinical Trials Registry Platform ( www.who.int/ictrp/search/en ). Search terms/keywords included 'Femtosecond laser' combined with 'cataract', 'cataract surgery'.

RESULTS

Based on quality of their methodology and their originality, 121 articles were reviewed, including randomised controlled trials, cohort studies, case-controlled studies, case series, case reports and laboratory studies. Each step of the femtosecond laser-assisted cataract surgery procedure (corneal incisions, arcuate keratotomies, capsulotomy and lens fragmentation) has been discussed with relevance to published outcomes, as well as complication rates of femtosecond laser-assisted cataract surgery, and what we can learn from the larger studies/meta-analyses and the economics of femtosecond laser-assisted cataract surgery within different healthcare settings.

CONCLUSION

Studies suggest that the current clinical outcomes of femtosecond laser-assisted cataract surgery are not different to conventional phacoemulsification surgery and it is not cost effective when compared with conventional phacoemulsification surgery. In its current technological form, it is a useful surgical tool in specific complex cataract scenarios, but its usage has not been shown to translate into better clinical outcomes.

Secondary glaucoma and visual outcome after paediatric cataract surgery with primary bag-in-the-lens intraocular lens

PURPOSE

To determine predictors of secondary glaucoma and poor visual outcome in children undergoing cataract surgery with bag-in-the-lens (BIL)-IOL implantation.

METHODS

Medical records were retrospectively analysed for children with primary implantation with BIL-IOL during 2009-2013.

RESULTS

The study included 109 eyes. Median age at surgery was 2.5 years (range 2 weeks-14.1 years), 26.6% being ≤12 weeks of age (= early group). Median follow-up time was 2.8 years (7 months-5.8 years). 15 eyes (13.8%) developed glaucoma, 14 (48.3%) in the early group and 1 (1.3%) in the late group (p < 0.001). Within the early group, mean time for surgery differed significantly. Patients developing glaucoma had cataract surgery at 3.5 ± 1.1 weeks (mean ± SD) and the non-glaucoma patients at 5.7 ± 3.3 weeks (p = 0.024). In the entire cohort, 21 eyes (19.3%) had conditions associated with glaucoma; 57.1% of these developed glaucoma compared to 3.4% without these conditions (p < 0.001). Corrected distance visual acuity (CDVA) (decimal) of ≥0.5 was seen in 50 eyes (48.5%), median 0.63 in the late group and 0.15 in the early group. Glaucoma eyes in the early group (surgery at 3.5 weeks) achieved 0.56 median (range, 0.4-1.0) logMAR, (0.28 decimal) CDVA, whereas non-glaucoma eyes (surgery at 5.7 weeks) achieved 0.89 median (range 0.7-1.6) logMAR (0.13 decimal) CDVA; p = 0.016. Glaucoma development in infants between 5 weeks and 2 years of age was 6.7% (n = 2/30).

CONCLUSIONS

Comorbidity strongly increases the risk of secondary glaucoma. Surgery during the first month is correlated with better CDVA outcome and glaucoma. After 5 weeks of age, glaucoma rate is low with the BIL-IOL.

Analysis and management of intraoperative and early postoperative complications of bag-in-the-lens intraocular lens implantation in different age groups of paediatric cataract patients: report of the Giessen Paediatric Cataract Study Group

PURPOSE

To report the rate and management of intra- and early postoperative complications of bag-in-the-lens intraocular lens (IOL) implantation technique for cataract treatment in paediatric patients of different age groups.

SETTINGS

Department of Ophthalmology, Justus-Liebig-University Giessen, University Hospital Giessen and Marburg GmbH, Campus Giessen, Giessen, Germany.

DESIGN

Retrospective non-randomized consecutive case series.

METHODS

Ninety eyes of 60 paediatric cataract patients were enrolled to this retrospective non-randomized observational consecutive case series single-centre study. All patients underwent cataract surgery with bag-in-the-lens IOL implantation between January 2008 and December 2018, performed by two experienced surgeons. The entire cohort was divided into four age groups: first - 0-<3 months, second - 3-<12 months, third - 12-<36 and fourth - >36 months-17 years of age. The intra- and postoperative complications were based on the clinical records. The description of management of complications related specifically to bag-in-the-lens IOL technique was based on the 39 consecutive cases operated since 1 Jan 2016 by one single surgeon that were all video documented. The early postoperative period was defined as 12 months after surgery.

RESULTS

Overall, there were 27 unilateral and 33 bilateral surgical cases of 24 female and 36 male children. The mean age at surgery was 45.25 months (range 1-200 months). The most common intraoperative events were vitreous prolapse and anterior capsule rupture with 28.9% and 13.3%, respectively. Within 12 months of follow-up, five eyes (5.6%) were re-operated because of visual axis reo-pacification (VAR). Intraocular hypertension was diagnosed in seven eyes (7.8%), including two cases that required surgical treatment. In all cases with intra- and early postoperative complications related specifically to bag-in-the-lens technique, it was possible to manage them and successfully implant bag-in-the-lens IOL.

CONCLUSIONS

Implementation of bag-in-the-lens technique in the treatment of paediatric cataract was associated with a relatively low rate of intra- and postoperative complications, including rare cases of VAR. The correct management of complications related specifically to bag-in-the-lens IOL implantation technique shall to be considered during the learning curve.

[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.

Cataract surgeon viewpoints on the need for novel preventative anti-inflammatory and anti-posterior capsular opacification therapies

Purpose: To determine cataract surgeon viewpoints on the efficacy of available therapies/preventatives for two common sequelae of cataract surgery: inflammation and posterior capsular opacification (PCO). Methods: Cataract surgeons practicing worldwide specializing in adult, pediatric and veterinary patients were interviewed between March and August 2018. Results: Ocular inflammation following cataract surgery is treated by either corticosteroids and/or nonsteroidal anti-inflammatories (NSAIDs). Adult and pediatric cataract surgeons are satisfied with current treatments whereas this inflammation is still considered a problem by some in veterinary practice due to its slow resolution. Yttrium-aluminum-garnet (YAG) laser therapy is the PCO treatment of choice for adult cataract surgeons and they are generally pleased with its outcome. However, pediatric cataract surgeons find YAG problematic, especially in patients under 6 years of age, and invasive surgery is often needed to correct PCO/visual axis opacification (VAO). Veterinary ophthalmologists report that YAG is not effective for PCO in animals, especially dogs, due to the density of the fibrotic plaques; 86% of adult and 100% of veterinary and pediatric cataract surgeons surveyed agree that effective anti-PCO therapeutics would improve clinical care. Conclusions: Surgeons treating human patients are pleased with the available treatments for ocular inflammation following cataract surgery, although some veterinary ophthalmologists disagree. The surgeons surveyed agree that PCO/VAO remains an unsolved problem in pediatric and veterinary cataract surgery while the long-term outcome of adult cataract surgery could be improved by additional attention to this issue.

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.

Transzonular capsulo-hyaloidal hydroseparation with optional triamcinolone enhancement: A technique to detect or induce anterior hyaloid membrane detachment for primary posterior laser capsulotomy

Primary posterior laser capsulotomy (PPLC) requires adequate visualization and spacing of the posterior lens capsule (PLC) and anterior hyaloid membrane (AHM). After intraocular lens implantation and watertight incision hydration, the laser is redocked for optical coherence tomography reimaging. If the PLC and AHM are not imaged or interspaced adequately, transzonular capsulo-hyaloidal hydroseparation is attempted by rinsing the zonular fibers with fluid. If the PLC or AHM are still not detected or discernable, an attempt follows to mark the Berger space using diluted triamcinolone acetate. Before hydroseparation, the AHM or PLC are often invisible or variably attached. If structures cannot be defined, triamcinolone-added hydroseparation is often effective in defining the AHM and Berger space. Transzonular capsulo-hyaloidal hydroseparation with an optional triamcinolone acetate addition can initiate or complete AHM detachment and improve visibility and patency of Berger space for augmenting control and feasibility of PPLC.

Immunohistochemical characteristics of the vitreolenticular interface in congenital unilateral posterior cataract

PURPOSE

To gain insight into the histology of the vitreolenticular interface in congenital unilateral posterior cataract.

SETTING

Antwerp University Hospital, Department of Ophthalmology, Edegem, and the University of Antwerp, Faculty of Medicine and Health Sciences, Antwerp, Belgium.

DESIGN

Prospective case study.

METHODS

Samples of the posterior lens capsule of patients with congenital posterior cataract (including opaque plaque on the anterior and adhesion to the vitreous on the posterior surface) were collected during the posterior capsulorhexis procedure. Staining for collagen types II and IV was performed using indirect immunohistochemistry. Results were compared with those of control posterior lens capsules of 3 children and 3 adults.

RESULTS

Samples were collected from 3 patients. All posterior lens capsules contained collagen type IV. Samples from congenital posterior cataract patients all showed a narrow band of collagen type II on the outer surface, indicating strong adherence of the anterior hyaloid membrane to the center of the posterior lens capsule. Surprisingly, collagen type II was also found in the posterior capsule plaques. Collagen type II was not found in any control posterior lens capsule.

CONCLUSION

The adherence of collagen type II to the center of the posterior lens capsule histologically supports the hypothesis that this subgroup of congenital cataract hints at an abnormality at the vitreolenticular interface.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Swivel haptics anterior capsule-fixated intraocular lens

The purpose of the study is to report the feasibility of implantation of a new design of anterior capsule-fixated intraocular lens (IOL). The new IOL design is a foldable, hydrophilic, open-loop posterior chamber IOL with two extra polymethyl methacrylate swivel haptics created on the optic surface to capture the anterior capsulotomy after the IOL is implanted in the bag. In the pilot phase, the new IOL was implanted in 10 eyes of 10 patients of which 8 eyes underwent phacoemulsification and 2 eyes had laser cataract surgery. The mean spherical equivalent changed from *1.75 D to −0.75 D at 6 months. Postoperatively, from 1 week to 6 months, all eyes showed stable refraction and anterior chamber depth with no evidence of decentration. Subjective questionnaire revealed high patient satisfaction with no complaints of dysphotopsia. No intra- or postoperative complications such as swivel haptic breakage, iris chafing, pigment dispersion, postoperative uveitis, or endophthalmitis occurred in any of the eyes necessitating explantation of the IOL. The new IOL design was feasible to implant and provided satisfactory outcomes in terms of no dysphotopsias and stable effective lens position.

Phacoemulsification and primary implantation with bag-in-the-lens intraocular lens in children with unilateral and bilateral cataract

PURPOSE

To report outcome in a paediatric cohort with cataract extraction and implantation of bag-in-the-lens intraocular lens (BIL-IOL).

METHODS

Children younger than 16 years of age subjected to phacoemulsification with primary implantation of BIL-IOL during 2009 through 2013 were analysed retrospectively. Exclusion criteria were uveitis or ≤6 months of follow-up.

RESULTS

In total, 109 eyes of 84 children were included; 40 unilateral and 44 bilateral cataracts. For all eyes, median age at surgery was 2.5 years (range 2 weeks to 14.1 years) and 16 children (24 eyes) were ≤6 weeks. Coexisting systemic disease was more common in children with bilateral cataract (24 patients, 54.5%) compared to unilateral cataract (6 patients, 15.0%, p < 0.0001). Ocular comorbidity was more common in unilateral cataracts; n = 14 eyes (35.0%) compared to bilateral cataracts; n = 10 eyes (14.5%; p = 0.017). Median follow-up was 2.8 years (range 7 months to 5.8 years). During the follow-up period, 15 (13.8%) eyes developed glaucoma and five (4.6%) eyes required treatment for visual axis opacification (VAO). Corrected distance visual acuity (CDVA) for bilateral cataracts at last follow-up was 0.42 ± 0.45 (logMAR; mean±SD) with 35 (55.6%) eyes attaining a CDVA of ≥0.5 (dec). For unilateral cataracts mean CDVA was significantly poorer; 0.67 ± 0.51 (p = 0.010) with 15 (37.5%) eyes attaining a CDVA of ≥0.5.

CONCLUSION

For children having cataract surgery with primary implantation of BIL-IOL, VAO is rare and visual outcome overall good. Unilateral cataracts are associated with a higher proportion of ocular comorbidity and poorer visual outcome.

Modified bean-shaped ring segments for suture fixation of the bag-in-the-lens intraocular implant

We describe a surgical technique for secondary stabilization of a bag-in-the-lens intraocular lens (BIL IOL) using 2 modified bean-shaped ring segments in cases of zonular dehiscence associated with pseudophakodonesis. The first modified bean segment is anchored in the sulcus with a suture to the sclera in the area of maximum zonular dehiscence, and the second segment is implanted in the opposite sulcus area. Both segments are placed in the BIL IOL interhaptic groove. The segments stabilize and center the BIL IOL by creating an artificial zonule that provides the necessary extra support for the IOL.

HEADS-UP SURGERY FOR VITREORETINAL PROCEDURES: An Experimental and Clinical Study

PURPOSE

To investigate the feasibility of performing vitrectomies while viewing a three-dimensional image on a large display in a heads-up position.

METHODS

Twenty volunteers were compared performing meticulous tasks using the heads-up and the traditional method. Some optical parameters, resolution and depth of field, were measured, and the possibilities of digital image processing were investigated. In addition, routine use of the heads-up method for >400 vitrectomies over 8 months was retrospectively analyzed.

RESULTS

Of note, 91.7% of the volunteers preferred the ergonomics of the heads-up technique. The two methods were judged to be similar regarding speed and ease of microscopic manipulations and sharpness of image. Significantly fewer mistakes were made with the heads-up method. The measured resolution of the eyepieces was approximately twice that of the three-dimensional display, whereas depth of the field was about equal. Electronic amplification of the camera's signal resulted in increased image brightness, allowing use of reduced endoillumination levels. In clinical routine, better ergonomics, digital image processing, and use of a large display are found to be major advantages.

CONCLUSION

The heads-up method is well suited for vitreoretinal surgery. With further technical improvements, the procedure should soon find widespread use.

A Meta-analysis on the clinical efficacy and safety of optic capture in pediatric cataract surgery

AIM

To evaluate the clinical efficacy and safety of optic capture in pediatric cataract surgery.

METHODS

Searches of peer-reviewed literature were conducted in PubMed, Embase and the Cochrane Library. The search terms were "optic capture" and "cataract". The retrieval period ended in December 2014. Relevant randomized controlled trials (RCTs), case-control studies and cohort studies were included. Meta-analyses were performed. Pooled weighted mean differences and risk ratios with 95% confidence intervals were estimated.

RESULTS

Ten studies involving 282 eyes were included, 5 of which were RCTs involving 194 eyes. The application of optic capture significantly reduced both opacification of the visual axis (RR: 0.12; 95% CI: 0.02 to 0.85; P=0.03) and occurrence of geometric decentration (RR: 0.09; 95% CI: 0.02 to 0.46; P=0.004). But it did not significantly affect best corrected visual acuity (BCVA) (WMD: -0.01; 95%CI: -0.07 to 0.05; P=0.75) and influence the occurrence of posterior synechia (RR: 1.53; 95% CI: 0.84 to 2.77; P=0.17). Deposits in the anterior intraocular lens were significantly increased in the optic capture group early after surgery (RR: 1.40; 95% CI: 1.05 to 1.86; P=0.02) and at the last follow-up (RR: 2.30; 95% CI: 1.08 to 4.92; P=0.03). The quality of the evidence was assessed as high.

CONCLUSION

The application of optic capture significantly reduces opacification of visual axis and occurrence of geometric decentration but do not significantly improve BCVA with notable safety.

An Optical Section-Assisted In Vivo Rabbit Model for Capsular Bend and Posterior Capsule Opacification Investigation

Purpose

To establish an optical section-assisted in vivo rabbit model for capsular bend and posterior capsule opacification (PCO) investigation.

Methods

A total of 10 rabbits underwent phacoemulsification surgery and intraocular lens (IOL) implantation. On the basis of the relationship between the anterior capsule and IOL, the rabbits were divided into complete overlap and incomplete overlap groups, in which six and four rabbits were included, respectively. The capsular bend optical sections were assessed using ultra-long scan depth optical coherence tomography (UL-OCT), and posterior capsule opacification was evaluated with slit lamp on postoperative day 3, 7, 14, and 28. In addition, histopathological section was used to verify the accuracy of capsular bend type captured by OCT in three rabbits.

Results

Based on the special animal model, six capsular bend types were observed, namely, anterior (A), middle (M), posterior (P), detachment (D), funnel (Fun) and furcate adhesion (Fur). On day 3, capsular bend began to form. On 14 days, the capsular bends were comprised of A, M and D types, which were almost maintained until day 28. Histopathological section findings were consistent with optical sectioning results. In the incomplete and complete groups, the earliest PCO within the optical zone were on day 7 and 28, respectively. The incomplete group exhibited higher incidence and faster PCO on day 7 (p = 0.038) and 14 (p = 0.002).

Conclusions

This animal model not only mimics capsular bend evolution and PCO processes but also produces OCT optical section images equivalent to and more repeatable than histopathology, thereby providing a promising method for the further investigations of PCO.

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.

Femtosecond laser-assisted cataract surgery--current status and future directions

Femtosecond laser-assisted cataract surgery (FLACS) putatively offers several advantages over conventional phacoemulsification. We review the current status of FLACS and discuss the evolution of femtosecond lasers in cataract surgery and the currently available femtosecond laser platforms. We summarize the outcomes of FLACS for corneal wound creation, limbal relaxing incisions, capsulotomy, and lens fragmentation. We discuss surgical planning, preoperative considerations, clinical experiences including the learning curve and postoperative outcomes with FLACS, and also the cost effectiveness of FLACS. We present the intraoperative complications and management of challenging cases where FLACS offers an advantage and also speculate on the future directions with FLACS. Further advancements in laser technology to refine its efficacy, advancement in intraocular lens design to harness the potential benefits of FLACS, and a reduction in cost are needed to establish a clear superiority over conventional phacoemulsification.

Cataract

Cataract is the leading cause of reversible blindness and visual impairment globally. Blindness from cataract is more common in populations with low socioeconomic status and in developing countries than in developed countries. The only treatment for cataract is surgery. Phacoemulsification is the gold standard for cataract surgery in the developed world, whereas manual small incision cataract surgery is used frequently in developing countries. In general, the outcomes of surgery are good and complications, such as endophthalmitis, often can be prevented or have good ouctomes if properly managed. Femtosecond laser-assisted cataract surgery, an advanced technology, can automate several steps; initial data show no superiority of this approach over current techniques, but the results of many large clinical trials are pending. The greatest challenge remains the growing 'backlog' of patients with cataract blindness in the developing world because of lack of access to affordable surgery. Efforts aimed at training additional cataract surgeons in these countries do not keep pace with the increasing demand associated with ageing population demographics. In the absence of strategie that can prevent or delay cataract formation, it is important to focus efforts and resources on developing models for efficient delivery of cataract surgical services in underserved regions. For an illustrated summary of this Primer, visit: http://go.nature.com/eQkKll.

Technology and Intraocular Lenses to Enhance Cataract Surgery Outcomes-Annual Review (January 2013 to January 2014)

PURPOSE

This article is aimed to provide a clinical update on recent developments in cataract surgical techniques, with specific focus on femtosecond laser technology. The article also focuses on recent improvements in the technology used in implanting intraocular lenses (IOLs).

DESIGN

Literature review.

METHODS

The authors conducted a review of literature available in the last 12 months in the English language using PubMed. The period used to conduct the literature search was from January 1, 2013, to December 31, 2013. The following search terms were used during the PubMed search: phacoemulsification, femtosecond laser, toric IOLs, multifocal IOLs, multifocal toric IOLs, manual small-incision cataract surgery, outcomes, surgically induced astigmatism, rotational stability, trifocal IOLs, laser cataract surgery, safety, and efficacy.

RESULTS

This review incorporates selected original articles that provide fresh insights and updates on the fields of toric and multifocal IOLs, femtosecond laser cataract surgery, and manual small-incision cataract surgery. Particular attention has been paid to observational, randomized controlled clinical trials, experimental trials, and analyses of larger cohorts with prospective and retrospective study designs. Letters to the editor, unpublished works, and abstracts do not fall under the purview of this review.

CONCLUSIONS

This review is not designed to be all-inclusive. It highlights and provides insights on literature that is most useful and applicable to practicing ophthalmologists.

[Femtosecond laser in cataract surgery. A critical appraisal]

BACKGROUND

The use of femtosecond lasers (FSL) is increasingly spreading in cataract surgery. Potential advantages over standard manual cataract surgery are the superior precision of corneal incisions and capsular openings as well as the reduction of ultrasound energy for lens nucleus work-up. Exact positioning and dimensioning of the anterior capsular opening should help reduce decentration and tilt of the intraocular lens (IOL) optics and thus achieve better target refraction. Together with the possibility to correct low-grade corneal astigmatism by precise arcuate incision, FSL technology is expected to convert cataract surgery from a purely curative into a refractive procedure.

METHODS

Apart from own experiences this review article critically analyses the pertinent literature published so far as well as congress presentations and personal reports of other FSL surgeons. The advantages and disadvantages are scrutinized with regard to their impact on the surgical and refractive results and compared with those experienced by the authors with manual cataract surgery over several decades. Economic and healthcare political aspects are also addressed.

RESULTS

The use of FSL surgery improves the precision and reproducibility of corneal incisions and the capsular opening and reduces the amount of ultrasound energy required for lens nucleus work-up. However, the clinical benefits must be put into perspective due to the subsequent surgical manipulation of the incisions (during lens emulsification, aspiration and IOL injection), the lacking possibility to visualize the crystalline lens equator as the reference for correct capsulotomy centration and the relativity of ultrasound energy consumption on the corneal endothelial trauma. This is of particular relevance against the background of the significantly higher costs. Conversely, tears of the anterior capsule edge which, apart from interfering with correct IOL positioning, may entail serious complications presently occur more frequently with all FSL instruments. From the economic and healthcare political viewpoint, thought should be given to the possible acquisition of the cataract surgical business by the industry or investors, as cataract surgery is a high-volume standardized procedure with enormous future potential. This could fundamentally change our currently decentralized and individualized structures and subsequently the steam of patient and make surgeons largely dependent or superfluous.

The intraocular lens: challenges in the prevention and therapy of infectious endophthalmitis and posterior capsular opacification

Cataract is the leading cause of visual impairment worldwide. In the UK, some 30% of the population over 65 years of age have visually impairing cataract. Importantly, 88% of those with treatable visual impairment from cataract are not in contact with any ocular healthcare service, representing a major potential healthcare need [1]. In the USA, it has been estimated that 17.2% of the population (approximately 20.5 million) over 40 years of age have cataract in either eye and by 2020, this number is expected to rise to 30.1 million. Currently, cataract is responsible for 60% of Medicare costs associated with vision [2]. Furthermore, as the populations of industrialized countries such as the UK and the USA continue to age, the costs associated with treatment of cataract can only be expected to increase. Consequently, the development of the intraocular lens to replace the cataractous lens and the advances in intraocular lens design and implantation represent a major development in cataract treatment. However, despite such advances, cataract surgery is not without complications, such as postoperative infectious endophthalmitis, a rare but potentially devastating condition, and posterior capsular opacification, a less serious but much more common problem. This review will examine the epidemiology of cataracts, the polymeric construction of intraocular lenses implanted during cataract surgery and the complications of postoperative infectious endophthalmitis and posterior capsular opacification with regard to therapeutic interventions and prophylactic strategies. Advances in biomaterial design and function will be discussed as novel approaches to prevent such postoperative complications.

Assessment of the bag-in-the-lens implantation technique in diabetic patients

Cataract is a common condition observed in patients with diabetes mellitus frequently requiring surgical intervention. The bag-in-the-lens (BIL) intraocular implant is an alternative approach to standard lens-in-the-bag cataract surgery. The lens is supported by anterior and posterior capsulorhexes, which confers a number of advantages in terms of lens centration, rotational stability and prevention of posterior capsular opacity. The purpose of this report is to describe the results of BIL cataract surgery in a retrospective cohort of diabetic patients. Fifty-four cases of BIL surgery are included with a follow-up period of 1 year. Visual acuity outcomes were comparable to previously published standard lens-in-the-bag procedures. There were no reports of posterior capsular opacification and the grade of diabetic retinopathy remained stable. Three cases of clinically significant macular edema were detected over the follow-up period. We conclude that the BIL implantation technique is an advantageous approach to treating cataract in the diabetic population.

Surgically induced astigmatism after intraocular lens implantation using the bag-in-the-lens technique

PURPOSE

To determine surgically induced astigmatism (SIA) after monofocal spherical intraocular lens (IOL) implantation using the bag-in-the-lens (BIL) technique.

SETTING

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

DESIGN

Case series.

METHODS

Adult patients had routine phacoemulsification followed by BIL IOL implantation, which requires a double capsulorhexis for IOL fixation. The 2.8 mm limbo-corneal self-sealing incision was temporally located. Preoperative and 3-month postoperative keratometries were measured by Scheimpflug imaging (Pentacam). The patients were divided into 2 groups based on corneal astigmatism. Group A0 consisted of eyes with physiological corneal astigmatism less than 1.00 diopter (D). Group A1 consisted of eyes with corneal astigmatism of 1.00 D or higher. Vector analysis of the corneal power was used to determine the SIA.

RESULTS

The study comprised 100 eyes (58 patients). There was no difference in SIA between Group A0 and Group A1. The mean preoperative and postoperative keratometries were highly correlated in both groups (A0: r(2) = 0.95; A1: r(2) = 0.83). The correlation between preoperative and postoperative vectorial astigmatism was low in Group A0 (J0: r(2) = 0.24; J45: r(2) = 0.10). The mean postoperative SIA was 0.06 D @ -24 degrees in Group A0 and 0.09 D @ 6 degrees in Group A1, with an uncertainty of ± 1.00 D.

CONCLUSIONS

After BIL IOL implantation, the SIA was not statistically significant. Based on these findings, the technique can be considered an option for spherocylindrical correction of corneal astigmatism of 1.00 D or more.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

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.