scholarly journals Pre-, Intra-, and Post-Operative Evaluation of Extraocular Muscle Insertions Using Optical Coherence Tomography: A Comparison of Four Devices

2019 ◽  
Vol 8 (10) ◽  
pp. 1732 ◽  
Author(s):  
Matthew S. Pihlblad ◽  
Andrew Troia ◽  
Sapna Tibrewal ◽  
Parth R. Shah
Keyword(s):  
Optical Coherence Tomography ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Correlation Coefficients ◽  
Rectus Muscle ◽  
Strabismus Surgery ◽  
Optical Coherence ◽  
Intraclass Correlation Coefficients ◽  
Muscle Insertion ◽  
Operative Evaluation

OCT (optical coherence tomography) is widely used in ophthalmology and pediatric ophthalmology, but limited research has been done on the use of OCT in strabismus. This study investigates the use of different OCT machines to image rectus muscle insertions pre-, intra-, and post-operatively in pediatric strabismus patients. The OCT machines used in the study were a Bioptigen (Leica Microsystems Inc., Buffalo Grove, IL, USA), Spectralis HRA+OCT with Anterior Segment Module (Heidelberg Engineering, Heidelberg, Germany), Visante (Carl Zeiss, Oberkochen, Germany), and Zeiss Rescan 700 (Carl Zeiss, Oberkochen, Germany). Measurements from the machines were compared with the caliper distance measured during the strabismus surgery before disinsertion or after reattachment. The OCT machines had moderate (Bioptigen: 0.62) to good intraclass correlation coefficients (Rescan: 0.83, Spectralis: 0.85, Visante: 0.88) with intra-operative measurements. To our knowledge, this is the first study to use an operating microscope with integrated intra-operative OCT to image rectus muscle insertions. OCT is a useful tool in strabismus surgical patients in the pre-, intra-, and post-operative settings, particularly in patients who have had previous surgery, when the muscle insertion is unknown. The ability to accurately image rectus muscle insertions has significant implications for the management of strabismus patients.

Reliability of Corneal, Epithelial, and Stromal Thickness Mapping for a 9-mm Zone Using Spectral-Domain Optical Coherence Tomography

2021 ◽  
Author(s):  
Daniel Krause ◽  
Niklas Mohr ◽  
Mehdi Shajari ◽  
Wolfgang J. Mayer ◽  
Siegfried Priglinger ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Intraclass Correlation ◽  
Age Groups ◽  
Corneal Stroma ◽  
Correlation Coefficients ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Noninvasive Technique ◽  
Intraclass Correlation Coefficients ◽  
Sd Oct

Abstract Purpose To evaluate the reliability of spectral-domain optical coherence tomography (SD-OCT; RTVue XR; Optovue, Inc., Fremont, CA, USA) for thickness mapping of the entire cornea (CT), corneal epithelium (ET). and corneal stroma (ST) over a 9-mm zone in healthy eyes. We sought to develop reference values for different age groups and elucidate potential sex- and age-dependent characteristics of corneal sublayer pachymetry maps. Methods Three consecutive SD-OCT scans were obtained in 166 healthy right eyes (mean age = 50 ± 20 years). The thickness maps contain 25 sectors over a 9-mm diameter zone. To test measurement reliability, intraclass correlation coefficients (ICC), coefficients of variation (CoV), and within-subject standard deviations (WSSD) were calculated. Results CT, ET, and ST ICCs ranged from 0.961 to 0.998, 0.896 to 0.945, and 0.955 to 0.998, respectively. CoV values for CT, ET, and ST ranged between 0.3 and 1.5%, 1.6 and 4.2%, and 0.4 and 1.7%, respectively. WSSD ranged from 6 to 41, 4 to 8, and 7 to 46 µm, respectively. A negative correlation was found between age and ET (p < 0.05) but not between age and ST or CT. No gender-related differences in CT, ET, or ST were detected. CoV of CT, ET, and ST measurements showed a positive correlation with age in 28, 64, and 28% of the sectors, respectively. Conclusion SD-OCT is a rapid and noninvasive technique that provides excellent reliability for corneal sublayer thickness measurements over a 9-mm zone. The reliability of the ET measurement seems to be negatively affected by age. Peripheral CT and global ET thin with age.

scholarly journals Comparison of Methods for Estimating Retinal Shape: Peripheral Refraction vs. Optical Coherence Tomography

2021 ◽  
Vol 10 (2) ◽  
pp. 174
Author(s):  
Katharina Breher ◽  
Alejandro Calabuig ◽  
Laura Kühlewein ◽  
Focke Ziemssen ◽  
Arne Ohlendorf ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Axial Length ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Clinical Parameter ◽  
Mean Difference ◽  
Optical Coherence ◽  
Shape Estimation ◽  
Intraclass Correlation Coefficients

Retinal shape presents a clinical parameter of interest for myopia, and has commonly been inferred indirectly from peripheral refraction (PRX) profiles. Distortion-corrected optical coherence tomography (OCT) scans offer a new and direct possibility for retinal shape estimation. The current study compared retinal curvatures derived from OCT scans vs. PRX measurements in three refractive profiles (0° and 90° meridians, plus spherical equivalent) for 25 participants via Bland–Altman analysis. The radial differences between both procedures were correlated to axial length using Pearson correlation. In general, PRX- and OCT-based retinal radii showed low correlation (all intraclass correlation coefficients < 0.21). PRX found flatter retinal curvatures compared to OCT, with the highest absolute agreement found with the 90° meridian (mean difference +0.08 mm) and lowest in the 0° meridian (mean difference +0.89 mm). Moreover, a negative relation between axial length and the agreement of both methods was detected especially in the 90° meridian (R = −0.38, p = 0.06). PRX measurements tend to underestimate the retinal radius with increasing myopia when compared to OCT measurements. Therefore, future conclusions from PRX on retinal shape should be made cautiously. Rather, faster and more clinically feasible OCT imaging should be performed for this purpose.

scholarly journals A New Optical Coherence Tomography Method for Subfoveal Choroidal Thickness Measurement: A Single-center Observational Study

2020 ◽  
Author(s):  
Kyung Tae Kang ◽  
Ji Hye Jang ◽  
Yu Cheol Kim
Keyword(s):  
Optical Coherence Tomography ◽  
Observational Study ◽  
Choroidal Thickness ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
New Method ◽  
Optical Coherence ◽  
Single Center ◽  
Intraclass Correlation Coefficients ◽  
Single Center Observational Study

Abstract Background: Several macular pathologies are associated with choroidal vascular supply, and thus require choroidal thickness evaluation. However, there is no standard subfoveal choroidal thickness (SFCT) measuring method. This study investigated a new method to measure the SFCT, using optical coherence tomography.Methods: This is a single-center observational study. Eighty-two senior medical students participated as observers and independently measured the SFCT on five standard optical coherence tomography images of healthy adults in a tertiary care setting. They used three different methods: (1) the observer’s own method, (2) the conventional method, perpendicular to the retinal pigment epithelium, and (3) the new method, along a virtual line connecting the umbo with the most elevated point of the ellipsoid. Additionally, the SFCT angle—the angle between the measurement line and the vertical line of the image—was measured and compared between methods. The intraclass correlation coefficient was used to determine interpersonal variability. Results: The intraclass correlation coefficients for SFCT measured by methods 1, 2, and 3 were 0.853, 0.880, and 0.896, respectively (P < 0.001 for all). It was the highest with method 3; the intraclass correlation coefficients SFCT angles were 0.647, 0.842, and 0.307, respectively (P < 0.001 for all).Conclusions: The new method showed the lowest interpersonal variability, and could therefore be a reliable standard for SFCT measurement, even in foveae with a steep slope on optical coherence tomography.Trial registration: Not applicable

scholarly journals Measurement of Photoreceptor Layer in Glaucoma: A Spectral-Domain Optical Coherence Tomography Study

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Ning Fan ◽  
Nina Huang ◽  
Dennis Shun Chiu Lam ◽  
Christopher Kai-shun Leung
Keyword(s):  
Optical Coherence Tomography ◽  
Confidence Interval ◽  
Outer Nuclear Layer ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Photoreceptor Layer ◽  
Intraclass Correlation Coefficients ◽  
Spectral Domain Oct

Objective.To measure and compare photoreceptor layer thickness between normal and glaucomatous eyes using spectral-domain optical coherence tomography (OCT).Methods. Thirty-eight healthy normal volunteers and 47 glaucoma patients were included in the analysis. One eye from each participant was randomly selected for macula imaging by a spectral-domain OCT (3D OCT-1000, Topcon, Tokyo, Japan). The foveal and parafoveal (1.5 mm from the fovea) outer nuclear layer (ONL) and inner and outer segments (IS+OS) layer thicknesses were measured by a single masked observer. The measurements were repeated 3 times in a random sample of 30 normal eyes to determine the repeatability coefficient and intraclass correlation coefficient.Results.The measurement variabilities of photoreceptor thickness were low. The respective intraclass correlation coefficients of ONL and IS+OS thicknesses were 0.96 (95% confidence interval: 0.94–0.98) and 0.82 (95% confidence interval 0.70–0.90). While there were no differences in parafoveal ONL and IS+OS thicknesses between normal and glaucoma groups (), the foveal ONL thickness was greater in glaucomatous eyes () than in normal eyes.Conclusions.Glaucomatous damage may involve structural change in the photoreceptor layer.

scholarly journals Morphological change of the posterior pole following the horizontal strabismus surgery with swept source optical coherence tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yooyeon Park ◽  
Yong Chan Kim ◽  
Ye Jin Ahn ◽  
Shin Hae Park ◽  
Sun Young Shin
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Error ◽  
Extraocular Muscle ◽  
Anterior Segment ◽  
Rectus Muscle ◽  
Strabismus Surgery ◽  
Posterior Segment ◽  
Reconstruction Technique ◽  
Optical Coherence ◽  
Swept Source

AbstractExtraocular muscle movement during strabismus surgery causes changes in eyeball shape. Because extraocular muscle insertion is in front of the equator, it is thought that changes due to strabismus surgery mainly occur in the anterior segment. However, changes in the posterior segment of eye may also occur, which may also result in changes in refractive error after strabismus surgery. Using a 3-dimensional reconstruction technique (en face imaging) of the swept source optical coherence tomography, we determined and quantitatively measured the posterior polar change. The deepest interface between Bruch’s membrane and the choroid could be identified as the deepest point of the eyeball (DPE), and the location of the DPE relative to the optic disc and the fovea was measured. After lateral rectus muscle recession, the DPE moved away from the fovea, but after medial rectus muscle recession, the DPE moved toward the fovea. The amount of DPE movement differed by age and preoperative refractive error. Our findings suggest that the positional shift of the rectus muscle in horizontal strabismus surgery causes a structural change in the posterior segment of the eye, and the postoperative refractive changes may be related to this shift.

Accuracy of anterior segment optical coherence tomography for pre-operative localization of insertions of extraocular recti muscles

2020 ◽  
pp. 112067212097119
Author(s):  
Sreeram Jayaraj ◽  
Anupam Singh ◽  
Ajai Agrawal ◽  
Rakesh Panyala ◽  
Ramanuj Samanta ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Observational Study ◽  
Anterior Segment ◽  
Accurate Method ◽  
Strabismus Surgery ◽  
Optical Coherence ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Squint Surgery ◽  
Level Of Agreement

Introduction: To study the accuracy of anterior segment optical coherence tomography (AS-OCT) function of Cirrus HD-OCT 500 (Carl Zeiss Meditec, Dublin, CA) in calculating the insertion of rectus muscles from the limbus in patients undergoing primary squint surgery. Methodology: A prospective, double-masked, observational study was conducted on 128 muscles of 46 patients with strabismus who were planned for strabismus surgery between January 2019 and December 2019. Insertion distance from limbus was measured using AS-OCT function of Cirrus HD-OCT 500 preoperatively. Intraoperative measurements were taken using Castroviejo caliper. A Bland-Altman analysis was performed to determine the agreement between the readings. Results: A total of 128 muscles were successfully imaged and evaluated, including 13 superior recti (10.15%), 23 inferior recti (17.96%), 35 medial recti (27.34%) and 57 lateral recti (44.53%). 124 muscles (96.9%) were within 1mm difference, which was considered clinically acceptable. Bland-Altman plots showed the level of agreement between the two methods was good. Conclusion: Anterior segment scan function of Cirrus HD-OCT 500 is an accurate method to detect the insertion of extraocular recti muscles in patients of primary strabismus surgery.

scholarly journals Comparison of Anterior Ocular Biometric Measurements Using Swept-Source and Time-Domain Optical Coherence Tomography

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sisi Chen ◽  
Rongrong Gao ◽  
Colm McAlinden ◽  
Junming Ye ◽  
Yiran Wang ◽  
...  
Keyword(s):  
Time Domain ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Random Order ◽  
Optical Coherence ◽  
Swept Source ◽  
Significant Difference

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P<0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P=0.111; 0.02 ± 0.05 mm, P=0.022, respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT.

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