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Purpose: To assess the functional outcomes in visual acuity, metamorphopsia, and vision-related quality of life (VR-QOL) and to evaluate prognostic factors after macular buckling (MB) surgery in eyes with high myopia and foveoschisis (FS)-associated macular detachment (MD)., Methods: Thirty-nine eyes of 39 patients with FS-associated MD who underwent MB surgery were enrolled. Measured outcomes comprised best-corrected visual acuity (BCVA), metamorphopsia, VR-QOL, axial length (AL), macular reattachment, and resolution of foveoschisis. In addition, factors affecting final BCVA and metamorphopsia were analyzed., Results: At 12 months postoperatively, 36 eyes (92.31%) achieved macular reattachment, 37 eyes (94.87%) achieved complete resolution of foveoschisis, and metamorphopsia diminished in 31 eyes (79.49%). LogMAR BCVAs at baseline and months 1, 3, 6, and 12 postoperatively were 0.62 ± 0.35 (20/83), 0.65 ± 0.3 (20/89), 0.59 ± 0.31 (20/77), 0.54 ± 0.31 (20/69), and 0.46 ± 0.27 (20/57) (P < 0.001), respectively. Metamorphopsia scores by M-CHARTS were 1.36° ± 0.51°, 1.04° ± 0.51°, 0.74° ± 0.47°, 0.59° ± 0.47°, and 0.13° ± 0.29° (P < 0.001). All Visual Function Questionnaire-25 subscales demonstrated significant improvement postoperatively, with the exception of "general health" (P = 0.08) and "driving" (P = 0.111). Preoperative BCVA was an independent risk factor for postoperative BCVA at month 12 (r = 0.638, P < 0.001), and the preoperative M-score was an independent risk factor for postoperative M-score at month 12 (r = 0.187, P = 0.045)., Conclusion: MB surgery significantly improved BCVA, metamorphopsia, and VR-QOL in patients with FS-associated MD. Preoperative BCVA and metamorphopsia score were prognostic factors for postoperative BCVA and metamorphopsia score at month 12., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Opthalmic Communications Society, Inc.)

Purpose of Review: With a decline in the use of scleral buckling for rhegmatogenous retinal detachment (RRD) repair in recent years, this review seeks to provide a summary of the most recent research findings regarding the role of scleral buckling in the repair of RRD., Recent Findings: Many recent studies have compared visual and anatomic outcomes between scleral buckling and pars plana vitrectomy (PPV) for RRD repair. Some suggest superior outcomes with primary scleral buckling, particularly in younger, phakic patients, and in association with other risk factors that we review. Children do best with primary scleral buckling surgery. Functionally, scleral buckling may also result in lower rates of retinal displacement compared to PPV. When PPV is necessary, a supplemental buckle may benefit certain patients, while the advantage remains unclear in other clinical scenarios and necessitates further investigation., Summary: Scleral buckling is an important technique for the repair of RRD and it is crucial to continue training retina surgeons in this technique to maximize patient outcomes., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Macular buckling surgery is used to treat certain cases of myopic traction maculopathy but is rarely performed in the United States. One of the main factors limiting its use is the lack of commercially available buckling elements. Here, we describe a novel technique for creating an effective macular buckle using readily obtainable buckling materials., Methods: By using a traditional circumferential 41 band as the anchoring point around the globe, a 240 band can then be attached and oriented posteriorly along the superonasal-inferotemporal axis. This posterior 240 band is then used to guide a grooved sponge (509G) under the macula to create a customizable and titratable tamponade effect along the posterior pole. This approach was used to provide external support in the case of a recurrent, complex tractional retinal detachment which had failed multiple prior vitrectomy-based repairs., Results: Placement of the macular sling resolved the patient's recurrent retinal detachment with return of the visual acuity to her preoperative baseline. There have been no adverse effects related to the surgery aside from a large hyperopic shift due to the buckle effect on the macula. We believe the technical and material complexity of this technique is comparable with that of more common scleral buckling techniques., Conclusion: This macular sling technique can be used to create an effective posterior buckle without requiring specialized materials.

Purpose: Our study aims to evaluate the surgical outcomes and clinical features of retinal detachment (RD) cases treated with segmental scleral buckling (SB), elucidating the role of segmental SB as a vital option in specific situations during the current era., Methods: We retrospectively reviewed 128 eyes with primary rhegmatogenous RD that underwent segmental scleral buckling between November 2008 and December 2020. Clinical features and success rates were recorded and analyzed., Results: A total of 128 eyes were included. The patient's ages ranged from 12 to 72 years, with a median age of 45. Most of the eyes were phakic (97%). Regarding the type of break, 47% were holes, and flap tears were found in 68 cases (53%). The break locations were superior-temporal (54%), inferior-temporal (31%), superior-nasal (9.5%), and inferior-nasal (5.5%). The length of the SB applied ranged from 3.5 to 8.0 clock hours, with a median of 6.0. Primary success was achieved in 121 eyes, and recurrence occurred in 7 eyes. All recurrent RD cases reattached after undergoing secondary VT. The causes of failure included 2 break reopens, 1 missed break, and 4 eyes with proliferative vitreoretinopathy. The single-surgery anatomic success (SSAS) rate for segmental SB was 94.5%. The final success rate was 100%., Conclusions: For phakic, low complexity retinal detachment in our study, segmental scleral buckling emerges as a surgical option with a high primary success rate and a lower incidence of complications., (© 2024. The Author(s).)

Purpose: To investigate the efficacy, safety, and indications for additional pneumatic retinopexy (PR) in patients with persistent retinal detachment after scleral buckling., Methods: This retrospective study included patients who underwent additional PR after scleral buckling for primary rhegmatogenous retinal detachment (n = 78). We defined "inadequate buckle" as retinal detachment persistence because of low buckle height despite accurate buckle placement and "buckle misplacement" as an uncovered tear because of incorrect buckle placement., Results: The anatomical success rate after additional PR was 52.6%. Development of proliferative vitreoretinopathy Grade B (hazard ratio, 5.73; P < 0.001) and inferior retinal tears (hazard ratio, 2.12; P = 0.040) were significant risk factors for anatomical failure. The most common cause of anatomical failure was proliferative vitreoretinopathy (19 of 37; 51.4%), and epiretinal membrane formation was a common complication after additional PR (22 of 78; 28.2%). The anatomical success rate with additional PR was significantly higher in the inadequate buckle group than in the misplacement group (8 of 9 [88.9%] vs. 1228 [42.9%]; P = 0.023)., Conclusion: Development of proliferative vitreoretinopathy Grade B and inferior retinal tears were significantly associated with anatomical failure after additional PR. Additional PR may benefit patients with superior retinal tears or low buckle height and those without proliferative vitreoretinopathy.

Purpose: To compare the efficacy of peribulbar bupivacaine with routine analgesics for pain management in patients undergoing scleral buckling., Methods: In total, 72 patients undergoing scleral buckling or combined with vitrectomy were enrolled in this study. Patients were randomized into two groups, each containing 36 patients. Patients of group A received 5 mL of bupivacaine (0.5%) injection at the end of surgery, whereas group B patients received routine analgesics. The postoperative pain score was assessed in the first 24 hours of the postoperative period with the visual pain analog score., Results: Maximum postoperative pain scores were lower in patients receiving bupivacaine block (median: 3; range: 3-7) than in the control group (median: 5; range: 3-9). Pain scores in group A were lower than in the control group both at 3 and 6 hours after surgery, which was statistically significant ( P < 0.001). Four patients in group A and 17 patients in group B needed additional analgesia in the first 24 hours of the postoperative period. In addition, two patients in group A and seven patients in group B experienced episodes of nausea and vomiting in the first 24 hours of surgery., Conclusion: The results of this study suggest that the postoperative experience of patients undergoing scleral buckling surgery can be made more comfortable with the use of bupivacaine block at the end of surgery., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: To introduce a surgical technique for temporary scleral buckling of noncomplex rhegmatogenous retinal detachment using a combination of nonabsorbable and absorbable sutures that would induce minimal permanent refractive changes., Methods: Twenty consecutive patients (20 eyes) with noncomplex rhegmatogenous retinal detachment were prospectively included. Scleral buckling was performed in all eligible subjects, and encircling buckling was added when necessary. The silicone elements were fixed on the sclera with 5-0 nonabsorbable sutures and tightened to form a ridge with 6-0 absorbable sutures. Best-corrected visual acuity, scleral ridge status, axial length, spherical diopter, and cylinder diopter were collected., Results: All patients achieved primary retinal reattachment with significant improvement of best-corrected visual acuity after surgery. Scleral ridge was obvious and in situ at the 1-month follow-up but diminished at the 3-month follow-up. At the 1-month follow-up, axial length increased from 24.78 mm ± 2.14 mm preoperatively to 25.22 mm ± 2.11 mm, and cylinder diopter increased from -1.99 ± 1.03 to -2.95 ± 1.55 (both P < 0.001). At the 3-month follow-up, axial length, spherical diopter, and cylinder diopter decreased significantly compared with the values at the 1-month follow-up (all P < 0.05). No obvious complications were observed during the whole follow-up. Patients who underwent additional encircling buckling exhibited greater changes in axial length and cylinder diopter at the 1-month follow-up (both P < 0.001)., Conclusion: The modified technique of scleral buckling with/without encircling buckling using both nonabsorbable and absorbable sutures offers a safe and effective option to repair noncomplex rhegmatogenous retinal detachment, which would offer an adequate temporary scleral buckling effect and induce minimal permanent refractive changes., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Opthalmic Communications Society, Inc.)

Purpose: To compare the surgical results in cases of primary rhegmatogenous retinal detachments between standard scleral buckling (SSB) and scleral buckling with chandelier illumination (SBC) and to analyse the differences in SBC surgical results between an experienced ophthalmologist and inexperienced ophthalmologists., Methods: Consecutive surgical case series of 155 eyes that underwent scleral buckling were retrospectively reviewed and divided into four groups: SSB performed by an experienced ophthalmologist (n = 54), SBC performed by an experienced ophthalmologist (n = 52), SBC performed by inexperienced ophthalmologists (n = 40) and SSB performed by inexperienced ophthalmologists (n = 9). Then, these four groups were compared., Results: No significant differences were observed between SSB and SBC procedures both performed by the experienced ophthalmologist with regard to demographics, preoperative findings, contents of the surgery, intraoperative complications, retinal reattachment, postoperative findings and postoperative complications. Between SBC performed by the experienced ophthalmologist and SBC performed by the inexperienced ophthalmologists, no significant differences were found regarding intraoperative complications, retinal reattachment, postoperative findings and postoperative complications. Between SSB and SBC procedures both performed by the inexperienced ophthalmologist, a significant difference was found regarding intraoperative complications., Conclusion: There were no significant differences in surgical results between SSB and SBC when both were performed by the experienced ophthalmologist. In addition, the surgical results were equal between the experienced ophthalmologist and the inexperienced ophthalmologist as far as SBC was concerned. Learning scleral buckling skills by using SBC is a reasonable course of action for inexperienced ophthalmologists., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

To compare the efficacy of scleral buckling with adjuvant pneumatic retinopexy (SB with PR) and scleral buckling (SB) alone for primary rhegmatogenous retinal detachment (RRD). This retrospective and comparative study included patients who underwent SB with PR (n = 88) or SB alone (n = 161) for primary RRD. The primary anatomical success rate for SB with PR was 81.8%, whereas that for SB alone was 80.7% (P = 0.836). Among patients who achieved primary anatomical success, those in the SB with PR group showed postoperative epiretinal membrane (ERM) formation more frequently than those in the SB alone group (11 of 72 [15.3%] vs. 6 of 130 [4.6%]) (P = 0.009). The mean time to subretinal fluid absorption was not significantly different between the SB with PR and SB alone groups (11.2 ± 6.2 vs. 11.4 ± 5.8 months, P = 0.881). In the SB with PR group, retinal detachment involving ≥ three quadrants was a significant risk factor for surgical failure (hazard ratio, 3.04; P = 0.041). Adjuvant pneumatic retinopexy does not provide additional benefit in improving the surgical outcomes of SB for primary RRD repair., (© 2024. The Author(s).)

Objective: To identify risk factors for surgical failure after scleral buckling (SB) for primary rhegmatogenous retinal detachment (RRD) repair., Design: Single-centre retrospective consecutive case series., Participants: All patients who underwent SB for repair of primary RRD at Wills Eye Hospital between January 1, 2015, and December 31, 2018, were included., Methods: Single-surgery anatomic success (SSAS) rate and risk factors associated with surgical failure were evaluated. A multivariable logistic regression model was completed to assess the effect of demographic, clinical, and operative variables on SSAS rate., Results: A total of 499 eyes of 499 patients were included. Overall SSAS rate was 86% (n = 430 of 499). Using multivariate analysis, surgical failure was more likely in males (adjusted odds ratio [adjusted OR] = 2.98; 95% CI, 1.58-5.62; p = 0.0007) with a macula-off status on preoperative examination (adjusted OR = 2.15; 95% CI, 1.10-4.20; p = 0.03) and preoperative proliferative vitreoretinopathy (adjusted OR = 4.26; 95% CI, 1.10-16.5; p = 0.04). Time interval between initial examination and surgery (p = 0.26), distribution of buckle or band material used (p = 0.88), and distribution of tamponade used (p = 0.74) were not significantly different between eyes with and without surgical failure., Conclusion: Male sex, macula-off status, and preoperative proliferative vitreoretinopathy were factors with increased odds of surgical failure after SB for primary RRD repair. Operative characteristics, such as type of band or use of tamponade, were not associated with surgical failure., (Copyright © 2023 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess epiretinal membrane (ERM) formation, severity, and the associated risk factors after scleral buckling using en face optical coherence tomography (OCT) images., Methods: Medical records of 61 consecutive patients (66 eyes) with rhegmatogenous retinal detachment who underwent scleral buckling were retrospectively reviewed. Posterior vitreous detachment (PVD) was determined based on B-scan OCT images. En face OCT images were used to visualize the ERM and retinal folds. ERM formation was identified by comparing en face images pre- and post-surgery. The maximum depth of the retinal folds (MDRF) was measured using en face imaging to objectively assess traction strength., Results: ERM formation occurred in 15 (22.7%) eyes at the final visit; the foveal pit was preserved in all cases. Parafoveal retinal folds were present in 5 (7.6%) eyes, with a mean MDRF of 21.8 ± 12.6 µm. No significant difference was observed in best-corrected visual acuity (logarithm of the minimal angle of resolution) between the ERM formation (-0.019 ± 0.128) and non-ERM formation (-0.001 ± 0.213) groups at the final visit (P = 0.593; Mann-Whitney U test). Multivariate logistic regression analysis revealed that older age and the presence of PVD were significant risk factors for ERM formation (odds ratio 1.07, 95% confidence interval 1.01-1.14, P = 0.032; odds ratio 5.26, 95% confidence interval 1.06-26.10, P = 0.042; respectively)., Conclusion: ERM occurred in 22.7% of cases but was mild and did not affect visual acuity. Older age and the presence of PVD are risk factors for ERM formation., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To describe modification of the suprachoroidal buckling technique for the treatment of rhegmatogenous retinal detachment (RRD), which may improve the safety profile., Methods: A single-surgeon foot-pedal-controlled automated suprachoroidal injection (SCI) of sodium hyaluronate 1%, namely ProVisc (Alcon Laboratories, Fort Worth, TX) was used for the treatment of RRD. MicroDose Injection Kit (MedOne Surgical, Sarasota, FL) including a connector and a 1-mL syringe, designed for subretinal injection, was used to adapt Constellation Vision System (Alcon Laboratories) console for SCI of ProVisc from the 1-mL syringe., Results: This approach enables better surgeon control during SCI. Three highly myopic eyes of three patients with primary macula-on RRD and single superior peripheral retinal break were treated. Complete retinal reattachment was achieved in all eyes without complications., Conclusion: Injecting ProVisc under foot-pedal control provides a more precise and potentially safer suprachoroidal buckling technique compared with the manual technique with more variable injection speed and pressure., Competing Interests: The authors have no conflicts of interest to declare.

Background: Macular hole (MH) development following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) repair is rare. This study presents both full-thickness MH (FTMH) and lamellar MH (LMH) cases following SB for the treatment of RRD., Methods: Clinical records of patients undergoing SB surgery for treatment of RRD at the Xi'an People's Hospital (Xi'an Fourth Hospital) from January 2016 to December 2021 were reviewed, and cases with postoperative MH were selected. Clinical features and follow-up data were summarised, and possible causes were analysed., Results: Among 483 identified cases (483 eyes), four eyes (three male patients, one female patient) had postoperative MH, with prevalence, mean age, and mean axial length of 0.83%, 43.5 ± 10.66 years, and 29.13 ± 3.80 mm, respectively. All patients did not undergo subretinal fluid (SRF) drainage. The mean time for detecting MH was 26 ± 15.5 days postoperatively. Macula-off RRD with high myopia and FTMH combined with retinal re-detachment were diagnosed in three patients. One patient had macula-on RRD with outer LMH. The average follow-up duration was 7.25 ± 1.5 months. The FTMH closed successfully after reoperation, while the outer LMH closed without intervention. Visual acuity insignificantly improved or slightly decreased in all patients., Conclusions: Patients with high myopia combined with macula-off RRD might be more susceptible to FTMH, causing MH related retinal detachment. Additionally, LMH following SB was noted in patients with macula-on RRD. Therefore, we should raise awareness of MH following SB for RRD repair., (© 2024. The Author(s).)

Purpose: To evaluate the changes of anterior segment and refractive parameters after scleral buckling (SB) surgery for uncomplicated rhegmatogenous retinal detachment (RRD) using anterior segment optical coherence tomography (AS-OCT)., Methods: Thirty-six RRD eyes were consecutively enrolled. Analysis concerned the central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), iris-trabecular contact (ITC), angel opening distance (AOD), angle recess area (ARA), trabecular-iris space area (TISA)，trabecular iris angle (TIA) and refractive parameters, including average keratometry (AvgK), cylindrical power (CYL), regular astigmatism, asymmetry and high order irregularity (HOI) at baseline and 1 day, 1 month, 2 months, 6 months and 12 months postoperatively. AS-OCT was performed at RRD diagnosis and day 1, week 1, month 1 and month 6 after SB to evaluate the scleral buckling., Results: A statistically significant postoperative CCT increase, ACD and ACV decrease were observed at 1 day and 1 month postoperatively. ITC analysis showed that the angle of the entire circumference narrowed at 1 month postoperatively. There was a significant decrease in all the angle parameters (AOD500/750, ARA500/750, TISA500/750, and ARA500/750) at 1 day and 1 month after SB surgery. However, all of the above parameters returned to the preoperative level at 12 months. Refractive parameters including AvgK, regular astigmatism, CYL, asymmetry, and HOI of anterior corneal surface and total corneal increased on the 1 day and 1 month after SB surgery and persisted even after 12 months follow-up. However, there was no significant difference in refractive parameters of posterior corneal surface during follow-up., Conclusion: The changes in the structure of anterior segments after SB surgery were almost returned to the preoperative levels at 12 months postoperatively. However, SB surgery has a long-term effect on refractive parameters throughout a 12-month follow-up.

Introduction: Retinal cysts are rare lesions of the fundus that are essentially fluid-filled cavities located or originating in the retina, with a diameter larger than the normal retinal thickness. To date, there have been few case reports of giant retinal cyst hemorrhage with retinoschisis., Case Presentation: A 32-year-old woman with no other medical history complained of decreased vision for 3 days after a severe cough. The best-corrected visual acuity in the right eye was 0.5. A comprehensive ophthalmological examination including slit-lamp fundoscopy, ultrasound scan of the eye, optical coherence tomography scan, and orbital magnetic resonance imaging was performed. Ophthalmological examination revealed grade III anterior chamber blood cells and grade III vitreous hemorrhage in the right eye and a large herpetic cyst on the nasal side of the retina. The cyst projected into the vitreous, with a large amount of hemorrhage vaguely visible within it. The cyst was clearly visible, and a superficial retinal limiting detachment was observed around it. Ultrasound showed a retinal cyst with retinal detachment in the right eye. Laboratory test results were unremarkable. After 3 months of conservative treatment, the patient's intracystic hemorrhage was significantly absorbed, but the size of the cyst cavity did not show any significant change. Scleral buckling with external compression combined with external drainage of the intracystic fluid was performed, the patient's visual acuity was gradually restored to a normal 1.0 after the operation, and the retina appeared flattened. The patient was finally diagnosed with a giant retinal cyst with retinoschisis in the right eye. The presumed cause was heavy coughing leading to rupture and hemorrhage of the retinal cyst, similar to the mechanism of rupture of an arterial dissection. To the best of our knowledge, this case of retinal cyst rupture and hemorrhage caused by heavy coughing with good recovery after external surgical treatment has never been reported before., Conclusions: Giant cystic retinal hemorrhage with retinoschisis is very rare. Orbital magnetic resonance imaging and ocular B-scan ultrasound are essential for its diagnosis, and the selection of an appropriate surgical procedure is necessary to maximize the benefit for affected patients., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: Compare the anatomical and functional outcomes, operation duration, and complication rates between standard scleral buckling (SSB) and chandelier-assisted scleral buckling (CSB) for phakic eyes with rhegmatogenous retinal detachment (RRD)., Methods: PubMed, Embase, and Cochrane Library databases were searched from inception to June 2024. The primary endpoint will be set as a final success. The secondary endpoint will be primary success, operation time, and final BCVA., Results: Our meta-analysis showed that there is no statistical difference between CSB and SSB for the final success rate (RR = 1.00, 95% CI = 0.97-1.03). For the primary success rate, there is no statistical difference between CSB and SSB (RR = 1.00, 95% CI = 0.94-1.06). For operation time, our meta-analysis showed that the CSB group is less than the SSB group (pooled MD = -15.8, 95% CI = -22.60 to -9.00). For postoperative complications, our study shows that the CSB group presented with lower pooled risk than the SSB group (RR = 0.59, 95% CI = 0.41-0.89). There is a trend that the ERM formation risk is higher in the CSB group if there is no routine suture for the sclerotomy (p = 0.08)., Conclusion: CSB showcases a significantly reduced operation duration and less postoperative complication in contrast to the SSB group, maintaining comparable primary and ultimate anatomical success rates as well as final BCVA., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

A simplified column-buckling model is developed to understand the buckling mechanism of thin-walled strips restrained by uniform lateral pressure in the milling process. The strip is simplified as two rigid columns connected by a rotation spring, resting on a smooth surface, restrained by a uniform pressure and loaded by an axial force. Two loading cases are considered, i.e., the dead load and the follower load. Analytical solutions for the post-buckling responses of the two cases are derived based on the energy method. The minimum buckling force, Maxwell force and stability conditions for the two cases are established. It is demonstrated that the application of higher uniform pressure increases the minimum buckling force for the column and thus makes the column less likely to buckle. For the same pressure level, the dead load is found to be more effective than the follower load in suppressing the buckling of the system. The effect of initial geometric imperfection is also investigated, and the imperfection amplitude and critical restraining pressure that prevent buckling are found to be linearly related. The analytical results are validated by finite element simulations. This analytical model reveals the buckling mechanism of strips under lateral pressure restraint, which cannot be explained by the conventional bifurcation buckling theory, and provides a theoretical foundation for buckling-prevention strategies during the milling process of thin-walled strips, plates and shells commonly encountered in aerospace or automotive industries.

Purpose: To evaluate the incidence, rate, and pattern of progression of myopic maculopathy in eyes operated with macular buckle (MB) for myopic traction maculopathy versus a control group without surgery to find out whether the progression varies due to the MB's indentation and to evaluate possible MB-related pigmentary changes or atrophy., Methods: Eyes operated with MB with two good quality fundus images: one preoperative or early postoperative image and a second image at least 12 months apart; the control group comprised the contralateral eyes. Demographics, axial length, follow-up, stage of myopic traction maculopathy, and myopic maculopathy were reported. Progression results of groups and subgroups (mid- and long-term follow-up) were reported and compared., Results: Overall, 116 eyes of 66 patients were included. Progression was found in 29 eyes (41.4%) and 23 eyes (50%) in the MB group and control group, respectively. The progression rate was 73 per 1,000 eye-years and 88.9 per 1,000 eye-years in the MB group and the control group, respectively. Axial length was found to predict progression (odds ratio [OR], 2.59; P = 0.02)., Conclusion: Progression of myopic maculopathy was similar in both groups and was mildly greater in the control group. No MB-related pigmentary changes or atrophy was detected.

Purpose: Long-term study to evaluate the clinical and surgical outcomes of scleral buckle (SB) surgery for primary rhegmatogenous retinal detachment (RRD) at a large tertiary eye center., Methods: Noncomparative, retrospective case series of 589 eyes of 569 patients with primary RRD who underwent SB surgery between 2004 and 2022 with a median follow-up of 6 months. The main outcome measures were best-corrected visual acuity, surgical outcomes, complications, and classification of RRD., Results: At baseline, 447/589 (76.1%) round hole RRD, and 133/589 (22.7%) retinal dialysis RRD. Overall primary SB success rate was 83.7% for all retinal detachment subtypes, with round hole retinal detachment 84.8% and dialysis RRD 81.2%. Overall, the baseline best-corrected visual acuity was 0.42 logarithm of the minimum angle of resolution (logMAR) and the final best-corrected visual acuity was 0.26 logMAR ( P < 0.0001). In macula-off RRD, the best-corrected visual acuity significantly improved from 0.79 to 0.48 logMAR ( P < 0.0001). In patients with macula-on RRD, it improved from 0.19 to 0.12 logMAR ( P = 0.014). Binary logistic regression showed registrar surgeon grade (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.01-0.55), and partial or complete posterior vitreous detachment (OR 0.21, 95% CI 0.10-0.49) was associated with reduced odds of primary success. Higher surgical failure was associated with low pre-fellowship SB surgeon experience ( P = 0.024)., Conclusion: Favorable visual and functional outcomes have been reported in a large series of SB for primary retinal detachment, mainly for patients with round hole RRD and retinal dialysis RRD.

This study investigates the effects of acid penetration and temperature on the buckling behavior of conical composite shells, to enhance structural integrity and longevity in corrosive environments. The study explores the impact of acid exposure on thermal properties and examines the efficacy of incorporating nano-silica and nano-clay in preventing buckling. Additionally, it analyzes the influence of nanoparticles on the thermal, moisture, and mechanical properties of the composite material. Experimental assessments are conducted to measure material properties during exposure to a sulfuric acid solution, providing a comprehensive understanding of the material's behavior under extreme conditions. However, due to the complexity of investigating the combined effects of temperature, acid, and nanoparticles on composite shell buckling, a combined numerical and experimental approach is adopted to predict the critical buckling load. To this end, equations of conical shells under hygrothermal loading are derived, and the critical buckling load is determined through pre-buckling analysis. The Generalized Differential Quadrature (GDQ) method is employed to solve the hygrothermal buckling of the composite shell using experimentally obtained material properties. Comparative results are presented for different nanoparticles, shell geometries, and exposure times in acidic environments. The experiments reveal that adding nanoparticles enhances mechanical properties and reduces thermal and moisture expansion coefficients. Conversely, the acidic conditions deteriorate these properties. Numerical analysis demonstrates that incorporating nanoparticles significantly increases the critical buckling temperature, with nano-silica and nano-clay particles resulting in an 11.5 % and 34.2 % increase, respectively. However, acidic environments decrease the critical buckling temperature, with reductions of 32 % for unreinforced, 29 % for nano-silica reinforced, and 46 % for nano-clay reinforced composites after three months of exposure., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Persistent subretinal fluid (PSF) after scleral bucking of rhegmatogenous retinal detachment may delay recovery and affect the final visual quality, but with no effective treatment. This study firstly investigated the safety and efficacy of 577 nm yellow subthreshold micropulse laser (SML) on PSF after scleral bucking surgery. This double-masked randomized clinical trial was conducted from December 2020 to October 2022 at Chongqing Aier Eye Hospital. Participants with PSF last for 1 month after scleral bucking surgery with break closed and retina reattachment were recruitment. These participants were treated by 577 nm yellow SML or sham treatment. Funduscopy, optical coherence tomography (OCT) volume change, best corrected vision acuity (BCVA) and visual field test were evaluated for six mouths follow-up. A total of 24 participants were randomized into SML group or Sham group equally. Compared with Sham group, the OCT volume within 6 mm of macular fovea was significantly less in SML group 6 months after therapy (P = 0.048). There were no statistically significant differences of OCT volume at 1, 2 and 3 months from baseline between groups. BCVA of ETDRS letters had no statistically significant difference. Pattern Standard Deviation amelioration (P = 0.039) had statistically significance in SML group compared with Sham group. There were no complications in the 2 groups. These preliminary findings suggest that 577 nm yellow SML therapy could accelerate PSF absorption after scleral bucking surgery.Trial registration: Chinese Clinical Trial Registry No. ChiCTR2000037838, 02/09/2020, https://www.chictr.org.cn/showproj.html?proj=51885 ., (© 2024. The Author(s).)

This research focuses on investigating the buckling strength of thin-walled composite structures featuring various shapes of holes, laminates, and composite materials. A parametric study is conducted to optimize and identify the most suitable combination of material and structural parameters, ensuring the resilience of structure under both mechanical and thermal loads. Initially, a numerical approach employing the finite element method is used to design the C-section thin-walled composite structure. Later, various structural and material parameters like spacing ratio, opening ratio, hole shape, fiber orientation, and laminate sequence are systematically varied. Subsequently, simulation data from numerous cases are utilized to identify the best parameter combination using machine learning algorithms. Various ML techniques such as linear regression, lasso regression, decision tree, random forest, and gradient boosting are employed to assess their accuracy in comparison with finite element results. As a result, the simulation model showcases the variation in critical buckling load when altering the structural and material properties. Additionally, the machine learning models successfully predict the optimal critical buckling load under mechanical and thermal loading conditions. In summary, this paper delves into the study of the stability of C-section thin-walled composite structures with holes under mechanical and thermal loading conditions using finite element analysis and machine learning studies.

Study Design: Experimental study., Objective: We sought to elucidate the association between ligamentum flavum thickening and tissue buckling, and the clinical and imaging factors related to buckling by comparing the ligamentum flavum thickness on MRI images and within the actual tissue., Summary of Background Data: Ligamentum flavum thickening is a main contributor to lumbar spinal canal stenosis. Buckling of the tissue may contribute to ligamentum flavum thickening along with tissue hypertrophy; however, this association has not been established conclusively., Materials and Methods: Ligamentum flavum samples (135 ligament samples) from 70 patients with lumbar spinal canal stenosis were evaluated. The ligamentum flavum thicknesses on magnetic resonance imaging (MRI) and in the tissue samples were compared to assess for the presence of buckling. The ligamentum flavum samples were divided into groups with or without buckling based on the difference between their thicknesses on MRI and in the tissues. The Pearson correlation coefficient test was used to assess the relationships between the LF thicknesses on MRI and in the tissues, MRI-tissue difference and LF thickness in the tissues, and MRI-tissue difference and LF thickness on MRI. Further, differences between the buckling+ and buckling- groups were compared using the unpaired t-test (LF thickness on MRI, LF thickness in the tissues, age, disc angle, and disc height) and χ2 (disc level, disc degeneration, and receival/nonreceival of dialysis) test., Results: The ligamentum flavum thickness on MRI and in the tissues had a positive linear relationship, although the thickness was estimated to be significantly larger on MRI than in the tissues themselves. The ligamentum flavum with buckling had a larger thickness on MRI, less tissue hypertrophy, more severe disc degeneration, and was present in patients with a higher rate of dialysis. There were no differences in age and disc height, angle, or level between the two groups., Conclusions: Buckling of the ligamentum flavum coexists with tissue hypertrophy and contributes to perceived ligamentum thickening on imaging. Buckling of the ligamentum flavum tends to occur in less hypertrophied tissues and is associated with the grade of disc degeneration and the presence of other characteristics associated with spinal degeneration., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To evaluate the long-term anatomic and visual outcomes in eyes with sickle cell retinopathy-related retinal detachments (RDs)., Methods: Patients who underwent surgery for sickle cell retinopathy-related RDs at the Wilmer Eye Institute or Wills Eye Hospital between 2008 and 2020 and followed for at least 6 months postoperatively were retrospectively reviewed. The primary outcome was the rate of single-surgery anatomic success and final reattachment., Results: This study included 30 eyes from 28 patients (16 women and 12 men) with tractional RD (n = 13), rhegmatogenous RD (n = 1), and combined tractional RD/rhegmatogenous RD (n = 16). Mean age was 42.1 ± 15.1 years. The mean follow-up duration was 47.8 ± 34.1 months. Twenty-five (83.3%) eyes underwent pars plana vitrectomy and five (16.7%) eyes underwent pars plana vitrectomy with scleral buckling. Single-surgery anatomic success was achieved in 21 (70.0%) eyes at 6 months. Final reattachment was achieved in 28 (93.3%) eyes (22 eyes [73.3%] without tamponade). Recurrence of RDs was significantly associated with male gender (P = 0.041), absence of previous laser (P = 0.032), iatrogenic breaks (P = 0.035), retinectomy (P = 0.034), and silicone oil tamponade (P = 0.024). Overall, the logarithm of the minimum angle of resolution visual acuity improved from 1.53 ± 0.57 (Snellen equivalent, 20/678) to 1.15 ± 1.01 (20/283) at the final visit (P = 0.03); however, eyes with recurrent RD did not achieve significant visual improvement., Conclusion: Pars plana vitrectomy to repair sickle cell retinopathy-related RDs was effective in achieving anatomic success and improving vision in most eyes. Single-surgery anatomic success is critical for optimizing visual outcomes.

The collapsible tubular mast (CTM) can be compactly folded for transport and deployed in orbit to serve as a key structural element. Once deployed, the CTM is vulnerable to buckling under axial load and bending moments, compromising its load-bearing capacity. The intricate relationship between the CTM's cross-section and its buckling behavior poses a significant challenge for designers. This is due to the ultra-thin nature of the CTM, which gives rise to highly localized buckling modes rather than global ones. To overcome this challenge, we developed surrogate models using a neural network (NN) trained with data from finite element analysis (FEA). These NN-based surrogate models provide high computational accuracy in predicting nonlinear buckling loads under axial force and bending moments around the two principal axes of the CTM's cross-section, achieving R2 values of 0.9906, 0.9987, and 0.9628, respectively. These models also significantly improve computational efficiency, reducing prediction time to a fraction of a second compared to several minutes with FEA. Furthermore, the NN-based surrogate models enable the usage of the non-dominated sorting genetic algorithm (NSGA-II) for multi-objective optimization (MOO) of the CTMs. These models can be integrated in the NSGA-II algorithm to evaluate the objective function of existing and new individuals until a set of 1000 non-dominated solutions, i.e., cross-sectional configurations optimizing buckling performance, is identified. The proposed approach enables the design of ultra-thin CTMs with optimized stability and structural integrity by promoting design decisions based on the quantitative information provided by the NN-based surrogate models.

A bimetallic steel bar (BSB) consisting of stainless-steel cladding and carbon steel substrate exhibits excellent corrosion resistance and good mechanical properties. The bimetallic structure of BSBs may affect their low-cycle fatigue performance, and current investigations on the above issue are limited. In this study, the low-cycle fatigue properties of bimetallic steel bars (BSBs) with inelastic buckling were investigated. Experiments and numerical studies were conducted to investigate the low-cycle fatigue capacity for BSBs, considering buckling. The buckling mode of BSBs is discussed. The hysteretic loops and energy properties of BSBs with various slenderness ratios ( L / D ) and fatigue strain amplitudes ( ε a ) are investigated. With increases in the L / D and ε a , the original symmetry for hysteresis loops disappears gradually, which is caused by the buckling. A predictive equation revealing the relation between the ε a and fatigue life is suggested, which considers the effects of the L / D . A numerical modelling method is suggested to predict the hysteretic curves of BSBs. The effect of buckling on the stress and energy properties of BSBs is discussed through the numerical analysis of 44 models including the effects of the L / D , ε a , and cladding ratios. The numerical analysis results illustrate that the hysteresis loops of BSBs with various ε a values exhibit similar shapes. The increase in the cladding ratio reduces the peak stress and the dissipated energy properties of BSBs. The hysteresis loop energy density decreases by about 3% with an increase of 0.1 in the cladding ratio. It is recommended that the proportion of stainless steel inBSBs should be minimized once the corrosion resistance requirements are met.

Background: The diagnosis of anterior cruciate ligament (ACL) tear relies on clinical evaluation and magnetic resonance imaging (MRI). Direct and indirect signs of ACL tear have been described with MRI evaluation. Posterior cruciate ligament (PCL) buckling has been described as an indirect radiographic sign of an ACL tear., Purpose: The aim of the present study was to assess the variations in PCL buckling angles in patients with ACL tears and in patients with isolated lesions in the posterior horn of the medial meniscus. In addition, the influence of different patterns of medial meniscus tears in ACL-deficient knees was investigated. Finally, the influences of risk factors such as tibial slope, delay from injury to surgery, absence of medial meniscus tear, degree of Lachman and pivot shift testing were also assessed., Study Design: This was a cohort study., Methods: A total of 154 patients (78 in the group with ACL tear and 76 in the control group) were assessed with MRI and lateral weight-bearing X-ray to assess PCL buckling angle and tibial slope by two independent observers. The presence of a medial meniscus bucket handle or ramp lesion of the medial meniscus was assessed and recorded at the time of surgery., Results: PCL buckling angle measurement was highly reliable, with an ICC of 0.866 and 0.894, respectively, in the study group and the control group for interobserver reliability. The intrarater reliability was found to be high in PCL buckling angle for the study group [ICC = 0.955] and the control group [ICC = 0.943]. The mean angle in patients with ACL tear was 110.7 ± 15.2° and 115.3 ± 16.2° (for the two examiners) and 111.4 ± 12° and 114 ± 14.5° (for the two examiners) in patients with an intact, healthy ACL. An association emerged between bucket handle tears of the medial meniscus ( p = 0.010) and a decreased PCL buckling angle and between ramp lesions of the medial meniscus and increased PCL buckling angle both ( p = 0.024)., Conclusions: Good inter- and intraobserver reliability for the measurement of the PCL buckling angle was observed. Increased PCL buckling angle values were observed in patients with concomitant ACL and bucket handle tears of the medial meniscus, while decreased angle values were observed in those who had ACL tear and ramp lesion of the medial meniscus. No statistically significant difference in the PCL buckling angle emerged between patients with ACL tears and those who had a healthy, intact ACL.

Objective: To investigate the difference in the effectiveness and refraction of the foldable capsular buckle (FCB) in rhegmatogenous retinal detachment (RRD)., Methods: Six patients with simple RRD were treated for FCB scleral buckling at Xiamen Eye Center of Xiamen University from October 2023 to February 2024. The parameters assessed included demographic data, clinical data such as preoperative ocular axis, corneal endothelial count, macular foveal thickness, operative time, preoperative and final follow-up intro ocular pressure (IOP), retinal attachment status, and postoperative complications. Refractive change before and after surgery, including sphere, cylinder degree, spherical equivalent, and absolute spherical equivalent difference were compared., Results: All six patients with sound retinal reattachment after FCB scleral buckling, including two men and four women, mean age 41.33 ± 12.40 years old, duration before surgery onset to 7.17 ± 7.16 days, FCB mean operation time 36.67 ± 13.07 min, Preoperative IOP mean 13.35 ± 2.64 mmHg and mean 21.12 ± 8.09 mmHg of final follow-up IOP; there was no significant difference between preoperative IOP and follow-up IOP ( p  = 0.050). The preoperative sphere range was -6.25 to +2.50 D, and the cylinder range was -2.50 to +1.00 D; the absolute spherical equivalent difference before and after was 1.60 ± 1.69 degrees., Conclusion: FCB can achieve retinal reattachment and restore visual function in cases of RRD. The shorter duration of external scleral buckle compression with FCB suggests that FCB scleral buckling holds greater promise in the clinical treatment of RRD caused by retinal tears., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Jiang, Lin, Chen and Wu.)

To compare the effectiveness and safety of scleral buckling and pars plana vitrectomy in treating retinal detachment without posterior vitreous detachment. A total of 88 eyes of 83 patients with retinal detachment without prior posterior vitreous detachment were investigated retrospectively. Group A comprised patients who underwent scleral buckling (n = 47) and Group B (n = 36) patients who were treated with pars plana vitrectomy. Anatomical success, postoperative visual acuity, and ocular adverse events were evaluated. The primary and final anatomical success rate showed a nonsignificant difference (p = 0.465 and p = 0.37 respectively). No significant difference was observed in the reoperation rate or development of epiretinal membrane between the groups (p = 0.254 and p = 0.254 respectively). However, scleral buckling resulted in significantly better visual acuity at the last follow-up (0.12 ± 0.23) compared to pars plana vitrectomy (0.37 ± 0.46, p = 0.001). The incidence of cataract progression was also significantly higher in the pars plana vitrectomy group (46%) compared to the scleral buckling group (10%, p < 0.001). Scleral buckling and pars plana vitrectomy show similar success rates in treating retinal detachment without vitreous detachment. However, due to less cataract progression and better visual acuity outcomes, scleral buckling is recommended for these cases. Determining vitreous status before surgery is crucial for optimal outcomes., (© 2024. The Author(s).)

Metamaterials show elaborate mechanical behavior such as strain stiffening, which stems from their unit cell design. However, the stiffening response is typically programmed in the design step and cannot be adapted postmanufacturing. Here, we show hydrogel metamaterials with highly programmable strain-stiffening responses by exploiting the out-of-plane buckling of integrated pH-switchable hydrogel actuators. The stiffening upon reaching a certain extension stems from the initially buckled active hydrogel beams. At low strain, the beams do not contribute to the mechanical response under tension until they straighten with a resulting step-function increase in stiffness. In the hydrogel actuator design, the acrylic acid concentration hard-codes the configuration of the metamaterial and range of possible stiffening onsets, while the pH soft-codes the exact stiffening onset point after fabrication. The utilization of out-of-plane buckling to realize subsequent stiffening without the need to deform the passive structure extends the application of hydrogel actuators in mechanical metamaterials. Our concept of out-of-plane buckled active elements that stiffen only under tension enables strain-stiffening metamaterials with high programmability before and after fabrication.

In an experimental study of two-branched beams bent transversely about the major stiffness axis, the elastic critical load from the lateral-torsional buckling condition was determined. The tests were conducted on simply supported two-branch beam models with a built-up section consisting of two cold-formed channel members (2C) bolted back-to-back. The bolts were located at the mid-height of the built-up cross-section. Five groups of members differing in longitudinal bolt spacing were examined. The models were gravitationally loaded (using ballast) at the centre of the beam span. This approach eliminated the undesirable effect of the lateral support of the beam, e.g., by the actuator head. The critical load, measured by the concentrated transverse force ( P z ), was determined using the modified Southwell method. It has been experimentally shown that, in built-up beams, there is an influence of bolt spacing on the elastic critical load from the lateral-torsional buckling condition. The lowest critical load capacity and the most non-linear behaviour of the built-up member were observed in beams bolted with only three bolts (at the supports and in the middle of the span). However, the experimental results obtained in this study show that increasing the number of bolts above a certain level (in the case of the tested models, it was seven bolts) does not result in a further increase in the critical load, which is a surprising result. The obtained values were 15 to 23% lower than the critical load determined numerically by the finite element method ( , cr ), was determined using the modified Southwell method. It has been experimentally shown that, in built-up beams, there is an influence of bolt spacing on the elastic critical load from the lateral-torsional buckling condition. The lowest critical load capacity and the most non-linear behaviour of the built-up member were observed in beams bolted with only three bolts (at the supports and in the middle of the span). However, the experimental results obtained in this study show that increasing the number of bolts above a certain level (in the case of the tested models, it was seven bolts) does not result in a further increase in the critical load, which is a surprising result. The obtained values were 15 to 23% lower than the critical load determined numerically by the finite element method ( LTBeamN ) for an analogous element with a uniform I-section., Competing Interests: The authors declare no conflicts of interest.

Background and Objective: To describe visual function, macular integrity, and fixation stability using MAIA microperimetry (macular integrity assessment) after retinal detachment surgery. Evaluate if there are statistically significant differences between surgical approaches., Materials and Methods: A prospective, comparative, interventional study was conducted, recruiting a total of 21 patients with rhegmatogenous retinal detachment and macula-off. Eleven patients underwent surgery using pars plana vitrectomy (PPV), and 10 patients underwent scleral buckle surgery. Clinical examinations and optical coherence tomography (OCT) were performed post-surgery. MAIA microperimetry was conducted at 6 months., Results: Best-corrected visual acuity (BCVA) and the number of letters read improved over time in the operated eye but did not reach the level of the control eye (p = 0.001). No significant differences were found between the two surgical approaches in BCVA (p = 0.230) or the number of letters read (p = 0.608). Macular integrity in the operated eye did not match that of the control eye in both procedures (p = 0.05). No differences were detected between the two surgeries, either in macular integrity (p = 0.512) or fixation stability (p = 0.835)., Conclusions: Following retinal detachment surgery, a decrease in BCVA and the number of letters read occurs, which does not reach the level of the control eye. No significant differences were observed between the two surgical approaches. Macular integrity in the operated eye does not match that of the control eye., (Copyright © 2024 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.)

Purpose: Despite recent developments in vitrectomy technology and instrumentation, rhegmatogenous retinal detachment in Stickler syndrome (RDS) remains a challenge for surgeons. RDSs are associated with a higher rate of complications and surgical failures than those not associated with Stickler syndrome. This study is a report about anatomic and visual outcomes of RDS surgery and describes the surgical techniques associated with the treatment of this specific condition., Methods: This is a retrospective, interventional, consecutive case series of patients with RDS undergoing retinal reattachment surgery from 1990 to 2020 at the Institute of Ocular Microsurgery (IMO) in Barcelona, Spain., Results: Twenty-four eyes of 18 patients with genetically confirmed Stickler syndrome were included in the study. Ten eyes (41.6%) presented a giant retinal tear. Retinal reattachment was achieved in all cases after an average of 1.21 (range 1-6) surgical interventions. Nineteen eyes (79%) required only one operation to achieve complete retinal reattachment. The most common first surgical procedure was a 4-mm scleral buckle with posterior pars plana vitrectomy and silicone oil endotamponade, performed on 16 (66.6%) of the eyes. The mean follow-up period was 10.2 years. Mean preoperative visual acuity LogMar was 1.10 (Snellen equivalent 20/252), which improved to 0.50 (Snellen equivalent 20/63) at final follow-up (p < 0.05)., Conclusion: In most RDS cases, anatomic success and visual acuity improvement can be achieved with the first surgical procedure, using a combination of silicone oil tamponade and a 4-mm scleral encircling band. In some early cases of RDS, other less invasive surgical techniques can be used., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The paper presents a static analysis of the buckling and post-buckling state of thin-walled cold-formed steel (TWCFS) lipped channel section beam-columns subjected to eccentric compression. Eccentricity is taken into consideration relative to both major and minor principal axes. An analytical-numerical solution to the buckling and post-buckling problems is described. The solution is based on the theory of thin plates. Equations of equilibrium of section walls are derived from the principle of stationary energy. Then, to solve the problem, the finite difference (FDM) and Newton-Raphson methods are applied. Linear (buckling) and nonlinear (post-buckling) analyses are performed. As a result, pre- and post-buckling equilibrium paths are determined. Comparisons of the obtained numerical results, FE simulation results, and experimental test results are carried out and presented in comparative load-shortening diagrams. Additionally, a comparison of the buckling forces and buckling modes obtained from theoretical analysis and experiments is presented., Competing Interests: The authors declare no conflicts of interest.

In this paper, the buckling behaviour of rectangular and skew plates with elastically restrained edges subjected to non-uniform mechanical edge loading is investigated. An analysis method is developed for calculating the critical buckling load of plates using the Ritz method under non-uniform mechanical edge loading, in which the shape function is expressed as Legendre polynomials. The in-plane stress distribution under non-uniform mechanical edge loading is defined by the pre-buckling analysis. Contributions of elastic boundary conditions are taken into accounted by giving different edge spring stiffnesses. The proposed method for buckling analysis of plates is validated by the comparison of exiting results in literature. Finally, the effects of the edge restrained stiffness, non-uniform edge loading, skew angle, aspect ratio and combined compression-shear load are discussed by parametric analysis., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright: © 2024 Wang, Liu. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: Uveitis is the most common ocular manifestation of syphilis. However, an association between syphilitic uveitis and rhegmatogenous retinal detachment (RRD) is not widely recognized. We report a consecutive series of six new cases of syphilitic uveitis complicated by RRD and describe the typical characteristics, clinical course, and surgical management of such cases., Methods: Consecutive case series and comprehensive review of the literature., Results: We identified a total of 19 cases (23 eyes) with syphilitic uveitis subsequently complicated by RRD, including six new cases (seven eyes) reported here and 13 cases (16 eyes) previously reported in the literature. Fifteen patients (79%) were positive for human immunodeficiency virus (HIV) and not on combination antiretroviral therapy. Most retinal detachments developed within two months of uveitis presentation; retinal breaks were often found in areas of previous retinitis. Sixteen eyes (70%) were complicated by early proliferative vitreoretinopathy. Twenty-one eyes underwent surgical repair, of which six (26%) suffered re-detachment. Surgical management commonly involved pars-plana vitrectomy and silicone oil tamponade, with or without scleral buckling. Visual outcomes were generally poor: only six eyes (26%) attained visual acuity of 20/40 or better and 11 eyes (48%) remained 20/200 or worse., Conclusions: Patients with syphilitic uveitis, as with viral retinitis, should be monitored closely for the development of retinal tears and RRD. A combination of pars plana vitrectomy with silicone oil tamponade and/or scleral buckle placement is a prudent surgical approach to most cases of syphilitic RRD, although visual prognosis remains guarded.

Objectives: To evaluate the characteristics and surgical outcomes of late-onset rhegmatogenous retinal detachment (RRD) associated with regressed retinopathy of prematurity (ROP) and the status of fellow eyes., Materials and Methods: Retrospective review of consecutive cases undergoing surgery for regressed ROP-related RRD and the fellow eyes between 2012-2022. Demographic data, fundus findings, retinal detachment characteristics, surgical procedures, and anatomic and functional outcomes were analyzed. Anatomic success was defined as retinal attachment after silicone oil removal at final follow-up., Results: Fifteen eyes of 14 patients with a history of regressed ROP underwent surgical repair for RRD at a mean age of 12 (range, 3-26) years. Primary surgical intervention yielded a 53% failure rate overall. This rate was 33% for scleral buckling (SB), 100% for pars plana vitrectomy (PPV), and 40% for combined SB-PPV surgery. Eyes with posterior cicatricial changes and/or proliferative vitreoretinopathy (PVR) demonstrated a higher tendency for recurrence. The final anatomic success rate was 73% after a mean number of 2.3 (range, 1-5) surgeries. The chances of restoring useful vision diminished with repeated surgery despite the improvement in anatomic success. In the fellow eyes, peripheral retinal pathologies were universally observed, with posterior cicatricial changes noted in 33%., Conclusion: The study reveals a significant initial failure rate in surgical treatment of cases with late-onset RRD associated with regressed ROP, particularly in eyes with posterior cicatricial changes or PVR, suggesting the need for a combined surgical approach as an initial strategy in such high-risk cases. The consistent presence of retinal abnormalities in fellow eyes calls for proactive monitoring and potential prophylactic intervention., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors., (©Copyright 2024 by the Turkish Ophthalmological Association / Turkish Journal of Ophthalmology published by Galenos Publishing House.)

We study the buckling of a clamped beam immersed in a creeping flow within a rectangular channel. Via a combination of precision experiments, simulations, and theoretical modeling, we show how the instability depends on a pressure feedback mechanism and rationalize it in terms of dimensionless parameters. As the beam can bend until touching the wall above a critical flow rate, we finally demonstrate how the system can be used as a tunable passive flow selector, effectively redirecting the flow within a designed hydraulic circuit.

Take a thin cylindrical shell and twist it; it will buckle immediately. Such unavoidable torsional buckling can lead to systemic failure, for example by disrupting the blood flow through arteries. In this study, we prevent this torsional buckling instability using a combination of auxeticity and orthotropy in cylindrical metamaterial shells with a holey pattern. When the principal axes of the orthotropic meta-shell are relatively aligned with that of the compressive component of the applied stress during twisting, the meta-shell uniformly shrinks in the radial direction as a result of a local buckling instability. This shrinkage coincides with a softening-stiffening transition that leads to ordered stacking of unit cells along the compressive component of the applied stress. These transitions due to local instabilities circumvent the usual torsional instability even under a large twist angle. This study highlights the potential of tailoring anisotropy and programming instabilities in metamaterials, with potential applications in designing mechanical elements for soft robotics, biomechanics or fluidics. As an example of such applications, we demonstrate soft torsional compressor for generating pulsatile flows through a torsion release mechanism., (© 2024. The Author(s).)

Purpose: The goal of the study is to introduce a modified technique for the removal of subretinal fluid during scntleral buckling (SB) to treat rhegmatogenous retinal detachment (RRD)., Methods: This case series study was comprised of 18 cases of RRD patients suffering from a novel automated aspiration of subretinal fluid method during SB. The cases took place from July 2023 to November 2023 at the First Affiliated Hospital of USTC. Preoperative and intraoperative situations were evaluated, and spectral-domain optical coherence (SDOCT) and scanning laser ophthalmoscopy were used to observe the absorption of SRF in the early postoperative period., Results: The SRF method's automated aspiration primarily eliminated the SRF of all 18 RRD cases during SB surgery, leading to retinal reattachment, as showed by SLO. The method did not cause extensive intraoperative hemorrhage and had no risk of retinal incarceration or other complications. The SDOCT showed that the height of SRF in the macular area decreased in 10 cases (66.67%), leaving just a thin layer; was completely cleared in two cases (13.33%); had just a macular single bleb in one case (6.67%); and had several blebs left in two cases (13.33%)., Conclusions: These findings suggest that the automated aspiration of the SRF method is effective, controllable, and beneficial for retinal reattachment, especially in the early postoperative period. Complications with this method were rare., Competing Interests: Conflict of Interest Disclosures: Dr Zhu reported a patent for a device for controlling the discharge and collection of subretinal fluid through scleral puncture licensed to ZL202320300007.X. None of the other author has any proprietary interests or conflicts of interest related to this submission., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Opthalmic Communications Society, Inc.)

During embryonic development, tissues undergo dramatic deformations as functional morphologies are stereotypically sculpted from simple rudiments. Formation of healthy, functional organs therefore requires tight control over the material properties of embryonic tissues during development, yet the biological basis of embryonic tissue mechanics is poorly understood. The present study investigates the mechanics of the embryonic small intestine, a tissue that is compactly organized in the body cavity by a mechanical instability during development, wherein differential elongation rates between the intestinal tube and its attached mesentery create compressive forces that buckle the tube into loops with wavelength and curvature that are tightly conserved for a given species. Focusing on the intestinal tube, we combined micromechanical testing with histologic analyses and enzymatic degradation experiments to conclude that elastic fibers closely associated with intestinal smooth muscle layers are responsible for the bending stiffness of the tube, and for establishing its pronounced mechanical anisotropy. These findings provide insights into the developmental role of elastic fibers in controlling tissue stiffness, and raise new questions on the physiologic function of elastic fibers in the intestine during adulthood.

By enabling the dissemination and storage of information, paper has been central to human culture for more than a millennium. Its use is, however, associated with a common injury: the paper cut. Surprisingly, the physics underpinning a flexible sheet of paper slicing into soft tissues remains unresolved. In particular, the unpredictable occurrence of paper cuts, often restricted to a limited thickness range, has not been explained. Here we visualize and quantify the motion, deformation, and stresses during paper cuts, uncovering a remarkably complex relationship between cutting, geometry, and material properties. A model based on the hypothesis that a competition between slicing and buckling controls the probability of initiating a paper cut is developed and successfully validated. This explains why paper with a specific thickness is most hazardous (65µm, corresponding, e.g., to dot matrix paper) and suggests a probabilistic interpretation of irregular occurrence of paper cuts. Stimulated by these findings, we finally show how a recyclable cutting tool can harness the surprising power of paper.

Purpose: To compare outcomes in inferior rhegmatogenous retinal detachment (RRD) repair using pars plana vitrectomy (PPV) or PPV with scleral buckle (PPV-SB)., Methods: Patients operated for inferior RRD at a tertiary care center between 2014 and 2018 were included. Inferior RRD was defined as retinal detachment with tears between 4:00 and 8:00 clock hours in detached retina. Non-RRD etiologies (e.g., traumatic, tractional), proliferative vitreoretinopathy (PVR) grade ≥C2, and silicone oil use were excluded. Single surgery anatomic success (SSAS) was defined as absence of reoperation for recurrent RRD during follow-up., Results: There were 366 patients included of which 260 (71%) were operated using PPV-SB. SSAS was achieved in 96 (91%) of PPV patients and 227 (87%) of PPV-SB patients (p=0.38) over a median follow-up of 15 months. At final follow-up, PHVA was 0.18 [0.10, 0.30] among PPV patients and 0.18 [0.10, 0.40] among PPV-SB (Snellen equivalent: 20/30; p=0.03). After adjusting for demographic (i.e., age and sex) and preoperative characteristics (i.e., macula on status, baseline PHVA, and grade C1 PVR), PPV-SB did not alter SSAS (p=0.210)., Conclusions: Following inferior RRD repair, there were no significant differences in SSAS between patients undergoing PPV and PPV-SB in this large, retrospective cohort., Competing Interests: Conflict of Interest: No conflicting relationship exists for any author.

Crystalline monolayers prevalent in nature and technology possess elusive elastic properties with important implications in fundamental physics, biology, and nanotechnology. Leveraging the recently discovered shape transitions of oil-in-water emulsion droplets, upon which these droplets adopt cylindrical shapes and elongate, we investigate the elastic characteristics of the crystalline monolayers covering their interfaces. To unravel the conditions governing Euler buckling and Brazier kink formation in these cylindrical tubular interfacial crystals, we strain the elongating cylindrical droplets within confining microfluidic wells. Our experiments unveil a nonclassical relation between the Young's modulus and the bending modulus of these crystals. Intriguingly, this relation varies with the radius of the cylindrical crystal, presenting a nonclassical mechanism for tuning of elasticity in nanotechnology applications.

Catastrophic cervical spine injuries in rugby often occur during tackling. The underlying mechanisms leading to these injuries remain unclear, with neck hyperflexion and buckling both proposed as the causative factor in the injury prevention literature. The aim of this study was to evaluate the effect of pre-impact head-neck posture on intervertebral neck loads and motions during a head-first rugby tackle. Using a validated, subject-specific musculoskeletal model of a rugby player, and computer simulations driven by in vivo and in vitro data, we examined the dynamic response of the cervical spine under such impact conditions. The simulations demonstrated that the initial head-neck sagittal-plane posture affected intervertebral loads and kinematics, with an extended neck resulting in buckling and supraphysiologic intervertebral shear and flexion loads and motions, typical of bilateral facet dislocation injuries. In contrast, an initially flexed neck increased axial compression forces and flexion angles without exceeding intervertebral physiological limits. These findings provide objective evidence that can inform injury prevention strategies or rugby law changes to improve the safety of the game of rugby., (© 2024. The Author(s).)

Tissue buckling is an increasingly appreciated mode of morphogenesis in the embryo, but it is often unclear how geometric and material parameters are molecularly determined in native developmental contexts to generate diverse functional patterns. Here, we study the link between differential mechanical properties and the morphogenesis of distinct anteroposterior compartments in the intestinal tract-the esophagus, small intestine, and large intestine. These regions originate from a simple, common tube but adopt unique forms. Using measured data from the developing chick gut coupled with a minimal theory and simulations of differential growth, we investigate divergent lumen morphologies along the entire early gut and demonstrate that spatiotemporal geometries, moduli, and growth rates control the segment-specific patterns of mucosal buckling. Primary buckling into wrinkles, folds, and creases along the gut, as well as secondary buckling phenomena, including period-doubling in the foregut and multiscale creasing-wrinkling in the hindgut, are captured and well explained by mechanical models. This study advances our existing knowledge of how identity leads to form in these regions, laying the foundation for future work uncovering the relationship between molecules and mechanics in gut morphological regionalization., Competing Interests: Competing interests statement:The authors declare no competing interest.