Corneal biomechanics and their association with severity of lens dislocation in Marfan syndrome.

PURPOSE: To investigate corneal biomechanical properties and its associations with the severity of lens dislocation in patients with Marfan syndrome. METHODS: A total of 30 patients with Marfan syndrome and 30 age-, sex- and axial length (AL)-matched controls were recruited. Corneal biomechanical parameters of both groups were measured by CorVis ST and were compared between groups. Potential associations between corneal biomechanical parameters and severity of lens dislocation were also investigated. RESULTS: Lower applanation 1 velocity (A1V) (0.13 ± 0.004 vs. 0.15 ± 0.003, P = 0.016), shorter applanation 2 time (A2T)(22.64 ± 0.11 vs. 22.94 ± 0.11, P = 0.013), longer peak distance (PD) (5.03 ± 0.07 vs. 4.81 ± 0.05, P = 0.008), longer radius (R) of highest concavity (7.44 ± 0.16 vs. 6.93 ± 0.14, P = 0.012), greater Ambrosio relational thickness horizontal (ARTh) (603 ± 20 vs. 498 ± 12, P < 0.001), and integrated radius (IR) (8.32 ± 0.25 vs. 8.95 ± 0.21, P = 0.033) were detected among Marfan eyes compared with controls (all P < 0.05). Marfan individuals with more severe lens dislocation tended to have increased stiffness parameter as longer A1T, slower A1V, shorter A2T, slower application 2 velocity (A2V), smaller PD and smaller Distance Amplitude (DA) (P < 0.05). CONCLUSION: Marfan patients were detected to have increased corneal stiffness compared with normal subjects. Corneal biomechanical parameters were significantly associated with the severity of lens dislocation in Marfan patients.

Metabolomic Profile in the Aqueous Humor of Congenital Ectopia Lentis.

PURPOSE: To explore the metabolic profiles in the aqueous humor (AH) of patients with congenital ectopia lentis (CEL). METHODS: We conducted a comprehensive analysis of the metabolites of AH samples of patients with CEL (n = 22) and age-matched patients (n = 22) with congenital cataract by ultra-high performance liquid chromatography tandem-mass spectrometry. The metabolomic characteristics were visualized by principal component analysis, orthogonal partial least squares discriminant analysis and heat map. The levels of the differential metabolites were also compared between CEL patients with and without FBN1 mutations. Pathway enrichment analysis was performed by using Kyoto Encyclopedia of Genes and Genomes. Receiver operating characteristic analysis was performed to select potential biomarkers. RESULTS: There were 175 differential metabolites identified between the two groups. Eight metabolites were found to be potential biomarkers in AH of CEL patients. The CEL group showed a significant increase in α-ketoglutarate and decrease in citrate, suggesting that the tricarboxylic acid (TCA) cycle was disturbed. l-proline, prolyl-hydroxyproline, and l-histidine were reduced, which prompted enhanced degradation of microfibrils and collagen. Insidious retinal nerve damage was implied because N-Acetyl-aspartylglutamic acid and N-Acetyl-l-aspartic acid were found to be significantly increased. Pathway enrichment analysis indicated that disturbances in amino acid metabolism and carbohydrate metabolism were the key processes in the pathogenesis of CEL and that TCA cycle disorder may be the driving force behind disease occurrence. CONCLUSION: These data reveal the characteristics in the metabolomic profiles of the AH of CEL patients, which help provide insights into the pathogenesis of this rare disease.

Identification and phenotypic analysis of novel LTBP2 mutations in a Chinese cohort with congenital ectopia lentis.

Purpose: To evaluate the frequency of LTBP2 mutations and to elaborate on LTBP2-related clinical phenotypes in a Chinese congenital ectopia lentis (CEL) cohort. Methods: In total, 145 Chinese probands with CEL were recruited for this study and underwent ocular and systemic examinations. Whole-exome sequencing was used to identify mutations, and Sanger sequencing and bioinformatics analysis were further performed to verify pathogenic mutations. Results: Overall, biallelic mutations in LTBP2 involving eight novel mutations (c.4370-7_4370-9delTCT, c.4370-5C>G, c.3452G>A, c.2253delG, c.4114T>C, c.1251G>A, c.4760G>A, and c.620G>A) were identified in four CEL probands (4/145, 2.76%). Patients with LTBP2 mutations were characterized by a megalocornea, spherophakia, high myopia, and glaucoma instead of a flat cornea, high corneal astigmatism, cardiovascular and skeletal abnormalities that were reported in other gene mutations. A novel homozygous frameshift mutation was detected, and this type of mutation was found to cause more complicated ocular symptoms than others, ranging from the anterior segment to the fundus. Conclusion: This study reported the mutation frequency of the LTBP2 gene in a Chinese CEL cohort and provided novel insight into LTBP2-related genotype-phenotype associations in CEL.

Characteristics of Anterior Segment in Congenital Ectopia Lentis: An SS-OCT Study.

Purpose: To investigate the characteristics of anterior chamber angle parameters in congenital ectopia lentis (CEL) patients and to evaluate the sensitivity and specificity of anterior segment parameters in distinguishing CEL from healthy controls. Setting. Zhongshan Ophthalmic Center, Guangzhou, China. Design: Cross-sectional study. Methods: 35 CEL patients and 35 age- and sex-matched healthy controls were recruited. Axial length (AL) and anterior segment parameters including anterior chamber width (ACW), angle open distance (AOD), angle recess area (ARA), trabecular-iris space area (TISA), and trabecular-iris angle (TIA) were measured. All the above parameters and the ratio index of angle parameters, which was defined as the angle parameter value of the narrower side to that of the contralateral side, were compared between CEL and controls. Receiver operating characteristic (ROC) curves were also plotted to evaluate the diagnostic performance of anterior chamber angle parameters in CEL patients. Results: All angle parameters of the contralateral side to the dislocated lens side were significantly smaller than those of the dislocated lens side in CEL (all P < 0.05). For the diagnostic performance of anterior chamber angle parameters, the ratio index of TIAr500 combined with TIAr750 had the best diagnostic performance for CEL screening (AUC = 0.798), and TIAr500 of 0.887 and TIAr750 of 0.917 were detected to be the optimal cut-off points, representing a sensitivity of 89.8% and specificity of 68.7%. Conclusion: The contralateral side to the dislocated lens side in the CEL had a narrower anterior chamber angle. TIAr500 combined with TIAr750 is the optimal combination strategy for ectopia lentis screening.

Posterior INFIX for Treating Unilateral Unstable Sacral Fractures.

OBJECTIVE: To evaluate the clinical outcomes of the treatment of unilateral unstable sacral fractures by fixation with the posterior INFIX (posterior pelvic ring screw-rod internal fxation). METHODS: Data of 60 patients with unilateral unstable sacral fractures who underwent surgery from March 2013 to March 2020 were retrospectively analyzed according to the selection criteria. All patients were associated with anterior pelvic ring injuries, and the operations were performed by the same team of surgeons. According to the different types of internal fixation, the patients were divided into two groups, which both included 30 patients: the posterior INFIX group and iliosacral screw fixation group. The demographic and clinical data of the two patient groups, such as age, sex, sacral fracture types based on the Denis classification, operation time, amount of intraoperative bleeding, intraoperative fluoros copy time, Majeed pelvic score at final follow-up, and quality of fracture reduction based on Mears and Velyvis's imaging classification criteria were collected by the same researcher and compared statistically. RESULTS: All patients were continuously followed up for 23.17 ± 3.34 months (range, 12 to 46 months). All sacral fractures healed with an average healing time of 9.3 ± 2.24 months (range, 6 to 18 months). None of the patients had re-displacement of the fracture or fixation failure. Compared to the iliosacral screw group, the posterior INFIX group patients had more intraoperative bleeding (t = 3.59, P < 0.001), shorter operation time (t = 4.49, P < 0.001), and shorter intraoperative fluoroscopy time (t = 6.26, P < 0.001). There were no statistical differences between the two groups in terms of age, sex, fracture type, Majeed score, and quality of fracture reduction (P > 0.05). In the posterior INFIX group, one patient had a superficial wound infection and one patient complained of discomfort due to a prominent fixation. In the iliosacral screw fixation group, one patient had intraoperative iatrogenic S1 nerve injury and vessel injury. The posterior INFIX fixation was a simpler manipulation with higher safety, shorter time of operation and intraoperative fluoroscopy, and similar clinical outcomes compared to iliosacral screw fixation. CONCLUSION: For the treatment of unilateral unstable sacral fractures, the posterior INFIX fixation can be recommended in clinic application.

Accuracy of intraocular lens power formulas for eyes with scleral-sutured intraocular lenses in congenital ectopia lentis.

PURPOSE: To compare the accuracy of intraocular lens (IOL) power calculation formulas in eyes with congenital ectopia lentis (CEL) that underwent scleral-fixated IOL implantation. SETTING: Zhongshan Ophthalmic Center, Guangzhou, China. DESIGN: Retrospective consecutive case-series study. METHODS: 158 eyes from 158 patients diagnosed from December 12, 2017, to November 16, 2020, with CEL and undergoing a lensectomy and scleral fixation of a Rayner 920H or 970C model IOL were retrospectively reviewed. The prediction errors (PEs) of the spherical equivalent of 8 formulas, Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO), Haigis, Hoffer Q, Holladay 1, Kane, Hill-RBF 3.0, and SRK/T, were compared. RESULTS: For CEL patients with scleral-sutured IOL, all 8 formulas yielded myopic PEs without constant optimization. After such optimization, the performance of each formula ranked by median absolute error (MedAE) from the lowest to highest in diopter (D) was as follows: SRK/T (0.47), EVO (0.48), Kane (0.52), BUII (0.53), Hoffer Q (0.58), Holladay 1 (0.59), Haigis (0.61), and Hill-RBF 3.0 (0.62) formulas. The EVO and SRK/T formulas had the highest prediction accuracy concerning the percentage of cases within ±0.50 D and ±1.00 D range of PE in eyes that experienced scleral-sutured IOL surgery, respectively. CONCLUSIONS: All formulas before constant optimization produced myopic PEs. After optimization, the SRK/T and EVO formulas had the lowest MedAE and the highest percentage of PE in the range within ±0.50 D for CEL patients with scleral-sutured IOL implantations.

Comparison of Outcomes Following TiRobot-Assisted Sacroiliac Screw Fixation with Bone Grafting and Traditional Screw Fixation without Bone Grafting for Unstable Osteoporotic Sacral Fracture: A Single-Center Retrospective Study of 33 Patients.

BACKGROUND This retrospective study from a single center aimed to compare patient outcomes following TiRobot-assisted sacroiliac screw fixation and bone grafting with traditional screw fixation without bone grafting in 33 patients with unstable osteoporotic sacral fracture (UOSF). MATERIAL AND METHODS Patients with UOSF were included and divided into 2 groups: a TiRobot-assisted surgical group with 18 patients (robot-aided sacroiliac screw fixation and bone grafting) and a standard surgical group with 15 patients (free-hand screw fixation without bone grafting). T values of bone mineral density (BMD) £-2.5 standard deviation (SD) were diagnosed as osteoporosis. Screw positioning and fracture healing time were evaluated. Functional outcomes were investigated at the final follow-up. RESULTS There were no statistically significant differences in screw positioning; however, there were satisfactory positioning rates in 94.4% (17/18) of patients in the TiRobot-assisted surgical group and 73.3% (11/15) in the standard surgical group. The advantages with TiRobot on surgical time of screw placement, fluoroscopy frequency, and total drilling times were noted (P=0.000). The nonunion rates were 5.6% (1/18) in the TiRobot-assisted surgical group and 33.3% (5/15) in the standard group (P=0.039). Healing time in the union cases had a significant difference (P=0.031). Functional outcome scores in the TiRobot-assisted surgical group were superior to that in the standard group (P=0.014). CONCLUSIONS The findings showed that TiRobot-assisted sacroiliac screw fixation and bone grafting was a safe and effective surgical treatment option that had a reduced radiation dose and improved fracture healing, when compared with standard screw fixation without bone grafting.

Robot-Aided Minimally Invasive Lumbopelvic Fixation in Treatment of Traumatic Spinopelvic Dissociation.

OBJECTIVE: To investigate the surgical strategy, safety, and efficacy of close reduction and robot-aided minimally invasive lumbopelvic fixation in treatment of traumatic spinopelvic dissociation. METHODS: Data of 32 patients (21 males and 11 females) with traumatic spinopelvic dissociation treated by lumbopelvic fixation with robot-aided minimally invasive technique or conventional open procedure in our institution from March 2010 to April 2019 were retrospectively analyzed, and divided into robot group and control group. Intraoperative blood loss, surgical time, fluoroscopy frequency, total drilling times, infection rate, hospitalization time, and sacral fracture healing time were reviewed. Radiographs and computed tomography (CT) scans were totally acquired to evaluate the reduction quality, residual fracture displacement, and Gras classification on screws insertion after surgery. According to the Majeed scoring system, functional outcome was assessed for each patient at the final follow-up. RESULTS: There were 12 patients in the robot group and 20 patients in the control group with no significant difference about the demographic data. The average surgical time was 148.3 ± 40.5 min with intraoperative blood loss of 142.5±36.7 mL in the robot group and 185.0 ± 47.8 min with 612.5 ± 182.7 mL in the control group (P = 0.034, P = 0.000). The robot group had a shorter mean hospitalization time at 19.9 ± 7.0 days compared to the control group with 28.6 ± 5.4 days (P = 0.010). The fluoroscopy frequency was 35.4 ± 3.0 in the robot group and 45.5 ± 3.6 in the control group (P = 0.000) and total drilling times were 7.1 ± 1.1 and 9.6 ± 1.3 (P = 0.000), respectively. The infection rate was 0% (0/12) in the robot group and 15% (3/20) in the control group (P = 0.159). According to the Gras classification on screw positioning, there were 11 cases in Grade I and 1 case in Grade II in the robot group, and 14 cases in Grade I and 6 cases in Grade II in the control group. All the patients were followed up consecutively for at least 12 months, with an average follow-up period of 17.1 ± 3.6 months. All sacral fractures healed with an average time of 3.8 ± 0.6 months in the robot group and 4.7 ± 0.7 months in the control group (P = 0.000). According to Majeed functional assessment investigation, the mean score of the patients was 87.2 ± 4.0 in the robot group and 83.1 ± 4.5 in the control group (P = 0.015). CONCLUSIONS: Robot-aided minimally invasive lumbopelvic fixation for traumatic spinopelvic dissociation is a safe and feasible option with advantages of less intraoperative blood loss, less radiation damage, less hospitalization time, and better functional outcome.

Parcellation of the human orbitofrontal cortex based on gray matter volume covariance.

The human orbitofrontal cortex (OFC) is an enigmatic brain region that cannot be parcellated reliably using diffusional and functional magnetic resonance imaging (fMRI) because there is signal dropout that results from an inherent defect in imaging techniques. We hypothesise that the OFC can be reliably parcellated into subregions based on gray matter volume (GMV) covariance patterns that are derived from artefact-free structural images. A total of 321 healthy young subjects were examined by high-resolution structural MRI. The OFC was parcellated into subregions-based GMV covariance patterns; and then sex and laterality differences in GMV covariance pattern of each OFC subregion were compared. The human OFC was parcellated into the anterior (OFCa), medial (OFCm), posterior (OFCp), intermediate (OFCi), and lateral (OFCl) subregions. This parcellation scheme was validated by the same analyses of the left OFC and the bilateral OFCs in male and female subjects. Both visual observation and quantitative comparisons indicated a unique GMV covariance pattern for each OFC subregion. These OFC subregions mainly covaried with the prefrontal and temporal cortices, cingulate cortex and amygdala. In addition, GMV correlations of most OFC subregions were similar across sex and laterality except for significant laterality difference in the OFCl. The right OFCl had stronger GMV correlation with the right inferior frontal cortex. Using high-resolution structural images, we established a reliable parcellation scheme for the human OFC, which may provide an in vivo guide for subregion-level studies of this region and improve our understanding of the human OFC at subregional levels.

[Comparison study on two operations for treatment of extra-articular distal tibial fracture].

OBJECTIVE: To compare the effectiveness between minimally invasive plate osteosynthesis (MIPO) and open reduction and internal fixation (ORIF) for treatment of extra-articular distal tibial fracture. METHODS: Between March 2009 and March 2012, 57 patients with extra-articular distal tibial fractures were treated, and the clinical data were retrospectively analyzed. Of 57 cases, 31 were treated with MIPO (MIPO group), and 26 with ORIF (ORIF group). There was no significant difference in gender, age, cause of injury, type of fractures, complication, and time from injury to operation between 2 groups (P > 0.05). The operation time, intraoperative blood loss, fracture healing time, and complications were compared between 2 groups. RESULTS: There was no significant difference in operation time and intraoperative blood loss between 2 groups (P > 0.05). Wound infection occurred in 5 cases [2 in MIPO group (6.5%) and 3 in ORIF group (11.5%)] showing no significant difference (Chi(2)=0.651, P=0.499). The other wound obtained healing by first intention. All cases were followed up 13-24 months (mean, 15 months). No significant difference was found in the average healing time between 2 groups and between patients with types A and B by AO classification (P > 0.05); in patients with type C, the healing time in MIPO group was significantly shorter than that in ORIF group (t= -2.277, P=0.033). Delayed union was observed in 3 cases of MIPO group (9.7%) and in 4 cases of ORIF group (15.4%), showing no significant difference (Chi(2)=0.428, P=0.691). Mal-union occurred in 4 cases of MIPO group (12.9%) and in 1 case of ORIF group (3.8%), showing no significant difference (Chi(2)=1.449, P=0.362). No significant difference was found in Mazur score between 2 groups (t=0.480, P=0.633). The excellent and good rate was 93.5% in MIPO group (excellent in 24 cases, good in 5 cases, fair in 1 case, and poor in 1 case) and was 92.3% in ORIF group (excellent in 18 cases, good in 6 cases, and poor in 2 cases), and the difference was not significant (Z= -0.687, P=0.492). CONCLUSION: Both MIPO and ORIF have good results in treating extra-articular distal tibial fractures. MIPO is superior to ORIF for treating complex and communited fractures.