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Magcalas KJ, Oe S, Yamato Y, Hasegawa T, Yoshida G, Banno T, Arima H, Mihara Y, Ushirozako H, Yamada T, Ide K, Watanabe Y, Matsuyama Y. Change in Line of Sight after Corrective Surgery of Adult Spinal Deformity Patients: A 2-Year Follow-up. Asian Spine J 2023; 17:272-284. [PMID: 36693431 PMCID: PMC10151636 DOI: 10.31616/asj.2021.0256] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/14/2022] [Indexed: 01/26/2023] Open
Abstract
Study Design Cohort study. Purpose There is currently no published study that focuses on the spinal corrective surgery effects with cranial parameters in adult spinal deformity (ASD) patients. It is an important factor to measure since it plays a critical role in maintaining the line of sight. The objective is to determine the change in cranial parameters using the slope of McGregor's line (McGS) after ASD surgery after 2 years of follow-up. Overview of Literature A study concluded that cervical spine alignment (C2-C7 lordosis) is strongly affected by thoracic kyphosis (TK). Another study showed that patients with ascending gaze had significantly more thoracolumbar malalignment. Methods This retrospective study includes 295 corrective surgery patients with ASD. Subjects were divided into two groups after propensity age matching analysis: cranial malalignment (McGS <-8 or >13) and normal cranial alignment (-8≤ McGS ≤13). Lumbar lordosis (LL), pelvic tilt (PT), TK, cervical lordosis (CL), and sagittal vertical axis (SVA) were evaluated between the two groups. Results SVA (95-56 mm) and PT (34°-25°) decreased and LL (19°-41°) increased 2 years after surgery (p <0.05), but McGS (-1.1° to -0.5°) and CL (21°-19°) did not change. Conversely, in the group with cranial malalignment, SVA (120-64 mm), PT (35°-26°), and LL (12°-41°) showed similar results to the normal cranial parameter group 2 years after surgery, but in contrast, McGS (-13° to -2°) and CL (24°-18°) improved significantly. Conclusions Severe ASD adversely affects to maintain horizontal gaze but can be improved by spinal corrective surgery.
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Affiliation(s)
- Ken Jeffrey Magcalas
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.,Department of Orthopaedic Surgery, The Medical City, Pasig, Philippines
| | - Shin Oe
- Department of Orthopaedic Surgery and Division of Geriatric Musculoskeletal Health, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yu Yamato
- Department of Orthopaedic Surgery and Division of Geriatric Musculoskeletal Health, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Tomohiko Hasegawa
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Go Yoshida
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Tomohiro Banno
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hideyuki Arima
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yuki Mihara
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hiroki Ushirozako
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Tomohiro Yamada
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Koichiro Ide
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yuh Watanabe
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yukihiro Matsuyama
- Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Zhang F, Zhang J, Li W, Zhou L, Feng D, Zhang H, Fang W, Sun R, Liu Z. Correlative Comparison of Three Ocular Axes to Tilt and Decentration of Intraocular Lens and Their Effects on Visual Acuity. Ophthalmic Res 2019; 63:165-173. [PMID: 31846979 DOI: 10.1159/000504716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/10/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE To evaluate which ocular axis, the corneal topographic axis (CTA), pupillary axis (PA) or line of sight (LOS), for measuring the tilt and decentration of intraocular lens (IOL) is most relevant to correct distance visual acuity (CDVA). METHODS A Scheimpflug device (Pentacam HR) was prospectively used to determine the tilt and decentration of IOLs in vivo 3 months after cataract surgery. A new method was developed to reliably measure PA and LOS. We further evaluated CTA and then used Spearman correlation coefficient and linear regression to assess the correlation between CDVA and IOL displacement based on the data of three different ocular axes. RESULTS Forty-six eyes from 46 patients were evaluated. The majority of decentration and tilt of IOL with reference to CTA, PA and LOS were towards the subtemporal direction. We found that the horizontal meridian data measured using CTA and PA were statistically significantly different (p = 0.011 for tilt; p = 0.005 for decentration). The correlation between CDVA and the distance of decentration temporally (r = -0.344, p = 0.035) and inferiorly (r = -0.336, p = 0.042) of the IOL with regard to CTA was significant. PA and LOS measurements had no correlation with any indices. CONCLUSION Assessment of tilt and decentration of the IOL with reference to different ocular axes was markedly different. IOL tilt and decentration measured by CTA were significantly correlated with CDVA.
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Affiliation(s)
- Fan Zhang
- Department of Ophthalmology, Qingdao Women and Children Hospital, Qingdao University, Qingdao, China.,Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jian Zhang
- Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China,
| | - Wei Li
- Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, USA
| | - Lin Zhou
- Department of Ophthalmology, First Hospital of Tsinghua University, Beijing, China
| | - Di Feng
- School of Instrumentation Science and Optoelectronics Engineering, Beihang University, Beijing, China
| | - Haixia Zhang
- Biomechanics, School of Biomedical Engineering, Capital Medical University, Beijing, China.,Biomechanics, Beijing Key Laboratory of Basic Research on Biomechanics in Clinical University, Beijing, China
| | - Wei Fang
- Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ran Sun
- Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhicheng Liu
- Biomechanics, School of Biomedical Engineering, Capital Medical University, Beijing, China.,Biomechanics, Beijing Key Laboratory of Basic Research on Biomechanics in Clinical University, Beijing, China
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Kosekahya P, Koc M, Tekin K, Uzel M, Atilgan CU, Caglayan M, Yilmazbas P. Evaluation of the shifting of the line of sight and higher order aberrations of eyes with keratoconus after corneal cross-linking. Cont Lens Anterior Eye 2017; 40:311-317. [PMID: 28336222 DOI: 10.1016/j.clae.2017.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/11/2017] [Accepted: 03/12/2017] [Indexed: 11/26/2022]
Abstract
AIM To evaluate changes in the coordinates of the line of sight (LoS) and higher order aberrations (HOAs) of eyes with keratoconus, following corneal cross-linking (CXL). METHODS All patients (93 eyes) underwent detailed ophthalmologic examination and Pentacam HR measurements at baseline and at 3, 6, and 12 months after corneal CXL. LoS coordinates on the horizontal (x) and vertical (y) axes, vertical coma, vertical trefoil, spherical aberration, total root-mean square (RMS), and HOA-RMS values were recorded along with visual acuity and topographical parameters. RESULTS LoS significantly shifted to the nasal region after corneal CXL in both right and left eyes (p=0.003 and p=0.01, respectively). Horizontal axis values of both eyes significantly shifted to the temporal region at postoperative 6th months compared to the baseline measurements (p=0.02 and p=0.02, respectively) and remained the same between postoperative 6th months and 12th months (p=1.00 and p=0.97, respectively). Total-RMS, HOA-RMS, vertical coma, and spherical aberration values significantly improved after corneal CXL (p<0.001, p=0.02, p=0.04, and p<0.001, respectively). The improvements in HOAs were significant at postoperative 6th months compared to the baseline measurements (p=0.003, p=0.02, p<0.001, and p=0.003, respectively) while remained the same between postoperative 6th months and 12th months (p>0.05 for all values). The changes in horizontal-axis coordinates in left eyes were significantly correlated with anterior elevation, anterior astigmatism, total-RMS and HOA-RMS changes (r2=0.20, p=0.03; r2=0.35, p<0.01; r2=0.50, p<0.001 and r2=0.35, p=0.004; respectively). CONCLUSIONS LoS significantly shifted to the nasal region and HOAs improved after corneal CXL and these changes stabilized 6th months after corneal CXL. It would be more better to perform refractive surgery in crosslinked corneas at least 6th months after corneal CXL.
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Affiliation(s)
- Pinar Kosekahya
- Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
| | - Mustafa Koc
- Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Kemal Tekin
- Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Murat Uzel
- Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | | | - Mehtap Caglayan
- Mardin State Hospital, Department of Ophthalmology, Mardin, Turkey
| | - Pelin Yilmazbas
- Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
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Abstract
The human eye is an asymmetric optical system and the real cornea is not a rotationally symmetrical volume. Each optical element in the eye has its own optical and neural axes. Defining the optimum center for laser ablation is difficult with many available approaches. We explain the various centration approaches (based on these reference axes) in refractive surgery and review their clinical outcomes. The line-of-sight (LOS) (the line joining the entrance pupil center with the fixation point) is often the recommended reference axis for representing wavefront aberrations of the whole eye (derived from the definition of chief ray in geometrical optics); however pupil centration can be unstable and change with the pupil size. The corneal vertex (CV) represents a stable preferable morphologic reference which is the best approximate for alignment to the visual axis. However, the corneal light reflex can be considered as non-constant, but dependent on the direction of gaze of the eye with respect to the light source. A compromise between the pupil and CV centered ablations is seen in the form of an asymmetric offset where the manifest refraction is referenced to the CV while the higher order aberrations are referenced to the pupil center. There is a need for a flexible choice of centration in excimer laser systems to design customized and non-customized treatments optimally.
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Affiliation(s)
- Samuel Arba Mosquera
- SCHWIND eye-tech-solutions, Kleinostheim, Germany ; Recognized Research Group in Optical Diagnostic Techniques, University of Valladolid, Valladolid, Spain ; Department of Ophthalmology and Sciences of Vision, University of Oviedo, Oviedo, Spain
| | | | - Colm McAlinden
- Flinders University, Adelaide, South Australia Australia ; Wenzhou Medical University, Wenzhou, Zhejiang China
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Abdo MM, Vali AR, Toloei AR, Arvan MR. Stabilization loop of a two axes gimbal system using self-tuning PID type fuzzy controller. ISA Trans 2014; 53:591-602. [PMID: 24461337 DOI: 10.1016/j.isatra.2013.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 11/17/2013] [Accepted: 12/03/2013] [Indexed: 06/03/2023]
Abstract
The application of inertial stabilization system is to stabilize the sensor's line of sight toward a target by isolating the sensor from the disturbances induced by the operating environment. The aim of this paper is to present two axes gimbal system. The gimbals torque relationships are derived using Lagrange equation considering the base angular motion and dynamic mass unbalance. The stabilization loops are constructed with cross coupling unit utilizing proposed fuzzy PID type controller. The overall control system is simulated and validated using MATLAB. Then, the performance of proposed controller is evaluated comparing with conventional PI controller in terms of transient response analysis and quantitative study of error analysis. The simulation results obtained in different conditions prove the efficiency of the proposed fuzzy controller which offers a better response than the classical one, and improves further the transient and steady-state performance.
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Affiliation(s)
- Maher Mahmoud Abdo
- Malek Ashtat University of Technology, Department of Electrical Engineering, Lavizan, Tehran, Iran.
| | - Ahmad Reza Vali
- Malek Ashtat University of Technology, Department of Electrical Engineering, Lavizan, Tehran, Iran.
| | - Ali Reza Toloei
- Shahid Behechti University, Department of Aerospace, Tehran, Iran.
| | - Mohammad Reza Arvan
- Malek Ashtat University of Technology, Department of Electrical Engineering, Lavizan, Tehran, Iran.
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