Ring-shaped caliper for better anterior capsulorhexis sizing and centration

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.

Real-time intraoperative OCT imaging of the vitreolenticular interface during pediatric cataract surgery

PURPOSE

To report on the use of intraoperative optical coherence tomography (OCT) imaging of the vitreolenticular interface (VLI) during pediatric cataract surgery and to determine the incidence of VLI dysgenesis and surgical difficulties.

SETTING

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

DESIGN

Retrospective cohort study.

METHODS

This study included 51 pediatric patients who underwent cataract surgery between April 2016 and December 2018. Video recordings and OCT images of the VLI were analyzed and compared. VLI dysgenesis was considered present when intraoperative OCT images demonstrated partial or total adhesions between the posterior lens capsule and the anterior hyaloid membrane. Video recordings were analyzed to describe surgical difficulties, more specifically: inability to create a calibrated primary posterior continuous curvilinear capsulorhexis (PPCCC), occurrence of vitreous prolapse, need for anterior vitrectomy, and complicated IOL implantation.

RESULTS

Of the 51 patients included, VLI dysgenesis was demonstrated in 27 patients (52.9%). The incidence of VLI dysgenesis was greater in children with unilateral cataract (72.4%), and children with a posterior capsule plaque (90%). PPCCC was challenging in 20 patients. A defect of the anterior hyaloid membrane was found in 16 patients. Anterior vitrectomy or cutting vitreous strands with scissors was necessary in 10 patients.

CONCLUSIONS

Intraoperative OCT images were an excellent tool to evaluate the VLI and to demonstrate the presence of VLI dysgenesis during pediatric cataract surgery. Performing a calibrated PPCCC was more challenging in the presence of VLI dysgenesis. This can subsequently expose a defect in the anterior hyaloid membrane, which may result in vitreous prolapse.

Perfect anterior capsulorhexis using a dented cystitome

We describe a novel intraoperative technique of measuring and creating an adequate size continuous curvilinear capsulorhexis (CCC) in phacoemulsification, using a dented cystitome as the ruler. A pair of curved tenotomy scissors is used to create a dent on the cystitome at a distance of 2.5 mm length (i.e., half of the desired approximate capsulorhexis diameter). The dented cystitome is used as a guide for making a CCC of approximately 5 mm diameter, which is considered adequate for phacoemulsification. This method of measuring the capsulorhexis helps in achieving a well centered and stable intraocular lens with a 360° overlap of the optic edge by the anterior capsular rim in the postoperative period. Using a dented cystitome for capsulorhexis mandates reliable and consistent results in the hands of the novice as well as the experienced surgeons.

Limbus-centered marking technique-assisted continuous circular capsulorhexis

To introduce a limbus-centered continuous circular capsulorhexis (CCC) marking technique.Compared with traditional capsulotomy diameter mark technique, a self-designed limbus-centered capsulotomy mark (LCM) was used to perform the routine cataract surgery in this observational study. Ten eyes were included in each group. The area outer/inner 5.5-mm CCC ring, the furthest/nearest distance from the capsule margin to the intraocular lens (IOL) margin, the CCC total coverage IOL area were measured and compared between this 2 groups.No significant differences were found for all the comparison parameters between the 2 groups (all P > .05). However, the capsule total coverage area, area inner 5.5-mm ring was lower in the LCM group, which demonstrated advantage of LCM.The limbus-centered capsulotomy diameter mark, as an inexpensive and convenient method, helps to perform limbus-centered capsulorhexis with not only a 360° overlapping capsular edge but also well-centered IOL optics.

Modified bandage-contact-lens used as a guide-marker for performing continuous-curvilinear-capsulorhexis by a first-year-post-graduate-ophthalmology-resident

Purpose

To define the use of modified bandage-contact-lens as a guide-marker for performing continuous-curvilinear-capsulorhexis by a first-year-post-graduate-ophthalmology-resident.

Observation

Phacoemulsification has now become the standard cataract surgery in which anterior capsulorhexis is the first and most crucial step. A perfect capsulorhexis is difficult to learn and even more difficult to master with a steep learning curve when performed free-hand especially by a first-year post-graduate ophthalmology-resident. There is paucity of simple, single-use, easily portable, cost-effective and affordable devices designed especially for performing CCCs in a safe and reproducible way.

In our technique, the bandage contact lens (BCL) is trephined using a 6mm corneal trephine. After topical or peribulbar block (as the case may be), the 6mm-guide-marker (trephined BCL) is placed on the cornea. The CCC is then completed using the edge of the contact-lens as a guide for CCC.

Conclusion

AND IMPORTANCE: CCC with contact-lens-guide-marker is expected to yield better results in carrying out the procedure more accurately being closer to the target in terms of size, circularity and centration as compared to contact-lens-unassisted conventional CCC. This would eventually facilitate better surgical outcomes and we recommend this to be applied as the standard protocol for first-year post-graduate ophthalmology-resident performing the surgery.

Effect of manual capsulorhexis size and position on intraocular lens tilt, centration, and axial position

PURPOSE

To evaluate the influence of a manual capsulorhexis size, shape, and position on postoperative axial position, tilt, and centration of intraocular lenses (IOLs).

SETTING

Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective cases series.

METHODS

Patients had cataract surgery and had follow-ups 1 hour and 3 months after surgery. Postoperatively, patients were divided into 3 groups according to the capsulorhexis shape and size as follows: control, symmetrical capsulorhexis between 4.5 mm and 5.5 mm; small group, capsulorhexis smaller than 4.5 mm; and eccentric, all other capsulorhexes. At both follow-ups, a retroillumination image, partial coherence interferometry measurements, and Purkinje meter measurements were performed.

RESULTS

This study comprised 255 eyes. The mean postoperative absolute anterior chamber depth shift in the control, eccentric capsulorhexis, and small capsulorhexis groups was 0.31 mm ± 0.27 (SD), 0.36 ± 0.24 mm, and 0.26 ± 0.24 mm, respectively (P = .419). The mean tilt in the control, eccentric capsulorhexis, and small capsulorhexis groups was 4.08 ± 2.13 degrees, 3.66 ± 2.04 degrees, and 2.82 ± 1.67 degrees, respectively (P = .370), and the mean decentration was 0.38 ± 0.23 mm, 0.40 ± 0.21 mm, and 0.17 ± 0.08 mm, respectively (P = .027).

CONCLUSIONS

Capsulorhexis size and shape had little effect on the capsular bag performance of modern IOLs. Only eyes with a severely malformed capsulorhexis had a slightly decentered IOL.

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.

Techniques of anterior capsulotomy in cataract surgery

Optimal outcomes of a cataract surgery largely depend on the successful performance of an anterior capsulotomy. It is one of the most important steps of modern cataract surgery which reduces the risk of capsular tears and ensures postoperative stable intraocular lens (IOL). Anterior capsulotomy is considered ideal if it is round, continuous, well-centered, and overlaps the implanted IOL around its circumference. If any of these features is missing, it can be a cause of impedance for desired surgical and visual outcomes. Manual can opener and manual capsulorhexis are the routine standard techniques employed for manual extracapsular cataract extraction and phacoemulsification, respectively. Recent increasing use of femtosecond laser cataract surgery has allowed cataract surgeons to obviate inherent inaccuracies of manual anterior capsulotomy techniques. There is an ongoing quest to find an ideal, risk free, and surgeon-friendly technique of anterior capsulotomy that can be employed for surgery in all types of cataracts.

Advances in capsulorhexis

PURPOSE OF REVIEW

Continuous curvilinear manual capsulorhexis is currently the standard of cataract surgery. In the past several years, new technologies have been developed to improve the consistency and safety of capsulorhexis creation. This article reviews the most recent technologies in capsulotomy formation and their advantages and disadvantages.

RECENT FINDINGS

Guidance devices, femtosecond laser capsulotomy and precision pulse capsulotomy improve the centration, circularity and precision of anterior capsulorhexis and capsulotomy. These developments show particular promise for complex cataract surgeries, though clinical data on the refractive outcomes and complication rates of these technologies are currently limited and warrant additional investigation.

SUMMARY

New technological advances in capsulorhexis help surgeons achieve a more ideal capsulotomy geometry. Whether this translates into more predictable refractive outcomes and safer surgeries remains an area of future study.

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.

Clinical results of the open ring PMMA guider assisted capsulorrhexis in cataract surgery

Background

To compare the results of continuous curvilinear capsulorrhexis(CCC) after application of an open ring-shaped guider compared with a free-hand procedure in eyes with cataracts.

Methods

This study comprised patients undergoing cataract surgery in Seoul St.Mary’s Hospital, The Catholic University of Korea. Eyes were grouped depending on the capsulotomy method; CCC was performed by free-hand procedure on 94 eyes (free-hand group), and it was performed under the guidance after introduction of an open ring-shaped guider on consecutive 89 eyes (guided group). Horizontal and vertical diameter, area and circularity of capsulotomy were measured postoperatively at one day, two months and six months. Differences in parameters and the percentage of ideal capsulorrhexis were analyzed between the two groups.

Results

On the first postoperative day, the vertical diameter in the guided group (5.24 ± 0.16 mm) was significantly longer than that of the free-hand group (5.01 ± 0.65 mm, P = 0.019). The area of capsulotomy was larger in the guided group (21.55 ± 0.87 mm²) than that of the free-hand group (20.34 ± 2.96 mm², P < 0.001). Circularity in the guided group (0.84 ± 0.03), was significantly greater than that of the free-hand group (0.69 ± 0.17, P = 0.036). Ideal capsulorrhexis was obtained in 60 eyes (67%) in the free-hand group and 81 eyes (86%) in the guided group.

Conclusions

After introduction of an open ring-shaped guider, CCC became larger and more circular with less anterior capsular contracture. The rate of acquiring ideal capsulorrhexis was higher in the guided group than it was in the free-hand group for six months after surgery.

Clinical performance in continuous curvilinear capsulorhexis creation supported by a digital image guidance system

PURPOSE

To test whether a default capsulorhexis diameter could be attained more precisely when manual continuous curvilinear capsulorhexis (CCC) creation was supported by a biomorphological detection unit.

SETTING

Ruhr University Eye Hospital, Bochum, Germany.

DESIGN

Prospective interventional study.

METHODS

Patients were assigned to either of 2 groups. In the first group, a digital image system was applied to guide capsulorhexis. In the second group, the CCC was created without digital support. Postoperatively, horizontal and vertical capsulorhexis dimensions were measured. A set target diameter of 5.5 mm was compared with intraoperative and postoperative CCC diameters, which were also compared with each other. The number of eyes with postoperative CCC diameters outside the reference range of 4.5 to 6.0 mm was assessed.

RESULTS

In 427 eyes, the capsulorhexis size was assessed. Digital image guidance was applied in 203 eyes. Intraoperatively, horizontal capsulorhexis diameters created with surgical guidance differed significantly less from the target diameter than in the control group (P < .001). Eyes treated with surgical guidance differed significantly less from the target diameter (P < .001). Analogously, vertical capsulorhexis diameters differed significantly less from the target when digital support was used, intraoperatively and postoperatively (P < .001). In 418 eyes, postoperative diameters were significantly larger than intraoperatively in both directions (P < .001). Vertical CCC diameters were more frequently within the reference range intraoperatively and postoperatively with surgical guidance (P = .009). Horizontally, eye tracking showed accordance with the target diameter in 87.6% (controls: 91.7%).

CONCLUSION

Intraoperative image guidance facilitated CCC creation significantly during standard phacoemulsification.

Novel device for creating continuous curvilinear capsulorhexis

Purpose

The purpose of this paper is to develop a novel capsulorhexis system.

Setting

Mechatronics Laboratory, University of Erciyes and Kayseri Maya Eye Hospital.

Design

A 3D model was created and simulations were conducted to develop a new device which was designed, fabricated and tested for continuous curvilinear capsulorhexis (CCC). The name of this system is the electro-mechanical capsulorhexis system (EMCS).

Methods

The 3D model was created by using a commercial design software and a 3D printer was used to fabricate the EMCS Finite element analysis and geometrical relation tests of the EMCS for different sized lenses were performed.

Results

The results show that the EMCS is a perfect solution for capsulorhexis surgeries, without mechanical or geometrical problems.

Conclusions

The EMCS can open the anterior lens capsule more easily and effectively than manual CCC applications and needs less experience.

Real-Time Intraoperative Optical Coherence Tomography Imaging Confirms Older Concepts About the Berger Space

BACKGROUND

The presence of a space between the posterior capsule and the anterior vitreous was first reported in 1887, but difficulties inherent in examining this structure made it impossible to visualize this area in vivo until now. Estimation of the size of this space was considered to be impossible.

MATERIALS AND METHODS

We utilized an optical coherence tomography (OCT) system attached to the Zeiss Opmi Lumera 700/Rescan microscope (Zeiss Ltd., Jena, Germany) to provide real-time images of the Berger space, the anterior hyaloid and the ligament of Wieger.

RESULTS

Imaging in 3 patients provided beautiful, real-time OCT images of the Berger space and of the ligament of Wieger. In one highly myopic eye, there was even evidence of anterior vitreous detachment.

CONCLUSION

Previously unseen transparent structures of the eye can now be imaged intraoperatively using real-time OCT. This new technology seems very promising in achieving a better understanding of the anterior vitreous interface, more specifically of the anterior hyaloid and its posterior capsule attachment by the ligament of Wieger. Changes in the anterior hyaloid and its capsular attachment may contribute to a better understanding of the posterior segment complications after cataract surgery.

Capsular Outcomes Differ with Capsulorhexis Sizes after Pediatric Cataract Surgery: A Randomized Controlled Trial

Capsular outcomes of anterior/posterior capsulorhexis opening (ACO/PCO) are essential for performing a secondary in-the-bag intraocular lens implantation. To compare the capsular outcomes with different primary capsulorhexis sizes, Thirty-eight eligible patients (45 eyes) were randomly assigned to three groups by anterior capsulorhexis diameter (Group A: 3.0-3.9, Group B: 4.0-5.0, and Group C: 5.1-6.0 mm). The areas of ACO/PCO and posterior capsule opening opacity (PCOO) as primary outcomes, while, the incidence of visual axis opacity (VAO) as secondary outcome were measured at follow-up visits. Among the thirty eyes included in the final analysis, the mean area of the ACO decreased significantly, whereas the PCO enlarged with time. Group A had the highest anterior capsule constriction and percentage reduction, which increased with time. There were significant differences in the percentage reductions at 6 months and 1 year compared to 1 month in Group A and B. Group C had the highest posterior capsule enlargement. The percentage of PCOO to PCO area and the incidence of VAO was highest in Group A and lowest in Group C. Thus, Capsulorhexis diameter of 4.0-5.0 mm may yield better capsular outcomes, considering moderate contraction of ACO, moderate enlargement of PCO, and lower percentage of PCOO and VAO.

New device for creating a continuous curvilinear capsulorhexis

PURPOSE

To describe the evolution of a new device to facilitate continuous curvilinear capsulorhexis (CCC) creation.

SETTING

Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado, USA.

DESIGN

Experimental study.

METHODS

Bench-side ex vivo testing of unique prototypes for guidance and assistance of CCC in bovine and human eyes was performed. Five designs were sequentially tested as follows: a flexible circular blade of nickel-titanium alloy (nitinol), a flexible nitinol guide wire, a flexible elastomeric suction device, a combination approach of a nitinol guide wire and flexible silicone ring, and a freestanding micropatterned silicone ring.

RESULTS

The first 3 designs were not amenable to insertion through a sub-2.4 mm corneal incision and failed to maintain adequate downward force to cut the capsule and/or prevent radial tears. The fourth design was successfully inserted through a 2.4 mm incision and maintained adequate downward pressure and contact to guide a manual CCC without radial tears. The final design was insertable through a 2.4 mm incision and exhibited self-adhesive characteristics after placement on the anterior capsule of an ophthalmic viscosurgical device-filled anterior chamber.

CONCLUSIONS

Given the steep learning curve of manual capsulorhexis and the high cost of capsulotomy-assistive devices, such as the femtosecond laser, an alternative approach for creating a CCC is desirable. Performance of a highly precise manual CCC through a small incision using a medical-grade silicone device with an adhesive micropatterned design is a viable and cost-effective option for use in cataract surgery across a wide range of user experience.

FINANCIAL DISCLOSURE

All authors are named as the inventors in a patent filed by the University of Colorado covering the details in this report.

Open ring-shaped guider for circular continuous curvilinear capsulorhexis during cataract surgery

We describe a new type of open-loop caliper for capsulorhexis during cataract surgery. This tool, which is made of poly(methyl methacrylate), can optimize capsulorhexis shape, size, and centration. One of the strengths of this tool, which derives from the open-loop design, is its ease of insertion and removal via a small incision site compared with other calipers used for capsulorhexis. The caliper is positioned on the anterior capsule after the anterior chamber is filled with an ophthalmic viscosurgical device and removed after creation of the continuous curvilinear capsulorhexis. The caliper enables the surgeon to achieve an ideal capsulorhexis and promotes long-lasting circularity.

FINANCIAL DISCLOSURE

Dr. Joo is one of the inventors on the patent filed by the Catholic University of Korea covering details in this manuscript. Dr. Lee has no financial or proprietary interest in any material or method mentioned.

Defining the ideal femtosecond laser capsulotomy

Purpose

We define the ideal anterior capsulotomy through consideration of capsular histology and biomechanics. Desirable qualities include preventing posterior capsular opacification (PCO), maintaining effective lens position (ELP) and optimising capsular strength.

Methods

Laboratory study of capsular biomechanics and literature review of histology and published clinical results.

Results

Parameters of ideal capsulotomy construction include complete overlap of the intraocular lens to prevent PCO, centration on the clinical approximation of the optical axis of the lens to ensure concentricity with the capsule equator, and maximal capsular thickness at the capsulotomy edge to maintain integrity.

Conclusions

Constructing the capsulotomy centred on the clinical approximation of the optical axis of the lens with diameter 5.25 mm optimises prevention of PCO, consistency of ELP and capsular strength.

Feasibility of multifocal intra-ocular lens exchange and conversion to the bag-in-the-lens implantation

PURPOSE

Our purpose was to evaluate the surgical outcome after intra-ocular lens exchange in patients who presented impairing visual complaints after primary multifocal intra-ocular lens (MIOL) implantation. In particular, the study was undertaken to look at the number of eyes that could be equipped with the bag-in-the-lens (BIL) IOL after MIOL exchange.

METHODS

This series consisted of 30 eyes of 21 consecutive patients scheduled for MIOL exchange. In 15 out of the 30 eyes, IOL misalignment was measured on slit lamp anterior segment photo's after defining the mathematical centres of the IOL optic, pupil and limbus.

RESULTS

Diffractive MIOL was more frequently explanted (25; 83%) when compared with refractive MIOL (4; 13%) and progressive optic IOL (1; 4%). In 21 out of the 30 eyes (70%) a bag-in-the-lens could be implanted. In 7 out of the 30 eyes (23%), the capsule was not considered sufficiently stable to accommodate an IOL. An iris-fixated IOL or a sulcus-fixated IOL was then implanted. In 2 out of the 30 eyes (6%) the remaining capsular bag could accommodate a traditional lens-in-the-bag only. Eyes that underwent Nd:YAG laser capsulotomy prior to the MIOL exchange needed anterior vitrectomy peroperatively (11 eyes; 37%). Visual acuity improved postoperatively in 13 out of the 30 eyes and remained stable in 17 out of the 30 eyes.

CONCLUSIONS

Since the BIL technique requires a very well-preserved capsular bag for the purpose of the IOL implantation, the success rate of BIL implantation after MIOL is a good indicator to evaluate the degree of difficulty to exchange MIOL.

Usefulness of a semicircular capsulotomy marker

PURPOSE

To evaluate usefulness of a new semicircular capsulotomy marker in continuous curvilinear capsulorrhexis (CCC).

METHODS

In 20 eyes of 20 patients who underwent cataract surgery, a newly designed semicircular marker with an internal diameter of 5.5 mm was used to place a circular mark directly on the lens capsule. The mark was then used as a guide to complete CCC of the set diameter. The resultant size of CCC in each case was confirmed by analysis of the video image.

RESULTS

The average CCC diameter size was 5.2 ± 0.3 mm. In all cases, the edge of the intraocular lens was completely covered by the anterior capsule.

CONCLUSION

The semicircular capsulotomy diameter marker was useful in making a complete CCC of a set diameter.

Clinical outcomes of cataract surgery after bag-in-the-lens intraocular lens implantation following ISO standard 11979-7:2006

PURPOSE

To assess the clinical outcomes of bag-in-the-lens intraocular lens (BIL IOL) implantation following the International Organization for Standardization (ISO) 11979-7:2006 in pediatric eyes and eyes with ocular comorbidities.

SETTING

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

DESIGN

Cohort study.

METHODS

This cohort included the first series of patients having IOL implantation using the bag-in-the-lens technique. Surgeries were performed between December 1999 and September 2006. In addition to IOL implantation, the technique comprised creation of a primary posterior continuous curvilinear capsulorhexis (PCCC) equal in size to the anterior capsulorhexis.

RESULTS

The study enrolled 807 eyes of 547 patients; 326 of the eyes (40.40%) had ocular comorbidity. In the 481 eyes without ocular comorbidity, the mean decimal corrected distance visual acuity was 0.52 ± 0.24 (SD) (0.276 ± 0.206 logMAR) preoperatively and 0.94 ± 0.18 (-0.012 ± 0.053 logMAR) postoperatively. The mean postoperative achieved spherical equivalent was 0.48 ± 0.83 diopter (D) and the mean targeted refraction, -0.24 ± 0.71 D. The A-constant was modified from 118.4 to 118.04. Posterior capsule opacification (PCO) did not occur in any adult eye during the follow-up. Retinal detachment after IOL implantation occurred in 10 eyes (1.24%). In 19 eyes, the iris was captured by the IOL haptics postoperatively. Hypopyon occurred in 3 patients and toxic anterior segment syndrome in 1 patient.

CONCLUSION

The BIL IOL met the ISO criteria; that is, primary PCCC was safe in healthy eyes and in eyes with ocular comorbidities and no eye developed PCO over a mean follow-up of 26.1 ± 21.3 months.

Delineating the extent of anterior capsulorhexis with gentian violet using capsulorhexis marker: a preliminary study of efficacy and toxicity in an animal model

Background:

The purpose of this study was to evaluate the efficacy and safety of a new instrument to optimize the size, shape, and centration of anterior capsulorhexis.

Methods:

The study was divided into two parts. The first part was done in 10 goats’ eyes. A specially designed capsulorhexis marker was used. The lower edge of the instrument was stained by gentian violet and then applied to the anterior capsule to produce a circular mark of 5.5 mm. In five eyes, the gentian violet was applied to the marker using a corneal marking pen; in the remaining five eyes, the gentian violet was applied using a corneal marking pad. In the second part, the toxicity of gentian violet was tested as follows: ten albino rabbits received a gentian violet injection into the anterior chamber in one eye (experimental group) and an equal volume of balanced salt solution in the fellow eye (control group). Five rabbits were sacrificed one day after surgery and the remaining five rabbits after one week.

Results:

In the first part, there was no difficulty in the introduction or removal of the instrument from all eyes. In the first two eyes, the circular mark was diffuse due to sliding of the marker on the surface of the anterior capsule. In the remaining eight eyes, there was a well-centered, rounded mark which was adequately stained. In the second part, there was no histopathological evidence of corneal toxicity in either group. There was loss of ganglion cells from the neurosensory retina one day after surgery in one eye from the experimental group. At one week, there was no evidence of retinal toxicity in any of the rabbits.

Conclusion:

This capsulorhexis marker can guide the surgeon to a better centration and proper sizing of anterior capsulorhexis using gentian violet staining. More refinement of the instrument is needed to be able to use it in human eyes.

Spherotoric bag-in-the-lens intraocular lens: power calculation and predictive misalignment nomogram

PURPOSE

To propose a method of calculating the power of the 1-sided posterior chamber toric bag-in-the-lens (BIL) intraocular lens (IOL) and propose a misalignment nomogram to calculate the postoperative rotational misalignment or predict the effect of preoperative existing irregular corneal astigmatism.

SETTING

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

DESIGN

Cohort study.

METHODS

The new IOL calculation formula uses the steepest corneal meridian and flattest corneal meridian separately (regular spherical IOL formula) followed by a customized A-constant approach based on the changes in the IOL principal plane depending on the spherical and cylindrical powers (thickness) of the IOL. The calculation of the remaining astigmatism (power and axis) in cases of postoperative rotational misalignment resulted in a nomogram that can also be used to predict the degree of tolerance for irregular corneal astigmatism correction at the lenticular plane. The calculation is performed using a worksheet.

RESULTS

Because 10 degrees of misalignment would result in 35% refractive inaccuracy, it is the maximum acceptable corneal astigmatic irregularity for correction at the lenticular plane.

CONCLUSIONS

Calculation of spherocylindrical power is specific to each toric IOL. Because the surgeon must fully understand the optical properties of the toric IOL that is going to be implanted, a comprehensive outline of a new calculation method specific to the toric BIL IOL is proposed. Primary rotational misalignment of the toric BIL IOL can be fine tuned postoperatively.

FINANCIAL DISCLOSURE

Drs. Gobin and Mathysen have no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

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.

[Advantages of the bag-in-the-lens intraocular lens in pediatric cataract surgery]

OBJECTIVE

Evaluate the advantages of the bag-in-the-lens intraocular lens in children undergoing cataract surgery.

PATIENTS AND METHODS

This prospective study included 54 eyes of 37 children and babies (age, 2 months to 14 years), consecutively operated on between December 1999 and January 2008 for unilateral or bilateral cataract using the "bag-in-the-lens" intraocular lens. Slit-lamp examination, intraocular pressure, visual acuity, and refraction were followed to the best possible degree over time.

RESULTS

The mean age of the 37 children at the last consultation visit was 8.3+/-4.9 years. The mean visual acuity improved from 0.2+/-0.1 to 0.8+/-0.3. On the other hand, visual acuity improvement in children presenting hyperplastic persistence of the vitreous was less favorable with a postoperative average visual acuity of 0.14+/-0.18. The mean postoperative refraction in 13 children (26 eyes) operated on for bilateral cataract was 0.5+/-1.5 D for eyes showing axial lengths with substantial variation. The refraction was stable over time in children over 2 years of age. Once the implant was positioned correctly, the remaining epithelial cells of the lens did not migrate toward the visual axis, which was the case in 93.8% of all eyes and in 100% of children over 1 year of age.

CONCLUSIONS

The "bag-in-the-lens" implant is particularly indicated in children in whom posterior rhexis and optic capture have been recommended since 1994. The implantation minimizes the use of anterior vitrectomy in pediatric cataract surgery, limiting it to those eyes presenting a proliferative hyperplastic vitreous.

Intraocular lens centration and visual outcomes after bag-in-the-lens implantation

PURPOSE

To examine the centration and visual outcomes after cataract surgery using the bag-in-the-lens (BIL) implantation technique.

SETTING

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

METHODS

This study comprised 180 eyes of 125 patients who had cataract surgery with implantation of the BIL intraocular lens (IOL) between March 2002 and September 2005. Postoperative data at 5 weeks, 6 months, and 1 year were evaluated. The geometric center of the IOL, measured on a red reflex slitlamp photograph, was compared with the geometric center of the pupil and the limbus.

RESULTS

The mean decentration compared with the limbus was 0.304 mm+/-0.17 (SD) at a mean angle of -24.9+/-113.3 degrees. Compared with the dilated pupil, the mean deviation was 0.256+/-0.15 mm at a mean angle of -5.2+/-119.0 degrees. The amount of decentration was stable during the postoperative follow-up period. There was no correlation between the amount of decentration and the visual outcomes (pupil: r=-0.07, P=.494; limbus: r=0.11, P=.304).

CONCLUSIONS

Surgeon-controlled BIL centration was predictable 5 weeks and unchanged 6 months and 1 year postoperatively. It can therefore be concluded that capsular bag healing has no influence on BIL IOL centration over time.

Bag-in-the-lens intraocular lens implantation in the pediatric eye

PURPOSE

To study the efficacy, safety, and feasibility of implantation of a bag-in-the-lens intraocular lens (IOL) in children and babies.

SETTING

Departments of Ophthalmology, University Hospital, Antwerp, Belgium, and the University Hospital, Ljubljana, Slovenia, and a private ophthalmology practice, Oudenaarde, Belgium.

METHODS

Thirty-four eyes of 22 children had implantation of a bag-in-the-lens IOL. The ages ranged from 2 months to 14 years. Congenital cataract was present in 26 eyes, and persistent fetal vasculature (PFV) was concomitantly present in 4 eyes. Fifteen patients had bilateral cataract, and 6 had unilateral cataract.

RESULTS

In 3 eyes, the IOL could not be properly implanted. In these cases, secondary intervention was necessary because of early posterior capsule opacification. The mean postoperative follow-up was 17.45 months +/- 17.12 (SD) (range 4 to 68 months). None of the children except those presenting with PFV had anterior vitrectomy during surgery. The optical axis remained clear during the follow-up in all patients who had successful IOL implantation.

CONCLUSIONS

The bag-in-the-lens implantation technique in children and babies was safe and kept the visual axis clear after cataract surgery. In the near future, 4.0 or 4.5 mm IOLs will be available that may improve the success rate of IOL implantation in the small eyes of babies.