Phacoemulsification: Proposals for Improvement in Its Application

Bridging the gap in managing dry eye disease: a consensus report by the Taiwan society of cataract and refractive surgeons

BACKGROUND

An impaired ocular surface presents substantial challenges in terms of planning for cataract surgery. As a multifactorial ocular disorder, dry eye disease (DED) is common in the general population and prevalent in patients scheduled for lens replacement surgery. Cataract surgery can exacerbate DED and worsen several ocular parameters. Timely diagnosis and appropriate treatment of DED are vital to ensuring positive ophthalmic surgical outcomes. This consensus report of the Taiwan Society of Cataract and Refractive Surgeons (TSCRS) regarding the management of DED before, during, and after cataract surgery highlights the gaps between clinical guidelines and several aspects of DED, including diagnostic testing, diagnostic criteria, and clinical practice treatment.

METHODS

An expert panel of five specialists in the field of ophthalmology was recruited to develop consensus statements regarding the management of DED in both the general population and in patients undergoing cataract surgery in Taiwan. Two separate meetings of the five specialists, who were endorsed by the TSCRS, were convened for this purpose. A survey questionnaire consisting of binary or multiple-choice questions was developed through a consensus-driven formulation process. A percentage value was calculated for each statement, and a minimum of 60% agreement (equivalent to three out of five members) was required to achieve consensus. The second discussion meeting involved the presentation of the finalized consensus statements and concluded the consensus development process. Lastly, the finalized consensus statements were approved by all the experts, and the formulated recommendations for DED in the general population and prospective cataract surgery patients were accordingly presented.

RESULTS

The optimal algorithm for managing DED in the general population and in patients scheduled for cataract surgery was developed to address the unmet needs of this cohort in Taiwan.

CONCLUSION

This report provides recommendations for managing dry eye disease. It is essential to screen and confirm DED through endorsed questionnaires and tests and then diagnose it. Treatment and management of DED should follow a stepwise approach. Screening and diagnosing DED is also recommended before cataract surgery. After cataract surgery, relatively aggressive treatment strategies are recommended to manage DED effectively.

Long-Term Outcomes of Phacoemulsification Surgeries at ECWA Eye Hospital: A Prospective Clinical Cohort Study

Background

Phacoemulsification has proven to be a breakthrough technique in cataract surgery. Its popularity has grown dramatically as procedures and equipment have advanced, improving both safety and efficiency. This study presents long-term outcomes from phacoemulsification surgeries performed at the Evangelical Church Winning All (ECWA) Eye Hospital, a tertiary eye care center.

Method

This prospective clinical cohort study followed standard practices for operations performed under local anesthesia. Ophthalmologists evaluated long-term outcomes and predictors of improved visual acuity after phacoemulsification cataract surgery. The visual recovery of the patients over time was evaluated, and the factors that influence the gains in vision were identified.

Results

A total of 177 patients were subjected to treatment at our facilities during the study period. There were 116 male and 61 female patients, which resulted to a male-to-female ratio of 1 : 0.53. The average age of the patients was 59.18 years with a standard deviation of 11.38 years. Of the 259 eyes treated, 249 eyes (96.1%) achieved a high success rate with visual acuity of 6/6 - 6/18. Ten (10) eyes (3.9%) had moderate acuity between <6/18 and 6/60. Follow-up examinations over five years after phacoemulsification showed poor vision outcomes among old patients. The primary factor that affected improvement in visual acuity among patients was amblyopia, present in 30% of cases. Posterior capsular opacification and macular edema collectively accounted for 20% of poor vision cases, while optic atrophy, glaucoma, and retinal hemorrhage each represented approximately 10% of poor vision cases.

Conclusions

The phacoemulsification approach demonstrated a highly effective restoration of vision for the vast majority, while long-term data analysis indicated the potential for age-related variability in postoperative visual gains.

Ocular Changes in Cystic Fibrosis: A Review

Cystic fibrosis (CF), also known as mucoviscidosis, is the most common autosomal recessive genetic disease in the Caucasian population, with an estimated frequency of 1:2000-3000 live births. CF results from the mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene localized in the long arm of chromosome 7. The product of CFTR gene expression is CFTR protein, an adenosine triphosphate (ATP)-binding cassette (ABC) transporter that regulates the transport of chloride ions (Cl-) across the apical cell membrane. Primary manifestations of CF include chronic lung and pancreas function impairment secondary to the production of thick, sticky mucus resulting from dehydrated secretions. It is well known that CF can cause both anterior and posterior ocular abnormalities. Conjunctival and corneal xerosis and dry eye disease symptoms are the most characteristic manifestations in the anterior segment. In contrast, the most typical anatomical and functional changes relating to the posterior segment of the eye include defects in the retinal nerve fiber layer (RNFL), vascular abnormalities, and visual disturbances, such as reduced contrast sensitivity and abnormal dark adaptation. However, the complete background of ophthalmic manifestations in the course of CF has yet to be discovered. This review summarizes the current knowledge regarding ocular changes in cystic fibrosis.

A systematic review of ultrasound-mediated drug delivery to the eye and critical insights to facilitate a timely path to the clinic

Ultrasound has long been identified as a promising, non-invasive modality for improving ocular drug delivery across a range of indications. Yet, with 20 years of learnings behind us, clinical translation remains limited. To help address this, and in accordance with PRISMA guidelines, the various mechanisms of ultrasound-mediated ocular drug delivery have been appraised, ranging from first principles to emergent applications spanning both ex vivo and in vivo models. The heterogeneity of study methods precluded meta-analysis, however an extensive characterisation of the included studies allowed for semi-quantitative and qualitative assessments. Methods: In this review, we reflected on study quality of reporting, and risk of bias (RoB) using the latest Animal Research: Reporting of In Vivo Experiments (ARRIVE 2.0) guidelines, alongside the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) RoB tools. Literature studies from 2002 to 2022 were initially characterised according to methods of ultrasound application, ultrasound parameters applied, animal models employed, as well as safety and efficacy assessments. This exercise contributed to developing a comprehensive understanding of the current state of play within ultrasound-mediated ocular drug delivery. The results were then synthesised and processed into a guide to aid future study design, with the goal of improving the reliability of data, and to support efficient and timely translation to the clinic. Results: Key attributes identified as hindering translation included: poor reporting quality and high RoB, skewed use of animals unrepresentative of the human eye, and the over reliance of reductionist safety assessments. Ex vivo modelling studies were often unable to have comprehensive safety assessments performed on them, which are imperative to determining treatment safety, and represent a pre-requisite for clinical translation. Conclusion: With the use of our synthesised guide, and a thorough understanding of the underlying physicochemical interactions between ultrasound and ocular biology provided herein, this review offers a firm foundation on which future studies should ideally be built, such that ultrasound-mediated ocular drug delivery can be translated from concept to the coalface where it can provide immense clinical benefit.

Visual outcomes and postoperative complications of eyes with dropped lens fragments during cataract surgery: multicenter database study

PURPOSE

To analyze the visual outcomes and postoperative complications of phacoemulsification cataract surgery in eyes with posterior capsule rupture (PCR) and dropped lens fragments (DLFs) in comparison with a reference group with uneventful surgery.

SETTING

8 UK National Health Service departments.

DESIGN

Retrospective comparative nonrandomized study.

METHODS

Demographic, medical history, and ocular examination data were automatically extracted from the electronic records. The main outcome variables were postoperative visual acuity (VA), and the development of postoperative cystoid macular edema (CME) as well as rhegmatogenous retinal detachment (RRD) and epiretinal membrane (ERM) requiring surgery.

RESULTS

The analysis included 175 589 eyes in the reference group, 2751 eyes in the PCR group, and 519 eyes in the DLF group. During all postoperative intervals, the mean VA in the DLF and PCR groups was significantly worse than the reference group ( P < .001). On multivariate analysis, the odds of having a VA ≤0.3 logMAR at 4 to 12 weeks postoperatively among eyes with DLF and PCR were 88% and 73% lower than the reference group ( P < .001). More eyes developed CME in the DLF and PCR groups ( P < .001). The odds of requiring RRD and ERM surgery were 3.6 and 2.1 times higher in the DLF group, and 1.8 and 1.3 times higher in the PCR group, respectively, as compared with the reference group.

CONCLUSIONS

Eyes undergoing phacoemulsification complicated by PCR, and more so with DLF, have worse visual outcomes and higher chances of CME, ERM, and RRD when compared with uneventful surgery.

Comparison of the reverse chopper-assisted prechop and phaco-chop nucleotomy techniques during phacoemulsification for cataracts with grade III nuclei: a randomized controlled trial

Background

Phacoemulsification surgery is the standard treatment for cataract. However, excessive ultrasound (US) energy may cause injury to the corneal endothelium and other ocular tissues. Recently, a new prechop technique assisted with the reverse chopper is showed to be more efficient and safe, by splitting the nuclei in situ without using any US energy. However, it is verified only in treating some kinds of complex cataracts such as grade IV hard nuclei cataract, small-pupil cataract, and ultra-high myopia cataract. Since grade III nuclei cataract is the most common type of cataract, it is necessary to evaluate the efficacy and safety of prechop technique with reverse chopper in routine cataract surgery.

Methods

This prospective, two-parallel, randomized controlled trial was conducted in Beijing Tongren Hospital from January 2022 to September 2022. A total of 89 cataract patients (89 eyes) were enrolled and then randomly assigned to either the reverse chopper-assisted prechop group (n=45) or the phaco-chop group (n=44). The patients were followed for 3 months postoperatively. The best-corrected visual acuity (BCVA), cumulative dissipated energy (CDE), corneal endothelial cell loss (ECL), and degree of corneal edema were evaluated and compared between these 2 groups. Data were analyzed using SPSS 23.0 and GraphPad Prism 8.0.

Results

The CDE of the reverse chopper-assisted prechop group was significantly less than that of the phaco-chop group (P=0.011). Compared with the phaco-chop group, the corneal edema in the reverse chopper-assisted prechop group was milder (P=0.026) and the BCVA was better (P=0.0012) at 1 day after surgery. No significant difference was found in the count or rate of corneal ECL between the 2 groups at 1 month after surgery (corneal ECL count: P=0.090; corneal ECL rate: P=0.053). The BCVA of the 2 groups at 1 week, 1 month, and 3 months after surgery was equivalent (P=0.052, 0.26, and 0.41, respectively).

Conclusions

The prechop technique assisted with the reverse chopper in treating cataract with grade III nuclei enables less phaco energy consumption, milder ocular structural damage, and faster recovery of vision, compared with traditional phaco-chop technique.

In situ assessment of lens elasticity with noncontact optical coherence elastography

Lens biomechanics has great potential for application in clinical diagnostics and treatment monitoring of presbyopia and cataracts. However, current approaches to lens elastography do not meet the desired safety or sensitivity for clinical application. In this regard, we propose a noncontact optical coherence elastography (OCE) method to facilitate quantitative in situ imaging of lens elasticity. Elastic waves induced by air-pulse stimulation on the limbus propagate to the lens and are then imaged using custom-built swept-source optical coherence tomography to obtain the elastic wave velocity and Young's modulus. The proposed OCE method was first validated by comparing the results of in situ and in vitro measurements of porcine lenses. The results demonstrate that the Young's modulus measured in situ was highly consistent with that measured in vitro and had an intraclass correlation coefficient of 0.988. We further investigated the elastic changes induced by cold storage and microwave heating. During 36-hour cold storage, the mean Young's modulus gradually increased (from 5.62 ± 1.24 kPa to 11.40 ± 2.68 kPa, P < 0.0001, n = 9) along with the formation of nuclear opacities. 15-second microwave heating caused a greater increase in the mean Young's modulus (from 6.86 ± 1.21 kPa to 25.96 ± 8.64 kPa, P < 0.0025, n = 6) without apparent cataract formation. Accordingly, this study reports the first air-pulse OCE measurements of in situ lenses, which quantified the loss of lens elasticity during simulated cataract development with good repeatability and sensitivity, thus enhancing the potential for adoption of lens biomechanics in the clinic.

Evolution of manual small-incision cataract surgery from 8 mm to 2 mm - A comprehensive review

Cataract is the most common cause of reversible blindness worldwide, accounting for approximately 50% of blindness worldwide. Cataract surgery is the most common surgical procedure performed in routine ophthalmic practice. It has undergone tremendous evolution, and the incision size has progressively reduced from 10-12 mm in extracapsular cataract surgery (ECCE) to 6-8 mm for manual small-incision cataract surgery (MSICS) and 2.2-2.8 mm in phacoemulsification. In a developing country like India, with a massive backlog of cataract, everyone cannot afford private surgery like phacoemulsification. Moreover, annual maintenance of the machine, cost of foldable IOLs, need for greater skill, learning curve, and difficulty in performing the surgery in mature and brown cataracts are other barriers. Due to these factors, MSICS is the surgery of choice in the developing world, with profound societal and economic benefits and similar visual recovery compared to phacoemulsification. During the last two decades, MSICS gained popularity in developing countries and has undergone tremendous advances. This article aims to review the various techniques of MSICS and how the surgery has evolved over the years, particularly focusing on the current technique of 2-mm MSICS.