Cataract surgery in small pupils

Practical Algorithm Evaluating Preoperative Risk Factors for Posterior Capsule Rupture During Phacoemulsification

PURPOSE

The purpose of the study is to create a practical and efficient tool for the preoperative assessment of cataract surgery based on statistical data.

METHODS

A two-phase study was conducted in a tertiary teaching ophthalmology department, including a retrospective cohort for 2014-2015 and a prospective cohort for 2017-2018. In the first phase of the study, all preoperative files of cataract patients (excluding trauma, uveitis related and pediatric cataracts) were gathered and analysed for 2014-2015. An algorithm was created based on their preoperative assessment and then tested in a prospective cohort for 2017-2018, following the same inclusion criteria.

RESULTS

The selection of predictors among the 1792 patients in the retrospective cohort was based on univariate and multivariate logistic regression analysis. The model with the lowest Akaike Information Criterion was formulated including three factors regardless of their p-value (age, sex, laterality) and the statistically significant factors, mature cataract, pseudoexfoliation, phacodonesis, diabetes, glaucoma, monocularity and resident surgeon at different rates of influence. The algorithm was tested in the prospective cohort (2017-2018) in 2057 cataract patients. The overall misclassification error rate was 5.9%, and the area below the ROC curve was 0.62 (CI 0.57-0.67).

CONCLUSIONS

The model created can assess patients and preoperatively evaluate their perioperative risk of complications while planning surgery with greater safety. Every population under study has unique characteristics, and safer assumptions can be made when particularities have been identified and taken into account. External validation would provide more information on its applicability in other teaching ophthalmology departments.

A Computational Framework for Intraoperative Pupil Analysis in Cataract Surgery

Purpose

Pupillary instability is a known risk factor for complications in cataract surgery. This study aims to develop and validate an innovative and reliable computational framework for the automated assessment of pupil morphologic changes during the various phases of cataract surgery.

Design

Retrospective surgical video analysis.

Subjects

Two hundred forty complete surgical video recordings, among which 190 surgeries were conducted without the use of pupil expansion devices (PEDs) and 50 were performed with the use of a PED.

Methods

The proposed framework consists of 3 stages: feature extraction, deep learning (DL)-based anatomy recognition, and obstruction (OB) detection/compensation. In the first stage, surgical video frames undergo noise reduction using a tensor-based wavelet feature extraction method. In the second stage, DL-based segmentation models are trained and employed to segment the pupil, limbus, and palpebral fissure. In the third stage, obstructed visualization of the pupil is detected and compensated for using a DL-based algorithm. A dataset of 5700 intraoperative video frames across 190 cataract surgeries in the BigCat database was collected for validating algorithm performance.

Main Outcome Measures

The pupil analysis framework was assessed on the basis of segmentation performance for both obstructed and unobstructed pupils. Classification performance of models utilizing the segmented pupil time series to predict surgeon use of a PED was also assessed.

Results

An architecture based on the Feature Pyramid Network model with Visual Geometry Group 16 backbone integrated with the adaptive wavelet tensor feature extraction feature extraction method demonstrated the highest performance in anatomy segmentation, with Dice coefficient of 96.52%. Incorporation of an OB compensation algorithm improved performance further (Dice 96.82%). Downstream analysis of framework output enabled the development of a Support Vector Machine-based classifier that could predict surgeon usage of a PED prior to its placement with 96.67% accuracy and area under the curve of 99.44%.

Conclusions

The experimental results demonstrate that the proposed framework (1) provides high accuracy in pupil analysis compared with human-annotated ground truth, (2) substantially outperforms isolated use of a DL segmentation model, and (3) can enable downstream analytics with clinically valuable predictive capacity.

Financial Disclosures

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

Real-world uptake of an innovative pupil expander device for cataract surgery: Implementation lessons learnt

Cataract surgery in the eyes, where the pupil does not dilate despite using eye drops, is fraught with vision-threatening complications. About 11 per cent of eyes undergoing cataract surgery have non-dilating, small pupils. The increasing prevalence of benign prostatic hyperplasia (BPH), hypertension, diabetes and medications used for the same are the contributing factors. The recent Food and Drug Administration (FDA) approval for the use of miotic agents in the treatment of presbyopia will lead to a further rise in the number of non-dilating pupils. While pharmacological agents and other methods have been used, mechanical pupil expander devices are the only fail safe option. However, available devices had a steep learning curve and limitations which made them difficult to use, unpredictable and unsafe. With its patented single plane, hexagonal, notches and flanges design, the US FDA registered B-HEX Pupil Expander (Med Invent Devices Pvt. Ltd., India) overcame these limitations and fulfilled an unmet need. The B-HEX is machinable, rapidly produced, consistent, easy to use, safe, and affordable. Despite such advantages, implementation hurdles have restricted its availability to healthcare systems worldwide. Peer acceptance has been steadily growing, with the B-HEX becoming the market leader in India, as evidenced by numerous publications, videos and papers presented at international conferences and comments from opinion leaders endorsing its use. However, impractical regulatory requirements and resource constraints remain a great impediment to the global distribution of this novel invention. This has denied many patients the benefits of a superior and more affordable option. Though value continues to be added to the B-HEX by maintaining a strong intellectual property portfolio with internationally granted Patents and Trademark, increasing its user base, and garnering support from key opinion leaders, only a collaboration with the right partner will help scale up the global reach and make it a leader in the global market.

A randomized control study on post-operative iris distortion following small-pupil cataract surgery using B-HEX pupil expander versus Malyugin ring

Background

The aim of the study was to evaluate postoperative pupil distortion following small pupil cataract surgeries performed using B-HEX and Malyugin rings (MR).

Methods

A randomized control trial was conducted from June 2020 to June 2023 at a tertiary eye-care hospital. The study consisted of 64 participants for cataract surgery with small pupil. There were two groups, one undergoing surgery with the use of B-HEX pupil expander and other with MR intraoperatively and the rest of the surgery was proceeded as per the convention. Areas of preoperative and postoperative images was calculated, put into an online software and pupil distortion was calculated in percentage. Two-tailed t-test was used to see the difference between the two groups.

Results

Mean age at presentation was 70.5 ± 10.12 years. Most common cause for small pupil was tamsulosin therapy. Mean size of small-pupil was 3.0 ± 1.1 mm. With the application of two rings, mean pupillary area preoperatively was 4178.23 ± 1589.46 and postoperatively was 6100.44 ± 2658.28 following the use of MR, respectively and 30,002.93 ± 13,193.40 preoperatively and 37,648.26 ± 15,207.01 postoperatively following the use of B-Hex ring respectively. Comparing baseline area from pupillary area at 1-month follow-up, a significant increase was noted for both the rings. Also, MR caused significantly more pupillary distortion compared to B-HEX ring (p < 0.05).

Conclusion

MR causes significantly more pupillary distortion in the postoperative period compared to B-HEX ring. Though, both the rings cause pupillary distortion, these devices expand the surgical area adequately, ease the procedure, decrease risk of complications achieving good functional visual outcomes.

Axial length and pharmacologic pupillary dilation in highly myopic patients

PURPOSE

To determine how high myopia impacts pharmacological pupillary dilation, and to evaluate the relationship between the extent of pharmacologic pupillary dilation and axial length.

METHODS

Patients were grouped into high myopes, defined as one or both eyes having a refractive error greater than - 6 diopters, and controls (between - 2 and + 2 diopters). Dilation was achieved with 1 drop each of tropicamide 1% and phenylephrine 2.5%. Pupil size was measured at full and dim light prior to dilation, then 15 and 30 min after dilation. Biometry was measured for each patient. Statistical analyses were performed using the Mann-Whitney-Wilcoxon tests, two-sample Welch's t-tests, and linear mixed effect models and generalized estimating equations models accounting for inter-eye correlation.

RESULTS

Forty patients (20 high myopes and 20 controls, 80 eyes total) participated in the study. High myopes had larger pupils at baseline and achieved significantly greater pupillary size (7.08 mm, 95% CI: 6.97 to 7.19 mm) than controls (6.23 mm, 95% CI: 5.94 to 6.52 mm) after 30 min of dilation (P < .0005). Fully dilated pupil size at 30 min was significantly correlated with both refractive error (r =  - 0.57, P < .0005) and axial length (r = 0.47, P < .0005). Generalized estimating equations and linear mixed effect models identified other predictive variables of pupil size after dilation including age and white-to-white diameter.

CONCLUSIONS

Highly myopic patients dilate to a larger pupillary size compared to other patients. Predicting dilation based on extent of myopia could facilitate intraocular surgery planning and reduce clinic wait times for myopic patients.

Adaptive Tensor-Based Feature Extraction for Pupil Segmentation in Cataract Surgery

Cataract surgery remains the only definitive treatment for visually significant cataracts, which are a major cause of preventable blindness worldwide. Successful performance of cataract surgery relies on stable dilation of the pupil. Automated pupil segmentation from surgical videos can assist surgeons in detecting risk factors for pupillary instability prior to the development of surgical complications. However, surgical illumination variations, surgical instrument obstruction, and lens material hydration during cataract surgery can limit pupil segmentation accuracy. To address these problems, we propose a novel method named adaptive wavelet tensor feature extraction (AWTFE). AWTFE is designed to enhance the accuracy of deep learning-powered pupil recognition systems. First, we represent the correlations among spatial information, color channels, and wavelet subbands by constructing a third-order tensor. We then utilize higher-order singular value decomposition to eliminate redundant information adaptively and estimate pupil feature information. We evaluated the proposed method by conducting experiments with state-of-the-art deep learning segmentation models on our BigCat dataset consisting of 5,700 annotated intraoperative images from 190 cataract surgeries and a public CaDIS dataset. The experimental results reveal that the AWTFE method effectively identifies features relevant to the pupil region and improved the overall performance of segmentation models by up to 2.26% (BigCat) and 3.31% (CaDIS). Incorporation of the AWTFE method led to statistically significant improvements in segmentation performance (P < 1.29  ×  10-10 for each model) and yielded the highest-performing model overall (Dice coefficients of 94.74% and 96.71% for the BigCat and CaDIS datasets, respectively). In performance comparisons, the AWTFE consistently outperformed other feature extraction methods in enhancing model performance. In addition, the proposed AWTFE method significantly improved pupil recognition performance by up to 2.87% in particularly challenging phases of cataract surgery.

Effects of music on the preoperative and intraoperative anxiety through the assessment of pupil size and vital signs (blood pressure, respiratory, and pulse rates) among cataract surgery patients at UNTH-Enugu

Background/Aim

To examine how music can impact preoperative and intraoperative anxiety via assessment of physiological markers such as pupil size, blood pressure, pulse rate, and respiratory rate.

Methods

This is a randomized interventional study of individuals aged 50 years and above who were scheduled for and undergoing cataract surgery under regional anesthesia, with music (test group) randomly matched with similar individuals undergoing the same procedure but without music (control group). The surgeries were performed in the operating theater of the Department of Ophthalmology, University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla, Enugu. Using a systematic random sampling method, a total of 98 patients were grouped into two. Both groups completed the State-Trait Anxiety Inventory (STAI) questionnaire at baseline, immediately upon entrance into the preoperative room and 5 min after intervention. Relevant study indices (blood pressure, pulse, respiratory rate, and pupil diameter) were measured and recorded, and these served as baseline parameters. The STAI questionnaire was then administered. Results were analyzed using the SPSS version 20 and analysis of variance was used to compare means of variables measured at baseline, preoperative before intervention, and preoperative after intervention. Categorical variables were compared using the Chi-square test. Student's t-test was used to analyze the continuous variables.

Results

Our analysis, using the multiple linear regression, showed that music has an effect on preoperative anxiety and intraoperative anxiety by positively affecting the blood pressure, pulse rate, respiratory rate, and pupil diameter (P ≤ 0.001).

Conclusion

Music reduces preoperative and intraoperative anxiety evidenced by its effect on the physiological biomarkers.

A new intraocular lens marker to guide the implantation of toric intraocular lenses in small and mid-dilating pupils

Insufficient pupillary dilatation is a significant challenge during cataract surgery, as it increases the risk of various intraoperative complications. Implantation of toric intraocular lenses (TIOL) is particularly difficult in eyes with small pupils, as the toric marks are provided in the periphery of the IOL optic, making the visualization of the same difficult for proper alignment. Attempts at visualizing these marks using a second instrument such as a dialler or iris retractor lead to additional manipulations in the anterior chamber resulting in increased chances of postoperative inflammation and intraocular pressure rise. A new intraocular lens (IOL) marker to guide the implantation of TIOLs in eyes with small pupils is described, which can potentially be beneficial in achieving accurate alignment of toric IOLs in small pupils, without the need for additional manipulations, thus improving safety, efficacy, and success rates of TIOL implantation in these eyes.

Dilation devices in cataract surgery

PURPOSE OF REVIEW

Cataract surgery in the setting of small pupil represent a major challenge and it is associated with a higher risk of complications. When pharmacologic pupil dilation fails, mechanical pupil expansion devices are needed to obtain and maintain sufficient intraoperative mydriasis. The purpose of this review is to assess the pupil expansion devices currently available.

RECENT FINDINGS

A variety of pupil expansion devices are offered on the market. They differ for design, material, shape, size, cost, and easiness of insertion/removal, nonetheless they all seem to be effective in improving the pupil size and easing the cataract surgery.

SUMMARY

Mechanical pupil expansion can be effectively achieved with a variety of devices, which are well tolerated and can facilitate cataract surgery in the setting of poor mydriasis.

Safety and efficacy of manual small-incision cataract surgery in patients with brunescent and black cataracts and other ocular comorbidities

Purpose

To determine the safety and efficacy of manual small-incision cataract surgery (MSICS) for brunescent and black cataracts in patients with other ocular comorbidities.

Methods

Medical records of patients with hard cataracts (grade 4 nuclear opalescence and above) with other ocular comorbidities such as spheroidal degeneration of the cornea (SDC), pseudoexfoliation (PXF), non-dilating pupil, and high myopia who underwent MSICS were retrieved retrospectively. Intraoperative and postoperative complications were noted. Preoperative and postoperative visual outcome comparisons were performed using paired t-tests. Statistical significance was set at P &lt; 0.05.

Results

A total of 124 cataract patients with brunescent or black cataracts and other ocular comorbidities underwent surgery during the study period. They ranged in age from 56 to 89 years (mean: 68.9 + 11.9 years), with 55.66% (n = 69) of the patients being female and 44.35% (n = 55) male. Of the 124 cases, 45.16% (n = 56) had SDC, 31.45% (n = 39) had PXF, 14.51% (n = 18) had non-dilating pupils, and 8.87% (n = 11) had high myopia. Preoperatively all patients had visual acuity &lt;6/60. At 1 month postoperatively 77.4% of patients achieved good vision &gt;6/18, 16.9% had a borderline vision (6/18-6/60), and 5.6% had a poor vision (&lt;6/60). No serious complications were observed. One patient had posterior capsular rent in a case of high myopia, and two cases had zonular dialysis for pseudoexfoliation.

Conclusion

MSICS with intraocular lens implantation is safe and effective in eyes with brunescent/black cataracts if associated with SDC, PXF, high myopia, and non-dilating pupils and provides good visual outcomes with minimal complications.

The safety of intracameral phenylephrine - A systematic review

Intracameral phenylephrine is commonly used in ophthalmic surgery as an alternative or supplement to mydriatic eye drops; hence, the importance of an evidence-based understanding of its risk-benefit profile is vital. We performed a comprehensive search in the PubMed, Google Scholar and Cochrane databases for published studies and case reports relating to the use of intracameral phenylephrine. Articles from 1958 to 2021 with the following keywords were used: "intracameral phenylephrine", "intracameral mydriatics", "phenylephrine", "pupil dilation", "complications". Intracameral phenylephrine was first used in 2003 as an alternative to topical mydriatics. Since then, it is being increasingly used with a variety of benefits, including rapid onset of mydriasis, and cost-effectiveness. There are various case reports, however, of ocular and systemic complications associated with intracameral phenylephrine such as generation of free radicals, toxic anterior segment syndrome, inconsistent pupillary dilation during surgery, and ventricular fibrillation. Alternatives to intracameral phenylephrine such as iris hooks, a Malyugin ring, intracameral epinephrine, and intracameral tropicamide were compared with intracameral phenylephrine. Intracameral phenylephrine appears to have a good safety profile.

Comparison of pre-chop technique using a reverse chopper and classic stop-and-chop technique in the treatment of high myopia associated with nuclear cataract

BACKGROUND

To evaluate the safety and efficacy of the pre-chop technique using a novel reverse chopper vs. the classic stop-and-chop technique in phacoemulsification for patients with high myopia and associated grade III-IV nuclear cataracts.

METHODS

In this prospective cohort study, a total of 44 consecutive patients (44 eyes) with grade III-IV nuclear cataracts who were admitted to our hospital for cataract surgery between March 2018 and September 2018 were enrolled. All patients had ocular axial length > 27 mm and myopic refraction more than -10 diopters. Patients were randomly divided into a pre-chop group and stop-and-chop group using a randomization table. Nucleus splitting was performed surgically in both groups using either the pre-chop technique with reverse chopper or the classic stop-and-chop technique.

RESULTS

Postoperative visual acuity was significantly improved in both groups compared with preoperative values. Significantly better visual acuity, lower degree of corneal edema and lower rates of corneal endothelial cell loss were observed in the pre-chop group compared to those in the classic stop-and-chop group. No complications were reported in either group.

CONCLUSIONS

In treating patients with high myopia associated with grade III-IV cataracts, the pre-chop technique using a reverse chopper reduces damage to corneal endothelial cells and improves visual acuity better than the classic stop-and-chop technique.

Cataract Surgery Considerations for Diabetic Patients

PURPOSE OF REVIEW

Given the epidemiology and demographic trends of diabetes mellitus and cataracts, ophthalmologists are likely to encounter patients with both comorbidities at an increasing frequency. Patients with diabetes represent a higher risk population than healthy patients for cataract surgery. In this review, we discuss key risks and risk-mitigation practices when performing cataract surgery on these patients.

RECENT FINDINGS

Patients with diabetes continue to represent a high-risk surgical population: Nagar et al. suggest a dose-dependent relationship may exist between number of intravitreal injections and likelihood of posterior capsular rupture. However, novel treatments are improving outcomes for patients with diabetes. Several studies have reported intracameral phenylephrine/ketorolac may reduce the incidence of post-operative cystoid macular edema while others have discussed the efficacy of pre-treatment and post-treatment with intravitreal bevacizumab on improving cataract surgery outcomes in patients with diabetic retinopathy. Pre-operatively, ophthalmologists should perform an enhanced evaluation, consider timing and lens selection decisions, and complete any appropriate pre-operative treatment. Peri-operatively, surgeons should be aware of pupillary dilation adjustments, combination surgery options, and potential complications. Post-operatively, clinicians should address pseudophakic cystoid macular edema, diabetic macular edema, diabetic retinopathy, and posterior capsular opacification.

Application of an iris speculum for removing Soemmerring's ring during secondary intraocular lens implantation in congenital cataract patients with small pupils

An application of the XpandNT iris speculum in eyes with small pupils during secondary intraocular lens (IOL) implantation in congenital cataract patients is described. The iris speculum was first positioned in the eye to expand the pupil. A 30-gauge needle was used to separate the adhesion of the iris tissue and the capsular rim. Vitrectomy was used to clean Soemmerring's ring near the capsular rim. The iris expander was retracted with the Williamson XpandNT Manipulator. The IOL was then implanted. Fourteen aphakic eyes from 10 consecutive patients were studied retrospectively; pupil expansion was achieved in all 14 eyes intraoperatively without serious intraoperative or postoperative complications. The iris speculum was a safe and excellent tool for removing Soemmerring's ring and solving small pupil problems during secondary IOL implantation in pediatric cataract surgery patients.

Evaluation of a uniplanar pupil expansion ring in small-pupil cataract surgery: a feasibility study

PURPOSE

The aim of this study was to evaluate the effectiveness of a disposable uniplanar pupil expansion device in small-pupil cataract surgery.

METHODS

This is a feasibility study carried out at the Rothschild Foundation, Paris, France. Patients undergoing routine cataract surgery with a dilated pupil size < 6 mm, and who agreed to participate in the study were included. The trial enrolled 25 patients, of whom 21 proceeded to cataract surgery using the pupil expansion device to be evaluated. The pupil diameter was measured at defined stages during the cataract surgery, which was performed by a single surgeon, in a single center setting. The 1st generation Bhattacharjee pupil expansion ring was used if the preoperative pupil size was < 6 mm. Intraoperative and postoperative adverse events were recorded.

RESULTS

Pupil size immediately after the Bhattacharjee ring implantation was ≥ 6 mm for 15 eyes (71.4%). The mean dilated pupil size before ring insertion was 4.5 ± 0.8 mm (range 2.5-5.8 mm), and the mean pupil size after ring insertion was 6.1 ± 0.3 mm (range 5.9-6.8 mm). Mean pupil size following removal of the ring was 4.2 ± 0.8 mm (range 2.5-5.4 mm). Two adverse events occurred during the surgeries: 1 Bhattacharjee ring broke prior to implantation, and 1 implanted Bhattacharjee ring was unstable and removed before the end of the surgery. No postoperative adverse event was recorded.

CONCLUSIONS

The Bhattacharjee ring is an effective pupil expansion device, which facilitates stable pupil expansion during cataract surgery. This study was registered as a clinical trial at clinicaltrials.gov under the number NCT02434588.

Outcomes of first 50 cases using a new pupil expander

PURPOSE

To describe the initial experience with the Assia Pupil Expander 200 (APX-200, APX Ophthalmology) in eyes that underwent phacoemulsification or intraocular lens repositioning surgery that required mechanical pupil expansion.

SETTING

Department of Ophthalmology, Meir Medical Center, Kfar-Saba, and Ein-Tal Eye Center, Tel Aviv, Israel.

DESIGN

Retrospective case series.

METHODS

The APX-200 is a single-use device, intended for mechanical expansion of the pupil during intraocular surgery. Two devices are inserted through 2 opposite 19-gauge incisions using designated forceps. The surgical course and early postoperative follow-up was recorded in 50 eyes.

RESULTS

The study included 50 consecutive eyes, with mean preoperative pupil diameter was 3.7 mm. The APX effectively dilated the pupils in all cases. No complication related to the use of the APX such as hyphema, iridodialysis, or Descemet membrane detachment were noted in this series. A central and round pupil was restored in all eyes at 1-month postoperatively, with 14 eyes (28%) having mild sphincter tears. Pupilloplasty was not required in any of the cases.

CONCLUSIONS

The APX-200 was an effective and safe device for pupil expansion during intraocular surgery.

Intraoperative floppy iris syndrome: an updated review of literature

Intraoperative Floppy iris syndrome(IFIS) remains a challenge for surgeons during phacoemulsification. Initially, it was related to the use of tamsulosin, an alpha adrenergic receptor blocker used in benign prostatic hyperplasia. Subsequently, other alpha adrenergic receptor such as alfuzosin, terazosin and doxazosin alongwith different other class of medications and systemic risk factors were identified. Other class of medications includes 5-alpha reductase inhibitor, angiotensin receptor antagonist, benzodiazepines, antipsychotics and antidepressants. Other risk factors include increasing age, male gender, diabetes, hypertension and decreased preoperative pupil diameter. It is very important for surgeons to identify these risk factors preoperatively and take appropriate preoperative and intraoperative measures to tackle the dreaded complications of IFIS. Sometimes, it is important for an ophthalmologist to work in cooperation with physician and urologist to minimize the complications. In conclusion, awareness of the risk factors associated with IFIS, their detailed preoperative assessment and intraoperative measures and surgical intervention is crucial in addressing IFIS. Lack of awareness can turn a routine, uneventful surgery into one with significant visual morbidity.

Iris manipulation during phacoemulsification: intraoperative and postoperative complications

AIM

To quantify intraoperative and postoperative complications in complex phacoemulsification cataract extraction (phacoemulsification) with iris manipulation compared to non-complex and complex phacoemulsification without iris manipulation.

METHODS

All phacoemulsification cases at the University of Colorado between January 1, 2014, and June 30, 2017 were included. Exclusion criteria for the primary outcome of intraoperative complications were planned combination surgery and eyes with less than 28d follow-up. Exclusion criteria for the secondary outcomes of postoperative complications were unplanned additional surgery, and chronic steroid eye drop use prior to surgery. Data including sex, race/ethnicity, surgery length, visual acuity, intraoperative and postoperative complications, and intraocular pressures (IOP) were collected and analyzed utilizing general linear and Logistic regression modeling.

RESULTS

The medical records of 5772 eyes were reviewed (500 complex without iris manipulation, 367 with iris manipulation). The number of any intraoperative complication in the complex with iris manipulation and complex without iris manipulation groups was 15 (4.1%) and 26 (5.2%), respectively, compared to 41 (0.8%) in the non-complex group. Postoperative inflammation was found in 135 (2.8%) non-complex cases, 20 (4.1%) complex cases without iris manipulation, and 20 (5.6%) complex cases with iris manipulation. The adjusted odds ratio of postoperative inflammation in phacoemulsification with iris manipulation compared to non-complex was 2.3 (95%CI: 1.3-4.0, P=0.005). The rate of IOP spikes >10 mm Hg was significantly greater in cases with iris manipulation (P=0.001).

CONCLUSION

Complex cases have more intraoperative complications. However, only complex cases with iris manipulation led to increase rates of postoperative inflammation and IOP spikes >10 mm Hg.

Application of a prechop technique using a reverse chopper in small pupil cataract surgery

Background

To analyze the value of a prechop technique for splitting the nucleus of the lens using a reverse chopper in small-pupil cataract surgeries. A prospective case-control study. Thirty-four cataract patients (34 eyes) who were treated in our center from March 2019 to December 2019 were enrolled and then divided into two groups: small pupil group (18 patients; 18 eyes) and normal pupil group (16 patients; 16 eyes).

Methods

The prechop technique was applied in both groups, and the patients were followed up for three months. The best-corrected visual acuity (BVCA), surgical complications, corneal endothelial cell loss, pupil function, operative time, and cumulative dissipated energy (CDE) were compared between these two groups, and the safety of the nucleus-chopping technique was evaluated. Data were analyzed using the SPSS 23.0 software packages. BVCA, surgical complications, rate of corneal endothelial cell loss, pupil function, operative time, and CDE.

Results

The surgery was smooth in all cases. The operative time, intraoperative ultrasound energy consumption, BVCA, and surgical complications indicated no significant difference between the two groups (all P>0.05). In the small pupil group, BVCA was significantly improved after surgery and achieved its optimal value three months after surgery (χ²=49.38; P=0). The diameter of the pupil was about 3.22 mm in the small pupil group before nucleus chopping. The postoperative pupil morphology was not statistically different from that before surgery (pupil morphology: χ²=0.131; P=0.717); however, the pupillary light reflex was significantly improved after surgery (χ²=8.378; P=0.004), and the pupil diameter was significantly increased (T=-3.494; P=0.003). The rate of corneal endothelial cell loss was higher in small pupil group than in the normal pupil group in the 3rd postoperative month, but the difference was not statistically significant (T=-0.023; P=0.982).

Conclusions

The prechop technique using a reverse chopper in small-pupil cataract surgery occupies a similar operative time, cumulative energy consumption during operation, BVCA, pupil morphology, and rate of corneal endothelial cell loss, comparing with those in normal-pupil cataract surgery. To such a degree, it is a safe, high-efficiency, a simple and easy-to-operate nucleus-chopping technique that can be used in small-pupil cataract surgery.

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

PURPOSE

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

SETTINGS

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

DESIGN

Retrospective non-randomized consecutive case series.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Modelling floppy iris syndrome and the impact of pupil size and ring devices on iris displacement

Introduction

The aim of this paper was to further develop a previously described finite element model which equates clinical iris billowing movements with mechanical buckling behaviour, simulating floppy iris syndrome. We wished to evaluate the impact of pupil dilation and mechanical devices on normal iris and floppy iris models.

Methods

Theoretical mathematical modelling and computer simulations were used to assess billowing/buckling patterns of the iris under loading pressures for the undilated and dilated normal iris, the undilated and dilated floppy iris, and additionally with a mechanical ring device.

Results

For the normal iris, billowing/buckling occurred at a critical pressure of 19.92 mmHg for 5 mm pupil size, which increased to 28.00 mmHg (40.56%) with a 7 mm pupil. The Malyugin ring device significantly increased critical initiating buckling pressures in the normal iris scenario, to 34.58 mmHg (73.59%) for 7 mm ring with boundary conditions I (BC I) and 34.51 mmHg (73.24%) with BC II. For the most floppy iris modelling (40% degradation), initiating buckling value was 18.04 mmHg (−9.44%), which increased to 28.39 mmHg (42.52%) with the 7 mm ring. These results were much greater than for normal undilated iris without restrictive mechanical expansion (19.92 mmHg).

Conclusion

This simulation demonstrates that pupil expansion devices inhibit iris billowing even in the setting of floppy iris syndrome. Our work also provides a model to further investigate the impact of pupil size or pharmacological interventions on anterior segment conditions affected by iris position.

A Simple, Novel Approach to Capsulorhexis Formation in the Setting of A Mature Cataract and Miotic Pupil

Purpose

To report a simple, effective technique for surgeons creating a capsulorhexis in patients with pupillary miosis and a dense, mature cataract.

Methods

A single center, two-year retrospective chart review examined 1408 phacoemulsification cataract surgeries. The criteria for inclusion involved a dense, mature cataract and a pupil that was unresponsive to pharmacologic dilation preoperatively. A standardized technique was used for all cases consisting of a 1mm corneal paracentesis and 2.4mm temporal clear corneal incision. Synecholysis was performed if present, followed by the insertion of a 6.25mm malyugin ring under cohesive viscoelastic. The cohesive viscoelastic was removed via the irrigation aspiration tip. The paracentesis was sealed with a small amount of viscoelastic and an air bubble was placed in the anterior chamber. The anterior capsule was then painted with trypan blue. The air bubble and trypan blue were then replaced by a dispersive viscoelastic. Curvolinear capsulorrhexis was performed followed by standard phacoemulsion.

Results

Nine patients ranging from 76 ± 12 years (mean ± standard deviation) met the criteria with a 4+ NS (n=5), white mature (n=3), or deep brunescent (n=1) cataract and 3mm pupil preoperatively. Pupillary miosis was caused by posterior synechia in 44.5% of the cases followed by pharmacologic interactions from tamsulosin and donepezil in 22.25% of cases respectively. One case involved idiopathic miosis likely from aging. Capsulorhexis formation was successful in all cases with no capsular tear, vitreous loss, or conversion to extracapsular cataract extraction (ECCE). However, one case had cortex retention requiring a second procedure for removal.

Conclusion

Dense, mature cataracts and small pupils both compromise the view for the surgeon and may be significant risk factors for training ophthalmologists. Thus, good visualization of the anterior capsule and peripheral nucleus with our simple technique facilitates a reliable capsulorhexis, potentially limiting the risk of complications for ophthalmic surgeons.

Series of cataract surgeries with I-ring pupil expansion ring

BACKGROUND

The retrospective review of I-ring pupil expansion ring use is designed to examine the patient characteristics and associated surgical challenges in a clinical practice. The hypothesis is that I-ring provides a necessary additive tool in dealing with challenging cataract surgeries with small pupils.

AIM

To document the safety profile and use of I-ring pupil expansion ring in a clinical practice.

METHODS

A retrospective chart review of 12 consecutive cases within the same year (2016) of cataract surgeries employing I-ring pupil expansion ring (Beaver-Visitec, International) by a single surgeon at the same ambulatory surgical center was conducted. Demographic, pre-op, intra-op, and post-op data were recorded. Total number of cataract cases performed was also recorded.

RESULTS

8 of 12 cases were planned I-ring cases. 1 case was decided intraoperatively when femtosecond laser caused the pupil to shrink. The other 3 cases were also decided upon intraoperatively when pupil was deemed to be small. 7 patients had IFIS from Flomax use. 2 patients had pseudoexfoliation syndrome as the cause of small pupil. 2 patients had narrow angles with brunescent cataracts. 2 patients had pre-op partial zonular dehiscence. 1 patient had 360^o of posterior synechiae. 2 cases had ruptured posterior capsule that required anterior vitrectomy. No complications were attributed to the pupil expansion ring. A total of 296 cataract surgeries were performed that year by the surgeon, making the rate of pupil ring use 4.1%.

CONCLUSION

Small pupil requiring pupil expansion ring during cataract surgery is often associated with other challenges, such as brunescent cataract, zonular weakness, and posterior synechiae in this series. I-ring helped to reduce at least one challenge in these difficult cases.

Outcomes of Complex Cataract Surgery in Patients with Primary Open-angle Glaucoma

Aim

Whether pupillary expansion during phacoemulsification causes a change in postoperative intraocular pressure (IOP) is currently unknown. However, a growing proportion of patients can present with concurrent glaucoma and cataracts, which poses an increased risk of having small pupils and makes finding the answer to this question imperative for treating physicians.

Materials and methods

This was a retrospective, observational cohort study which utilized data from 2008 to 2016 from the University Hospital, Newark, New Jersey, USA. All patients with primary open-angle glaucoma (POAG) who underwent phacoemulsification with pupillary expansion were considered for inclusion. Cases were subsequently excluded if they had prior incisional glaucoma surgery, if phacoemulsification was combined with another surgery, or if they had any incisional surgery in the eye 1 year preoperatively or postoperatively. The control group was made up of patients without POAG. The primary outcome was IOP.

Results

Thirty-seven eyes from 31 glaucoma patients and 29 eyes from 28 control patients met inclusion criteria. The mean IOP in the POAG group increased from 15.0 ± 4.6 mm Hg to 15.9 ± 3.5 mm Hg after 1 year, whereas the control group decreased from 14.1 ± 3.6 mm Hg to 11.9 ± 3.9 mm Hg. Multivariate analysis showed that glaucoma was associated with a 5.56 mm Hg increase in IOP at 12 months postoperatively. The average number of glaucoma medications decreased significantly from 1.7 ± 1.4 at the baseline to 1.3 ± 1.3 after 1 year.

Conclusion

In contrast with non-POAG patients, no significant drop in the mean IOP was noted after complex cataract surgery for this cohort of glaucoma patients, although medication burden significantly decreased and VA improved significantly.

Clinical significance

Phacoemulsification with intraoperative pupillary expansion in POAG patients may not decrease IOP after 12 months but it can decrease the number of anti-glaucoma medications they take.

How to cite this article

Bargoud AR, Parikh H, et al. Outcomes of Complex Cataract Surgery in Patients with Primary Open-angle Glaucoma. J Curr Glaucoma Pract 2019;13(2):62–67.

Diabetes and Phacoemulsification Cataract Surgery: Difficulties, Risks and Potential Complications

Diabetes mellitus is one of the most prevalent chronic diseases worldwide. Diabetic patients are at risk of developing cataract and present for surgery at an earlier age than non-diabetics. The aim of this study was to review the problems associated with cataract surgery in a diabetic patient. Corneal complications in diabetic patients include delayed wound healing, risk of developing epithelial defects or recurrent erosions due to the impairment of epithelial basement membranes and epithelial-stromal interactions. Diabetic patients present lower endothelial cell density and their endothelium is more susceptible to trauma associated with cataract surgery. A small pupil is common in diabetic patients making cataract surgery technically challenging. Finally diabetic patients have an increased risk for developing postoperative pseudophakic cystoid macular edema, posterior capsule opacification or endophthalmitis. In patients with pre-proliferative or proliferative diabetic retinopathy, diabetic macular edema or iris neovascularization adjunctive therapy such as an intravitreal anti-vascular endothelial growth factor injection, can inhibit exacerbation related to cataract surgery.

Iris hooks versus a pupil expansion ring: Operating times, complications, and visual acuity outcomes in small pupil cases

PURPOSE

To compare iris hooks and a pupil expansion ring (Malyugin ring) in eyes with a small pupil.

SETTING

Epsom and St. Helier University National Health Service Trust, London, United Kingdom.

DESIGN

Retrospective case series.

METHODS

Patients who had primary phacoemulsification cataract surgery from January 1, 2012, to December 30, 2016, were included. Combined procedures and surgeons with fewer than 50 cases were excluded. Anonymized data were demographics, surgeon grade, case complexity, iris hooks or Malyugin ring use, posterior capsule rupture, zonular fiber rupture or dialysis, vitreous loss, operating time, postoperative complications, and visual acuity.

RESULTS

Of the 9552 cases included, 425 (4.4%) had a small pupil, 314 of which required a pupil expansion ring and 95 iris hooks. Compared with no pupil expander, iris hooks were associated with an additional operating time of 14 minutes for consultants and 24 minutes for trainees. The pupil expansion ring was associated with an additional operating time of 4 minutes and 6 minutes, respectively. Neither pupil expander was associated with more intraoperative complications. The pupil expansion ring was associated with higher postoperative anterior uveitis and corneal edema rates. Pupil expander cases achieved equivalent visual acuity gains.

CONCLUSIONS

The pupil expansion ring and iris hooks were safe and effective in minimizing intraoperative complications in eyes with a small pupil. The pupil expansion ring was faster to use than iris hooks. Monitoring for signs of postoperative anterior uveitis or cornea edema with careful insertion or removal of pupil expansion rings is advocated.