Impact of Ophthalmic Surgeon Experience on Early Postoperative Central Corneal Thickness After Cataract Surgery

Clinical Outcomes in Scleral Fixation Secondary Intraocular Lens with Yamane versus Suture Techniques: A Systematic Review and Meta-Analysis

Background: The purpose of the study is to compare the visual outcomes and complications of sutured scleral fixation (SSF), a traditional and conservative surgical approach, and the newer and faster Yamane technique for secondary intraocular lens placement. Methods: A literature search was performed on PubMed, Embase, and Scopus on studies published between 1 July 2017 to 29 September 2023. Outcomes analyzed included the final best corrected visual acuity (BCVA) between 3 and 12 months to assess the effectiveness of the procedure, post-operative month (POM) 1 BCVA to assess the speed of visual recovery, endothelial cell count (ECC), absolute refractive error, surgical duration, and complication rates. Additional subgroup analyses were performed based on surgeon experience with the technique. Single-surgeon studies had an average of 26 procedures performed, whereas multiple-surgeon studies averaged only 9 procedures performed; these were then used to delineate surgeon experience. A sample-size weighted mean difference (MD) meta-analysis was performed across all variables using RevMan 5.4.1; p < 0.05 was considered statistically significant. Results: Thirteen studies with 737 eyes were included: 406 eyes were included in the SSF group, and 331 eyes were included in the Yamane group. There was no significant difference in the final BCVA between groups in both the single-surgeon versus multiple-surgeon studies (MD = -0.01, 95% CI: [-0.06, 0.04], p = 0.73). In the single-surgeon studies, the BCVA at POM1 was significantly improved in the Yamane group compared to SSF (MD = -0.10, 95% CI: [-0.16, -0.04], p = 0.002). In the multiple-surgeon studies, there was no significant difference in BCVA at POM1 (MD = -0.06, 95% CI: [-0.16, 0.04], p = 0.23). The Yamane group had a shorter surgical duration than SSF in both single-surgeon and multiple-surgeon studies (MD = -24.68, 95% CI: [-35.90, -13.46], p < 0.0001). The ECC, refractive error, and complication rates did not significantly differ amongst all groups. Conclusions: The Yamane technique demonstrated similar long-term visual outcomes and complication rates to the traditional SSF. Visual recovery was significantly faster in the Yamane group in the single-surgeon studies. The operative times were shorter across all Yamane groups. Based on these findings, it is advisable to consider the Yamane technique as a viable, and perhaps preferable, option for patients requiring secondary IOL placement, alongside traditional SSF methods.

Changes in straylight after cataract surgery

PURPOSE

To investigate straylight in the immediate postoperative period after cataract surgery.

SETTING

Amphia Hospital, Breda, the Netherlands.

DESIGN

Prospective, comparative, single-arm, single-center, single-surgeon study.

METHODS

Patients underwent cataract surgery on both eyes. 1 eye was randomly selected for implantation with a Clareon CNA0T0 intraocular lens (IOL); the fellow eye received a Vivinex XY1 IOL. Straylight was measured with the C-Quant straylight meter.

RESULTS

25 patients were included. Preoperatively, 1 day, 1 week, 1 month, and 3 months postoperatively, eyes with a CNA0T0 IOL had straylight levels (mean ± SD) of 1.48 ± 0.23, 1.26 ± 0.20, 1.06 ± 0.19, 1.11 ± 0.25, and 1.09 ± 0.20 log(s), respectively. For eyes with an XY1 IOL, these values were 1.48 ± 0.21, 1.41 ± 0.41, 1.10 ± 0.20, 1.13 ± 0.20, and 1.16 ± 0.20 log(s), respectively. From 1 week postoperatively, straylight values did not change (1 week vs 3 months: P = .40 and P = .14 and 1 month vs 3 months: P = .74 and P = .50 for CNA0T0 and XY1, respectively). The Pearson correlation coefficient for straylight values between the 2 eyes of individual subjects was 0.80 at 3 months.

CONCLUSIONS

Straylight levels can be considered stable 1 week after cataract surgery. We believe it is safe to use straylight measurements 1 month postoperatively for clinical trials. Straylight is highly correlated between the 2 eyes of an individual postoperatively.

Corneal Edema after Cataract Surgery

This systematic review investigates the prevalence and underlying causes of corneal edema following cataract surgery employing manual phacoemulsification. A comprehensive search encompassing databases such as PubMed, Embase, ProQuest, Cochrane Library, and Scopus was conducted, focusing on variables encompassing cataract surgery and corneal edema. Two independent reviewers systematically extracted pertinent data from 103 articles, consisting of 62 theoretical studies and 41 clinical trials. These studies delved into various aspects related to corneal edema after cataract surgery, including endothelial cell loss, pachymetry measurements, visual performance, surgical techniques, supplies, medications, and assessments of endothelial and epithelial barriers. This review, encompassing an extensive analysis of 3060 records, revealed significant correlations between corneal edema and endothelial cell loss during phacoemulsification surgery. Factors such as patient age, cataract grade, and mechanical stress were identified as contributors to endothelial cell loss. Furthermore, pachymetry and optical coherence tomography emerged as valuable diagnostic tools for assessing corneal edema. In conclusion, this systematic review underscores the link between corneal edema and endothelial cell loss in manual phacoemulsification cataract surgery. It highlights the relevance of factors like patient demographics and diagnostic modalities. However, further research is essential to unravel the complexities of refractive changes and the underlying mechanisms.

Research on Establishing Corneal Edema after Phacoemulsification Prediction Model Based on Variable Selection with Copula Entropy

BACKGROUND

Corneal edema (CE) affects the outcome of phacoemulsification. Effective ways to predict the CE after phacoemulsification are needed.

METHODS

On the basis of data from patients conforming to the protocol of the AGSPC trial, 17 variables were selected to predict CE after phacoemulsification by constructing a CE nomogram through multivariate logistic regression, which was improved via variable selection with copula entropy. The prediction models were evaluated using predictive accuracy, the area under the receiver operating characteristic curve (AUC), and decision curve analysis (DCA).

RESULTS

Data from 178 patients were used to construct prediction models. After copula entropy variable selection, which shifted the variables used for prediction in the CE nomogram from diabetes, best corrected visual acuity (BCVA), lens thickness and cumulative dissipated energy (CDE) to CDE and BCVA in the Copula nomogram, there was no significant change in predictive accuracy (0.9039 vs. 0.9098). There was also no significant difference in AUCs between the CE nomogram and the Copula nomogram (0.9637, 95% CI 0.9329-0.9946 vs. 0.9512, 95% CI 0.9075-0.9949; p = 0.2221). DCA suggested that the Copula nomogram has clinical application.

CONCLUSIONS

This study obtained a nomogram with good performance to predict CE after phacoemulsification, and showed the improvement of copula entropy for nomogram models.

Study of corneal endothelial cells in diabetic patients

Background: The cornea is the anterior transparent part of the eye. In addition to its optical and refractive function, it is an important protective structure.Aim: The aim of this study was to assess corneal endothelium (counts, morphology and structure) as well as corneal thickness of Type 2 diabetic participants.Setting: This is a hospital-based case–control study and was carried out at Ibn Al Haitham tertiary eye hospital in Baghdad, Iraq.Methods: The sample size was 240 eyes of 120 diabetic participants and 120 healthy participants. Non-contact specular microscopy was utilised to evaluate corneal endothelial cells, including endothelial cell density (ECD), coefficient of variation in cell area (CV), hexagonality (HEX) of cells as well as central corneal thickness (CCT).Results: The ECD was lower in the diabetic corneas (2584.87 ± 259.15 cell/mm2) compared with the healthy corneas (2717.56 ± 289.67 cell/mm2) (p = 0.017, statistically significant). Coefficient of variance (CV) was greater in the diabetic group (40.8 ± 4.17) as opposed to the group with healthy corneas (37.3 ± 2.89) (p = 0.019, statistically significant). The corneas of the diabetic group showed lower hexagonality (44.36% ± 9.87%) compared with the healthy corneas (59.35% ± 9.67%) (p  0.001, statistically significant). Furthermore, the corneas of the diabetic group had greater central thickness (581.1 ± 32.4 µm) when compared with the control group (511.8 ± 29.8 µm), (p  0.001, statistically significant). No correlation was found between the severity level of diabetic retinopathy and corneal endothelial pathological alterations.Conclusion: Long-term poorly controlled glycaemia has a remarkable impact on corneal endothelium (counts, morphology and structure) as well as corneal thickness.

Corneal Endothelial Cell Loss After Endocapsular and Supracapsular Phacoemulsification: The PERCEPOLIS Randomized Clinical Trial

PURPOSE

Subluxation techniques are superior to divide-and-conquer in procedure duration, pain, and ultrasound quantity, but their safety in endothelial cell loss (ECL) is unclear. This randomized single-blind noninferiority clinical trial aimed to determine whether subluxation supracapsular phacoemulsification techniques are inferior to a reference endocapsular technique (divide-and-conquer) regarding postoperative corneal ECL.

METHODS

Patients (aged18 years or older) with greater than +0.2 logarithm of the minimum angle of resolution best spectacle-corrected visual acuity and normal to severe density cataract were randomized to subluxation or divide-and-conquer phacoemulsification in 2015 to 2016. Follow-up with ophthalmic tests was conducted on day 4 and months 1, 3, and 12. The primary study outcome was ECL at all time points. Secondary study end points were operative variables, including effective phaco time and procedure duration. A clinically relevant noninferiority ECL limit was established on the basis of the literature.

RESULTS

In total, 292 patients (mean age, 73 yrs; 59% female) were randomized and underwent subluxation (n = 148) or divide-and-conquer (n = 144). Day 4 and month 1, 3, and 12 data were available for 243, 270, 275, and 198 patients, respectively. The unexpectedly high dropout at 12 months meant that the 12-month ECL data could only be assessed qualitatively. Surgery was successful in all patients. Subluxation was noninferior to divide-and-conquer in ECL. Effective phaco times were similar, but subluxation associated with shorter procedure duration.

CONCLUSIONS

The subluxation technique was noninferior to divide-and-conquer regarding postoperative ECL, at least in the first 3 months, and associated with reduced intervention time. Subluxation techniques may be suitable alternatives to endocapsular techniques.Clinical Trial Registration-URL: ClinicalTrials.gov. Unique identifier: NCT02535819.

Early corneal pachymetry maps after cataract surgery and influence of 3D digital visualization system in minimizing corneal oedema

PURPOSE

To describe the early topography of corneal swelling occurring after cataract surgery and to evaluate the impact of the three-dimensional (3D) digital visualization system in minimizing corneal oedema.

METHODS

Prospective observational, single-centre, consecutive case series of 134 patients undergoing cataract surgery performed by the same surgeon, with either 3D or conventional visualization systems. Eyes were assigned to two groups based on their anterior chamber depth (group ACD ≤3 mm and group ACD >3 mm). Optical coherence tomography was performed to evaluate postoperative corneal swelling.

RESULTS

Three corneal swelling profiles were identified on the first postoperative day type 1, limited corneal oedema near peripheral corneal incisions; type 2, dome-shaped corneal swelling spreading from the principal corneal incision and reaching the paracentral cornea; type 3, continuous oedema spreading from the principal incision to central cornea, with a generalized oedema predominating in the upper part of the cornea. On the first day after surgery, in group ACD ≤3 mm, visual acuity was significantly better in patients undergoing surgery with 3D visualization (0.023 vs 0.072 logMar, p = 0.014) with reduced central corneal thickening 17.3 µm (±3.2) in comparison with conventional visualization 44.0 µm (±9.3) (p = 0.0082). In group ACD >3 mm, no significant association was found between the use of the 3D system and pachymetry changes and early visual rehabilitation. On day 21 after surgery, no significant differences in corneal pachymetry values were observed between the two surgical approaches in both groups.

CONCLUSIONS

We describe early postoperative corneal map profiles providing insight into the pathogenesis of postoperative corneal swelling and possible prevention strategies. By improving visualization of the narrow surgical space in patients with shallow anterior chambers, the 3D system could help to minimize postoperative corneal oedema.

Defining the surgical footprint in cataract surgery: patient-related outcomes dependent on the experience of the surgeon

PURPOSE

To investigate which patient-related outcomes are dependent on the experience of the cataract surgeon.

METHODS

The study was designed as a prospective observational study. Novice (<150 surgeries performed) and experienced (>1000 surgeries performed) cataract surgeons from the Department of Ophthalmology, Rigshospitalet - Glostrup and Nordsjaellands Hospital - Hillerød were included in the study. Patients operated by the included surgeons were examined preoperatively, 1 day, 3 days, and 3 weeks after standard, noncomplicated cataract surgery. Primary outcomes were change in central corneal thickness and endothelial cell loss. Secondary outcomes were best-corrected visual acuity, intraocular pressure, aqueous flare, central macular thickness, and surgical complications.

RESULTS

Surgery performed by novice surgeons resulted in significantly lower visual acuity (mean -3.6 letters (Early Treatment Diabetic Retinopathy Study (ETDRS)); 95% CI: -7.3; -0.4, p = 0.03) and greater corneal thickness (mean 26.7 µm; 95% CI: 6.8; 46.6, p = 0.01) on the first day postoperative than surgery performed by experienced surgeons.

CONCLUSION

The experience of the cataract surgeon affected visual acuity and central corneal thickness in the immediate postoperative period. In the future, these patient-related outcomes may be used to assess the technical proficiency of surgical trainees and investigate the effect of different training programs.

Impact of surgical experience on early post-operative regional corneal thickness after phacoemulsification

Background: Currently, phacoemulsification is a very common cataract surgical procedure in which the lens is emulsified and aspirated from the eye through a small corneal incision.Aim: To compare early regional corneal thickness changes following phacoemulsification done by experienced surgeons versus trainee surgeons.Setting: A prospective cohort study was done at Ibn Al Haitham tertiary eye hospital in Baghdad, Iraq.Methods: The data were collected for 5 months, from 01 March 2018 until 31 July 2018. Adult patients undergoing phacoemulsification and intraocular lens surgery were prospectively evaluated and divided into two groups. Group 1 comprised those operated by experienced surgeons, whilst Group 2 patients were operated by trainee surgeons. Slit lamp examination and endothelial specular microscopy were assessed with the measurement of central corneal thickness (CCT) and peripheral corneal thickness (PCT), using Scheimpflug imaging (Pentacam).Results: There was a significant statistical difference in post-operative CCT between Groups 1 and 2, being 596.72 ± 50.69 µm compared to 631.54 ± 67.84 µm in Groups 1 and 2, respectively, with a mean difference of 34.82 µm (p = 0.000). More difference was observed in post-operative PCT (148.38 µm) as it was 734.8 ± 88.55 µm in the experienced group, compared to 883.18 ± 128.43 µm in the trainee group (p = 0.005).Conclusion: Phacoemulsification done by trainee surgeons was associated with higher CCT and PCT.

Comparing Resident Outcomes in Cataract Surgery at Different Levels of Experience

Purpose

To evaluate outcomes of resident-performed cataract surgeries in different training levels in a retrospective case series.

Patients and Methods

A total of 730 surgeries performed by residents were evaluated into three groups: surgeries performed during residents’ first semester of training in phacoemulsification (Level 1 – L1), surgeries performed during the second semester (Level 2 – L2), and surgeries performed during the third semester (Level 3 – L3). The primary outcome was the incidence of intraoperative complications in each group. Secondary outcomes were the comparisons between initial and final corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), and central corneal thickness (CCT) in each group. Descriptive statistical analyses were employed in the presentation of the results using central tendency and variance measurements.

Results

The rate of complications within six weeks of follow-up was 24 out of 102 eyes (23.53%) in the L1 group, 63 out of 301 eyes (20.93%) in the L2 group, and 37 out of 327 (11.31%) in the L3 group (p=0.001). Posterior capsule rupture (PCR) was the most frequent intercurrence observed in all three semesters: it occurred in 12.7% of the surgeries in the first semester (13/102), 16.9% of surgeries in the second semester (51/301), and 9.5% of surgeries in the third semester (31/327). There was no significant difference in CDVA (p=0.298), ECD (p=0.067), IOP (p=0.217), or CCT (p=0.807) between the groups.

Conclusion

When measured by rates of complications and by the aforementioned parameters, surgical competency was found to improve as surgical experience and frequency increased. Therefore, this study identified some patterns of skill development that can be applied to teaching strategies and better assist surgeons in training.

Real-Time Surgical Problem Detection and Instrument Tracking in Cataract Surgery

Surgical skill levels of young ophthalmologists tend to be instinctively judged by ophthalmologists in practice, and hence a stable evaluation is not always made for a single ophthalmologist. Although it has been said that standardizing skill levels presents difficulty as surgical methods vary greatly, approaches based on machine learning seem to be promising for this objective. In this study, we propose a method for displaying the information necessary to quantify the surgical techniques of cataract surgery in real-time. The proposed method consists of two steps. First, we use InceptionV3, an image classification network, to extract important surgical phases and to detect surgical problems. Next, one of the segmentation networks, scSE-FC-DenseNet, is used to detect the cornea and the tip of the surgical instrument and the incisional site in the continuous curvilinear capsulorrhexis, a particularly important phase in cataract surgery. The first and second steps are evaluated in terms of the area under curve (i.e., AUC) of the figure of the true positive rate versus (1-false positive rate) and the intersection over union (i.e., IoU) obtained by the ground truth and prediction associated with the region of interest. As a result, in the first step, the network was able to detect surgical problems with an AUC of 0.97. In the second step, the detection rate of the cornea was 99.7% when the IoU was 0.8 or more, and the detection rates of the tips of the forceps and the incisional site were 86.9% and 94.9% when the IoU was 0.1 or more, respectively. It was thus expected that the proposed method is one of the basic techniques to achieve the standardization of surgical skill levels.

The Ethical Dilemma in the Surgical Management of Low Grade Gliomas According to the Variable Availability of Resources and Surgeon Experience

Low grade gliomas (LGGs) affect young individuals in the prime of life. Management may alternatively include biopsy and observation or surgical resection. Recent evidence strongly favors maximal and supramaximal resection of LGGs in optimizing survival metrics. Awake craniotomy with cortical mapping and electrical stimulation along with other preoperative and intraoperative surgical adjuncts, including intraoperative magnetic resonance and diffusion tensor imaging, facilitates maximization of resection and eschews precipitating neurological deficits. Intraoperative imaging permits additional resection of identified residual to be completed within the same surgical session, improving extent of resection and consequently progression free and overall survival. These resources are available in only a few centers throughout the United States, raising an ethical dilemma as to where patients harboring LGGs should most appropriately be treated.

Real-Time Extraction of Important Surgical Phases in Cataract Surgery Videos

The present study aimed to conduct a real-time automatic analysis of two important surgical phases, which are continuous curvilinear capsulorrhexis (CCC), nuclear extraction, and three other surgical phases of cataract surgery using artificial intelligence technology. A total of 303 cases of cataract surgery registered in the clinical database of the Ophthalmology Department of Tsukazaki Hospital were used as a dataset. Surgical videos were downsampled to a resolution of 299 × 168 at 1 FPS to image each frame. Next, based on the start and end times of each surgical phase recorded by an ophthalmologist, the obtained images were labeled correctly. Using the data, a neural network model, known as InceptionV3, was developed to identify the given surgical phase for each image. Then, the obtained images were processed in chronological order using the neural network model, where the moving average of the output result of five consecutive images was derived. The class with the maximum output value was defined as the surgical phase. For each surgical phase, the time at which a phase was first identified was defined as the start time, and the time at which a phase was last identified was defined as the end time. The performance was evaluated by finding the mean absolute error between the start and end times of each important phase recorded by the ophthalmologist as well as the start and end times determined by the model. The correct response rate of the cataract surgical phase classification was 90.7% for CCC, 94.5% for nuclear extraction, and 97.9% for other phases, with a mean correct response rate of 96.5%. The errors between each phase’s start and end times recorded by the ophthalmologist and those determined by the neural network model were as follows: CCC’s start and end times, 3.34 seconds and 4.43 seconds, respectively and nuclear extraction’s start and end times, 7.21 seconds and 6.04 seconds, respectively, with a mean of 5.25 seconds. The neural network model used in this study was able to perform the classification of the surgical phase by only referring to the last 5 seconds of video images. Therefore, our method has performed like a real-time classification.

Supracapsular phacoemulsification: Description of the "Garde à vous" technique and comparative clinical results

Phacoemulsification techniques can be divided into 2 categories: endocapsular and supracapsular techniques. Supracapsular techniques involve phacoemulsification of the nucleus outside and above the capsular plane. The "Garde-à-vous" technique described in this manuscript is a modified and improved version of the supracapsular procedure with up-to-date technology in micro-coaxial surgery. It maintains the known advantages of supracapsular techniques such as faster surgical times and lower rates of capsular tears and brings a standardized technique with well-defined surgical steps in order to achieve tilting of the nucleus in a vertical or oblique position in almost 100% of cases by performing a double-wave hydro-dissection. The authors also give the results of a non-randomized prospective study, comparing the "Garde-à-vous" technique and the standard "cracking" technique in 2856 cases. The results show that for the "Garde-à-vous group", the patients were significantly younger (P<0.001), the power of ultrasound used was greater (P<0.001) for lower UST (ultrasound time or average phacoemulsification time APT) and EPT (effective phacoemulsication time) (P<0.001), the duration of the procedure was shorter (P<0.001), patient discomfort was less (P<0.001), and the power of the implants used was lower (P<0.01). With regard to the gender of the patients, the percentage of topical anesthesia and the rate of intraoperative complications (posterior capsular rupture), there was no statistically significant difference.

Comparison of two popular nuclear disassembly techniques for cataract surgeons in training: divide and conquer versus stop and chop

PURPOSE

To compare two common phacoemulsification techniques in the learning curve phase, and their effect on ultrasound energy dissipation.

METHODS

One hundred and ten consecutive patients scheduled for cataract surgery with the same surgeon in training were prospectively enrolled. Study was divided in two parts. In the first one, 60 patients were stratified for cataract grade [nuclear opalescence (NO) grade 2-4] and divided in two groups receiving surgery with the divide-and-conquer technique (Group-1) and with the stop-and-chop technique (Group-2). In the second part, 50 patients were stratified according to cataract grade (NO2-6), and the surgeon had to choose one of the two techniques according to personal preference. The primary outcome was the cumulative dissipated energy (CDE).

RESULTS

Significant differences of CDE were observed between the NO3 and NO4 cataracts in Group-1. In Group-2, this difference was not significant, suggesting that with more advanced cataracts, the stop-and-chop technique allows less ultrasound use. In the second part of the study, the stop and chop was most frequently used for more advanced cataracts. When considering harder cataracts (NO5-NO6), patients receiving surgery with the divide-and-conquer technique had higher CDE values compared to stop and chop.

CONCLUSIONS

Both divide-and-conquer and stop-and-chop techniques are efficient in the learning curve. Stop and chop dissipates less energy in harder nuclei. Once surgeons reach sufficient experience with both techniques, they should switch to a stop-and-chop technique, allowing lower levels of ultrasound energy.

Central corneal epithelial thickness changes after half-moon supracapsular nucleofractis phacoemulsification technique

PURPOSE

To find out the effect of half-moon supracapsular nucleofractis technique on central corneal epithelial thickness (CET) measured by spectral domain anterior segment optical coherence tomography (AS-OCT).

MATERIALS AND METHODS

Patients who underwent uneventful cataract surgery by the same surgeon with the same technique were recruited in this study. The effective phaco time (EPT) was recorded in each surgery. Central CET was measured by AS-OCT 1 day before and 1, 3, 7 days after surgery. CET was measured without precorneal tear film layer, and non-epithelial central corneal thickness was also calculated manually. Preoperative and postoperative values were compared by statistical analysis.

RESULTS

Thirty-one eyes of 31 patients were included in this study. The mean age of patients was 65.03 ± 11.47 years. On the first day of surgery, increase in mean CET was statistically significant, but on the 3rd and 7th day after surgery, this increase was declined (p = 0.001, p = 0.367, p = 1, respectively). A statistically significant positive correlation was found between mean EPT and mean CET on the first postoperative day (p = 0.013, r = 0.470). On the 3rd and 7th day, this correlation was not statistically significant (p = 0.055, p = 0.454, respectively).

CONCLUSION

Mean central CET was statistically thicker and positive correlated with EPT on the first postoperative day. But on the 7th day, it declined to preoperative values.