Surgical approach for management of complete anterior capsular contraction syndrome

Anterior capsular contraction syndrome is an uncommon but well-known complication associated with continuous curvilinear capsulorhexis performed during cataract surgery. It remains asymptomatic unless the constriction progresses to involve the visual axis or causes late intraocular lens-related complications. A male patient in his 50s presented with severely decreased vision in his right eye 2 years after uneventful cataract surgery. Slit-lamp biomicroscopy revealed capsular phimosis and a dense, central, fibrous plaque with total occlusion of the anterior capsulorhexis opening. Neodymium-doped yttrium aluminium garnet laser anterior capsulotomy and vitrectorhexis were attempted, but proved ineffective. Surgical excision with manual cutting of the fibrotic membrane was performed, successfully clearing the visual axis and restoring vision.

Capsule Dynamics, Implantation, and Explantation of the Smaller Incision, New-Generation Implantable Miniature Telescope: a Miyake-Apple Study

PURPOSE

The smaller incision, new-generation implantable miniature telescope is a novel implant to optimize vision in retinal patients with central vision loss. Using Miyake-Apple techniques we visualized the device implantation, repositioning, and explantation, while noting capsular bag dynamics.

METHODS

Using the Miyake-Apple technique, we assessed capsular bag deformation after successful implantation of the device in human autopsy eyes. We assessed rescue strategies for converting a sulcus implantation to a capsular implantation and explantation strategies. We noted the occurrence of posterior capsule striae, zonular stress, and the haptics' arc of contact with the capsular bag after implantation.

RESULTS

Acceptable zonular stress was observed during the successful implantation of the SING IMT. When it was implanted in the sulcus, one could reposition the haptics into the bag with two spatulas using counter-pressure in an effective strategy despite inducing tolerable, medium zonular stress. A similar technique, in reverse, allows safe explantation without damaging the rhexis or the bag, while inducing similar medium, tolerable zonular stress. In all eyes we examined, the implant considerably stretches the bag, inducing a capsular bag deformation and posterior capsule striae.

CONCLUSION

The SING IMT can be safely implanted without significant zonular stress. In sulcus implantation and explantation, repositioning of the haptic is achievable without perturbing zonular stress using the presented approaches. It stretches average-sized capsular bags to support its weight. This is achieved by an increased arc of contact of the haptics with the capsular equator.

The Ganesh-Grewal cystitome maker - A step in standardizing cataract surgery

A well-centered, adequately sized continuous curvilinear capsulorhexis (CCC) is a prerequisite for successful cataract surgery. A perfect capsulorhexis ensures safe and effective performance of various steps of surgery as well as a correctly positioned intraocular lens (IOL) with optimal rotational stability. Ganesh and Grewal (GG) cystitome maker is a step toward standardizing the creation of a cystitome to reduce variations and complications associated with the crucial step of CCC in cataract surgery. We conducted a study to measure the repeatability and precision of cystitomes made by the GG cystitome maker versus those made manually with a needle holder. The results showed that the cystitomes made with GG cystitome maker had a lesser degree of variation. This indicates a more repeatable cystitome, which will inadvertently help in reducing the error caused by the instrument in making a good CCC during cataract surgery.

Training ambidexterity - A survey-based analysis on the dexterity of ophthalmologists in performing standard ophthalmic procedures

Purpose

Our study was designed to determine ophthalmologists' dexterity in performing standard ophthalmic procedures at various levels of expertise via a structured questionnaire.

Methods

A structured questionnaire was administered via the Google platform from August 20 to September 19, 2022, to assess the perspectives and preferences of ophthalmologists concerning their proficiency in using their right hand, left hand, or both hands to perform routine tasks required in the practice of ophthalmic medicine and surgery.

Results

Two hundred and three participants took part in the survey. A majority (n = 162, 79.8%) of the clinicians considered themselves right-handed, nine (4.4%) considered themselves left-handed, and 32 (15.7%) considered themselves ambidextrous. Also, 86% (n = 174) of the participants considered ambidexterity an essential trait in the practice of ophthalmic medicine and surgery. The number of cataract surgeries performed had an impact on the comfort of using both hands for performing anterior vitrectomy (P < 0.001), injection of viscoelastic (P < 0.001), and toric marking (P < 0.05), but not on the performance of capsulorhexis and switching of foot pedals. The number of procedures carried out had an impact on the comfort of using both hands in gonioscopy (P < 0.001), 90 D evaluation (P < 0.001), and 20 D evaluation (P < 0.05). More years of experience had an impact on skills involving the use of both hands for slit lamp joystick usage (P < 0.05) and laser procedures (P < 0.001).

Conclusion

Irrespective of a person's handedness, trained ambidexterity in the required fields is achievable and has a significant impact on one's ability to perform the required skill optimally and appropriately.

Surgical management of lifebuoy cataract

Lifebuoy cataract is a rare form of congenital cataract with anatomical characteristics. Herein, we present a case of an otherwise healthy 42-year-old female with a long-standing history of blurred vision. Examination showed the presence of esotropia and bilateral horizontal nystagmus. Visual acuity was limited to light perception in both eyes. Slit-lamp examination showed a calcified lens capsule with the absence of lens material in the right eye and the presence of an annular cataract in the left eye, corresponding to a unilateral lifebuoy cataract. She underwent cataract surgery with intraocular lens implantation. We report the clinical findings, anterior segment optical coherence tomography (AS-OCT), and surgical management tips. We noticed that during surgery, both anterior capsulorhexis and central membrane removal were the most challenging steps due to the absence of central nucleus and the strong adherence of central membrane to the anterior hyaloid.

Intraocular lens tilt and decentration after cataract surgery with and without primary posterior continuous curvilinear capsulorhexis

PURPOSE

To evaluate intraocular lens (IOL) tilt and decentration and their effects on higher-order aberrations (HOAs) after cataract surgery with and without primary posterior continuous curvilinear capsulorhexis (PPCCC).

SETTING

Fujian Provincial Hospital, Fujian, China.

DESIGN

Prospective, intraindividual, randomized, comparative clinical trial.

METHODS

64 eyes of 32 patients with age-related cataract who underwent bilateral cataract surgery and IOL implantation were enrolled in this study. In randomized order, all patients had phacoemulsification cataract surgery with PPCCC in 1 eye (PPCCC group) and routine cataract surgery in the contralateral eye (NPCCC group). IOL decentration, tilt, HOAs, modulation transfer function, and point spread function were measured at 1 day, 1 week, 1 month, and 3 months after surgery using OPD-Scan III.

RESULTS

52 eyes of 26 patients were available for analysis. The mean overall decentration in the NPCCC group was significantly higher than in the PPCCC group at 3 months (0.302 ± 0.157 mm vs 0.187 ± 0.099 mm, P < .001). Under 3 mm pupil, internal spherical aberration (SA) 1 day after surgery and coma 1 week after surgery were lower in the PPCCC group compared with the NPCCC group (0.15 ± 0.10 μm vs 0.30 ± 0.21 μm, P < .001, and 0.34 ± 0.18 μm vs 0.47 ± 0.31 μm, P = .03, respectively). IOL decentration was significantly correlated with ocular and internal coma, ocular and internal SA, and internal HOAs at 5 mm pupil ( R = 0.083 and R = 0.099, R = 0.650 and R = 0.613, and R = 0.418, respectively, all P < .01).

CONCLUSIONS

Less IOL decentration was observed in the PPCCC group at 3 months after surgery, indicating that PPCCC may result in better IOL centrality.

Video-based assessment of intraoperative surgical skill

PURPOSE

Surgeons' skill in the operating room is a major determinant of patient outcomes. Assessment of surgeons' skill is necessary to improve patient outcomes and quality of care through surgical training and coaching. Methods for video-based assessment of surgical skill can provide objective and efficient tools for surgeons. Our work introduces a new method based on attention mechanisms and provides a comprehensive comparative analysis of state-of-the-art methods for video-based assessment of surgical skill in the operating room.

METHODS

Using a dataset of 99 videos of capsulorhexis, a critical step in cataract surgery, we evaluated image feature-based methods and two deep learning methods to assess skill using RGB videos. In the first method, we predict instrument tips as keypoints and predict surgical skill using temporal convolutional neural networks. In the second method, we propose a frame-wise encoder (2D convolutional neural network) followed by a temporal model (recurrent neural network), both of which are augmented by visual attention mechanisms. We computed the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and predictive values through fivefold cross-validation.

RESULTS

To classify a binary skill label (expert vs. novice), the range of AUC estimates was 0.49 (95% confidence interval; CI = 0.37 to 0.60) to 0.76 (95% CI = 0.66 to 0.85) for image feature-based methods. The sensitivity and specificity were consistently high for none of the methods. For the deep learning methods, the AUC was 0.79 (95% CI = 0.70 to 0.88) using keypoints alone, 0.78 (95% CI = 0.69 to 0.88) and 0.75 (95% CI = 0.65 to 0.85) with and without attention mechanisms, respectively.

CONCLUSION

Deep learning methods are necessary for video-based assessment of surgical skill in the operating room. Attention mechanisms improved discrimination ability of the network. Our findings should be evaluated for external validity in other datasets.

Influence of anterior capsulorhexis shape, centration, size, and location on intraocular lens position: finite element model

PURPOSE

To evaluate the influence of anterior capsulorhexis shape, dimension, and eccentricity on intraocular lens (IOL) position.

SETTING

Laboratory investigation.

DESIGN

Computational model.

METHODS

A finite element model of the human crystalline lens capsule and zonule was created and the anterior capsule opened to simulate centered and decentered circular and elliptic rhexis. The model calculated capsular bag stress, IOL rotation, tilt, decentration, and vaulting, related to both capsular landmarks (absolute) and a reference IOL position defined as that obtained with a 5.0 mm circular and centered rhexis.

RESULTS

Mean von Mises stress along the IOL major z-axis was significantly higher than that along the perpendicular x-axis in all cases (P < .001), both at the equator and at the rhexis edge. Stress at the equator was always greater than that at the rhexis edge (P < .001) regardless of the rhexis shape and position. As rhexis eccentricity increased, the stress difference between the z- and x-axes increased. Absolute IOL tilt (range 10-1 to 10-7 degrees), decentration (10-3 to 10-7 mm), rotation (10-2 to 10-3 degrees), and vaulting (10-1 mm) were negligible from an optical standpoint, but all of them were significantly greater for decentered rhexis (both round and elliptic) compared with centered (P < .05).

CONCLUSIONS

Anterior capsulorhexis irregularity and/or eccentricity increase IOL tilt, decentration, rotation, and vaulting in a numerically significant but optically negligible way. Von Mises stress is much greater at the capsular bag equator compared with the rhexis edge and highly asymmetrically distributed in all cases. Stress asymmetry may influence postoperative biologic processes of capsular bag shrinking and further IOL tilting or decentration.

USE OF A FEMTOSECOND LASER IN CATARACT SURGERY

AIMS

Cataracts continue to be the leading cause of blindness worldwide. Phacoemulsification is the gold standard in the treatment of cataracts. The aim of the study was to compare the postoperative results of the phacoemulsification technique in comparison with femtosecond laser-assisted cataract surgery (FLACS).

MATERIAL AND METHODS

Our work retrospectively evaluates the results of patients after implantation of an artificial intraocular lens for cataract from May 2017 to March 2019. The study evaluated a total of 80 implanted lenses in 47 patients operated on by two surgeons. Of the 47 patients, 28 were women. The mean age in the group at the time of surgery was 63.7 years, ranging from 34-79 years. Patients could choose FLACS (n = 45) surgery or standard phacoemulsification procedure (n = 35).

RESULTS

Upon a comparison of the group regarding uncorrected distal visual acuity (UCDVA) up to 12 months after surgery, the group FAKO CATARACTS recorded 0.85 ±0.18 vs. 0.93 ±0.12 in the FEMTO CATARACTS group (p = 0.021), comparably uncorrected near visual acuity (UCNVA) was 0.77 ±0.18 vs. 0.84 ±0.17 (p = 0.034) respectively. A difference in the use of phacoemulsification energy (OZIL) was measured in patients with phacoemulsification 3.5 ±3.1 and in the use of femtosecond laser 2.2 ±3.1, (p = 0.005). In all cases, an AT LISA 839 trifocal lens (Carl Zeiss Meditec, Germany) was implanted.

CONCLUSION

The femtosecond platform assists the surgeon in cataract surgery with capsulorhexis and pre-fragmentation of the lens nucleus, which can be advantageous especially for complicated cataracts. We recorded significantly higher uncorrected distance and near visual acuity in the FLACS group, and also a significantly lower value of the phacoemulsification energy used.

Recent developments in anterior capsulotomy for cataract surgery

PURPOSE OF REVIEW

Successful anterior capsulotomy is an important step in cataract surgery. This article reviews the various anterior capsulotomy techniques available to surgeons to optimize the step, including those that have become available since the introduction of femtosecond-laser-assisted cataract surgery (FLACS). Studies comparing the relative advantages of each technique will be emphasized.

RECENT FINDINGS

Manual continuous curvilinear capsulorhexis (CCC) and FLACS remain the two most widely studied techniques for achieving anterior capsulotomy. Each technique has been shown to be effective for a wide range of patients and cataract surgery complications. Meta-analyses have shown that FLACS provides similar results to manual CCC for long-term cataract surgery outcomes. Several alternative methods for anterior capsulotomy have been described, which aim to provide some of the advantages of laser capsulotomy at a lower cost; among these, precision pulse capsulotomy (PPC) and selective laser capsulotomy (SLC) have been investigated the most in the literature so far.

SUMMARY

Cataract surgeons have an increasing number of techniques for anterior capsulotomy available. Manual CCC and FLACS remain the most widely used, and most well studied. The latest techniques, PPC and SLC, have shown promise in the few studies performed since they were introduced.

Sewing needle microcapsulotomy to avert Argentinian flag sign

The Argentinian flag sign is a known complication in intumescent white cataracts, which arises instantly after an initial prick with a sharp hypodermic needle on a stretched out anterior capsule. Increased intralenticular pressure is believed to be responsible for propagation of the initial prick into a radial capsular tear. However, it is the linear cut configuration of the initial prick, created by the hypodermic needle on the tense anterior capsule, which spontaneously opens up and propagates toward the periphery along its margins. To overcome this, a new instrument was devised, sewing needle microcapsulotome, to puncture the capsule and create a single or multiple round openings with smooth margins, allowing the bag to decompress satisfactorily without yielding to disruptive intralenticular forces. This technique of sewing needle microcapsulotomy, to prevent the Argentinian flag sign, was found to be highly effective and safe in a series of surgeries on intumescent cataracts.

Intralenticular metallic foreign body 'locked-in' the posterior capsule and the utility of multimodal imaging

Intraocular foreign bodies (FBs) are common ocular injuries reporting to the emergency services all over the world. The authors highlight the findings and surgical management of a case of intralenticular metallic FB following an injury while using chisel and hammer. The ocular path of the FB (2 mm) could be traced from a self-sealed corneal perforation, extending through the anterior capsule rupture, terminating at the posterior capsule, forming a posterior capsule tent with a part embedded in clear lens. Preoperative ultrasound biomicroscopy gave clues on posterior capsule integrity and the exact site of FB, and helped prognosticate and plan the surgical management of the case. The 'locked-in' FB was extracted after clear lens aspiration and posterior capsulorrhexis. The posterior capsule acted as a natural barrier between anterior and posterior segment, where the FB was found embedded.

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.

Capsular tension ring explant complication rate comparison using Miyake-Apple video analysis

PURPOSE

To compare the complication rate and time required to explant standard capsular tension rings (CTRs) vs suture-guided CTRs (SGCTRs).

SETTING

Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.

DESIGN

Experimental study.

METHODS

Eight cadaver eyes were prepared using standard Miyake-Apple protocol with digital video recording. A 4 clock-hour zonular dialysis was created, followed by a capsulorhexis, hydrodissection, and CTR (n = 4) or SGCTR (n = 4) implantation. With the CTR hidden from view by the overlying iris, ophthalmic surgical instruments were used to remove the CTRs. Time required to remove the CTR and any complications were recorded. A limit of 180 seconds was imposed to determine inability to remove the CTR.

RESULTS

In the standard CTR group (n = 4), removal was associated with high rates of complication (100%). Complications included capsular tears (n = 2), dialysis extension (n = 1), and inadvertent intracapsular cataract extraction (n = 1). The SGCTR group had no complications associated with removal (n = 4). Time required to explant a CTR was significantly reduced from 164.5 seconds with standard CTRs to 6.9 seconds with SGCTRs (P = .001).

CONCLUSIONS

Attempts to remove a standard CTR from the capsular bag was met with a high complication rate. The addition of suture to the leading eyelet of the CTR prior to implantation significantly reduced the time and effort required to remove the CTR and was associated with a significant reduction in complication rates.

Two-hole assisted phaco-chop technique: a more efficient method for safe nucleofractis vertical chopping

Purpose

To evaluate the use of the two-hole technique in augmenting the efficiency of surgeons-in-training when performing the phaco-chop technique. We hypothesized that drilling two holes in opposite angles to each other adjacent to the capsulorhexis would mimic a new lens equator. The phaco-tip and the chopper can be inserted into these holes at appropriate depths and may sandwich and fracture the lens more easily than conventional methods.

Methods

The two-hole technique described above was performed by three first-year surgeons before they performed the standard phaco-chop technique. We collected data of their first 8 cases and analyzed a total of 64 cases: 16, divide-and-conquer; 24, two-hole method; 24, phaco-chop. The main outcome measures included the cumulative dissipated energy (CDE) and case ultrasound time (UST) with different phacoemulsification techniques.

Results

The young practicing surgeons eventually performed the standard phaco-chop more safely after repeated practice using the two-hole method. The drilling of holes enabled deep and effortless impaling of the nucleus. Although there was no significant difference in the CDE among the techniques, there was a significant difference in the UST (P < 0.05).

Conclusion

The two-hole method enabled surgeons-in-training to acquire standard phaco-chop skills more efficiently. However, further studies with higher statistical power will be needed to validate these findings. Additionally, a variation of this technique, the four-hole method, is applicable even for experienced surgeons in cases of a hardened nucleus.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10792-021-01872-4.

A study for lens capsule tearing during capsulotomy by finite element simulation

BACKGROUND AND OBJECTIVE

During capsulotomy, the force applied to the anterior capsule is a crucial parameter controlling capsule tears, that affects the clinical performance. This study aims to investigate the tear force in capsulotomy and analyze the effects of different tearing conditions on the tear force.

METHODS

A three-dimensional model of the human lens was constructed based on published clinical data using the finite element (FE) method. The lens model consisted of four layers: the anterior and posterior lens capsule, the cortex, and the nucleus. Distortion energy failure criterion combined with the bilinear interface law was used to express the crack propagation process at the edge of the anterior lens capsule. At the clamping position, a local coordinate system was established to parameterize the capsule tearing. The simulation results were then validated by conducting a capsulorhexis experiment using isolated porcine eyes with force-sensing forceps.

RESULTS

The simulation results showed a good agreement with the experimental data of two porcine specimens (No. 6 and 9) during a stable tearing process (p-values = 0.76 and 0.10). The mean force differences between the experimental data and the simulation were 3.10 ± 2.24 mN and 2.14 ± 1.73 mN, respectively. The tear direction with a minimum mean tear force was at θ₁ = 0° and θ₂ = 30°. The tear velocity was not significantly different to the variation in the tear force. However, an appropriate capsulorhexis diameter was found to contribute to the reduction of tear force.

CONCLUSIONS

The outcome of this paper demonstrates that our FE model could be used in modeling lens capsule tearing and the theoretical study of tear mechanism.

Three-Dimensional Assessments of Intraocular Lens Stability With High-Speed Swept-Source Optical Coherence Tomography

PURPOSE

To evaluate the effect of intraocular lens (IOL) optic overlapping on IOL stability and to determine the relationship between the capsulorhexis and IOL movement with the three-dimensional method of swept-source optical coherence tomography (SS-OCT).

METHODS

This study identified patients with age-related cataracts and divided them into two groups according to their anterior capsule and IOL optic relationship: total anterior capsule overlap (360°) and partial anterior capsule overlap (< 360°). Standard SS-OCT radial scanning was performed in all eyes at 1 day, 1 week, 1 month, and 3 months after cataract surgery, respectively. The obtained photographs were used for the postoperative position measurements of capsulorhexis and IOL after three-dimensional reconstruction.

RESULTS

This study included 46 eyes of 34 patients: total overlap group (n = 29) and partial overlap group (n = 17). The postoperative aqueous depth significantly decreased in the first week after surgery (P < .001). The IOL tilt was greater in the partial overlap group than that in the total overlap group (P = .014). The IOL moved significantly in the first week postoperatively (both P < .001). IOL decentration in the x-axis was greater in the partial overlap group than that in the total overlap group (P = .024). The IOL and capsulorhexis both moved sharply in the first week (both P < .05). The IOL moved consistently with the capsulorhexis in the 3 months after surgery (all P > .05).

CONCLUSIONS

The total overlap group showed better IOL centrality and stability. IOL movement may be driven by capsular bag contraction and fibrosis. Thus, it was demonstrated that postoperative IOL position and IOL performance were closely linked with proper size of central continuous curvilinear capsulorhexis. [J Refract Surg. 2020;36(6):388-394.].

Three-Year Outcomes of Cionni-Modified Capsular Tension Ring Implantation in Children Under 8 Years Old With Ectopia Lentis

PURPOSE

This study evaluated visual outcomes and complications at 3 years post-implantation of a Cionni-modified capsular tension ring (MCTR) with an intraocular lens (IOL) in ectopia lentis patients ≤8 years old.

DESIGN

Prospective clinical cohort study.

METHODS

Included were 101 eyes from 57 patients <8 years of age, who underwent surgery for nontraumatic ectopia lentis between November 2015 and December 2016. Exclusion criteria were planned IOL fixation in the ciliary sulcus, severe intraoperative complications, and incomplete follow-up. All eyes received in-the-bag implantation of a posterior IOL and Cionni-MCTR. Posterior capsulectomy and anterior vitrectomy were performed through the pars plana in 23 eyes of children <5 years of age. Patients were examined at 1 day, and 1, 6, and 12 months, and at 2 and 3 years postoperatively. Outcome; measurements included best-corrected visual acuity (BCVA), intraocular pressure (IOP), IOL centration, and posterior capsule opacification (PCO).

RESULTS

In all eyes, BCVA improved significantly after surgery, especially during the first 12 months (P < .05). Three years post-operatively, 44 eyes had BCVA 0.9 or better. Prophylactic Nd:YAG laser capsulotomy was performed 3 months post-surgery in 24 eyes; 34 eyes underwent this; procedure 6 months post-surgery because of PCO. A second surgery was; warranted in 4 eyes because of severe IOL decentration and combined anterior capsule contraction. No severe postoperative complications, such as retinal detachment or endophthalmitis, occurred.

CONCLUSIONS

Implantation of in-the-bag IOL with Cionni MCTR is effective for visual rehabilitation in young children with ectopia lentis. A close follow-up of these patients is necessary to monitor IOL centration and stability.

Autologous tenon plug and patch in phacoburn

This 75-year-old woman had phacomorphic angle closure, dense nuclear sclerosis, deep set eye, miotic pupil and tight corneal wound during phacoemulsification. Phacoemulsification wound burn was noted at the end of surgery. Tenon was harvested from the inferior conjunctiva, placed over the gape and anchored by two radial corneoscleral 10-0 nylon. Ten days later, anterior optical coherence tomography showed good wound apposition and sutures were removed with visual recovery to 20/25 (6/7.5) without astigmatism.

The human capsular bag model of posterior capsule opacification

Posterior capsule opacification (PCO) is the most common complication following cataract surgery and affects millions of patients. PCO is a consequence of surgical injury promoting a wound-healing response. Following surgery, residual lens epithelial cells grow on acellular regions of the lens capsule, including the central posterior capsule. These cells can undergo fibrotic changes, such that cell transdifferentiation to myofibroblasts, matrix deposition and matrix contraction can occur, which contribute to light scatter and the need for further corrective Nd:YAG laser capsulotomy in many patients. It is therefore of great importance to better understand how PCO develops and determine better approaches to manage the condition. To achieve this, experimental systems are required, and many are available to study PCO. While there may be a number of common features associated with PCO in different species, the mechanisms governing the condition can differ. Consequently, where possible, human systems should be employed. The human capsular bag model was established in a laboratory setting on donor eyes. A capsulorhexis is performed to create an opening in the anterior capsule followed by removal of the lens fibre mass. Residual fibre cells can be removed by irrigation/aspiration and if required, an intraocular lens can be implanted. The capsular bag is isolated from the eye and transferred to a dish for culture. The human capsular bag model has played an important role in understanding the biological processes driving PCO and enables evaluation of surgical approaches, IOLs and putative therapeutic agents to better manage PCO.

Late postoperative capsular bag distension syndrome

PURPOSE

Capsular bag distension syndrome is to be seen as a relatively rare complication after cataract surgery.

MATERIALS AND METHODS

We describe our experience of late-onset capsular bag distension syndrome with one case onset 4 years after cataract surgery. Nowadays diagnostic imaging methods were used. The literature was reviewed to summarize the diagnosis, classification, use of diagnostic aids, and the current treatments for the capsular bag distension syndrome. Visual acuity was assessed using the ETDRS (Early Treatment Diabetic Retinopathy Study) chart.

DISCUSSION

A 72-year-old woman presented with decreased visual acuity and blurred vision 4 years after phacoemulsification with continuous curvilinear capsulorhexis (CCC) and in-the-bag IOL implantation. After the slit lamp examination, patient was investigated with Scheimpflug camera (OCULUS Pentacam HR) and anterior segment spectral domain OCT (Optovue, Avanti RTVue XR), which confirmed the diagnosis of capsular block syndrome. Aspiration of the turbid fluid behind the lens and capsular bag lavage resulted in resolution of her symptoms. Aspirated fluid was examined. We have observed no CBS recurrence.

CONCLUSION

CBS is the relatively rare complication of the standard cataract surgery, which can occur during surgery and in a postoperative period. CBS can be solved successfully after regular diagnosis using modern imaging methods.

Influence of the vitreolenticular interface in pediatric cataract surgery

PURPOSE

To report the status of Berger space in pediatric cataract cases and the influence of anterior vitreolenticular interface dysgenesis during primary posterior continuous curvilinear capsulorhexis (PCCC).

SETTING

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

DESIGN

Prospective case series.

METHODS

The study comprised consecutive pediatric cataract cases planned for bag-in-the-lens intraocular lens (BIL IOL) implantation. A video-based analysis of the surgical interventions included the type of crystalline lens opacification, presence of a posterior capsule plaque (PCP), presence of anterior vitreolenticular interface dysgenesis, complications during primary PCCC, integrity of the anterior hyaloid membrane, need for anterior vitrectomy, and feasibility of BIL IOL implantation.

RESULTS

Abnormalities in Berger space were observed in 35 of the 64 pediatric cataract cases. Anterior vitreolenticular interface dysgenesis was most often found in cases with persistent fetal vasculature (PFV) and those with posterior cataract. Anterior vitreolenticular interface dysgenesis was diagnosed significantly more often in eyes with unilateral cataract and those with PCP. In pediatric cataract cases presenting with PCP and anterior vitreolenticular interface dysgenesis, the primary PCCC procedure was surgically more demanding, often resulting in detectable breaks in the anterior hyaloid membrane (58.6%) and sometimes necessitating an unplanned anterior vitrectomy (13.8%). Bag-in-the-lens IOL implantation was feasible in all except 1 eye with PFV, which was left aphakic.

CONCLUSIONS

Primary vitreolenticular interface abnormalities are often encountered during pediatric cataract surgeries, especially when confronted with PCP in a unilateral cataract. The presence of anterior vitreolenticular interface dysgenesis may complicate a primary PCCC procedure, resulting in an unplanned anterior vitrectomy in some cases.

[Intumescent cataract surgery]

Intumescent cataract surgery is one of the topical problems of ophthalmology. The article reviews methods of intumescent cataract diagnostics and structural features of swelling lens. Manual or femtolaser-assisted anterior continuous circular capsulorhexis and intumescent cataract phacoemulsification techniques require further research.

Unusual Internal Astigmatism Due to Severe Capsule Contraction Syndrome

PURPOSE

To describe a case of severe capsule contraction syndrome causing significant astigmatism due to intraocular lens (IOL) folding.

METHODS

Case report.

RESULTS

Capsule fibrosis and contraction resulted in bending of the hydrophilic IOL along its long axis. Anterior Nd:YAG capsulotomy resolved the situation and restored the patient's visual acuity.

CONCLUSIONS

Hydrophilic IOLs are more susceptible to capsule contraction due to the increased flexibility of highly hydrated materials. They should be avoided in patients at risk of capsule contraction to prevent ocular complications. [J Refract Surg. 2018;34(1):65-67.].

Change of Capsulotomy Over 1 Year in Femtosecond Laser-Assisted Cataract Surgery and Its Impact on Visual Quality

PURPOSE

To compare the shape of the capsulotomy, its change, and its impact on visual quality over 1 year using the femtosecond laser system from the manual technique.

METHODS

In this two-center cross-sectional study from May 2012 to June 2013, each patient had femtosecond laser-assisted cataract surgery in one eye (FLACS group) and conventional phacoemulsification cataract surgery in the other eye (CPCS group). An evaluation of the capsulotomy was performed using retroillumination slit-lamp photographs at 7 days, 6 months, and 1 year after surgery. Effective lens position (ELP), refractive error, and corrected distance visual acuity (CDVA) were analyzed.

RESULTS

Thirty-three patients were included in the study. Diameters of capsulorhexis were more precise and deviation surfaces were lower in the FLACS group than in the CPCS group at each evaluation (P < .05). Femtosecond laser capsulotomies were less modified over time than manual continuous curvilinear capsulorhexis. No significant differences were observed for CDVA, refractive error, and ELP between groups.

CONCLUSIONS

More precise capsulotomy sizing can be achieved with the femtosecond laser compared to continuous curvilinear capsulorhexis. Femtosecond laser capsulotomies are less modified over time but did not improve ELP or visual quality. [J Refract Surg. 2017;33(1):44-49].

The effect of single-piece hydrophobic acrylic intraocular lenses on the development of posterior capsule opacification

PURPOSE

To evaluate the long-term effect of a single-piece hydrophobic acrylic intraocular lens (IOL), AcrySof SN60AT (Alcon Laboratories, Fort Worth, Texas, USA), on the development of posterior capsule opacification (PCO) 5 years postoperatively.

DESIGN

Prospective, observational, consecutive, case series.

METHODS

setting: Iladevi Cataract and IOL Research Center, Ahmedabad, India.

STUDY POPULATION

Three hundred and ninety eyes with uncomplicated age-related cataract were included. Patients with diabetes mellitus, glaucoma, high myopia, pseudoexfoliation, traumatic cataract, subluxated cataract, previous ocular surgeries, and allergy to dilating drops were excluded. intervention procedures: Digital retroillumination photographic documentation was performed and analyzed for PCO using Evaluation of Posterior Capsule Opacification software. The scores and areas were calculated.

MAIN OUTCOME MEASURES

PCO development and the influence of the anterior capsule cover (total on and part on) on the IOL optic was studied within the capsulorrhexis margin and the central 3.0 mm optic area.

RESULTS

There was a significant increase in PCO up to 3 years. No significant change in PCO was observed between 3 and 5 years within the capsulorrhexis margin and central 3.0 mm optic area. In the total on group, within the capsulorrhexis margin, significantly lower scores and areas were observed when compared with part-on scores and areas.

CONCLUSION

The increase in PCO up to 3 years was significant. Stabilization in PCO was observed between 3 and 5 years with no difference at 5 years. There was a low incidence of PCO in eyes with total anterior capsule cover over the IOL optic.

[Preliminary evaluation of the femtosecond laser-assisted cataract surgery in 300 cases]

OBJECTIVE

To evaluate the clinical outcome of the femtosecond laser-assisted cataract surgery (FLACS) in our first 300 cases.

METHODS

In this retrospective study, the study group comprised 300 cases (300 eyes) in which FLACS was done. The control group comprised 300 cases (300 eyes) in which phacoemulsification was performed. The steps of the FLACS included capsulotomy, lens fragmentation, corneal incisions, and creation of incisions within the peripheral cornea to aid the correction of pre-existing astigmatism. After the FLACS, 2.2-mm coaxial micro-incision phacoemulsification and implantation of an intraocular lens were operated. The preoperative best corrected visual acuity (BCVA) and postoperative uncorrected visual acuity (UCVA), the cumulative dissipated energy (CDE) of the phacoemulsification, and the parameters of the FLACS, including the docking time, the suction time and the laser time, were recorded. The complications of the FLACS were analyzed.

RESULTS

The FLACS was successfully completed in 99.33% of the cases. The docking time was (24.6 ± 16.8) sec, the suction time was (101.27 ± 20.09) sec, and the laser time was (23.3 ± 5.5) sec. The most common complications of the FLACS included suction break (7/300, 2.33%), subconjunctival hemorrhage (58/300, 19.33%), pupillary constriction (47/300, 15.67%), incision at a wrong site (13/300, 4.33%), anterior capsular tag (17/300, 5.67%), decentration of the capsulorhexis (11/300, 3.67%), failure to split the lens nucleus (5/300, 1.67%), and posterior capsular ruptures (1/300, 0.33%). The CDE was 5.52 ± 5.18 in the FLACS group and 8.37 ± 7.91 in the traditional phaco group (P < 0.05). The UCVA was 0.12 ± 0.08 and 0.13 ± 0.11 at 1 month after the FLACS and traditional phaco, respectively (P > 0.05).

CONCLUSIONS

Compared with the conventional phacoemulsification surgery, the FLACS can achieve less CDE and better early postoperative visual acuity. Long-term effects remain to be investigated.

Outcomes after accommodative bioanalogic intraocular lens implantation

PURPOSE

To evaluate the outcomes after Wichterle Intraocular Lens-Continuous Focus (Medicem, Kamenné Zehrovice, Czech Republic) accommodative bioanalogic intraocular lens implantation.

METHODS

In this prospective case series, 50 eyes of 25 patients (mean age: 65.3 ± 8.4 years; range: 53 to 83 years) were included. All patients underwent routine cataract surgery and Wichterle Intraocular Lens-Continuous Focus implantation.

RESULTS

Mean follow-up was 11.44 ± 2.46 months (range: 9 to 17 months). Both monocular uncorrected and corrected distance visual acuity statistically and significantly (P < .05) improved from 0.31 ± 0.17 (20/63 Snellen) (range: counting fingers to 0.7) to 0.74 ± 0.19 (20/25 Snellen) (range: 0.2 to 1) and from 0.61 ± 0.19 (20/32 Snellen) (range: 0.2 to 1) to 0.82 ± 0.13 (20/25 Snellen) (range: 0.4 to 1), respectively. Target postoperative refraction was -0.5 diopters (D) and preoperative and 1-year postoperative spherical equivalent refraction were 0.72 ± 2.71 D (range: -7.25 to 2.37 D) and -0.24 ± 0.65 D (range: -1.0 to 1.0 D), respectively. No eyes lost lines of corrected distance visual acuity during the follow-up period, whereas 88% of patients gained one or more lines of corrected distance visual acuity. Uncorrected intermediate and near visual acuity were J2 (Snellen 20/25) or better in 72% of patients. No complications occurred intraoperatively or postoperatively. The evaluation of the mean values of root mean square of third and fourth order higher-order aberrations at 1 year postoperatively revealed a mean negative spherical aberration of -0.18 ± 0.13 μm.

CONCLUSIONS

Wichterle Intraocular Lens-Continuous Focus accommodative bioanalogic IOL implantation provides satisfactory visual acuity for far, intermediate, and near distances and the promising results remain stable throughout the follow-up period.

Comparison of refractive stability after non-toric versus toric intraocular lens implantation during cataract surgery

PURPOSE

To compare refractive state changes in eyes implanted with toric intraocular lenses (IOLs) vs non-toric IOLs, after cataract extraction.

DESIGN

Retrospective, comparative.

METHODS

In a single institution, 121 eyes underwent phacoemulsification and implantation with either non-toric IOLs or toric IOLs. The spherical value, cylindrical value, spherical equivalent (SE) of refractive error, and visual acuity were measured preoperatively and 1, 3, and 6 months after surgery. Main outcome measures were the pattern of changes of spherical, cylindrical, and SE values based on postoperative time, between different IOL types.

RESULTS

The groups, which included patients who underwent surgery with SN60WF (Group I), SA6AT3 (Group II-3), SA6AT4 (Group II-4), and SA6AT5 lenses (Group II-5), contained 37, 29, 23, and 32 eyes, respectively. The cylindrical value was significantly decreased in all groups (P < .05). Before surgery, the SE of refractive errors was estimated as -0.21, -0.10, -0.20, and -0.22 in the respective groups. The actual remaining SE values were -0.19, -0.24, -0.42, and -0.56 at 1 month; -0.17, -0.26, -0.57, and -0.64 at 3 months; and -0.17, -0.26, -0.70, and -0.74 at 6 months postoperatively, respectively. The follow-up SE values in groups I and II-3 were similar (P > .05 in both groups); however, significant myopic changes were observed in Groups II-4 and II-5 after surgery, vs Group I (P < .05).

CONCLUSION

Selection of toric IOLs for cataract surgery requires a refined formula to precisely determine necessary IOL power, especially in cases with high levels of astigmatism, to reliably and accurately prevent myopic outcomes.

Fellow-eye comparison of posterior capsule opacification between 2 aspheric microincision intraocular lenses

PURPOSE

To compare posterior capsule opacification (PCO) between 2 microincision hydrophilic intraocular lenses (IOLs) and with a conventional spherical hydrophobic IOL.

SETTING

St. Thomas' Hospital, London, United Kingdom.

DESIGN

Prospective randomized comparative study.

METHODS

A microincision Acri.Smart 36A (negatively aspheric) or Akreos MI-60 (aspherically neutral) IOL was randomized to the first eye of patients with the alternative IOL implanted in the fellow eye within 3 weeks. Postoperatively, 100% and 9% logMAR corrected distance visual acuity (CDVA) were assessed. Retroillumination photographs were analyzed using the posterior capsule opacity software system. The data on PCO scores were compared with those of a conventional spherical hydrophobic IOL (Acrysof SN60AT).

RESULTS

One hundred percent CDVA was significantly better at 12 months and 9% CDVA was better at 6, 12, and 24 months (P<.05) with the negatively aspheric IOL. One eye in each group with microincision IOLs developed capsule phimosis at 1 month. Neodymium:YAG capsulotomies were required by 2 years in 2 eyes with a negatively aspheric IOL and 8 eyes with an aspherically neutral IOL. At 24 months, the mean PCO score remained less than 10% with the conventional spherical IOL, whereas it increased with time in the negatively aspheric IOL (up to 16%) and the aspherically neutral IOL (up to 23%).

CONCLUSIONS

The negatively aspheric IOL had a better PCO profile than the aspherically neutral IOL. This may be attributed to the difference in the edge design between the IOLs. The microincision IOLs had more PCO than the conventional 1-piece hydrophobic IOL.

Finite element analysis of neodymium: yttrium-aluminum-garnet incisions for the prevention of anterior capsule contraction syndrome

BACKGROUND

Anterior capsular contraction syndrome is a potential complication of continuous curvilinear capsulorhexis (CCC). Three neodymium: yttrium-aluminum-garnet (Nd:YAG) laser relaxing incisions decrease anterior capsular contraction but the mechanism is unknown. The present study analyzed the biomechanical mechanism of three Nd:YAG laser relaxing incisions made to reduce anterior capsular contraction.

METHODS

A three-dimensional control model and a three-dimensional Nd:YAG model of the anterior capsule with an opening diameter of 6 mm were created. Three incisions of 1 mm in length were made centrifugally at intervals of 120° around the opening circle. The stress alterations of the anterior capsule after CCC with and without Nd:YAG relaxation were numerically simulated and compared.

RESULTS

In the control model, the stress was axially uniform in the inner area and relatively high near the inner rim of the opening. Meanwhile, in the Nd:YAG model, the stress level was very low in the inner opening areas, especially near the three incisions. The relaxing incisions in the Nd:YAG model significantly released the relatively high stress on the anterior capsule. Additionally, there was a high stress gradient near the relaxing incisions.

CONCLUSION

Biomechanical effects of stress release may be the preventive mechanism of Nd:YAG incision against anterior capsular contraction syndrome.

Unintentional staining of the posterior lens capsule with trypan blue dye during phacoemulsification: case report

We report a complication related to the use of trypan blue during capsular staining of the anterior lens capsule during phacoemulsification surgery. In phacoemulsification surgery of the left eye, trypan blue was injected using an air bubble technique. Unintentionally, trypan blue was administered under high pressure, dispersing the dye through the zonules leading to staining of the posterior capsule. This caused a temporary disturbance of visual acuity during the postoperative period.

Evaluation of anterior-segment inflammation and retinal thickness change following cataract surgery

PURPOSE

To investigate the physiological retinal response to uneventful cataract surgery using conventional time-domain (TD-OCT) and current spectral-domain optical coherence tomography (SD-OCT) in combination with an assessment of the anterior chamber inflammatory reaction by laser flare/cell meter (LCFM).

METHODS

Thirty-four patients scheduled for cataract surgery were included in this prospective pilot study. Retinal parameters were examined according to a standardized examination procedure using TD-OCT (Stratus; Carl Zeiss Meditec, Dublin, California, USA) and SD-OCT (Cirrus; Carl Zeiss Meditec) devices. The inflammatory reaction of the anterior chamber was measured by LFCM (Kowa FC-1000, Kowa Co. Ltd, Tokyo, Japan). Examinations were carried out preoperatively and at day 2, week 1 and week 4 postoperatively.

RESULTS

A slight decrease of central retinal thickness values was identified at day 2 postoperatively followed by an increase of these parameters at week 4. LFCM showed peak values in all patients at day 2 postoperatively with a constant decrease at the following visits. No visible pathological retinal changes were seen after surgery.

CONCLUSION

A biphasic retinal response after surgery could be shown with SD-OCT and TD-OCT technology. By using the advantages of rasterscanning mode, SD-OCT technology is superior to TD-OCT imaging in the investigation of the physiological retinal response to cataract surgery.

Estimation of effective lens position using a method independent of preoperative keratometry readings

PURPOSE

To evaluate the validity of a keratometry (K)-independent method of estimating effective lens position (ELP) before phacoemulsification cataract surgery.

SETTING

Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland.

DESIGN

Evaluation of diagnostic test or technology.

METHODS

The anterior chamber diameter and corneal height in eyes scheduled for cataract surgery were measured with a rotating Scheimpflug camera. Corneal height and anterior chamber diameter were used to estimate the ELP in a K-independent method (using the SRK/T [ELP(rs)] and Holladay 1 [ELP(rh)] formulas).

RESULTS

The mean ELP was calculated using the traditional (mean ELP(s) 5.59 mm ± 0.52 mm [SD]; mean ELP(h) 5.63 ± 0.42 mm) and K-independent (mean ELP(rs) 5.55 ± 0.42 mm; mean ELP(rh) ± SD 5.60 ± 0.36 mm) methods. Agreement between ELP(s) and ELP(rs) and between ELP(h) and ELP(rh) were represented by Bland-Altman plots, with mean differences (± 1.96 SD) of 0.06 ± 0.65 mm (range -0.59 to +0.71 mm; P=.08) in association with ELP(rs) and -0.04 ± 0.39 mm (range -0.43 to +0.35 mm; P=.08) in association with ELP(rh). The mean absolute error for ELP(s) versus ELP(rs) estimation and for ELP(h) versus ELP(rh) estimation was 0.242 ± 0.222 mm (range 0.001 to 1.272 mm) and 0.152 ± 0.137 mm (range 0.001 to 0.814 mm), respectively.

CONCLUSION

This study confirms that the K-independent ELP estimation method is comparable to traditional K-dependent methods and may be useful in post-refractive surgery patients.

Visual results and complications of primary intraocular lens implantation in infants aged 6 to 12 months

BACKGROUND

To present the visual results and the complications of primary intraocular lens (IOL) implantation in infants aged 6 to 12 months between January 2002 and July 2007.

METHODS

A total of 26 consecutive eyes, of 16 infants with cataract aged 6 to 12 months, were reviewed in the study. All patients had cataract extraction with anterior and posterior capsulorrhexis combined with anterior vitrectomy and primary hydrophobic acrylic IOL implantation. Six infants (six eyes) had unilateral congenital cataract and ten (20 eyes), bilateral cataract. Visual acuity and complications were recorded throughout the 46.4-month mean follow-up (range 22 to 79 months).

RESULTS

All eyes had primary IOL implantation. The mean best-corrected visual acuity (logMAR) was 0.98 +/- 0.18,0.50 +/- 0.14 and 0.61 +/- 0.25 for unilateral, bilateral and all eyes respectively at the last follow-up. IOLs were implanted in the capsular bag of 25 eyes (96.2%) and in the sulcus of the remaining one eye (3.8%). Seven eyes (26.9%) developed visual axis opacification (VAO), and four eyes required secondary pars plana vitrectomy (PPV). IOL opacification occurred in one eye 54 months after implantation. Late onset open-angle glaucoma developed in one eye, and required trabeculectomy surgery. The predictors of good best-corrected visual acuity (BCVA) included partial cataract, bilateral cataract, absence of strabismus or nystagmus, and good amblyopic treatment. The greatest annual myopic change (5.15 +/- 2.08 D) was observed during the first 12 months after surgery. In unilateral cases, there was no significant difference in the axial length between the cataractous eye and the fellow normal eye both at the time of surgery (P = 0.891) and final follow-up (P = 0.693).

CONCLUSIONS

Primary IOL implantation was safe and effective for infantile cataract surgery. Total or unilateral cataract, nystagmus or strabismus, and inadequate amblyopic therapy were predictors of poor BCVA. Significant myopic shifts occurred especially in infants in the first year of surgery. The pseudophakic eye had a similar growth rate, as measured by axial length, to that of the fellow normal eye, in unilateral cases.

[Dry pars plana capsulotomy and anterior vitrectomy using 25-gauge vitrectomy system during children cataract surgery]

OBJECTIVE

To describe the initial surgical experience and report the safety and feasibility of dry pars plana capsulotomy and anterior vitrectomy using a 25-gauge vitrectomy system in pediatric cataract surgery.

METHODS

This was a prospective case series study. After anterior continuous curvilinear capsulorhexis (ACCC) and phacoemulsification with intraocular lens (IOL) implantation in the capsule for all patients, a pars plana capsulotomy and anterior vitrectomy was performed with a 25-gauge vitrectomy system using a dry technique in 40 eyes of 30 children with cataracts.

RESULTS

All procedures were uneventful and all IOLs were implanted in the capsular bag. No intraoperative complications were noted attributable to the small-gauge instruments. The average follow-up period was eight months (range, 4 to 30). Postoperative intraocular pressure remained stable in most cases, except two eyes (5%) with transient hypotony during the first day after surgery. The postoperative inflammatory response was mild. Ultrasound biomicroscopy showed complete healing of the sclerotomy at four weeks after surgery. No posterior synechia, posterior capsule opacification, IOL capture, vitreous prolapse, choroidal detachment or retinal detachment was observed throughout the follow-up period.

CONCLUSIONS

Dry pars plana capsulotomy and anterior vitrectomy using a 25-gauge vitrectomy system is safe and effective for the management of posterior lens capsules and anterior vitreous in pediatric cataract surgery. Prospective and comparative study is recommended to evaluate this procedure and traditional method.

Fiber-based fracture model for simulating soft tissue tearing

In this paper, we propose a novel approach for simulating soft tissue tearing, using a model that takes into account the existence of fibers within the tissue. These fibers influence the deformation by introducing anisotropy, and impact the direction of propagation for the fracture during tearing. We describe our approach for simulating, in real-time, the deformation and fracture of anisotropic membranes, and we illustrate our method with the simulation of capsulorhexis, one of the critical steps of cataract surgery.

Prevention of anterior capsule contraction by anterior capsule relaxing incisions with neodymium:yttrium-aluminum-garnet laser

PURPOSE

To examine the effect of two or three neodymium:yttrium-aluminum-garnet (Nd:YAG) laser relaxing incisions made in the anterior capsular rim on prevention of anterior capsule contraction after cataract surgery.

DESIGN

Randomized clinical trials.

METHODS

One hundred patients scheduled for bilateral cataract surgery were randomized to one of two groups: two or three relaxing incisions in the left eye and no incisions in the right eye, and relaxing incisions in the right eye and no incisions in the left eye. The anterior capsule opening area was measured using Scheimpflug photography immediately after capsulotomy and at one, three, and six months after capsulotomy, and the percentage reduction was calculated. The degree of intraocular lens (IOL) decentration and tilt and of posterior capsule opacification (PCO) also were examined.

RESULTS

There was no significant difference in the anterior capsule opening area between fellow eyes at baseline (P > or = .1770). In patients who underwent two incisions, no significant difference was found between fellow eyes in the opening area (P > or = .4098) or in the percentage of reduction (P > or = .8730) throughout follow-up. In patients who underwent three incisions, the opening area in eyes with capsulotomy was significantly greater than that in eyes without capsulotomy (P < or = .0154), and the percentage reduction was significantly smaller in eyes with capsulotomy than in eyes without capsulotomy (P < or = .0016). No significant differences were found in the IOL decentration and tilt, or in PCO.

CONCLUSIONS

Three relaxing incisions made in the anterior capsule decrease the anterior capsule contraction, whereas two incisions do not.

Risk factors for complications after congenital cataract surgery without intraocular lens implantation in the first 18 months of life

PURPOSE

To determine individual risk factors for the development of postoperative complications after pediatric cataract surgery in the first 18 months of life.

DESIGN

Interventional, consecutive case series.

METHODS

We retrospectively reviewed the records of 71 eyes of 46 children who underwent surgery for congenital cataract within the first 18 months of life. A limbal approach bimanual lens aspiration, posterior capsulorrhexis, and anterior vitrectomy without intraocular lens implantation was performed in all children. We examined the interrelationships of operative and postoperative complications with other variables such as patient age, family history, or ocular abnormalities. The mean follow-up period was 39 months.

RESULTS

The most frequent postoperative complications were late-onset open-angle glaucoma (10.8%) and vitreous hemorrhage (10.8%), whereas early-onset glaucoma (4.6%) was less common. Secondary cataract was observed in seven eyes (9.2%). We determined a family history of aphakic glaucoma in first-degree relatives (P = .007) as well as cataract surgery in the first three months of life (P = .039) and nuclear cataracts (P = .0009) to be strong predictors of late-onset glaucoma. Secondary cataract formation was associated strongly with lensectomy in the first five months of life. The diagnosis of postoperative hemorrhages was associated significantly with the presence of persistent fetal vasculature (P < .0001).

CONCLUSIONS

Patients with preoperative predictors at presentation such as young age at the time of surgery, a family history of aphakic glaucoma, nuclear cataract, or persistent fetal vasculature syndrome offer a clear target for extensive postoperative care after congenital cataract surgery.

[Comparison of postoperative results after implantation of hydrophilic acrylic or hydrophobic acrylic intraocular lens: data of one-year prospective clinical study]

OBJECTIVE

To evaluate and compare the impact of two sharp-edge optic foldable intraocular lenses (IOLs) of similar design made from different material (hydrophilic acrylic or hydrophobic acrylic) on visual function, anterior and posterior capsule opacification at one-year follow-up after cataract phacoemulsification.

MATERIAL AND METHODS

Seventy-two eyes of 72 patients scheduled for cataract surgery were included in a prospective clinical study. Two foldable sharp-edge optic posterior chamber acrylic IOLs of similar design were used. Thirty-nine eyes of 39 patients received a single-piece hydrophilic acrylic (PC 511, Ophtec) IOL and 33 eyes of 33 patients - single-piece hydrophobic acrylic (AcrySof, SA60AT, Alcon) IOL. Visual acuity, anterior capsule opacification (ACO), capsulorrhexis/optic overlapping, and posterior capsule opacification (PCO) were evaluated. The intensity of ACO was assessed subjectively. PCO values in the entire IOL optic area and in the central 3-mm optic zone were assessed using a photographic image analysis system (EPCO 2000). The patients were examined at one year postoperatively.

RESULTS

There were no significant differences in best-corrected visual acuity and capsulorrhexis/optic overlapping between IOL types at 1-year follow-up after surgery. In the single-piece hydrophilic acrylic IOL group, the grade of ACO density was significantly higher in capsulorrhexis rim area (1.56+/-0.71 and 1.00+/-0.75) and in the capsule/optic area (1.62+/-0.67 and 1.00+/-0.75) (P<0.05). PCO values of the entire IOL optic area (0.12+/-0.13 and 0.024+/-0.02) as well as in the central 3-mm optic zone (0.06+/-0.11 and 0.001+/-0.003) was significantly higher in the single-piece hydrophilic acrylic IOL group one year postoperatively (P<0.05). In 33.3% of cases of the single-piece hydrophilic acrylic IOL group, contraction of haptics to IOL optics was present one year postoperatively, which was not present in any case of the single-piece hydrophobic acrylic IOL group.

CONCLUSIONS

One-year follow-up after cataract surgery has shown a significant difference in ACO and PCO development comparing single-piece hydrophilic acrylic and single-piece hydrophobic acrylic intraocular lenses. The effect of hydrophobic acrylic foldable lenses on preventing anterior and posterior capsule opacification is mainly a result of the acrylic hydrophobic biomaterial.