Intraoperative trypan blue central landmark and its use in capsulotomy and capsulorhexis centration

PURPOSE

To compare 3 capsulotomy centration methods.

SETTING

Private clinic, Zlin, Czech Republic.

DESIGN

Prospective, consecutive case series.

METHODS

180 eyes undergoing cataract surgery had anterior capsule staining with microfiltered 0.4% trypan blue solution before selective laser capsulotomy. The first 60 eyes (Group 1) had mydriatic dilated pupil centered capsulotomies. The next 60 eyes (Group 2) were centered on the trypan blue central landmark (TCL). The final 60 capsulotomies (Group 3) were centered on the patient fixated coaxial Purkinje reflex (CPR). Measurements between key anatomical landmarks and the TCL, CPR capsulotomies, and implanted intraocular lens (IOL) center were made.

RESULTS

The TCL, observed in >94% of eyes in the study, coincided with the CPR with a displacement of <0.1 ± 0.1 mm. Group 1 capsulotomies were noticeably decentered on the IOLs by 0.3 ± 0.2 mm. The Group 2 symmetrical IOL relationship was maintained with a decentration of 0.15 ± 0.1 mm. Group 3 had a similar decentration with the IOLs with 0.15 ± 0.1 mm. Verification with IOLMaster 700 data and CALLISTO Eye System showed that the CPR and the TCL were coincident with the measured visual axis.

CONCLUSIONS

The clearly visible TCL served as an alternate landmark to the patient fixated CPR, and being on the anterior capsule was not sensitive to tilt. Further patient compliance was not required. Both were superior to dilated pupil centration, to achieve symmetric IOL coverage. This has application for both capsulotomies and capsulorhexes.

[Treatment of early capsular blockage syndrome with Nd:YAG laser anterior capsulotomy containing neodymium-doped yttrium aluminum garnet in a case]

A 62-year-old female patient presented with no improvement in vision 10 days after undergoing cataract extraction in the right eye. The unaided visual acuity in the right eye was 0.1, and examination with a slit lamp revealed the presence of the intraocular lens with an increased gap between the intraocular lens and the posterior capsule. Anterior segment optical coherence tomography showed a distance of 3.236 mm between the posterior capsule and the posterior surface of the intraocular lens. Based on the medical history, ocular examination, and auxiliary examinations, a diagnosis of right eye capsular blockage syndrome was made. Nd:YAG laser capsulotomy was performed at the anterior capsule outside the optical zone of the intraocular lens. One week later, the posterior capsule adhered to the posterior surface of the intraocular lens, and there was a significant improvement in vision compared to before the procedure.

Influence of a Capsular Tension Ring on Capsular Bag Behavior of a Plate Haptic Intraocular Lens: An Intraindividual Randomized Trial

PURPOSE

To evaluate the influence of a capsular tension ring (CTR) on rotational stability, decentration, tilt, and axial stability of an 11.0-mm plate haptic intraocular lens (IOL).

DESIGN

Intraindividual, randomized, double-masked, controlled clinical trial.

PARTICIPANTS

Patients scheduled for sequential same-day bilateral cataract surgery.

METHODS

All patients were randomized to receive a CTR and a plate haptic IOL in one eye and a plate haptic IOL in the fellow eye only. Intraocular lens axis assessment was performed at the end of surgery, 1 hour, 1 week, 1 month, and 6 months using a high-precision evaluation method. Decentration and tilt of the crystalline and pseudophakic lenses were assessed before surgery and at 1 week and 6 months using an anterior segment OCT.

MAIN OUTCOME MEASURES

Rotational stability from the end of surgery to 6 months and at all follow-up visits, decentration and tilt at 6 months, and differences in axial shift between 1 week and 6 months.

RESULTS

One hundred thirty eyes of 65 patients were included in the study. Absolute rotation from the end of surgery to 6 months was 2.8 ± 3.9° and 3.2 ± 5.3° for the CTR and control groups, respectively (P = 0.613). Intraocular lens decentration and IOL tilt at 6 months were 0.29 ± 0.1 mm and 0.24 ± 0.1 mm and 6.7 ± 2.8° and 5.6 ± 1.6° for the CTR and control groups, respectively (P = 0.058; P < 0.01). A posterior IOL shift of 0.31 ± 0.31 mm and 0.19 ± 0.14 mm was observed in the CTR and control groups, respectively.

CONCLUSIONS

Concomitant implantation of a CTR and a plate haptic IOL did not improve the overall rotational stability of the IOL compared with the control group. Against expectations, higher values of decentration, tilt, and axial shift were observed in the CTR group. The simultaneous use of a CTR and a plate haptic IOL in the absence of zonular weakness at the time of cataract surgery should be considered with caution.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Reopening the capsular bag by removing the capsular proliferative membrane to enable secondary in-the-bag intraocular lens implantation in pediatric aphakic eyes

PURPOSE

To present a surgical technique for reopening the capsular bag in pediatric aphakia.

SETTING

Zhongshan Ophthalmic Center, Guangzhou, China.

DESIGN

Case series study.

METHODS

Consecutive pediatric patients with bilateral aphakia requiring secondary intraocular lens (IOL) implantation between July 2021 and June 2022 were included. The diameter of the capsular proliferative membranous ring (PMR) and position of IOL implantation were documented. Various parameters of capsular bag opening during primary cataract removal and secondary surgery were also analyzed.

RESULTS

48 eyes were included with a mean follow-up of 8.1 ± 4.4 months. Using the surgical technique developed in this study, the capsular bag was successfully reopened with in-the-bag (ITB) implantation in 43 eyes (89.6%). ITB implantation was accomplished in all eyes with an outer diameter of PMR ≤5.5 mm and in 3 of 8 eyes (37.5%) with an outer diameter of PMR >5.5 mm. A positive correlation was observed between the primary and secondary anterior capsular opening diameters (ACODs) ( r = 0.422, P = .007) and the primary and secondary posterior capsular opening diameters (PCODs) ( r = 0.619, P < .001). The inner diameter of PMR was found to be positively correlated with secondary PCOD ( r = 0.728, P < .001) and the outer diameter with secondary ACOD ( r = 0.669, P < .001).

CONCLUSIONS

This was a safe and effective surgical technique for pediatric secondary IOL implantation with maximum preservation of the peripheral capsule. Aphakic eyes with an outer diameter of PMR ≤5.5 mm are preferred for secondary ITB implantation.

A potential role for inflammatory cytokines in a rare late-onset capsular block syndrome: a case report

BACKGROUND

Late-onset capsule block syndrome (CBS) is a rare complication of cataract phacoemulsification and the implantation of a posterior chamber intraocular lens (PCIOL), which manifests six months to years after surgery. The hallmark of CBS is the formation of an opaque liquid substance between the implanted intraocular lens (IOL) and the posterior capsule. However, its pathogenesis remains unclear.

CASE PRESENTATION

A 64-year-old female patient with chronic angle-closure glaucoma (axis length < 21 mm) underwent trabeculectomy surgery combined with phacoemulsification and PCIOL. After a 4-year follow-up, a decline in visual acuity occurred in her right eye due to the location of opaque fluid in the visual axis and distension of the capsular bag. The initial course of action was to release the trapped fluid. Neodymium: yttrium-aluminum-garnet (Nd: YAG) laser capsulotomy could not be employed due to her non-dilating pupil and high extension of the posterior capsule. Subsequently, anterior capsule peeling and anterior segment vitrectomy surgery were performed. The depth of the anterior chamber (ACD), the distance between the face of the retro-IOL and the posterior capsule, the best-corrected visual acuity (BCVA), and the visual quality (VQ) were measured both before and after surgery. Inflammatory cytokine levels in the opaque substances (OS) trapped between the PCIOL and the posterior capsule were assessed using a flow cytometer and compared to normal statistical data in aqueous humor. After surgery, the patient experienced a significant improvement in BCVA and VQ. The distance between the face of the retro-IOL and the posterior capsule was on the verge of disappearing. However, ACD did not differ between pre- and post-operatively. Interleukin-8 (IL-8) and basic fibroblast growth factor (BFGF) concentrations were higher in the OS than in aqueous humor, especially in the former. However, the concentration of vascular cell adhesion molecule (VCAM) in the OS was lower than in aqueous humor.

CONCLUSIONS

Anterior segment vitrectomy surgery proved to be a successful treatment for late-onset CBS, presenting a challenging case. In the human lens, inflammatory cytokines originating from the opaque substances may contribute to abnormal metabolism in the sealed area, a consequence of late-onset CBS.

Influence of posterior capsule abnormalities in pediatric cataract surgery

PURPOSE

To report how to manage posterior capsule abnormalities (PCAs) in pediatric cataracts and evaluate the influence of PCAs during intraocular lens (IOL) optic implantation in Berger space surgeries.

SETTING

Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China.

DESIGN

Retrospective case series study.

METHODS

Pediatric patients with PCAs who underwent cataract surgery were evaluated. A video-based analysis of the surgical interventions included the type of crystalline lens opacification, types and management of PCAs, complications during primary posterior continuous curvilinear capsulorhexis (PCCC), need for anterior vitrectomy (AV), and feasibility of IOL optic capture.

RESULTS

There were 227 pediatric cataract surgeries performed during the study period, and 76 eyes of 66 children with PCAs were evaluated (33.5%, 76/227). Unilateral cataract with PCAs were found in 50 eyes (22.0%, 50/227) and bilateral were found in 26 eyes (11.5%, 26/227). The PCAs were posterior capsule plaque (19.8%, 45/227), posterior capsule defect (6.2%, 14/227), posterior lenticonus (3.1%, 7/227), and persistent fetal vasculature (4.4%, 10/227). In the PCA cases, primary PCCC was successful in 44.7% of the cases (34/76). An unplanned AV during the surgeries was performed in 47.4% (36) of the 76 eyes. IOL optic implantation in Berger space was achieved in 63.2% of the eyes (48/76).

CONCLUSIONS

PCAs are often encountered during pediatric cataract surgeries, especially in unilateral cases. The presence of PCAs may complicate a primary PCCC procedure, resulting in an unplanned AV in some cases. IOL optic implantation in Berger space can also be performed fortunately with well-designed and skilled operation.

Improvements to a GLCM-based machine-learning approach for quantifying posterior capsule opacification

BACKGROUND

Posterior capsular opacification (PCO) is a common complication following cataract surgery that leads to visual disturbances and decreased quality of vision. The aim of our study was to employ a machine-learning methodology to characterize and validate enhancements applied to the grey-level co-occurrence matrix (GLCM) while assessing its validity in comparison to clinical evaluations for evaluating PCO.

METHODS

One hundred patients diagnosed with age-related cataracts who were scheduled for phacoemulsification surgery were included in the study. Following mydriasis, anterior segment photographs were captured using a high-resolution photographic system. The GLCM was utilized as the feature extractor, and a supported vector machine as the regressor. Three variations, namely, GLCM, GLCM+C (+axial information), and GLCM+V (+regional voting), were analyzed. The reference value for regression was determined by averaging clinical scores obtained through subjective analysis. The relationships between the predicted PCO outcome scores and the ground truth were assessed using Pearson correlation analysis and a Bland-Altman plot, while agreement between them was assessed through the Bland-Altman plot.

RESULTS

Relative to the ground truth, the GLCM, GLCM+C, and GLCM+V methods exhibited correlation coefficients of 0.706, 0.768, and 0.829, respectively. The relationship between the PCO score predicted by the GLCM+V method and the ground truth was statistically significant (p < 0.001). Furthermore, the GLCM+V method demonstrated competitive performance comparable to that of two experienced clinicians (r = 0.825, 0.843) and superior to that of two junior clinicians (r = 0.786, 0.756). Notably, a high level of agreement was observed between predictions and the ground truth, without significant evidence of proportional bias (p > 0.05).

CONCLUSIONS

Overall, our findings suggest that a machine-learning approach incorporating the GLCM, specifically the GLCM+V method, holds promise as an objective and reliable tool for assessing PCO progression. Further studies in larger patient cohorts are warranted to validate these findings and explore their potential clinical applications.

Preventing the Argentinian flag sign and managing anterior capsular tears: A review

The Argentinian flag sign (AFS) is a feared complication during cataract extraction. Intralenticular pressures, especially excessive posterior pressure, have been identified as potential mechanisms for capsular stress and tearing associated with AFS. Capsular tension is created by positive intralenticular pressures, which cause the irido-lens diaphragm to move anteriorly once the manual capsulorhexis has been initiated. This tension can cause inadvertent tears that self-propagate to the lens equator, causing an AFS, among other intraoperative complications. Thus, this review highlights the importance of identifying intumescent cataracts as well as a combination of techniques to relieve intracapsular pressures needed to prevent AFS. However, some instances of anterior capsular tears are unavoidable. Therefore, focus will also be placed on techniques during cataract extraction used to manage anterior capsular tears, mitigating extension to the posterior capsule.

Flow capsulorhexis: A novel technique in white and hypermature cataracts

We described a novel "flow capsulorhexis" technique in white and hypermature cataracts and compared it with the standard "needle decompression capsulorhexis" technique. Six hundred and eight eyes of 420 patients with intumescent or non-intumescent mature white cataracts who had undergone phacoemulsification or manual small incision cataract surgery with "flow capsulorhexis" (Group 1) or "needle decompression capsulorhexis" (Group 2) were assessed. The mean continuous curvilinear capsulorhexis (CCC) completion time was 6.6 ± 3.4 seconds in Group 1 and 10.4 ± 4.2 seconds in Group 2 (P < 0.001). The mean number of times for an ophthalmic viscosurgical device (OVD) supplement was 0.4 ± 0.2 and 1.8 ± 0.8 in Group 1 and Group 2, respectively (P < 0.001). CCC success rate was 95.8% in Group 1 and 87.2% in Group 2 (P = 0.001). The new technique was observed to have better outcomes in terms of surgical time, OVD supplement times, and success rate than the standard needle decompression technique.

Influence of Nd:YAG laser capsulotomy on toric intraocular lens rotation and change in cylinder power

PURPOSE

To investigate toric monofocal intraocular lens (TIOL) rotation and associated changes in cylinder power caused by Nd:YAG laser capsulotomy performed due to posterior capsule opacification (PCO).

SETTING

Ekol Eye Hospital, Izmir, Turkey.

DESIGN

Prospective case series.

METHODS

41 eyes of 20 women and 21 men were included in the study. Before and 1 month after Nd:YAG laser capsulotomy, TIOL tilt and decentration were determined with Scheimpflug camera, and TIOL axial rotation and the change in cylinder power induced by this rotation were measured by ray tracing aberrometry. The time interval between cataract surgery and Nd:YAG laser capsulotomy was noted.

RESULTS

Rotational misalignment of the TIOL was measured as 4.65 ± 2.75 degrees (range 0 to 11 degrees) before vs 6.97 ± 2.92 degrees (range 0 to 13 degrees) after capsulotomy, and absolute rotation was 2.75 ± 1.94 degrees (range 0 to 7 degrees, P = .028). Before and after Nd:YAG laser capsulotomy, cylinder power was 0.24 ± 0.70 diopter (D) (range 0.00 to 0.63 D) vs 0.56 ± 0.77 D (range 0.02 to 0.91 D), respectively, with an absolute change in cylinder power of 0.34 ± 0.22 D (range 0.01 to 0.90 D, P = .001). After capsulotomy, there was a significant decrease in IOL tilt in the horizontal and vertical planes and an increase in decentration ( P < .05). Time interval (33.02 ± 12.9 months) and IOL horizontal decentration were independent factors affecting IOL rotation after capsulotomy ( P < .05).

CONCLUSIONS

Nd:YAG laser capsulotomy may cause TIOL rotation as well as tilt and decentration, resulting in a change in the TIOL's corrective effect on corneal astigmatism. Although this change was clinically insignificant, it may be beneficial to consider that TIOL rotational misalignment may occur in patients undergoing early capsulotomy.

Surgical challenges of posterior optic capture in pediatric cataract surgery

PURPOSE

The efficacy of posterior optic capture (POC) in reducing posterior capsule opacification (PCO) in pediatric cataract is well recognized. The purpose of this paper was to identify the surgical challenges when attempting this technique and highlight the etiquettes to follow when performing this maneuver.

METHODS

Prospective observational noncomparative case series. Children diagnosed with congenital or developmental cataracts undergoing cataract surgery and primary IOL implantation with posterior optic capture (and no anterior vitrectomy) from June 2017 to April 2022 at a tertiary care referral institute were included. Records of all intraoperative findings and postoperative complications until the last follow-up were noted.

RESULTS

Posterior optic capture was attempted in 53 eyes of 49 children aged 2.4 ± 1.98 years. The mean follow-up of the patients was 16.5 ± 14.2 months (range 6 months-5 years). Successful POC could be performed in 46 eyes (86.8%). Two eyes developed posterior capsular opacification at the last follow-up. In eyes where POC could not be performed, five of these (83%) were children below 12 months of age with half of them having a preexisting posterior capsular defect.

CONCLUSION

Posterior optic capture is technically challenging with a steep learning curve that can be mastered over time. Adequate relative sizing of the anterior and posterior capsulorhexis is important. Caution is advised when using this technique in infants and in cases with posterior capsular defects.

Video analysis of optic-haptic-interaction during hydrophobic acrylic intraocular lens implantation using preloaded injectors

OBJECTIVE

To compare the optic-haptic interaction of different hydrophobic acrylic IOLs after using six preloaded injectors.

METHODS

We reviewed the video-recordings of procedures on a total of 388 eyes that underwent phacoemulsification and intraocular lens (IOL) implantation. For six preloaded injectors: multiSert (Hoya Surgical Optics) [System 1], TECNIS Simplicity (Johnson & Johnson Vision) [System 2], TECNIS iTec (Johnson & Johnson Vision) [System 3], AutonoMe (Alcon, Laboratories) [System 4], Bluesert (Carl Zeiss Meditec) [System 5], and Prosert (OphthalmoPro GmbH) [System 6], we noted in each case the time of IOL delivery and made a descriptive observation of IOL insertion and optic-haptic-interaction.

RESULTS

We defined standard haptic behavior where the haptics emerged "folded" from the injector and quickly recovered their pre-implantation appearance. The incidence where the leading haptic emerged in a deformed way for System 1 was 20%, System 2: 19%, System 3: 14%, System 4: 56%, System 5: 24% and System 6: 5%. For trailing haptic deformed behavior, the incidence was 36%, 6%, 4%, 8%, 18% and 2%, respectively for Systems 1 to 6. Optic-haptic adhesion occurred in 2% of cases for System 1, 44% for System 2, 52% for System 3, 48% for System 4, and 11% for System 6 (P < 0.05). Adhesion was not found with System 5.

CONCLUSIONS

We observed different deformed behavior for leading and trailing haptics in the six preloaded systems, some systems had as much as 52% optic-haptic adhesion.

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.

Passive CAP-VAC: a simple and safe technique to clean the posterior capsule

PURPOSE

To describe a new and less risky technique for the cleaning of posterior capsule during phacoemulsification called passive cap vac.

METHOD

Passive cap vac consisted in the removal of residual posterior capsule opacities using a disconnected 0.3 mm aspiration cannula. The hole of the aspiration cannula was faced toward posterior capsule and gently rubbed against it to achieve a complete cleaning of posterior capsule. The video of the technique is available online.

RESULT

With this new technique, the aspiration was ruled by the gravity and by the height of the balanced saline solution (BSS), in addition the Venturi's effect and the absence of active aspiration beyond the cannula avoided an excessive aspiration of posterior capsule.

CONCLUSION

Passive cap vac allowed to clean posterior capsule using softer forces than traditional way, minimizing the risk of capsular tear.

Evaluation of continuous curvilinear capsulorhexis based on a neural-network

PURPOSE

Continuous curvilinear capsulorhexis (CCC), as a prerequisite for successful cataract surgery, is one of the most important and difficult steps in phacoemulsification. In clinical practice, the size and circularity of the capsular tear and eccentricity with the lens are often employed as indicators to evaluate the effect of CCC.

METHODS

We present a neural network-based model to improve the efficiency and accuracy of evaluation for capsulorhexis results. The capsulorhexis results evaluation model consists of the detection network based on U-Net and the nonlinear fitter built from fully connected layers. The detection network is responsible for detecting the positions of the round capsular tear and lens margin, and the nonlinear fitter is utilized to fit the outputs of the detection network and to compute the capsulorhexis results evaluation indicators. We evaluate the proposed model on an artificial eye phantom and compare its performance with the medical evaluation method.

RESULTS

The experimental results show that the average detection error of the proposed evaluation model is within 0.04 mm. Compared with the medical method (the average detection error is 0.28 mm), the detection accuracy of the proposed evaluation model is more accurate and stable.

CONCLUSION

We propose a neural network-based capsulorhexis results evaluation model to improve the accuracy of evaluation for capsulorhexis results. The results of the evaluation experiments show that the proposed results evaluation model evaluates of the effect of capsulorhexis better than the medical evaluation method.

Posterior Capsulotomy Size Affects the Formation of Significant Visual Axis Opacification in Congenital and Developmental Cataract

PURPOSE

To assess the relationship between posterior capsulotomy size and significant visual axis opacification (VAO) in congenital and developmental cataract.

METHODS

The charts of children aged 7 years and younger who underwent cataract surgery including primary posterior capsulotomy (PPC) and limited anterior vitrectomy between 2012 and 2022 were retrospectively reviewed. Eyes with PPC size smaller than the anterior capsulotomy size were considered as group 1. Eyes with PPC size larger than the anterior capsulotomy size were considered as group 2. Clinical characteristics, the need for Nd:YAG laser treatment or further surgery for significant VAO, and other postoperative complications were compared between the groups.

RESULTS

Sixty eyes of 41 children were included in the study. The median age at the time of surgery was 5.5 and 3 years in groups 1 and 2, respectively (P = .076). Primary intraocular lens implantation was performed in 23 (85.2%) eyes in group 1 and 25 (75.8%) eyes in group 2 (P = .364). There was no difference between the groups in terms of postoperative visual acuity (P = .983) and refractive errors (P = .154). Eight (29.6%) pseudophakic eyes received Nd:YAG laser treatment in group 1, but none of the eyes in group 2 (P = .001). Four (14.8%) eyes in group 1 and 1 (3%) eye in group 2 underwent further surgery for VAO (P = .100). The need for further intervention for significant VAO was statistically higher in group 1 (44.4% vs 3%, P < .001).

CONCLUSIONS

Larger PPC size in pediatric cataract may reduce the need for further intervention for significant VAO. [J Pediatr Ophthalmol Strabismus. 2023;60(6):441-447.].

Incidence of Nd:YAG laser capsulotomy following cataract surgery: a population-based nation-wide study - FreYAG1 study

RATIONALE

Nd:YAG (neodymium:yttrium-aluminum-garnet) capsulotomy (Nd:YAG-caps) is the gold standard for the treatment of PCO (Posterior Capsule Opacification). There is a lack of real-world data about Nd:YAG-caps use.

PURPOSE

This study's objectives were to estimate Nd:YAG-caps incidence in France, to describe the patient characteristics, and to analyze the time between surgeries and capsulotomies.

SETTING

The study was based on data extracted from the EGB database, a 1/97th sample representative of the French population.

DESIGN

observational, retrospective, cohort study using national claims data.

METHODS

French adult patients who underwent Nd:YAG-caps between 2014 and 2017 were selected. Main outcomes were the number of patients and procedures performed and the risk factors associated with early Nd:YAG-caps.

RESULTS

During the study period, Nd:YAG-caps were performed in 8,425 patients accounting for 10,774 procedures. The extrapolation to the French population led to estimate that 253.103 patients had Nd:YAG-caps, representing 312.103 procedures in 2017. The mean age at Nd:YAG-caps was 75.1 (± 10.2) years. About 36% of patients presented at least one ocular comorbidity. Nd:YAG-caps was performed within 2 years after surgery in 33.0% of patients and within one year in 9.8% of patients. Patients with Nd:YAG-caps within the first year (OR CI95 0.721 [0.673-0.772]) or in the first two years (OR CI95 0.721 [0.673-0.772]) were younger than patients with later Nd:YAG-caps and had a more frequent history of treated ocular diseases (OR 1.516 and 1.178, respectively).

CONCLUSIONS

This study brought new real-world and large-scale data regarding Nd:YAG-caps use and gave an updated insight into the patients' characteristics.

Dead bag syndrome-in the capsular bag subluxated intraocular lens centration and refixation: A new technique

We describe a technique of scleral IOL fixation and optic centration of in the capsular bag subluxated IOL in a patient of "dead bag syndrome." A 29-year-old male diagnosed case of thalassemia presented with painless progressive diminution of vision in the left eye following uncomplicated sequential phacoemulsification in both eyes 15 years back. The right eye revealed completely centered IOL with significant amount of anterior capsular opacification (ACO), while the left eye revealed inferior subluxation of the IOL within capsular bag. The capsular bag was dilated, diaphanous with clear anterior and posterior capsule without any evidence of capsular fibrosis or opacification. Thus, a diagnosis of "dead bag syndrome" was made. The haptics were sutured to sclera (Hoffman's pockets) using two loops of 9-0 polypropylene, passed anterior and posterior to IOL haptics within the capsular bag. Postoperatively, the patient had a vision of 20/40 with a centered intraocular lens.

Nd:YAG Laser Capsulotomy: Efficacy and Outcomes Performed by Optometrists

SIGNIFICANCE

An increasing number of optometrists are performing Nd:YAG laser capsulotomy procedures; however, there is limited published information on the outcomes of these procedures.

PURPOSE

This study aimed to assess the efficacy and safety of capsulotomy procedures performed by optometrists.

METHODS

Subjects diagnosed with posterior capsule opacification causing reduced vision and subjective visual complaints were recruited for this study. A baseline examination was performed to ensure that the subjects met all the necessary criteria. The procedure was performed by a licensed doctor of optometry at six different clinics, and each subject was monitored for visual outcome and any potential complications.

RESULTS

Subjects' Snellen visual acuity improved from an average of 20/40 to 20/23 ( P < .001) with no complications of increased intraocular pressure, inflammation, visually significant lens pitting, macular edema, or retinal detachment. Of 78 subjects who responded to a post-procedure survey, 77 (99%) reported subjective improvement in vision after capsulotomy.

CONCLUSIONS

Based on the outcomes of this study, YAG laser capsulotomies are effective treatments to improve patient vision that can be safely and effectively performed by optometrists.

Relationship between anterior capsule opening and direction of intraocular lens decentration

PURPOSE

To compare intraocular lens (IOL) decentration between patients in whom the continuous curvilinear capsulorhexis (CCC) completely covers the IOL optic and those in whom it incompletely covers the IOL optic and determine how an incompletely covered CCC affects the IOL position.

SETTING

Tertiary hospital in Japan.

DESIGN

Single-center retrospective study.

METHODS

57 eyes of 57 patients (mean age 70.8 ± 6.2 years) that underwent phacoemulsification and IOL (SN60WF) implantation in the bag between April 2010 and April 2015 were included in this study. The patients were classified based on whether the CCC completely (CC group) or incompletely (NCC group) covered the IOL optic using an anterior eye segment analysis system (EAS-1000). The IOL decentration of the groups was analyzed using EAS-1000 at 1 week, 1 month, 3 months, and 6 months postoperatively and compared. The relationship between the NCC location and the IOL direction at 3 months postoperatively was analyzed.

RESULTS

The NCC group (25 eyes) had a significantly higher amount of IOL decentration than the CC group (32 eyes) at 1 week, 1 month, 3 months, and 6 months postoperatively ( P < .05). There was a correlation between the direction of IOL decentration and the NCC location, and IOL decentration in the NCC group occurred in the opposite direction to the NCC area.

CONCLUSIONS

An anterior capsule opening that completely covers the IOL optic is important to control IOL decentration.

Assessing the validity of flap motility sign in predicting the extent of anterior capsular tears in phacoemulsification

Capsulorhexis is an integral step of cataract surgery, and continuous curvilinear capsulorhexis is crucial during phacoemulsification to prevent intraoperative complications. However, sometimes during phacoemulsification in complicated and hard cataract cases, rhexis extension may occur, resulting in posterior capsular rent, nucleus drop, cortex drop, and aphakia. It may not always be possible to continue with phacoemulsification in all cases. In this perspective, the authors describe a novel flap motility sign (FMS) to predict the extent of anterior capsular tear during phacoemulsification. A total of 21,678 patients underwent phacoemulsification for three years, from July 2016 to June 2019. One hundred and twenty-one patients had an anterior capsular tear. There were 102 cases (84.3%) with pre-equatorial tears and 19 cases (15.70%) with postequatorial tears. All pre-equatorial flaps were everted and fluttering, and all postequatorial flaps were inverted and nonfluttering. Posterior capsule rupture (PCR) was observed in all 19 cases of postequatorial flaps (100%). No PCR was observed in patients with fluttering and everted flaps (0%). In-the-bag and scleral-fixated intraocular lens implantations succeeded in pre-equatorial and postequatorial tears, respectively. There was no case of a nucleus drop. This study validates FMS as a predictor for identifying the extent of anterior capsular tears, thereby determining the endpoint of safe phacoemulsification and the site for intraocular lens implantation. Pre-equatorial tears allow for the continuation of safe phacoemulsification and in-the-bag intraocular implantation. Postequatorial tears necessitate timely conversion to small-incision cataract surgery or extracapsular cataract extraction.

Acute Effects of Neodymium-Doped Yttrium Aluminum Garnet Laser Capsulotomy on Anterior Segment Parameters in Capsular Bag Distension Syndrome

Background: Capsular bag distension syndrome (CBDS) can be effectively treated using either Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser capsulotomy or surgery. Assessing anterior segment, particularly immediately after Nd:YAG laser capsulotomy, could provide clinically relevant information on ocular dynamics, refractive changes, and complication mechanisms, especially in late postoperative CBDS. Objective: To explore the acute effects of Nd:YAG laser posterior capsulotomy on anterior segment parameters in late postoperative CBDS. Methods and results: In this study, 20 patients underwent Nd:YAG laser posterior capsulotomy after cycloplegia, during which milky-white fluid material migrated into the anterior vitreous. Anterior segment parameters were assessed before and immediately after laser using Scheimpflug-Placido topographer. The main outcome measures were differences in best-corrected visual acuity (BCVA), aqueous depth (AqD), anterior chamber volume (ACV), iridocorneal angle (ICA), corneal volume (CV), and central corneal thickness (CCT) at the baseline versus at immediately after laser. The mean age and duration since surgery for CBDS presentation were 70.25 ± 6.21 and 6.15 ± 1.31 years, respectively. The AqD, ACV, ICA, and spherical equivalent increased significantly compared with baseline (4.18 vs. 4.02 mm, p = 0.001; 177 vs. 173.55 mm3, p = 0.004; 51.15° vs. 50.15°, p = 0.023; -1.00 vs. -2.00 D, p = 0.003, respectively). These changes were also associated with significantly improved BCVA an hour after capsulotomy [0.2 (0.05-0.2)] relative to baseline [0.3 (0.2-0.5)], (p = 0.001). CCT and CV decreased nonsignificantly; horizontal AC diameter and K1 and K2 increased nonsignificantly (p > 0.05). Conclusions: Nd:YAG laser posterior capsulotomy appears to be an effective CBDS treatment for acutely improving vision, potentially due to immediate refractive changes caused by altered anterior segment parameters.

Rotating the Intraocular Lens to Prevent Posterior Capsular Opacification in Cataract Surgeries

Posterior capsule opacification (PCO) is a common postoperative complication of extracapsular cataract surgery, which is caused by the proliferation and migration of lens epithelial cells and can affect long-term visual outcomes significantly. The most effective treatment for PCO is neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy; however, this treatment is associated with posterior segment complication and can break the stability of capsular bag, affecting the position and function of trifocal or toric intraocular lenses (IOLs). Advances in surgical procedures, IOL design, and pharmacy have reduced the rate of PCO in recent years, concentrating on the inhibition of proliferative lens epithelial cells (LECs). This protocol aimed to clear LECs more thoroughly during phacoemulsification and IOL implantation. The first several steps, including clear corneal incision, continuous circular capsulorhexis, hydrodissection, hydrodelineation, and phacoemulsification, were completed as conventional procedures. After placing the IOL into the capsular bag, rotation of the IOL by at least 360° was performed using an irrigation/aspiration tip or a hook, with slight stress on the posterior capsule. Some residuals occurred in the originally transparent capsular bag after rotation of the IOLs. Then, these materials and the viscoelastic were cleared completely using an irrigation/aspiration system. A clear posterior capsule was observed after the surgery in patients undergoing this method. This method of rotating IOLs is a simple, effective, and safe way to prevent PCO by clearing residual LECs and can be carried out without extra tools or skills.

The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: Report 9, Risk factors for posterior capsule opacification

BACKGROUND/OBJECTIVES

Posterior Capsule Opacification (PCO) is the most common long-term post-operative adverse occurrence after cataract surgery often requiring treatment with YAG laser posterior capsulotomy. This study aimed to identify potential risk factors, known at the time of cataract surgery, that influence the development of PCO.

SUBJECT/METHODS

A retrospective study of publicly funded cataract surgery from The Royal College of Ophthalmologists' National Ophthalmology Database. Eligible for analysis were 500,872 cataract operations performed in 41 participating centres.

RESULTS

The 500,872 operations were performed on 243,167 (48.5%) left eyes and 257,705 (51.5%) right eyes from 373,579 patients by 2196 surgeons. Post-cataract PCO was recorded for 61,778 (12.3%) eyes and the six month, one, three, five and nine year observed rates of PCO were 2.3%, 4.4%, 19.7%, 34.0% and 46.9% respectively. Different PCO profiles were observed between IOL materials and the identified risk factors that increased the risk of developing PCO included hydrophilic IOL material, axial length >26 mm, the presence of high myopia and implantation of lower IOL powers and previous vitrectomy surgery, along with younger age and female gender.

CONCLUSIONS

Many factors influence the development of PCO relating to the patient, the eye, the lens and the surgery. Some factors are modifiable such as IOL material, therefore the opportunity exists to attempt to reduce PCO rates, benefitting patients and the UK NHS.

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.

Different strokes for anterior capsulorhexis in pediatric cataract

Background

A successful outcome in pediatric cataract surgery is determined by an intact, curvilinear anterior capsulotomy which is dependent on the type and density of cataract, the morphology of the anterior capsule, and associated anterior segment pathologies.

Purpose

This video highlights 10 different techniques which can be used for capsulorhexis in pediatric cataract.

Synopsis

The choice of technique for capsulorhexis in pediatric cataract is on case basis, namely the gold standard manual capsulotomy aided by rhexis forceps (1. Standard capsulorhexis/2. Vitrector, Vitrectorhexis), with an assistance from capsular staining (3. Blue-rhexis), or by coaxial illumination (4. Coaxial-rhexis) or by just the sheen of capsule (5. Sheen-rhexis). The anterior chamber can be maintained using ophthalmic visco-elastic device (Visco-rhexis) or by irrigation fluid (6. Hydro-rhexis). A speed-breaker in the routine capsulotomy is the presence of plaque which is managed by rhexis forceps (7. Plaque-rhexis) or by a vitrector (vitrectorhexis) or a pair of micro-scissors (8. Scissor rhexis). Above all, the technology of femto-second-laser-assisted (9. Femto-rhexis) and zepto-pulse-precision capsulotomy (10. Zepto-rhexis) is also illustrated.

Highlights

This video highlights the 10 different techniques of capsulorhexis in pediatric cataract surgery.

Video Link

https://youtu.be/TgDrk5RYdbI.

Nd:YAG laser capsulotomy rates in the Netherlands: practice variation and association with physician practice styles

PURPOSE

To determine the practice variation in the rate of Nd:YAG laser capsulotomy within 1 year after cataract surgery and to identify possible associations with physician practice styles.

SETTING

All hospitals and private clinics in the Netherlands.

DESIGN

Retrospective observational study.

METHODS

In the national medical claims database, we identified all laser capsulotomies performed in the Netherlands within a year after cataract surgery in the years 2016 and 2017. Centers with the lowest and highest percentages of Nd:YAG laser capsulotomies were interviewed on their physician practice styles related to the development of posterior capsule opacification.

RESULTS

The incidence of Nd:YAG laser capsulotomy varied between 1.2% and 26.0% in 2016 (median 5.0%) and between 0.9% and 22.7% in 2017 (median 5.0%). The rate of capsulotomy was highly consistent over time for each center (Pearson correlation coefficient, 0.89, P < .001). In general, ophthalmology centers with a high rate of Nd:YAG laser capsulotomy more often did not (routinely) polish the posterior lens capsule, performed cortex removal with coaxial irrigation/aspiration (I/A, instead of bimanual), and more often used hydrophilic intraocular lenses (IOLs) (compared with only using hydrophobic IOLs).

CONCLUSIONS

We found a significant practice variation in performing Nd:YAG laser capsulotomy within 1 year after cataract surgery in the Netherlands. Routinely polishing the posterior capsule, using bimanual I/A, and the use of hydrophobic IOLs are associated with a lower incidence in Nd:YAG laser capsulotomy. Incorporating these practice styles may lower the practice variation and thus prevent added medical burden for the patient and decrease costs.

NEW, SIMPLE, AND SAFE SURGICAL TECHNIQUE FOR THE REMOVAL OF A DISLOCATED CAPSULAR TENSION RING-INTRAOCULAR LENS-CAPSULAR BAG COMPLEX

BACKGROUND/PURPOSE

To report a safe and simple surgical technique for the removal of a dislocated capsular tension ring (CTR)-intraocular lens (IOL)-capsular bag (CB) complex.

METHODS

We present an extraocular surgical removal technique for a dislocated CTR-IOL-CB complex. Although the entire complex is typically removed with a large incision, this approach applies a CTR injector and anterior capsule forceps in a less invasive manner.

RESULTS

After vitrectomy, the complex was moved to the anterior chamber, where the tip of the CTR was separated from the IOL-CB using anterior capsule forceps and hooked onto the tip of the CTR injector. Subsequently, the CTR, as well as part of the CB, was gradually separated from the IOL-CB and stored in the CTR injector. This was completed while also supporting the IOL-CB complex using the forceps. Once the whole CTR and the part of CB were removed from the anterior chamber, the residual IOL and CB were then removed.

CONCLUSION

Our methodology, using the CTR injector and anterior capsule forceps, enables the procedure to be completed with only a small corneal incision, thereby allowing for the safe and simple removal of a CTR-IOL-CB complex.

Capsular tension ring as protective measure against in-the-bag dislocations after cataract surgery

PURPOSE

To assess the influence of capsular tension ring (CTR) implantation on the development of in-the-bag (ITB) dislocations after cataract surgery.

SETTING

Department of Ophthalmology Graz, Graz, Austria.

DESIGN

Single-center, retrospective cohort study.

METHODS

The medical records of patients who underwent cataract operation between 1996 and 2017 were analyzed. Cox proportional hazards regression analysis was used to assess the influence of CTR implantation and other predisposing factors (pseudoexfoliation [PEX], age, retinitis pigmentosa, sex, zonular weakness, uveitis, high myopia, and intraocular lens design and material) on ITB dislocations.

RESULTS

ITB dislocations were found in 111 (0.16%) of 68199 eyes (46 632 patients). In the multivariate analysis adjusted for other predisposing risk factors, a CTR implantation was associated with a lower risk of an ITB dislocation (hazard ratio [HR], 0.29; 95% CI, 0.11-0.80; P = .017). In eyes with PEX, a CTR implantation was associated with an HR of 0.16 (95% CI, 0.04-0.70; P = .015), whereas eyes without PEX had an HR of 0.80 (95% CI, 0.14-4.41; P = .793). A CTR implantation in eyes with zonular weakness resulted in a potentially lower risk (HR, 0.37; 95% CI, 0.12-1.12; P = .078).

CONCLUSIONS

According to the dataset, implantation of a CTR was a protective measure against an ITB dislocation. Especially in patients with zonular weakness and PEX, the CTR implantation was association with a lower risk of ITB dislocations. In patients without PEX, no association was established.

Advances in interdisciplinary medical and engineering research of intraocular lens surface modifications to prevent posterior capsule opacification

Posterior capsule opacification (PCO), a common complication after cataract surgery, impacts a patient's long-term visual quality to various degrees. Although a neodymium:yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy is a very effective treatment, it may lead to a serial of complications. Accordingly, the search for simple, safe, and effective methods to prevent PCO has received widespread attention. Various researchers are committed to the interdisciplinary collaboration between medicine and engineering fields, such as functionalizing the surface of the intraocular lens (IOL) via supercritical fluid impregnation, coating the surface of the IOL, high-concentration drug immersion, and application of a drug delivery system, to effectively reduce the incidence and severity of PCO.

[A case of dislocation of the empty capsular bag into the anterior chamber]

A highly myopic patient complained of 2 months of visual acuity loss and 4 months of ocular pain in the right eye after 16 years after bilateral cataract extraction. The slit lamp microscopy examination showed a residual lens capsule dislocation in the right anterior chamber of the eye, which was diagnosed as a residual lens capsule dislocation in the right eye. After diagnosis and timely treatment, the patient's postoperative vision and visual field recovered well.

An Experimental Laboratory Study Using the Miyake-Apple Posterior View Technique to Investigate the Dynamics Between Capsular Bags and Different IOL Models

PURPOSE

To evaluate the dynamics between capsular bags and different intraocular lens (IOL) models in human cadaver eyes using the Miyake-Apple posterior view technique.

METHODS

In an in vitro laboratory study, human cadaver eyes were prepared according to the Miyake-Apple posterior view technique. Five IOLs from each of the six groups (Avansee 1P [Simonvision], Avansee 3P [Simonvision], CT Lucia [Carl Zeiss Meditec], Acrysof [Alcon Laboratories, Inc], RayOne [Rayner], and CT Asphina [Carl Zeiss Meditec]) were implanted into capsular bags with different diameters. The empty capsular bag diameter and capsular bag diameter with an IOL in it were evaluated based on the Miyake-Apple view pictures. Posterior capsule striae were observed and compared between groups. The arc of contact between IOLs and the capsular equator was noted. Correlations between the empty capsular bag diameter and the capsular bag diameter with IOL, as well as between the empty capsular bag diameter and the arc of contact, were examined. With the Avansee 3P as a reference, the area deviation of the haptics of IOL models with looped haptics was compared.

RESULTS

The capsular bag diameter with IOL inside and the arc of contact were proportional to the empty capsular bag diameter. The RayOne, Avansee 3P, and CT Lucia showed a longer arc of contact. Posterior capsule striae were observed in the Avansee 1P (1, 20%), Avansee 3P (5, 100%), Acrysof (1, 20%), and RayOne (2, 40%). Areas of deviation were 0.38 mm² (Avansee 1P), 0.24 mm² (CT Lucia), 0.34 mm² (Acrysof), and 0.31 mm² (RayOne), respectively.

CONCLUSIONS

Different IOL models showed varied characteristics in terms of capsular bag fitting and arc of contact. Understanding these dynamics is critical to optimizing postoperative outcomes. [J Refract Surg. 2022;38(10):654-660.].

Age-related appearance of lamellar structures in lens capsule of cataractous eyes and its pathological significance

PURPOSE

To determine morphological changes in the lens capsule with aging.

SETTING

Hayashi Eye Hospital, Fukuoka, Japan.

DESIGN

Cross-sectional study.

METHODS

25 eyes from the older patient group (aged 80 years or older) and 25 eyes from the younger patient group (aged 65 years or younger) who were diagnosed with cataract and indicated for surgery were included in the study. After continuous curvilinear capsulorhexis, the anterior lens capsule was collected, immediately fixed, and processed for electron microscopy analysis. Backscattered electron images of the cross-section of the anterior lens capsule were observed under a scanning electron microscope. The ultrastructure of the anterior lens capsule was observed and compared between the groups. Factors associated with the occurrence of the lamellar structure were also identified, with the presence or absence of a lamellar structure as an objective variable and preoperative clinical characteristics as the explanatory variables.

RESULTS

50 eyes of 50 patients were included. In the younger patient group, 20 eyes (80%) had a homogeneous lens capsule, whereas 5 eyes had lamellar structures. By contrast, in the older patient group, 5 eyes had homogeneous structures, while the remaining 20 eyes (80%) had lamellar structures. 1 eye showed capsular delamination. The only significant factor for the occurrence of lamellar structures was age group ( P < .01, nominal logistic regression analysis).

CONCLUSIONS

Lamellar structures appear in the anterior capsule during aging. The appearance of lamellar structures indicates fragility of the lens capsule, which may, in turn, lead to capsular delamination or lens dislocation in some cases.

Refraction Shift After Nd:YAG Posterior Capsulotomy in Pseudophakic Eyes: A Systematic Review and Meta-analysis

PURPOSE

To explore ocular refraction shift after Neodymium: yttrium aluminum garnet (Nd:YAG) posterior capsulotomy in pseudophakic eyes.

METHODS

A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases until November 10, 2021. Studies on the evaluation of changes in spherical equivalent (SE), cylindrical error (CE), or anterior chamber depth (ACD) after Nd:YAG laser capsulotomy were included in the meta-analysis. The review was registered in the international platform of registered systematic review and meta-analysis protocols (INPLASY202120059).

RESULTS

A total of 805 eyes from 18 studies were included in the final analysis. The pooled mean differences in SE from baseline to postoperative follow-up points were not significant (1 hour: 0.04 diopters [D], 95% CI: -0.13 to 0.21, P = .644; 1 week: 0.04 D, 95% CI: -0.12 to 0.20, P = .640; 1 month: 0.05 D, 95% CI: -0.06 to 0.16, P = .349). There was no significant difference between baseline CE and any subsequent visit (1 week: 0.14 D, 95% CI: -0.06 to 0.33, P = .172; 1 month: 0.17 D, 95% CI: -0.04 to 0.38, P = .108). No statistical difference in ACD from baseline was observed either (1 hour: 0.01 mm, 95% CI: -0.07 to 0.09, P = .846; 1 week: -0.12 mm, 95% CI: -0.24 to 0.01, P = .079; 1 month: -0.06, 95% CI: -0.14 to 0.01, P = .110).

CONCLUSIONS

Neither ocular refraction nor ACD changed within 1 month after laser capsulotomy, suggesting laser capsulotomy did not affect ocular refraction in short-term observation. [J Refract Surg. 2022;38(7):465-473.].

Late capsular blockage syndrome: Clinical and anterior segment optical coherence tomography characteristics

BACKGROUND

Late capsular blockage syndrome (CBS) is a rare phenomenon which is found after cataract surgery. The mechanism, anterior segment optical coherence tomography (OCT) presentation, and clinical characteristics are not well studied.

METHODS

We studied patients who developed late CBS in Taipei Veterans General Hospital from 2012 to 2019. Age, sex, systemic disease, ocular disease, interval between cataract surgery and CBS, axial length, type of intraocular lens implanted, grading of posterior capsular opacity, refraction, visual acuity, and anterior segment OCT findings were documented. Patients are categorized into two groups according to anterior segment OCT findings. All patients underwent Nd:YAG laser capsulotomy and were prescribed a low-dose topical steroid for 7 days. Postcapsulotomy refraction and visual acuity were recorded. All the clinical data were compared in the two groups.

RESULTS

This study included 18 eyes with late CBS. Patients' median age was 80 (range, 54-92) years. The mean duration between cataract surgery and CBS diagnosis was 80.28 (range 15-136) months. According to anterior segment OCT findings, we subcategorized the patients into two groups: gravel appearance (n = 7) and milky (n = 11) appearance. After laser capsulotomy, mean visual acuity improved 0.18 ± 0.10 on the LogMAR. A significant myopic shift in refraction after laser capsulotomy was noted in the gravel appearance group compared to the milky appearance group ( p = 0.027). No patient developed complications or needed further treatment for CBS during the median follow-up of 14.5 months (range 1-84 months).

CONCLUSION

High-resolution anterior segment OCT is useful for analyzing patients with late CBS. Our study implies that the two types of CBS presentation indicate different causes of late CBS formation, as well as distinct clinical presentation and postlaser capsulotomy refractive outcome. In addition, YAG laser capsulotomy is a safe late CBS treatment modality.

Predicting the biomechanical stability of IOLs inside the postcataract capsular bag with a finite element model

BACKGROUND AND OBJECTIVES

Although cataract surgery is a safe operation in developed countries, there is still room for improvement in terms of patient satisfaction. One of the key issues is assessing the biomechanical stability of the IOL within the capsular bag to avoid refractive errors that lead to a second surgery. For that purpose, a numerical model was developed to predict IOL position inside the capsular bag in the short- and long-term.

METHODS

A finite element model containing the implanted IOL, the postcataract capsular bag, the zonules, and a portion of the ciliary body was designed. The C-loop hydrophobic LUCIA IOL was used to validate the numerical model and two more worldwide IOL designs were tested: the double C-loop hydrophobic POD FT IOL and the plate hydrophilic AT LISA IOL. To analyze the biomechanical stability in the long-term, the effect of the fusion footprint, which occurs days following cataract surgery, was simulated. Moreover, several scenarios were analyzed: the size and location of the capsulorexhis, the capsular bag diameter, the initial geometry of the capsular bag, and the material properties of the bag.

RESULTS

The biomechanical stability of the LUCIA IOL was simulated and successfully compared with the in vitro results. The plate AT LISA design deformed the capsular bag diameter up to 11.0 mm against 10.5 mm for the other designs. This design presented higher axial displacement and lower rotation, 0.19 mm and 0.2^∘, than the C-loop design, 0.09 mm and 0.9^∘.

CONCLUSIONS

All optomechanical biomarkers were optimal, assuring good optical performance of the three IOLs under investigation. Our findings showed that the capsulorexhis size influences the stiffness of the capsular bag; however, the shape in the anterior and posterior curvature surfaces of the bag barely affect. The results also suggested that the IOL is prone to mechanical perturbations with the fusion footprint, but they were not high enough to produce a significant refractive error. The proposed model could be a breakthrough in the selection of haptic design according to patient criteria.

Dynamic changes of Elschnig pearls posterior capsule opacification

An adolescent female with underlying bilateral pseudophakia and idiopathic intermediate uveitis had reduced visual acuity due to posterior capsule opacification (PCO). The rapid progression and different morphological formations of Elschnig pearls were not influenced by the uveitis and immunosuppressive treatment. No capsulotomy was performed, and the PCO regressed spontaneously over time.

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.

[Historical development of energetic cataract surgery]

This article reviews scientific literature analyzing the history of ultrasound and laser phaco surgery of combined or isolated designs: erbium YAG laser, 1.064 μm Nd:YAG laser for dissection of the lens capsule and nucleus, exclusively-laser technique of lens destruction with 1.44 µm Nd:YAG laser without manual, vacuum or ultrasonic action, femtosecond laser assistance with automated transcorneal delivery of radiation into the eye cavity.

[On studying the mechanisms and assessing the safety of Nd:YAG laser irradiation of the posterior lens capsule (experimental and clinical study)]

YAG laser interventions are associated with the risk of complications, including corneal.

PURPOSE

To study the mechanisms of laser destruction in exposing the posterior lens capsule (PLC) tissue to Nd:YAG laser irradiation, and to evaluate its side effects on the cornea.

MATERIAL AND METHODS

The experiment involved 6 autopsy samples of human posterior lens capsule with different optical and mechanical properties, which were exposed to laser irradiation. We used the Nd:YAG ophthalmic laser LPULSA SYL-9000 Premio manufactured by «LightMed» (Taiwan/USA) and an experimental Nd:YAG laser system (1.064 μm). The following parameters were compared: the power of the incident radiation and radiation transmitted through the PLC, the mechanical stresses in the PLC tissue, the kinetic energy of the laser ablation products, and the pressure of gas bubbles during laser exposure in capsule samples of different densities. In the clinical part of the work, the negative effects of Nd:YAG laser on the cornea at different PLC densities were assessed using the endothelial microscope SP 3000P («Topcon», Japan).

RESULTS

The experiment showed that in hard samples of PLC there are star-shaped point perforations with a diameter of 50±20 μm with partial rarefaction around the point defects. Damage to soft PLC samples in the form of large complete perforations was up to 200 µm in size. The temperature of laser irradiation necessary to achieve breakdown in soft PLC samples was 90 °C, in hard samples - 120 °C. The results of the experiment indicate that the final outcome - destruction of the PLC tissue - is safer to achieve not by increasing the energy, but by increasing the number of laser pulses. Clinical study results confirm a significant effect of the density of PLC on the values of laser energy and on the state of the cornea after laser intervention.

CONCLUSION

The experimental data on the mechanisms of laser destruction of the lens capsule should contribute to the development of new and improvement of already known technologies aimed at reducing the risks associated with laser surgeries.

Loose zonules in cataract surgery

PURPOSE OF REVIEW

This review will focus on identifying causes of zonulopathy during cataract surgery and discuss various modalities for treatment.

RECENT FINDINGS

There are multiple different options for capsular bag support in the setting of zonulopathy, including capsular or iris hooks, capsular tension rings as well as capsular tension segments (CTS). Surgical techniques on how to insert these devices are many and can be customized based upon the surgeon's preference and the patient's eye anatomy.

SUMMARY

Recognizing zonular weakness is critical to achieve stable postoperative vision and avoid future complications. Depending on the degree of zonulopathy, various treatment options can be pursued, ranging from capsular tension hooks or iris hooks, capsular tension rings or sutured or scleral fixated CTS.

Reopening the severely contracted lens capsular bag post-phacovitrectomy by injecting OVD and removing the fibrous membranous material

Implantation of an intraocular lens (IOL) after combined vitrectomy and cataract surgery is usually required to reduce postoperative refraction errors. However, because of the severe fibrosis of the anterior capsule and the adhesion between the anterior and posterior capsules, it is difficult to reopen the capsular bag to complete the secondary IOL implantation. In this study, a surgical approach is described for reopening the severe adhesion between capsules and removing the significant fibroproliferative membranous material by injecting ophthalmic viscosurgical device into the periphery of the capsular bag to separate the anterior and posterior capsules. The IOL was implanted into the capsular bag without any zonular rupture or posterior capsule tear. The position of the IOL was stable during postoperative follow-up up to 3 months. This procedure to open a severely fibrosis capsule was safe and effective.

Role of Preoperative Nd:YAG Laser Anterior Capsulotomy in Mature Intumescent Cataracts

PURPOSE

The aim of this study was to examine the role of preoperative Nd:YAG laser anterior capsulotomy in preventing intraoperative complications in mature intumescent cataracts.

DESIGN

A prospective, interventional, observational study.

METHODS

A total of 52 eyes of 52 patients were selected in this prospective study. Preoperative Nd:YAG laser anterior capsulotomy was performed in all eyes with 1 shot of 1.2 mJ and a gush of the liquified cortex was noted. Anterior chamber depth was measured using anterior segment optical coherence tomography and intraocular pressure using Goldmann applanation tonometer were measured pre- and post-laser. Intraoperative complications and surgeon's operative comfort were noted.

RESULTS

There was a mean increase in anterior chamber depth by 0.24 mm and a mean decrease in intraocular pressure by 1.61 mm Hg postlaser. No intraoperative complications were noted except for capsulorhexis extension in 1 eye (1.92%). The surgeon experienced a good control while performing the capsulorhexis and overall an uneventful surgery.

CONCLUSIONS

Preoperative Nd:YAG laser anterior capsulotomy is a safe and effective technique in reducing intralenticular pressure and avoiding intraoperative complications in mature intumescent cataracts.

Effect of lens capsular tension ring on preventing capsular contraction syndrome in the surgery of retinitis pigmentosa combined with cataract: Retrospective case series

PURPOSE

To observe the effect of phacoemulsification and intraocular lens (IOL) implantation with or without lens capsular tension ring (CTR) on retinitis pigmentosa (RP) combined with cataract patients.

DESIGN

Retrospective cases series study.

METHODS

Sixty-three cases (84 eyes) of RP with cataract were collected, including 30 males and 33 females. Phacoemulsification with 3.0 mm clear corneal incision was performed in all the patients. IOL and CTR implantation were performed in 44 eyes, and IOL implantation alone was performed in 40 eyes. All cases were followed up at 1 day, 1 week and 1, 3, 6,12 months after the surgery to compare the best-corrected visual acuity (BCVA), intraocular pressure (IOP), corneal endothelial cell count (ECC) and complications before and after the surgery.

RESULTS

All surgery were successfully completed by the same physician, and IOL and CTR were all implanted in capsule without complications. The BCVA at 6 months after surgery was 0.91 ± 0.88 LogMAR, showing an improvement compared with the BCVA(1.3 ± 0.7LogMAR) before surgery and there was a statistically significant difference (P = .003). Four cases of capsule contraction syndrome (CCS) occurred in no CTR implantation group and there was no CCS in CTR group. There was a statistically significant difference in the incidence of CCS between two groups (P = .047).

CONCLUSIONS

Phacoemulsification for RP combined with cataract is safe and reliable, and CTR implantation is conducive to reducing the complications caused by capsule contraction.

[Capsule polishing during cataract surgery: techniques and its role in preventing posterior capsular opacification]

Posterior capsular opacification (PCO) is the most common complication that leads to vision loss after cataract surgery. It is classically divided into fibrotic type and regenerative type according to clinical manifestations or pathological mechanisms. The widely used technique for preventing PCO is to mechanically polish anterior and posterior capsules after an uneventful phacoemulsification surgery. However, the efficacy of polishing anterior capsules on prevention of PCO is debatable. It has been found that polishing anterior capsules has an inhibitory or no effect on fibrotic PCO, but a stimulating effect on regenerative PCO. Therefore, whether to polish anterior capsules is dependent on the condition of individual patients and the type of intraocular lenses. (Chin J Ophthalmol, 2021, 57: 492-494).

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.

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-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.