Femtosecond laser-assisted cataract surgery for complex cataracts - A review.

Since its inception in 2009, femtosecond laser-assisted cataract surgery (FLACS) has become an alternative to conventional phacoemulsification cataract surgery (CPCS). Clinical studies were unable to demonstrate superior visual outcomes, but revealed reduced endothelial cell loss. More recently, the cost-effectiveness of FLACS over CPCS in routine cataract surgeries has been challenged. However, the unique abilities of FLACS to customize anterior capsulotomies precisely, soften and fragment the nucleus without capsular bag stress, and create corneal incisions may have special utility in complex cataract and less-common scenarios. In this article, we review the unique role of FLACS in complex cataract surgeries and how it could play a role to improve the safety and predictability of nonroutine cataract surgery.

Association between sleep and myopia in children and adolescents: a systematic review and meta-analysis.

PURPOSE: There is a scarcity of literature focusing on sleep's impact on myopia in children despite an epidemic rise of myopia among the age group and the importance of early prevention. As such, this systematic review-meta-analysis aims to evaluate the association between various aspects of sleep and myopia in children and adolescents aged 0-19 years. METHODS: We searched PubMed, EMBASE, and Cochrane Library on 08/12/2022 for studies reporting sleep in relation to myopia among children and adolescents. Myopia was defined as spherical equivalent refraction < -0.5 diopter. The primary outcome was the relationship between sleep duration and myopia prevalence. Secondary outcomes include the effect of sleep quality, bedtime, and waketime on myopia prevalence, incidence, and progression. Odds ratio (OR) was estimated with a 95% confidence interval (95% CI). RESULTS: Eighteen studies (49,277 participants) were included in the review, and six studies (14,116 participants) were included in the meta-analysis for the primary outcome. There was no significant correlation between sleep and myopia prevalence (OR = 0.905, 95% CI = 0.782 to 1.047). Some studies suggested that better sleep quality (2 of 6 studies), earlier bedtime (3 of 5 studies), and later waketimes (2 of 3 studies) had protective effects on myopia. CONCLUSION: Sleep duration did not affect myopia prevalence in children, while other aspects of sleep had plausible but inconclusive impacts on myopia development and progression. More research with diverse populations and standardized methods of reporting is needed.

Preoperative computed tomography in Fournier's gangrene does not delay time to surgery.

PURPOSE: Fournier's gangrene (FG), a rapidly progressive necrotizing soft tissue infection of the external genitalia and perineum, necessitates urgent surgical debridement. The time to surgery effect of preoperative computed tomography (CT) in managing this condition is yet to be fully explored. The purpose of this study was to assess whether obtaining a preoperative CT in patients with FG impacts the time to surgical intervention. METHODS: This was a single-center retrospective study of patients who underwent CT prior to surgical debridement of FG during a 9-year period vs patients who did not undergo CT. In 76 patients (male = 39, mean age = 51.8), 38 patients with FG received a preoperative CT, and 38 patients with FG did not receive CT prior to surgical debridement. Time to operating room and outcome metrics were compared between CT and non-CT groups. RESULTS: The time from hospital presentation to surgical intervention was not significantly different between patients who underwent CT and those who did not (6.65 ± 3.71 vs 5.73 ± 4.33 h, p = 0.37). There were also no significant differences in cost ($130,000 ± $102,000 vs $142,000 ± $152,000, p = 0.37), mortality (8 vs 7, p = 1), duration of hospital stay (15.5 ± 15 vs 15.7 ± 11.6 days, p = 0.95), average intensive care unit stay (5.82 ± 5.38 days vs 6.97 ± 8.58 days, p = 0.48), and APACHE score (12 ± 4.65 vs 13.9 ± 5.6, p =0.12). CONCLUSION: Obtaining a preoperative CT did not delay surgical intervention in patients with FG.

Computed Tomography Attenuation of Three-Dimensional (3D) Printing Materials-Depository to Aid in Constructing 3D-Printed Phantoms.

Three-dimensionally printed phantoms are increasingly used in medical imaging and research due to their cost-effectiveness and customizability, offering valuable alternatives to commercial phantoms. The purpose of this study was to assess the computed tomography (CT) attenuation characteristics of 27 resin materials from Formlabs, a 3D printing equipment and materials manufacturer. Cube phantoms (both solid and hollow constructions) produced with each resin were subjected to CT scanning under varying tube current-time products with attenuation measurements recorded in Hounsfield units (HU). The resins exhibited a wide range of attenuation values (-3.33 to 2666.27 HU), closely mimicking a range of human tissues, from fluids to dense bone structures. The resins also demonstrated consistent attenuation regardless of changes in the tube current. The CT attenuation analysis of FormLabs resins produced an archive of radiological imaging characteristics of photopolymers that can be utilized to construct more accurate tissue mimicking medical phantoms and improve the evaluation of imaging device performance.

Analysis of Superficial Subcutaneous Fat Camper's and Scarpa's Fascia in a United States Cohort.

Together, the Camper's and Scarpa's fasciae form the superficial fat layer of the abdominal wall. Though they have clinical and surgical relevance, little is known about their role in body composition across diverse patient populations. This study aimed to determine the relationship between patient characteristics, including sex and body mass index, and the distribution of Camper's and Scarpa's fascial layers in the abdominal wall. A total of 458 patients' abdominal CT examinations were segmented via CoreSlicer 1.0 to determine the surface area of each patient's Camper's, Scarpa's, and visceral fascia layers. The reproducibility of segmentation was corroborated by an inter-rater analysis of segmented data for 20 randomly chosen patients divided between three study investigators. Pearson correlation and Student's t-test analyses were performed to characterize the relationship between fascia distribution and demographic factors. The ratios of Camper's fascia, both as a proportion of superficial fat (r = -0.44 and p < 0.0001) and as a proportion of total body fat (r = -0.34 and p < 0.0001), showed statistically significant negative correlations with BMI. In contrast, the ratios of Scarpa's fascia, both as a proportion of superficial fat (r = 0.44 and p < 0.0001) and as a proportion of total body fat (r = 0.41 and p < 0.0001), exhibited statistically significant positive correlations with BMI. Between sexes, the females had a higher ratio of Scarpa's facia to total body fat compared to the males (36.9% vs. 31% and p < 0.0001). The ICC values for the visceral fat, Scarpa fascia, and Camper fascia were 0.995, 0.991, and 0.995, respectively, which were all within the 'almost perfect' range (ICC = 0.81-1.00). These findings contribute novel insights by revealing that as BMI increases the proportion of Camper's fascia decreases, while the ratio of Scarpa's fascia increases. Such insights expand the scope of body composition studies, which typically focus solely on superficial and visceral fat ratios.

A data-driven approach to evaluate factors affecting resident performance in cataract surgery.

PURPOSE: To evaluate the operative duration and clinical performance of ophthalmology residents performing standard phacoemulsification cataract surgeries using information available from electronic health records (EHR). METHODS: This is a retrospective cohort study. De-identified surgical records of all standard phacoemulsifications performed in a tertiary institution between 1st January 2015 and 8th August 2018 were retrieved from the hospital EHR. The main outcome measures were improvement in operative duration with case experience, corrected distance visual acuity (CDVA) improvement, and intra-operative complication rates. RESULTS: Twelve ophthalmology residents performed a total of 1427 standard phacoemulsifications. The median operative duration was 27 min (interquartile range, 22-34 min), which improved from 31 to 24 min (before the 101st case [Group 1] versus 101st case onwards [Group 2], p < 0.001). Gradient change analysis (non-linear regression) showed significant reduction until the 100th case (p = 0.043). Older patients (0.019), worse pre-operative CDVA (0.343), and surgery performed by Group 1 (1.115) were significantly associated with operative duration above 30 min. LogMAR CDVA improved from a mean of 0.57 ± 0.52 pre-operatively to 0.10 ± 0.18 post-operatively (p < 0.001). Posterior capsule rupture (PCR) rate decreased from 4.0% [Group 1] to 2.1% [Group 2] (p = 0.096), while overall complication rate decreased from 8.9% to 3.1% (p < 0.001). CONCLUSION: The median operative duration reduced consistently with surgical experience for the first 100 cases. Older patients, poorer pre-operative VA, and surgical experience of less than 100 cases were significantly associated with an operative duration above 30 min. There was a statistically significant decrease in complication rate between Group 1 and 2.

Teleophthalmology and its evolving role in a COVID-19 pandemic: A scoping review.

INTRODUCTION: Teleophthalmology may assist the healthcare sector in adapting to limitations imposed on clinical practice by a viral pandemic. A scoping review is performed in this study to assess the current applications of teleophthalmology for its suitability to diagnose, monitor or manage ophthalmological conditions with accuracy. METHODS: A search of PubMed was conducted for teleophthalmology-related articles published from 1 January 2018 to 4 May 2020. Only articles that focused on the use of teleophthalmology in terms of diagnosis and management, as well as its benefits and detriments, were included. The Mixed Methods Appraisal Tool (MMAT) was used to assess the quality of the included articles. RESULTS: A total of 38 articles were assessed at the full-text level. There were 2 qualitative studies and 1 quantitative randomised controlled trial, while the majority were either quantitative descriptive studies (19, 50.0%) or quantitative non-randomised studies (16, 42.1%). Overall, 8 studies described reducing manpower requirements, 4 described reducing direct patient-doctor contact, 17 described storage of medical imaging and clinical data, and 9 described real-time teleconferencing. The MMAT analysis revealed limitations in appropriate sampling strategy in both quantitative non-randomised studies (9 of 16, 56.3%) and quantitative descriptive studies (9 of 19, 47.4%). Cost-effectiveness of teleophthalmology was not performed in any included study. CONCLUSION: This current review of the various aspects of teleophthalmology describes how it may potentially assist the healthcare sector to cope with the limitations imposed by a viral pandemic through technology. Further research is required to evaluate the cost-effectiveness of the various strategies.

Phacoemulsification vs phacoemulsification with micro-bypass stent implantation in primary angle closure and primary angle closure glaucoma: A randomized single-masked clinical study.

IMPORTANCE: Primary angle closure glaucoma (PACG) is a major cause of irreversible visual impairment in Asia, but there is no published data on the effect of iStent on these patients. BACKGROUND: To compare the efficacy and safety of combined phacoemulsification and iStent implantation with standard phacoemulsification in an Asian population. DESIGN: A prospective, single-masked, randomized study in a public tertiary eye clinic. PARTICIPANTS: Patients with concomitant visually significant cataracts and primary angle closure (PAC) or PACG. METHODS: Patients were randomized and underwent either phacoemulsification alone (phaco) or with concurrent iStent injection (phaco-iStent). Demographic and clinical data were collected. MAIN OUTCOME MEASURES: Complete and qualified success rates at 12 months were compared between both treatment arms. RESULTS: Thirty-two patients were recruited between September 2015 and February 2016. All patients completed 12 months of follow-up. There was no statistically significant difference in preoperative IOP (phaco, 17.5 ± 3.1 mmHg; phaco-iStent, 18.6 ± 4.7 mmHg, P = .65) and 12-months postoperative IOP (phaco, 15.0 ± 2.5 mmHg; phaco-iStent, 14.7 ± 3.1 mmHg, P = .86) between both groups. Complete success rates were 43.8% (95% CI, 19.8-65.6) for the Phaco group and 87.5% (95% CI, 58.6-96.7) for the Phaco-iStent group (P = .01). Thinner preoperative optical coherence tomography (retinal nerve fibre layer) thickness (hazard ratio [HR] = 7.34 [95% CI, 1.53-35.30]) and phacoemulsification alone (HR = 0.93 [95% CI, 0.87-0.02]) were independent factors associated with failure to achieve complete success. CONCLUSIONS AND RELEVANCE: Combined phacoemulsification with iStent implantation is associated with a higher likelihood of complete success compared with phacoemulsification alone in eyes with primary angle closure disease at 12 months postoperatively. Further studies are required to establish the longer term efficacy of iStent implantation and to identify other predictors for surgical success.

Discontinuous rate-stiffening in a granular composite modeled after cornstarch and water.

Cornstarch in water exhibits impact-activated solidification (IAS) and strong discontinuous shear thickening, with "shear jamming". However, these phenomena are absent in cornstarch in ethanol. Here we show that cornstarch granules swell under ambient conditions. We postulate that this granule swelling is linked to an interparticle force scale that introduces a discontinuous rate-dependence to the generation of stable contacts between granules. We studied this force scale by coating sand with ~ 2 µm-thick polydimethysiloxane, creating a material that exhibits a similar IAS and discontinuous deformation rate-stiffening despite being a granular composite, not a suspension. This result suggests rate-dependence can be tuned by coating granular materials, introducing an interparticle force scale from rate-dependent properties present in the coating material. Our work provides insights into the unique behavior of cornstarch in water, bridges our understanding of suspensions and dry granular materials, and introduces a method to make discontinuous rate-dependent materials without suspending particles.

Potent Antineoplastic Effects of Combined PI3Kα-MNK Inhibition in Medulloblastoma.

Medulloblastoma is a highly malignant pediatric brain tumor associated with poor outcome. Developing treatments that target the cancer stem cell (CSC) population in medulloblastoma are important to prevent tumor relapse and induce long-lasting clinical responses. We utilized medulloblastoma neurospheres that display CSC characteristics and found activation of the PI3K/AKT pathway in sphere-forming cells. Of all class IA PI3Ks, only the PI3Kα isoform was required for sphere formation by medulloblastoma cells. Knockdown of p110α, but not p110ß or p110δ, significantly disrupted cancer stem cell frequencies as determined by extreme limiting dilution analysis (ELDA), indicating an essential role for the PI3Kα catalytic isoform in medulloblastoma CSCs. Importantly, pharmacologic inhibition of the MAPK-interacting kinase (MNK) enhanced the antineoplastic effects of targeted PI3Kα inhibition in medulloblastoma. This indicates that MNK signaling promotes survival in medulloblastoma, suggesting dual PI3Kα and MNK inhibition may provide a novel approach to target and eliminate medulloblastoma CSCs. We also observed a significant reduction in tumor formation in subcutaneous and intracranial mouse xenograft models, which further suggests that this combinatorial approach may represent an efficient therapeutic strategy for medulloblastoma. IMPLICATIONS: These findings raise the possibility of a unique therapeutic approach for medulloblastoma, involving MNK targeting to sensitize medulloblastoma CSCs to PI3Kα inhibition.

Peripheral retinal changes in highly myopic young Asian eyes.

PURPOSE: To determine the type and prevalence of peripheral retinal changes and its relationship with axial length (AL) in a population of young Asian adult males. METHODS: This was a cross-sectional study of male subjects aged between 19 and 25 years old. High myopes [spherical equivalent refraction, (SER) < -6.00 D] were recruited and underwent further ocular investigations including dilated retinal photography and binocular indirect ophthalmoscopy by two trained ophthalmologists. The frequency of peripheral retinal changes within high myopes was correlated with axial length and also compared with a group of emmetropes (SER between -0.50 D and +1.00 D). RESULTS: A total of 593 high myopes and 156 emmetropes were recruited. White without pressure (WWOP; n = 458, 46.5%) and lattice degeneration (LD; n = 109, 14.6%) were the commonest findings, and their prevalence was significantly higher among high myopes (LD, 16.9% versus 5.8%; WWOP, 57.2% versus 5.8%; both p < 0.001). Among high myopes, temporal LD was more common (71%) and 35% had more than one area in the same eye. Increasing AL was associated with LD (odds ratio 1.28, p = 0.01) and retinal holes (odd's ratio 1.44, p = 0.02) on multivariate analysis. CONCLUSION: White without pressure (WWOP) and LD were the commonest peripheral retinal changes. One-third of high myopes with LD had more than one area in the same eye. Increasing AL was associated with LD and retinal holes. Studies in older adults should be conducted to develop clinical guidelines for the management of high myopes.

Safety and Efficacy of Microinvasive Glaucoma Surgery.

Microinvasive glaucoma surgery (MIGS) is emerging as a new therapeutic option for glaucoma patients who wish to reduce their medication burden and avoid the postoperative complications of conventional glaucoma filtration surgery. These devices differ in terms of their efficacy and safety profile. Schlemm's canal devices have the most favorable safety profile at the compromise of modest efficacy, while subconjunctival and suprachoroidal devices are potentially more effective at lowering the intraocular pressure at the expense of a higher rate of complications. This review consolidates the latest evidence on the efficacy and safety of the MIGS devices in clinical use and provides an overview on upcoming devices which would likely also become viable treatment options in the near future. These clinical data would assist a glaucoma surgeon in selecting the most appropriate MIGS device for each patient based on the glaucoma severity and patient expectations.

Fractal atomic-level percolation in metallic glasses.

Metallic glasses are metallic alloys that exhibit exotic material properties. They may have fractal structures at the atomic level, but a physical mechanism for their organization without ordering has not been identified. We demonstrated a crossover between fractal short-range (<2 atomic diameters) and homogeneous long-range structures using in situ x-ray diffraction, tomography, and molecular dynamics simulations. A specific class of fractal, the percolation cluster, explains the structural details for several metallic-glass compositions. We postulate that atoms percolate in the liquid phase and that the percolating cluster becomes rigid at the glass transition temperature.