Refractive features and amblyopia in Duane's Retraction Syndrome: A review of the 582 patients / Características refractivas y ambliopía en el síndrome de retracción de Duane: una revisión de los 582 pacientes

Purpose: To report the visual and refractive characteristics and the prevalence of amblyopia in patients with different types of Duane's Retraction Syndrome (DRS). Method: This retrospective study was performed on hospital records of 582 DRS patients at Farabi Hospital, Iran, from 2012 to March 2022. Results: The mean age of patients was 19.4 ± 11.9 (range, 3–70) years [335 (57.6 %) females and 247 (42.4 %) males (P < .001)]. DRS type I, II, III, and IV were presented in 347 (59.6 %), 148 (25.4 %), 82 (14.1 %), and 5 (0.9 %) patients, respectively. There were 530 (91.1 %) patients with unilateral and 52 (8.9 %) with bilateral involvement. In the unilateral patients, the DRS eyes' corrected distance visual acuity (CDVA) and astigmatism were significantly worse than the Non-DRS Eyes (P < .001). The mean amount of all refractive and visual parameters in bilateral patients' right or left eyes was significantly lower than in unilateral patients' non-DRS eyes (all P < .05). Anisometropia was observed in 75(12.9 %) of the patients. Amblyopia was observed in 18.5 % (98 patients) and 36.5 % (19 patients) of unilateral and bilateral DRS patients, respectively (P < .001). In unilateral patients, amblyopia was found in 57 (16.4 %) patients with Type I, 22 (14.9 %) patients with Type II, 16 (19.5 %) patients with Type III, and 3 (60 %) patients with Type IV. Forty-four (37.6 %) of patients with amblyopia had anisometropia. Conclusion: This large-scale study indicates that DRS types differ in terms of refractive error, visual acuity, and the prevalence of amblyopia and anisometropia. Clinicians should be aware of the clinical features associated with different types of DRS.(AU)

Lateral Rectus Disabling and Simultaneous Modified Nishida Procedure for Exotropic Duane Retraction Syndrome.

Exotropic-Duane Syndrome (XT-DRS) is a congenital cranial nerve dysinnervation disorder characterized by exotropia, anomalous head posture (contralateral face turn), limited adduction, globe retraction, palpebral fissure narrowing, upshoot and downshoot in adduction, and varying levels of limitation of abduction. Patients with XT-DRS often have poor convergence because attempted convergence induces co-contraction of the lateral rectus muscle (LR) due to anomalous LR innervation. We describe two patients with XT-DRS who underwent simultaneous lateral rectus muscle (LR) disinsertion and periosteal fixation (LRDAPF) and modified Nishida procedure (MNP) and discuss their outcome. In one patient, we combined this procedure with a contralateral LR recession. Anomalous head posture, exotropia, globe retraction, and palpebral fissure narrowing were reduced. Upshoot and downshoot were also reduced. Convergence improved in both patients.

Lower eyelid retraction repair using autologous auricular scapha cartilage.

PURPOSE: To assess the efficacy of lower eyelid retraction surgery utilizing autologous auricular scapha cartilage (located within the anterior surface groove between the helix and anti-helix) and to present the surgical outcomes in a patient cohort. METHODS: Medical records of 21 patients who underwent lower eyelid retraction surgery with scapha cartilage were retrospectively reviewed. Retractions, present for an extended duration (6 months to 20 years), exhibited 1 mm or more inferior scleral show, attributed to prior lower eyelid blepharoplasty, facial palsy, or as a normal anatomical variation. Surgical interventions included lateral canthotomy, cantholysis, incision of the subtarsal conjunctiva-lower eyelid retractors, lower eyelid retractor lysis, cartilage graft suturing to the defect area without conjunctival cover, and tightening of the lateral canthal corner in all patients. RESULTS: A total of 29 eyelids in 21 patients underwent surgery without intraoperative complications. Over a mean follow-up period of 11 months (range: 6-30 months), lower lid retraction improved in 96.5% of eyelids. Postoperative margin-to-reflex distance measurements (MRD2) significantly decreased compared to preoperative values (p = 0.001; p < 0.01). Average improvements in MRD2-a (midpupil to lower lid) and MRD2-b (lateral limbus to lower lid) were 1.77 ± 0.80 and 2.04 ± 0.81, respectively (p = 0.001; p < 0.01). Four eyelids (4/29) required revision due to canthal corner loosening, with correction necessitating periosteal flaps. All four patients had previously undergone two or more repairs elsewhere. The graft was visible in two lids but did not require further revision. One patient experienced mild helix deformity at the donor site, which did not warrant additional intervention. CONCLUSION: In cases of lower lid retraction associated with middle/posterior lamellar shortening, utilizing an autologous auricular scapha cartilage spacer graft offers notable benefits. These advantages comprise straightforward harvesting with minimal donor site complications, stability without experiencing shrinkage, a softer texture in comparison to posterior cartilage, a concave shape that facilitates proper fitting on the globe, and its autologous nature.

Percutaneous triamcinolone injection for upper eyelid retraction in thyroid eye disease.

Purpose: To evaluate percutaneous triamcinolone (TA) injection efficacy in treating upper eyelid retraction (UER) for Australian thyroid eye disease (TED) patients. Methods: We conducted a retrospective analysis across 8 years and multiple diverse Australian centres identified UER patients who received TA injections. A single operator administered 40mg/1ml TA through upper eyelid skin. Assessments at 4-6 weeks and subsequent eyelid measurements gauged treatment response and complications. Results: 24 patients and 25 eyelids were included in the study. 91.6% were female, mean age 40.8 ± 10.3 years with mean follow-up of 17.5 months (± 18.5). Pre-treatment MRD1 was 6.2mm ± 1.4, and we observed a mean improvement of 2.2mm from pre-treatment to post-treatment (p<0.001). The mean UER measurement before treatment (defined as MRD1 - 4.0mm) was 3.0mm ± 1.3 (range, 0-6mm). After treatment, the mean UER measurement was -0.1mm. Quality of life (QOL) assessment improved significantly, from pre-treatment score of 4.13 ± 2.4 to post-treatment 8.0 ±1.7 (p<0.001). Conclusions: Percutaneous injection of TA is an effective and safe treatment option for UER in patients with TED. This technique can be performed without upper eyelid eversion, which makes it more tolerable for patients and less complex for the operator compared to the transconjunctival injection approach. Our results show a significant improvement in MRD1 and UER, as well as patient QOL. Moreover, we found a low rate of complications (4.2% induced ptosis) and no cases of raised intraocular pressure. Percutaneous TA injection can greatly reduce the need for eyelid lowering surgery in this patient population.

Friction versus frictionless mechanics during maxillary en-masse retraction in adult patients with Class I bimaxillary dentoalveolar protrusion: a randomized clinical trial.

BACKGROUND: Extraction space closure is a challenging phase during orthodontic treatment that affects not only the total treatment duration but also the whole treatment outcome. OBJECTIVE: To compare the efficiency of friction and frictionless mechanics during en-masse retraction of maxillary anterior teeth in adult patients with bimaxillary dentoalveolar protrusion. TRIAL DESIGN: Two-arm parallel group, single-center randomized clinical trial. MATERIALS AND METHODS: Thirty-two adult patients with bimaxillary protrusion were recruited and randomly allocated to two different retraction mechanics. A friction group, using NiTi coil springs and a frictionless group using closing T-loops for en-masse retraction. Randomization in a 1:1 ratio was generated by Microsoft Excel. The randomization numbers were secured in opaque sealed envelopes for allocation concealment. Retraction started in all patients following first premolars extraction using miniscrews as a source of indirect anchorage. Activation was done on a monthly basis until complete retraction of anterior segment. The rate of retraction, amount of anchorage loss, the dental, and soft tissue changes were analyzed on digital models and lateral cephalograms taken before retraction and after space closure. BLINDING: The outcome assessor was blinded through data concealment during assessment. RESULTS: Two patients were lost to follow up, so 30 patients completed the trial. The rate of anterior segment retraction was 0.88 ±â€…0.66 mm/month in the frictionless group compared to 0.72 ±â€…0.36 mm/month in the friction group which was statistically significant. Anchorage loss of 1.18 ±â€…0.72 mm in the friction group compared to 1.29 ±â€…0.55 mm in the frictionless group with no significant difference. Comparable dental and soft tissue changes following en-masse retraction were reported in both groups, with no statistically significant difference. HARM: one patient complained of soft tissue swelling following miniscrew insertion, but the swelling disappeared after one week of using mouth wash. LIMITATION: The study focused only on the maxillary arch. CONCLUSION: Both mechanics have successfully achieved the required treatment objectives in patients with bimaxillary dentoalveolar protrusion. Frictionless group showed a faster rate of retraction than the friction group, which was statistically but not clinically significant. TRIAL REGISTRATION: Clinicaltrials.gov with the identifier NCT03261024.

Instrumentless liver suspension for liver retraction in robotic pancreatoduodenectomy.

The popularity of robotic pancreatoduodenectomy (RPD) is increasing, yet it remains a complex procedure. Outcomes are influenced by various factors, including patient-specific variables, disease characteristics, and surgical technique. Numerous and intricate details contribute to the technical success of RPD. In this study, our focus is on achieving effective and "gentle" liver retraction. The use of liver retractors has been associated with the risk of retractor-related liver injury (RRLI), which can have serious consequences. Here, we introduce a refined technique for instrumentless liver retraction in RPD, developed progressively through a series of over 300 procedures. The core concept of this technique involves suspending the liver to the diaphragmatic dome. This is accomplished by securing the round ligament to the anterior abdominal wall using transparietal sutures and attaching the fundus of the gallbladder and the anterior margin of liver segment number 3 to the diaphragm. Our consecutive series of over 300 RPDs demonstrates the feasibility and safety of this approach, with no clinically relevant RRLI observed. Instrumentless liver retraction offers a valuable refinement in RPD, streamlining the procedure while reducing potential complications associated with dedicated retractors.

Hyperbaric oxygen attenuates chronic postsurgical pain by regulating the CD73/adenosine/A1R axis of the spinal cord in rats.

Chronic postsurgical pain (CPSP) affects postoperative rehabilitation and quality of life in patients, but its mechanisms are still poorly understood. Hyperbaric oxygen (HBO) attenuates neuropathic pain in animal and human studies, but its efficacy for CPSP treatment and its underlying mechanism have not been elucidated. This study aimed to investigate the analgesic effect of HBO in a CPSP rat model and the role of spinal cord adenosine circulation in HBO-induced analgesia. A skin/muscle incision and retraction (SMIR) rat model was used to mimic CPSP, and HBO treatment (2.5 ATA, 60 min) was administered once daily for five consecutive days beginning three days after surgery. The role of spinal cord adenosine circulation in HBO-induced analgesia was investigated using APCP (a CD73 inhibitor), DPCPX (an A1R antagonist) or an intrathecal injection of adenosine. The mechanical paw withdrawal threshold (PWT) was determined at different time points before and after surgery. The spinal cord adenosine and ATP contents were analyzed using high-performance liquid chromatography (HPLC), and the spinal cord expression of A1R, CD73, and ADK was examined by Western blotting and immunofluorescence staining. The results showed that the mechanical PWT of the ipsilateral hind paw and the adenosine content decreased, and the spinal cord expression of A1R, CD73, and ADK and ATP content increased within 14 days after surgery. HBO treatment alleviated mechanical allodynia, reduced ATP content, and increased adenosine content by activating CD73 but downregulated the spinal cord expression of A1R, CD73, and ADK. Intrathecal adenosine alleviated mechanical allodynia after SMIR and downregulated the spinal cord expression of A1R and CD73, and intrathecal APCP or DPCPX attenuated the analgesic effect of HBO treatment on SMIR-induced CPSP. PERSPECTIVE: Spinal cord adenosine is involved in the occurrence and development of CPSP, and HBO treatment alleviates CPSP by regulating adenosine production/metabolism in the spinal cord. Thus, HBO may be employed for the treatment of CPSP with favorable efficacy.

An analysis of retracted studies in cardiology in the last two decades.

Background: The aim of this study is to analyze retracted studies in cardiovascular field. Methodology: PubMed and Embase databases were used to identify retracted publications from 2002 to 2022. Various characteristics of articles were retrieved, and an analysis was performed using R software. Results: We finally included 979 articles. Authors from China have the highest number of retracted studies (35.5%), followed by the USA (22.1%), and Japan (4%). The most common causes of retraction are mistakes and honest errors (24.5%) and duplicate data (17.7%). From 2002 to 2022, there has been a significant increase in retracted studies and a decrease in the impact factor of journals, number of citations, and time to retraction. Conclusion: The trend of retracting publications in cardiology is increasing.

Retracted publications are withdrawn publications. Recently, the number of retracted publications has increased. In our research, we try to find the characteristics and pattern of the retracted studies in heart published studies. PubMed and Embase databases were used to identify retracted publications from 2002 to 2022. Various characteristics of articles were retrieved, and statistical software was used to analyze them. We finally included 979 articles. Findings from our research showed authors from China, the USA, and Japan have the highest number of retracted studies. Honest errors, duplicate data, and fabricated data are common causes of retractions. From 2002 to 2022, there has been an increase in the number of retracted studies and a decrease in the impact factor of journals, the number of citations, and the time to retraction. We also compared the results between the first (2003­2012) and the second decade (SD; 2013­2022). In the SD, there are more retracted publications. We saw that in the first decade, the USA had more retractions; however, in the SD, China had more retractions. The retracted publications in the SD have less time to retract and fewer citations. There is no change regarding the funding of research or the parties' interest in conducting research. In the end, the trend of retracting publications in heart studies is increasing. Making the scientific world aware would be the most important to tackle this problem.

Poly-L-lactic acid fillers for nasal alar retraction: safety and effectiveness in 13 cases.

OBJECTIVE: To assess the effectiveness and safety of poly-L-lactic acid (PLLA) fillers in treating nasal alar retraction. We conducted a series of case reports on 13 patients treated for nasal alar retraction at the Chengdu Ningyue FRESKIN Medicine Cosmology Clinic from September 2022 to July 2023. Patients ranged from 23 to 49 years, comprising 12 females and 1 male. Of these, 5 had no prior medical history, 7 had previously undergone rhinoplasty, and 1 had a history of nasal trauma. Treatment outcomes and adverse reactions were monitored following PLLA filler injections. The mean pre-treatment severity score was 1.62±0.65, improving to 0.54±0.66 post-treatment (t=4.19, df=23, P<0.001). All participants reported satisfaction with their results without adverse effects. PLLA facial fillers are a safe and effective treatment for nasal alar retraction, presenting no embolism risk. This treatment merits consideration for broader clinical application.

New insights into the early morphological evolution of sea turtles by re-investigation of Nichollsemys baieri, a three-dimensionally preserved fossil stem chelonioid from the Campanian of Alberta, Canada.

The early evolution of Pan-Chelonioidea (sea turtles) is poorly understood. This is in part due to the rarity of undeformed skulls of definitive early stem chelonioids. In this work, we redescribe the holotype of Nichollsemys baieri using µCT scans and segmentations of the skull. This fossil is the best 3D preserved skull of any Campanian sea turtle, and includes partial "soft tissue" preservation. Nichollsemys is morphologically similar but clearly distinct from Toxochelys spp., and both show a mosaic of plesiomorphic and derived chelonioid features. The internal cranial anatomy documents the presence of derived characters in Nichollsemys baieri that are absent in Toxochelys spp., such as the loss of the epipterygoids and the rod-like shape of the rostrum basisphenoidale. Among the numerous plesiomorphic characters is the presence of a splenial bone, which was unnoticed before. An updated phylogenetic analysis retrieves Nichollsemys baieri as a non-protostegid early stem chelonioid in a slightly more crownward position than Toxochelys latiremis. Our phylogeny includes macrobaenids and protostegids as pan-chelonioids, and we find unorthodox results for dermochelyids. Thus, although Nichollsemys baieri provides important new insights into the early morphological evolution of sea turtles, much work remains to be done. As a completely 3D preserved specimen, we included Nichollsemys baieri into a recent landmark-based skull shape dataset of turtles. Morphospace analysis reveals an intermediate position between cryptodires and crown chelonioids. Based on these data, we also predict that Nichollsemys baieri was still capable of neck retraction, constraining the loss of this trait to more crownward pan-chelonioids. Supplementary Information: The online version contains supplementary material available at 10.1186/s13358-024-00323-8.

Retraction note to: RNA-binding protein CPSF6 regulates IBSP to affect pyroptosis in gastric cancer.

[This retracts the article on p. 1531 in vol. 15, PMID: 37746647.].

Retraction note: Clinical analysis of colistin sulfate in the treatment of pneumonia caused by carbapenem-resistant Gram-negative bacteria.

[This retracts the article on p. 2173 in vol. 12, PMID: 38808336.].

When Uveitis and Hypotony Meets Bilateral Iris Retraction Syndrome: A Rare but Serious Complication of Nivolumab Treatment.

Introduction: Iris retraction syndrome (IRS) is a rare clinical condition characterized by a backbowing of the iris positioned on the lens with a complete pupillary block. Immune checkpoint inhibitors (ICIs) are a new class of immunomodulating agents used in cancer therapy, and although they have high response rates, ophthalmic-related side effects have been reported. We report a rare case of bilateral IRS with hypotony after therapy with nivolumab. Case Presentation: We present a case of bilateral IRS with hypotony, 3 mm Hg OD and 5 mm Hg OS, after therapy with nivolumab. The patient presented with decreased vision, corneal edema, keratic precipitates, deep anterior chamber with posterior synechiae, and hypotony maculopathy. Anterior segment OCT revealed a sharp posterior displacement of the iridolenticular diaphragm consistent with IRS. Discontinuation of nivolumab until ocular improvement was suggested, following oncologic consultation. Four months later, the patient exhibited iris bombé with angle closure and increased IOP. This was managed with phacoemulsification and concomitant surgical iridectomy. One month after surgery, the patient's IOP had returned to physiologic values, and the iris configuration had returned to normal. Conclusion: The exact mechanism of IRS remains unclear, but it is suggested that an aqueous imbalance, in conjunction with uveitis and hypotony, creates an anterio-posterior movement of the iridolenticular diaphragm when the pupillary block is present. Our case highlights the importance of monitoring patients receiving ICIs for ophthalmic adverse effects and prompt management to prevent permanent visual damage. In conclusion, this is the first reported case of IRS after therapy with ICIs. Further research is needed to fully understand the exact mechanism by which it is induced.

Finite element analysis of the effects of different archwire forms and power arm positions on maxillary incisors in en masse retraction using fixed lingual orthodontic appliances.

Objective: This study aimed to investigate the effects of archwire form and power arm positions on maxillary incisors during lingual en masse retraction supported by miniscrew implants, using the finite element analysis method. Methods: Sliding mechanics for lingual en masse retraction were simulated using the finite element method. Power arms were placed mesial and distal to the maxillary canine with straight and mushroom-shaped archwires. Miniscrews provided absolute anchorage for retraction force. Results: When power arms were positioned mesial to the canine teeth, an increase in the intercanine distance was observed, while a decrease was noted when the power arms were distal to the canine tooth. Lateral incisors exhibited a greater torque loss, particularly when the power arm was mesial to the canine tooth. In the central incisors, the mushroom archwire resulted in intrusion, while the straight archwire showed an extrusion tendency. Movements in groups using the straight archwire were less controlled compared to those in groups using the mushroom archwire. Conclusions: The archwire form and the position of the power arm affected the torque loss and vertical position of incisors during lingual en masse retraction supported by miniscrew implants. The most controlled movement was achieved with the combination of a power arm positioned distal to the canine tooth and a mushroom archform.

Position and root resorption of the incisors following anterior segment retraction using friction versus frictionless mechanics: A randomised controlled trial.

AIM: To evaluate the three-dimensional position and root resorption of incisors after anterior segment retraction (ASR) using friction versus frictionless mechanics. PARTICIPANTS AND METHODS: Thirty female patients (13-18 years) with bimaxillary protrusion were randomly allocated into two groups. In the intervention group, ASR was undertaken using an elastomeric chain rendering 160 g/side extending between mini-screw implant and a hook crimped on 0.017 × 0.025-inch stainless-steel wire distal to the lateral incisor. In the comparison group, ASR was undertaken using closing T-loops fabricated from 0.017 × 0.025-inch titanium molybdenum alloy (TMA) wire rendering comparable retraction force. In both groups, the canine brackets were ligated after retraction to the mini-screw implants that were inserted in both the upper and lower arches bilaterally. The primary outcome was the three-dimensional changes in the position of the incisors. The secondary outcome was root resorption. These were measured from cone-beam computed tomography scans. RESULTS: Statistically significant decreases in the upper (UI) and lower incisors (LI) crown torque were seen in both groups; however, the difference between groups was not statistically or clinically significant (UI MD -2.04°; 95% confidence interval [CI] = -8.02-3.95; LI MD -0.49°; 95% CI = -7.06-6.08). Significant tipping of upper (MD -1.17°; 95% CI = -2.06--0.27) and lower (MD -1.13°; 95% CI = -1.66--0.60) incisors was found in the friction, but not the frictionless group after retraction; however, the changes were not clinically significant. Significant lower incisor intrusion was found in both groups after retraction; however, the difference between groups was not statistically or clinically significant (MD -0.61°; 95% CI = -1.99-0.77). Statistically significant decreases in the UI and LI root length were seen in both groups. The difference between groups for UI changes was statistically significant (MD 0.54 mm; 95% CI = -0.02-1.07) but probably not clinically significant. CONCLUSION: Considering the limitations in the current study, there was no advantage of either mechanics over the other regarding the final position of incisors. The likelihood of root resorption should be considered when frictionless mechanics are used for retraction of incisors. REGISTRY: Clinicaltrials.gov (NCT04878939).

Unraveling retraction dynamics in COVID-19 research: Patterns, reasons, and implications.

Amid the COVID-19 pandemic, while the world sought solutions, few scholars exploited the situation for personal gains through deceptive studies and manipulated data. This paper presents the extent of 400 retracted COVID-19 papers listed by the RetractionWatch database until the month of February 2024. The primary purpose of the research was to analyze journal quality and retractions trends. Evaluating the journal's quality is vital for stakeholders, as it enables them to effectively address and prevent such incidents and their future repercussions. The present study found that one-fourth of publications were retracted within the first month of their publication, followed by an additional 6% within six months of publication. One third of the retractions originated from Q1 journals, with another significant portion coming from Q2 (29.8%). An analysis of the reasons for retractions indicates that a quarter of retractions were attributed to multiple causes, predominantly associated with publications in Q2 journals, while another quarter were linked to data issues, primarily observed in Q1 publications. Elsevier retracted 31% of papers, with the majority published as Q1, followed by Springer (11.5%), predominantly as Q2. The study also examined author contributions, revealing that 69.3% were male, with females (30.7%) mainly holding middle author positions.

An Evaluation of the Rate and Type of Orthodontic Tooth Movement When Injecting Platelet-Rich Plasma During Mini-Implant-Based Segmented en-Masse Retraction of Upper Anterior Teeth.

INTRODUCTION: The study aimed to determine the influence of palatal injection of platelet-rich plasma (PRP) on the rate and type of orthodontic tooth movement (OTM) during the en-masse retraction of upper anterior teeth. MATERIALS AND METHODS: Two-arm parallel-group trial, in which 30 class II division 1 adult patients (7 males and 23 females) aged 16 to 27 years were recruited. The sample was randomly divided into two groups: the experimental group, in which PRP was injected in the palatal mucosa of the maxillary six anterior teeth immediately before starting the en-masse retraction of upper anterior teeth, whereas in the control group, traditional treatment was employed. Following the first premolar extraction, space closure was accomplished using frictionless mechanics for the en-masse retraction of upper anterior teeth. In both groups, a rigid segmented arch made of stainless steel with a diameter of 0.021 x 0.025 inch and an 8-mm power arm was used for the upper anterior teeth, and mini-implants were inserted between the upper second premolar and first molar at 8 mm apical from the archwire line. NiTi coil springs were used for retraction. Measurements were recorded at the onset of space closure (T0) and every 40 days till the middle of the en-masse retraction of upper anterior teeth (T1). RESULTS: Thirty patients completed the trial, and no patients were lost to follow-up in both groups. The OTM rate in the PRP group was similar to that of the control group (P = 0.596). The upper anterior teeth in the two groups were retracted mostly by controlled tipping and partially by translation. Statistically insignificant differences were observed between the two groups regarding the rest of the cephalometric variables. No serious harms were observed in either group. CONCLUSIONS: PRP was ineffective in accelerating the OTM rate during the en-masse retraction of upper anterior teeth and it did not affect the type of tooth movement.

Rates of Reoperation in Duane Retraction Syndrome.

Purpose: To investigate the types of strabismus surgeries performed and the reoperation rate in patients with Duane retraction syndrome (DRS). Design: Retrospective cohort analysis. Participants: An insurance claims data set was used to identify patients diagnosed with DRS between 2007 and 2021. Methods: We recorded the type of strabismus surgery performed and the timing and frequency of reoperations. The hazard ratios (HRs) for reoperation were estimated according to the surgical methods using Cox regression analysis. Results: Of the 9435 patients diagnosed with DRS, 1023 (10.8%) underwent ≥ 1 strabismus operation. The median age at surgery was 5.0 years, and patients were followed for an average of 3.8 ± 3.0 years after their initial strabismus surgery. Most of the surgeries only involved horizontal muscle(s) (n = 734 [71.7%]). However, some patients underwent surgeries on vertical muscle(s) (n = 132 [12.9%]), vertical muscle(s) with transposition (n = 102 [10.0%]), and horizontal muscle with transposition (n = 51 [5.0%]). The estimated 5-year rate of reoperation was 18.2% (95% confidence interval [CI], 15.0%-22.2%). Compared with surgery on horizontal muscle(s) only, vertical muscle surgery (HR, 2.01; 95% CI, 1.30-3.11; P = 0.002) and vertical muscle surgery coupled with transposition (HR, 1.79; 95% CI, 1.06-3.02; P = 0.03) had an increased risk of reoperation. Conclusions: Strabismus surgery on ≥ 1 horizontal muscles is the most common type of strabismus surgery performed on patients with DRS. Approximately 1 in 7 patients with DRS who had strabismus surgery underwent a reoperation. Patients who underwent vertical muscle surgery had a higher risk of undergoing a reoperation. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

From low-rank retractions to dynamical low-rank approximation and back.

In algorithms for solving optimization problems constrained to a smooth manifold, retractions are a well-established tool to ensure that the iterates stay on the manifold. More recently, it has been demonstrated that retractions are a useful concept for other computational tasks on manifold as well, including interpolation tasks. In this work, we consider the application of retractions to the numerical integration of differential equations on fixed-rank matrix manifolds. This is closely related to dynamical low-rank approximation (DLRA) techniques. In fact, any retraction leads to a numerical integrator and, vice versa, certain DLRA techniques bear a direct relation with retractions. As an example for the latter, we introduce a new retraction, called KLS retraction, that is derived from the so-called unconventional integrator for DLRA. We also illustrate how retractions can be used to recover known DLRA techniques and to design new ones. In particular, this work introduces two novel numerical integration schemes that apply to differential equations on general manifolds: the accelerated forward Euler (AFE) method and the Projected Ralston-Hermite (PRH) method. Both methods build on retractions by using them as a tool for approximating curves on manifolds. The two methods are proven to have local truncation error of order three. Numerical experiments on classical DLRA examples highlight the advantages and shortcomings of these new methods.

Various retraction techniques for laparoscopic pancreaticoduodenectomy.

The laparoscopic pancreaticoduodenectomy (LPD), introduced by Gagner and Pomp in 1994, is typically done in high-volume centers due to its technical demands. Our methods aim to provide effective traction, enabling efficient surgery despite limited staffing. A retrospective analysis of 29 patients undergoing LPD by a single surgeon between September 2021 and December 2022 showed promising outcomes: median intraoperative bleeding of 425 mL, operation time of 505 minutes, and postoperative hospital stay of 10 days. With only one case requiring open conversion, our external retraction techniques demonstrate efficacy in overcoming challenges associated with manpower constraints, highlighting potential utility for surgeons in similar settings. We share LPD external retraction techniques and outcomes.