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The aim of this paper is to present an analytical study for the investigation of the reciprocal metamaterial gyro-bianisotropy effects on the input impedance of a dipole antenna. This study is based on the numerical resolution, using the spectral method of moments (SMoM), of the integral equation developed through the mathematical derivation of the appropriate spectral Green’s functions of the studied dipole configuration. The original obtained results are discussed and showed good agreements with the isotropic studied cases available in published literature. It is found that the imaginary valued magnetoelectric elements (chiral medium) exhibit an inverse effect on the resonant length compared to purely real elements (Tellegen medium), while negative elements decrease the input impedance. Combination of the two cases has led to more general complex media with further inspiring features.

Purpose To evaluate the association between baseline demographic and spectral domain OCT (SD-OCT) features with visual acuity (VA) in the Study of COmparative Treatments for REtinal Vein Occlusion 2 (SCORE2) over 2 years. Design Post hoc analysis of prospective clinical trial data. Participants A total of 362 SCORE2 participants with macular edema secondary to central retinal (CRVO) or hemiretinal vein occlusion (HRVO). Methods Spectral domain OCT volume scans were assessed at the SCORE2 reading center at baseline, month 01 (M01), month 06 (M06), month 12 (M12), and month 24 (M24) for central subfield thickness (CST), subretinal fluid, intraretinal fluid, vitreoretinal interface abnormalities, disorganization of retinal inner layers (DRIL), and ellipsoid zone (EZ) within the central subfield (CSF). Main Outcome Measures Visual acuity at M06, M12, and M24. Results Mean baseline age was 68.9 years. Mean VA at M01 was 63.2 letters, and CST was 299.7 μm. At M01, subretinal fluid was seen in 28.5% intraretinal fluid in 67.2%, DRIL was seen in 73.8%, mostly within the CSF, and the EZ was absent in 9.8 and patchy in 31.7%. In multivariate analysis including all M01 demographics and SD-OCT parameters and their association with VA at M06, M12, and M24, VA at M01 remained significant across all time points up to M24 (P Conclusions In this 2-year follow-up of eyes that were treated with both per protocol and off protocol for RVO, VA at M01 was an important predictor of long-term vision and change in vision. Establishing predictors of visual recovery helps identify causes for poor responders to treatment in patients with RVO.

Objective The purpose of this study was to test the diagnostic accuracy of optical coherence tomography (OCT) in differentiating optic disc drusen (ODD) from papilledema in children. Design Retrospective cross-sectional study at a tertiary-care pediatric hospital. Participants Children with high-quality OCT imaging of ODD or papilledema. Methods Quantitative OCT parameters and qualitative OCT features were compared for diagnostic accuracy. Results There were 41 eyes with ODD and 21 eyes with papilledema. Both the quantitative and qualitative OCT parameters showed highly statistically significant differences between ODD and papilledema (p ≤ 0.01 for all). For quantitative parameters (Bruch's membrane opening and retinal nerve fiber layer thicknesses), the area under the curve from the receiver operator curves ranged from 0.81 to 0.90. For qualitative parameters, the sensitivity for ODD ranged from 27% to 100% and specificity ranged from 67% to 100%. The presence of at least 1 of 3 qualitative OCT parameters (hyporeflective boot-shaped area, isolated/clustered hyperreflective bands, or signal-poor regions in the core) had a sensitivity of 90% and a specificity of 100% for ODD. Conclusions Both quantitative and qualitative OCT parameters differed significantly between ODD and papilledema in this cohort of children. A combination of several qualitative OCT features had high sensitivity for ODD while effectively ruling out papilledema.

Purpose To assess the additive value of foveal swept-source optical coherence tomography (OCT)–based biometry to the preoperative fundus examinations for diagnosing macular abnormalities in patients scheduled for cataract surgery. Design Diagnostic testing evaluation. Methods Consecutive patients 50 years of age and older planned for cataract surgery from one institution were retrospectively enrolled. All patients underwent foveal swept-source OCT, and macular spectral domain (SD) OCT scans before pupil dilation as well as dilated fundus biomicroscopy examination. The effectiveness of fundus biomicroscopy examinations, foveal swept-source OCT scans, and the combination of both in identifying macular diseases was analyzed with macular spectral-domain OCT scans as reference. Results Seventy-eight of the eligible 442 eyes (442 patients) were excluded because of noninterpretable macular spectral-domain OCT OCT scans or foveal swept-source OCT scans. The remaining 364 eyes of 364 patients (mean age 73.59±9.26 years [range 49-96], 172 males) formed the study group. Fundus biomicroscopy alone vs fundus biomicroscopy with the addition of foveal swept-source OCT yielded 36% vs 63% sensitivity, 94% vs 72% specificity, 79% vs 58% positive predictive value (PPV), and 71% vs 76% negative predictive value (NPV), respectively. This diagnostic improvement was significant compared with fundus biomicroscopy alone (P = 2.98–8). Conclusion Combined fundus biomicroscopy and foveal swept-source OCT scans improved the detection of macular abnormalities prior to cataract surgery but it was inferior to macular spectral-domain OCT scans. Additional studies to assess the cost-effectiveness of adding foveal swept-source OCT scan in comparison to macular spectral-domain OCT scan to the preoperative cataract evaluation are required.

Summary Purpose The purpose of this study was to evaluate microvascular changes in the retina and choriocapillaris in central serous chorioretinopathy (CSCR) patients with resolved serous detachment using optical coherence tomography angiography (OCTA). Method 49 eyes of 46 patients with CSCR were included in the study. 32 eyes of 16 age-matched controls were included in the control group. Fundus photography, fluorescein angiography, spectral-domain optical coherence tomography and OCTA were used. Choriocapillaris (CC) flow area, foveal avascular zone (FAZ), parafoveal vascular density of superficial and deep capillary plexus of the acute and chronic CSCR groups were compared with the values of the control group. Contrary to previous studies, OCTA data were obtained at a time when there was no serous detachment. This was because we aimed at minimizing erroneous measurements that might arise due to serous detachment. Results 1- The acute CSCR patients (1.705 ± 0.292 mm2) were found to have lower choriocapillaris (CC) flow area compared to the control group (2.155 ± 0.069 mm2). (P Conclusion Our study showed that the pathogenesis of CSCR is characterized by choriocapillaris and retinal microvascular changes.

Purpose To evaluate the performance of retinal specialists in detecting retinal fluid presence in spectral domain OCT (SD-OCT) scans from eyes with age-related macular degeneration (AMD) and compare performance with an artificial intelligence algorithm. Design Prospective comparison of retinal fluid grades from human retinal specialists and the Notal OCT Analyzer (NOA) on SD-OCT scans from 2 common devices. Participants A total of 1127 eyes of 651 Age-Related Eye Disease Study 2 10-year Follow-On Study (AREDS2-10Y) participants with SD-OCT scans graded by reading center graders (as the ground truth). Methods The AREDS2-10Y investigators graded each SD-OCT scan for the presence/absence of intraretinal and subretinal fluid. Separately, the same scans were graded by the NOA. Main Outcome Measures Accuracy (primary), sensitivity, specificity, precision, and F1-score. Results Of the 1127 eyes, retinal fluid was present in 32.8%. For detecting retinal fluid, the investigators had an accuracy of 0.805 (95% confidence interval [CI], 0.780–0.828), a sensitivity of 0.468 (95% CI, 0.416–0.520), a specificity of 0.970 (95% CI, 0.955–0.981). The NOA metrics were 0.851 (95% CI, 0.829–0.871), 0.822 (95% CI, 0.779–0.859), 0.865 (95% CI, 0.839–0.889), respectively. For detecting intraretinal fluid, the investigator metrics were 0.815 (95% CI, 0.792–0.837), 0.403 (95% CI, 0.349–0.459), and 0.978 (95% CI, 0.966–0.987); the NOA metrics were 0.877 (95% CI, 0.857–0.896), 0.763 (95% CI, 0.713–0.808), and 0.922 (95% CI, 0.902–0.940), respectively. For detecting subretinal fluid, the investigator metrics were 0.946 (95% CI, 0.931–0.958), 0.583 (95% CI, 0.471–0.690), and 0.973 (95% CI, 0.962–0.982); the NOA metrics were 0.863 (95% CI, 0.842–0.882), 0.940 (95% CI, 0.867–0.980), and 0.857 (95% CI, 0.835–0.877), respectively. Conclusions In this large and challenging sample of SD-OCT scans obtained with 2 common devices, retinal specialists had imperfect accuracy and low sensitivity in detecting retinal fluid. This was particularly true for intraretinal fluid and difficult cases (with lower fluid volumes appearing on fewer B-scans). Artificial intelligence–based detection achieved a higher level of accuracy. This software tool could assist physicians in detecting retinal fluid, which is important for diagnostic, re-treatment, and prognostic tasks.

Purpose To evaluate the agreement between detection of activity of choroidal neovascularization (CNV) in neovascular age-related macular degeneration (AMD) by fundus fluorescein angiography (FFA) and spectral-domain (SD) OCT in the HARBOR study. Most retina specialists rely on OCT to guide treatment decisions in neovascular AMD. However, OCT may not always detect exudative activity. Traditionally, FFA was frequently performed in clinical practice, but its use has diminished due to reliance on OCT. Design Retrospective post hoc analysis of prospective clinical trial (HARBOR; ClinicalTrials.gov identifier, NCT00891735 ). Participants Patients with neovascular AMD in the HARBOR Trial. Methods Baseline to month 24 data from all randomized study eyes in HARBOR with both FFA and SD OCT data were analyzed for (1) evidence of CNV activity on SD OCT (presence of subretinal fluid, intraretinal fluid, and/or cystoid spaces); (2) evidence of CNV activity on FFA identified by the presence of leakage, and (3) cross-tabulation of CNV activity identified by FFA and SD OCT by office visit. Main Outcome Measures The percent agreement between FFA and SD OCT in detecting CNV activity and sensitivity and specificity of SD OCT to detect fluorescein leakage in neovascular AMD using FFA as the reference standard. Results At baseline, 1094 patients (99.9%) had agreement between SD OCT and FFA in detecting CNV activity. By month 24, of the 779 total active cases, the agreement was only 36% (277 cases). By month 24, most cases (n = 452 [58%]) had evidence of CNV activity on SD OCT only, whereas 6% of cases (n = 50) had CNV activity identified by FFA only. At screening and months 3, 6, 12, and 24, 92% to 100% of cases identified by FFA only were occult CNV lesions. Using FFA as the reference standard, the sensitivity and specificity of SD OCT in detecting CNV activity was 91% (95% confidence interval [CI], 84%–99%) and 13% (95% CI, 4%–22%). Conclusions Spectral-domain OCT alone can be relied upon for detecting CNV activity while monitoring eyes with neovascular AMD. However, FFA may still be of value in those with occult lesions that appear quiescent on SD OCT, as this type of lesion may show leakage on FFA.

OBJECTIVE: To evaluate the association between retinopathy of prematurity and vitreous findings in premature infants detected by handheld spectral-domain optical coherence tomography. DESIGN: Prospective, observational cohort study. PARTICIPANTS: Consecutive sample of 92 premature infants requiring retinopathy of prematurity screening at two academic neonatal intensive care units, between July 2015 and March 2018. METHODS: Infants underwent handheld spectral domain optical coherence tomography at the time of routine retinopathy of prematurity examinations. Two masked, trained graders analyzed right eye vitreoretinal findings including semi-automated quantification of punctate hyperreflective vitreous opacities within 5 foveal/parafoveal B-scans (Vitreous Opacity Ratio). MAIN OUTCOME MEASURES: Excluding post-treatment data, vitreous findings were compared to clinical retinopathy of prematurity diagnoses. RESULTS: Agreement between image graders for all vitreoretinal findings was 91% (kappa=0.86 [95% confidence interval, 0.82–0.90], P

Assess epidermolysis bullosa (EB)-related corneal pathology using anterior segment optical coherence tomography (AS-OCT) and correlate imaging with clinical metrics in EB patients versus age-matched controls.EB patients and controls were recruited during an EB conference (July 2018) and at Tufts Medical Center (June-August 2019). Subjects completed a questionnaire, had best corrected visual acuity (BCVA) tested, and underwent AS-OCT scanning. Stromal and epithelial thickness were measured. Depth, length, and type of the three largest lesions were assessed by a masked examiner using a novel pathology grading system. Multivariate analysis of AS-OCT findings and clinical metrics was performed.62 EB patients and 60 age-matched controls were enrolled. Mean BCVA was 1.8 lines worse in patients (p 0.001). Vision loss was associated with increased stromal thickness. Discrete lesions were seen in 60.2% of patient eyes, averaging 1.71 ± 1.75 lesions in patients and 0.14 ± 0.42 in controls (p 0.001). Mean primary lesion depth was 151.88 ± 97.49 μm in patients. Patients showed significant stromal thickening versus controls and lesions were most common in the periphery and inferiorly. Differences in frequency and duration of abrasions and severity of pain were all statistically and clinically significant in patients versus controls (p 0.001).AS-OCT can visualize and quantify differences in the corneas of EB patients compared with age-matched controls. Novel findings include quantification of average depth, length, and severity of discrete lesions, and sparing of the superior quadrant from stromal thickening in EB patients. These results support use of AS-OCT and a questionnaire in clinical trials for new EB therapies.

To investigate anterior scleral canal (ASC) area in the eyes with glaucoma using spectral-domain optical coherence tomography (SDOCT).Cross-sectional study.This study included 206 eyes of 103 patients with glaucoma, classified as 66 eyes of 33 patients with unilateral glaucoma and 140 eyes of 70 patients with bilateral glaucoma. Radial scan enhanced depth imaging SDOCT centered on the optic disc was performed, and parameters that present ASC area such as ASC opening and the largest ASC area were obtained in each eye. The largest ASC area was the largest cross-sectional area of the ASC region identified between the ASC opening and anterior lamina cribrosa insertion. These parameters were compared between eyes with and without glaucoma in unilateral glaucoma, and eyes with worse and better visual field defect (VFD) in bilateral glaucoma.In the patients with unilateral glaucoma, ASC opening and largest ASC area were significantly larger in the eyes with glaucoma than in those without glaucoma (both P.001). In bilateral glaucoma, these parameters were significantly larger in the eyes with worse VFD than in those with better VFD (P = .0080 and P = .0018, respectively). Intereye differences of the ASC parameters in the glaucoma patients were significantly greater than that in the normal subjects.Significantly larger ASC area was first observed in the living human eyes with glaucoma compared to the normal eyes. Further longitudinal studies are required to determine if the ASC area is useful in the prevention and treatment of glaucoma.

Automatic extraction of buildings in remote sensing images is an important but challenging task and finds many applications in different fields such as urban planning, navigation and so on. This paper addresses the problem of buildings extraction in very high-spatial-resolution (VHSR) remote sensing (RS) images, whose spatial resolution is often up to half meters and provides rich information about buildings. Based on the observation that buildings in VHSR-RS images are always more distinguishable in geometry than in texture or spectral domain, this paper proposes a geometric building index (GBI) for accurate building extraction, by computing the geometric saliency from VHSR-RS images. More precisely, given an image, the geometric saliency is derived from a mid-level geometric representations based on meaningful junctions that can locally describe geometrical structures of images. The resulting GBI is finally measured by integrating the derived geometric saliency of buildings. Experiments on three public and commonly used datasets demonstrate that the proposed GBI achieves the state-of-the-art performance and shows impressive generalization capability. Additionally, GBI preserves both the exact position and accurate shape of single buildings compared to existing methods.

Purpose To evaluate whether loss of 5 μm or more in global retinal nerve fiber layer (RNFL) thickness on spectral-domain (SD) between 2 consecutive visits is specific for glaucoma progression. Design Prospective cohort. Participants Ninety-two eyes of 49 control participants and 300 eyes of 210 glaucoma patients. Methods Patients completed at least 5 standard automated perimetry and SD OCT examinations at 6-month intervals over at least 2 years. Eyes were categorized as progressing from glaucoma if the average RNFL declined by 5 μm or more between 2 consecutive visits. The false-positive proportion was estimated by 2 methods: (1) 5-μm or more loss in control participants and (2) 5-μm or more gain in glaucoma. The false-positive proportion was subtracted from the cumulative proportion of eyes categorized with glaucoma progression to estimate the true progression prevalence. Main Outcome Measures False-positive and true progression prevalence of patients with glaucoma detected as progressing on SD OCT. Results After 5 years of semiannual testing, the cumulative proportion of false-positive results based on 5-μm or more RNFL losses between visits was 24.8% in the control participants. Although 40.6% of glaucoma eyes were diagnosed with progression at 5 years, only 15.8% would have been considered to show true progression based on the expected false-positive ratio from the control participants (i.e., 40.6%–24.8%). The cumulative proportion of an intervisit gain of 5 μm or more at 5 years was 27.4% in glaucoma eyes, suggesting that only 13.2% of eyes with glaucoma truly had progressed (i.e., 40.6%–27.4%). Conclusions Loss of 5 μm or more in average RNFL thickness between consecutive SD OCT tests is not specific for glaucoma progression. Application of this intervisit rule of 5 can result in a high cumulative proportion of false-positive results over time, which could lead to unnecessary interventions in patients whose disease is stable. More specific diagnostic criteria are needed to help clinicians determine whether patients with glaucoma are progressing so that therapy escalation is both timely and appropriate.

Purpose To test the hypothesis that the anatomic correlate of the gray optic disc crescent is pigmentation of externally oblique border tissue of Elschnig. Design Retrospective study. Participants African-American adult men with or without clinically apparent gray optic disc crescents. Methods McNemar's test for paired data and kappa statistic with 95% confidence intervals were used to examine the relationships between eyes with or without gray optic disc crescents and corresponding spectral-domain (SD) OCT images with enhanced depth imaging (EDI). Main Outcome Measures Correlation between clinical gray optic disc crescents and hyperreflectivity of externally oblique border tissue of Elschnig by SD OCT with EDI. Results Twenty-five eyes had clinically apparent gray optic disc crescents, of which SD OCT with EDI revealed hyperreflectivity (interpreted as increased pigmentation) of externally oblique (obtuse angle) border tissue of Elschnig in 22 eyes, that is, extending into Bruch's membrane opening and presumably visible by funduscopy. Thirty-two eyes from matched participants had no apparent gray optic disc crescent, of which SD OCT with EDI revealed hyperreflectivity of the border tissue of Elschnig in 23 eyes, but with a nonoblique (right angle) or internal (acute angle) angle, which would presumably obstruct funduscopic visualization. Conclusions Observations by SD OCT with EDI suggest that the anatomic correlate of the gray optic disc crescent is pigmentation of externally oblique border tissue of Elschnig.

Objective The aim of this in vitro study was to evaluate the ability of optical coherence tomography (OCT) to display calculus on root surfaces. Material and methods Ten teeth with calculus on the root surface were embedded in resin, omitting the root surface. A region of interest (ROI) was marked by small drill holes coronally and apically of the calculus and imaged by spectral-domain optical coherence tomography ([SD OCT], Telesto SP5, centre wavelength 1310 nm) and light microscopy (LM). To evaluate the impact of different fluids on calculus visualisation, using OCT, root surfaces were covered by a layer of NaCl and blood and displayed by OCT. Subsequently, teeth were completely covered with resin and sectioned for histological evaluation. Within the ROI, lengths of root surface and calculus were measured by LM and OCT, and the ratio [%] was calculated. In addition, at three sites of each ROI, agreement of presence and length of calculus was evaluated. Both methods were compared using Pearson’s correlation. Results Regarding the presence of calculus, agreement between LM and OCT was strong (κi = 0.783, p = 0.033), and measurements regarding the length of the calculus were strongly correlated (ri >0.906; pi Conclusion Calculus on the root surface can be displayed by SD-OCT, which therefore may be suited as imaging technology for subgingival calculus in periodontal pockets.

Spectral Domain Optical Coherence Tomography (SD-OCT) with 1300 nm wavelength is employed to detect three-dimensional (3-D) volumetric structure, surficial characteristic and thickness of oil slicks on water surface. The results show that petroleum slick possesses bigger diffusion area but much thinner than diesel slick at the same volume on water. Through reconstructing the thickness of oil slick by single-pixel optical intensity of SD-OCT structure image, the axial depth accuracies of reconstructed dataset image with 2.2 μm in petroleum slick and 2.6 μm in diesel slick were obtained, respectively. To our knowledge, it is the first time to obtain 3-D structure and surficial characteristic of oil slick on water by using SD-OCT imaging, and employing single-pixel optical intensity for reconstructing the thickness of oil slick with higher accuracy.

Purpose To investigate optic disc margin anatomic features in myopic eyes with open-angle glaucoma (OAG) using spectral-domain (SD) OCT. Design Cross-sectional study. Participants Two hundred four eyes of 102 participants with OAG and 106 eyes of 53 participants without glaucoma with axial length of 24 mm or more. Methods Radial SD OCT B-scans centered on the optic discs were acquired in each eye, and the SD OCT data were colocalized with the optic disc stereophotographs. Optic disc margin anatomic features were evaluated as (1) SD OCT structure coinciding with the disc margin identified in the stereophotograph, (2) border tissue configuration, and (3) presence of Bruch’s membrane overhang, and their frequency was computed in each clock-hour position. Further, paired eyes of myopic participants with OAG were divided into eyes with better or worse visual field defect (VFD), according to the mean deviation of the Humphrey visual field test, and associated factors were compared. Main Outcome Measures Spectral-domain OCT structures coinciding with the visible optic disc margin in stereophotographs. Results In myopic eyes with OAG, mean axial length was 25.96±1.07 mm and mean deviation was –8.87±7.78 dB. In approximately 90% of the participants, anterior scleral opening (ASO) coincided with the temporal disc margin and Bruch’s membrane opening (BMO) with the nasal disc margin. Border tissue configuration was externally oblique in the temporal region and internally oblique in the nasal region of the optic disc. Bruch’s membrane overhang was observed in a relatively small percentage of eyes. The same pattern of disc margin anatomic features was observed in the myopic eyes without glaucoma. The myopic optic disc was shaped by the temporal shifting of the BMO from the ASO, and the extent of shifting was expressed as the width of γ zone parapapillary atrophy (PPA). The greater γ zone PPA width was associated significantly with the worse VFD between paired eyes. Conclusions The myopic eyes with OAG exhibited characteristic optic disc margin anatomic features that was considered to be derived from myopic deformation of the eye. The greater γ zone PPA width may increase susceptibility to the glaucomatous stress.

OBJECTIVE(S) To evaluate the potential of spectral domain optical coherence tomography (SD-OCT) as a tool for detecting subgingival cervical lesions and to characterize 2 different types of cervical lesions—noncarious cervical lesion (NCCL) and root caries lesion (RC)—based on tissue properties using signal intensity (SI). STUDY DESIGN A total of 30 human extracted teeth were collected: teeth with no cervical lesion (n = 10), RC (n = 10), and NCCL (n = 10). Micro-CT imaging was performed as the gold standard to confirm the status of the teeth in each group. In order to examine the efficacy of SD-OCT in the detection of subgingival lesions, a thin layer (0.5 mm) of dental baseplate wax was used as simulated gingival tissue to cover the cervical region, where NCCL or RC is present. Teeth were then mounted on custom-made cylindrical blocks made of vinyl polysiloxane with the buccal surface facing toward the SD-OCT probe. The probe was set at a fixed distance from the specimen with the scanning beam oriented perpendicular to the root surfaces. Cross-sectional images were obtained along the long axis of the teeth. SI of the root surfaces was used to quantitatively characterize the root surface changes among the 3 study groups. Morphologic profiles of the root surface in RC and NCCL were also examined. RESULTS The pilot study showed that the presence of the simulated gingiva reduced the clarity of the cross-sectional images only marginally; SI profiles of the root surfaces in all 3 groups did not change significantly in the presence of simulated gingiva compared with no gingiva. In addition, SI and morphologic profiles of the root surfaces among the 3 groups were statistically different. DISCUSSION/CONCLUSIONS The result suggests that SD-OCT can be used to detect subgingival RC and further distinguish between RC and NCCL based on SI and morphologic profiles.

Aims Pilot study to determine whether an instrument combining a non-mydriatic retinal camera and spectral domain optical coherence tomography (SD-OCT) is effective for screening patients with diabetic retinopathy (DR). Methods Case series conducted between 2012 and 2013. DR imaged with a retinal camera/SD-OCT instrument viewed remotely was compared to a dilated examination by a retina specialist. Results The combination instrument was better than the retina specialist in detecting more severe retinopathy, primarily because of the SD-OCT. For severe retinopathy (grade ≥ 3), the image grader had better sensitivity (87.3% [95% CI: 75.5%, 94.7%]) than the retina examiner (76.4% [95% CI: 63.0%, 86.8%]). Specificities were similar between the instrument grader (96.0% [95% CI: 86.3%, 99.5%]) and retina examiner (100.0% [95% CI: 92.9%, 100.0%]). When identifying diabetic macular edema (ME), the retina examiner only identified 47.6% (20/42) of eyes with ME detected by SD-OCT. The instrument was better than a dilated retinal examination in detecting ME and not as good at detecting mild or proliferative retinopathy. Conclusions As used in this study, the instrument was more effective in identifying DR than was the current recommendation of a dilated and comprehensive eye examination. SD-OCT is needed to accurately identify DR in a screening setting.

Purpose To develop a new scoring system that uses topographic diagnostic signs of spectral-domain (SD) OCT to enhance glaucoma diagnostic performance for myopic eyes and to validate the system’s diagnostic ability. Design Cross-sectional study. Participants A total of 517 patients (517 eyes; spherical equivalent [SE] 24.0 mm), including 175 highly myopic eyes (SE 26.0 mm), were recruited and divided into 2, training (241 eyes) and validation (276 eyes) test sets. Methods Retinal nerve fiber layer (RNFL) and ganglion cell–inner plexiform layer (GCIPL) topographic signs were selected based on the morphologic patterns of RNFL (size, shape, location, and agreement between deviation and thickness maps) and GCIPL (size, shape, location, color tone, agreement between maps, and step sign) abnormalities indicative of higher likelihood of myopic glaucoma on deviation and thickness maps. The diagnostic score was compiled according to the sensitivity, specificity, and positive likelihood ratio (PLR) of each diagnostic sign using the training set. The area under the receiver operating characteristic curve (AUC) was plotted and compared between the OCT-provided parameters and the scoring system in the validation set. Main Outcome Measures The diagnostic performance of a new scoring system as validated by AUC. Results Among all of the RNFL and GCIPL parameters, the presence of temporal hemifield asymmetry on the GCIPL thickness map (PLR, 5.98) showed the highest diagnostic ability, followed by location of the RNFL defect (PLR, 5.79) and color tone of the GCIPL defect (PLR, 5.04). The AUC of the topographic scoring system in myopic eyes was 0.979, which was significantly higher than those of the inferior (0.895; P Conclusions Our scoring system including OCT topographic parameters demonstrated to be beneficial for clinicians to differentiate real glaucomatous damage from myopic healthy eyes. Our results support the value of using multitopographic OCT parameters for detecting glaucoma in myopic eyes.

Purpose To review the current published literature on the use of spectral domain (SD) OCT to help detect changes associated with the diagnosis of glaucoma. Methods Searches of the peer-reviewed literature were conducted on June 11, 2014, November 7, 2016, August 8, 2017, and April 19, 2018, in the PubMed and Cochrane Library databases and included only articles published since the last glaucoma imaging Ophthalmic Technology Assessment, which included articles up until February 2006. The abstracts of these 708 articles were examined to exclude reviews and non-English articles. After inclusion and exclusion criteria were applied, 74 articles were selected, and the panel methodologist (K.N.-M.) assigned ratings to them according to the level of evidence. Two articles were rated level I, 57 articles were rated level II, and the 15 level III articles were excluded. Results Spectral-domain OCT is capable of detecting damage to the retinal nerve fiber layer (RNFL), macula, and optic nerve in patients with preperimetric and perimetric glaucoma (level I and II evidence). The most commonly studied single parameter was RNFL thickness. Of note, RNFL thickness measurements are not interchangeable between instruments. Various commercially available SD OCT instruments have similar abilities to distinguish patients with known glaucoma from normal subjects. Despite different software protocols, all SD OCT instruments are able to detect the same typical pattern of glaucomatous RNFL loss that affects primarily the inferior, inferior temporal, superior, and superior temporal regions of the optic nerve (level II evidence). Across many SD OCT instruments, macular imaging also can detect a preferential inferior, inferior temporal, and superior temporal thinning in patients with glaucoma compared with controls. Best disc parameters for detecting glaucomatous nerve damage are global rim area, inferior rim area, and vertical cup-to-disc ratio. Studies suggest that newer reference-plane independent optic nerve parameters may have the same or better detection capability when compared with older reference-plane dependent disc parameters (level II evidence). Conclusions Structural glaucomatous damage can be detected by SD OCT. Optic nerve, RNFL, and macular parameters can help the clinician distinguish the anatomic changes that are associated with patients with glaucoma when compared with normal subjects.

Purpose Bedside examination of premature infants at risk for retinopathy of prematurity (ROP) is performed predominantly with ophthalmoscopic en face viewing of the retina. Although postmortem retinal microstructures have been studied at the vascular–avascular junction, a critical location for pathogenesis of ROP, to date this has not been possible in vivo. Herein we present bedside, nonsedated in vivo cross-sectional imaging and analysis of retinal microstructures at the vascular–avascular junction in infants with ROP using handheld spectral-domain (SD) OCT. Design Prospective observational study. Participants Eleven preterm infants whose parents or guardians gave consent for research imaging during ROP screening examinations. Methods We imaged the vascular–avascular junction in the temporal retina using an SD OCT system (Envisu; Bioptigen, Inc., Research Triangle Park, NC) in 18 eyes from 11 preterm infants with zone I or II and stage 0 through 4 ROP. B-scan and en face images were analyzed and compared with historical light micrographs. Main Outcome Measures Spectral-domain OCT morphologic features at the vascular–avascular junction. Results Multiple bedside SD OCT findings at the vascular–avascular junction were comparable with historic light micrographs. Thickened inner retinal ridge structure in stage 2 ROP was comparable with thickened vanguard and rear guard cells visible on micrographs; vascular tufts on the posterior retinal surface in stage 2 ROP, broad arcs of neovascularization above the retina in stage 3 ROP, and splitting of inner retinal layers into clefts on either side of neovascularization mimicked findings on historic light micrographs. A unique finding was thickening of the avascular inner retinal band adjacent to neovascularization. On SD OCT imaging over several weeks, neovascularization and retinal clefts diminished after intravitreal bevacizumab therapy. Conclusions Retinal morphologic features at the vascular–avascular junction imaged with handheld SD OCT are consistent with known histopathologic features and provide the advantage of monitoring change in vivo over time. These unique findings provide new insights into preterm retinal neurovascular development in ROP.

Objective To report reference values for the horizontal rectus muscles thickness using Spectral Domain optical coherence tomography (SD-OCT), and to evaluate whether there are any correlations between the muscle thickness and gender, age, or axial length (AL). Materials and methods A cross-sectional study was conducted on 131 right eyes of healthy subjects. The gender and age were recorded, and axial length was measured using an optical biometer. The medial rectus (MR) muscle thickness was measured at 7.2 and 9.2 mm from the limbus, and the lateral rectus (LR) at 8.5 and 10.5 mm from the limbus using OCT. A multivariate model was adjusted to determine whether gender, age, and axial length could have an impact on the muscle thickness. Results Mean age was 43.3 ± 20.9 years (range 6–86), and 59% were women. Mean AL was 24.9 ± 2.7 mm (range: 20.4–33.8). Mean thickness was 188.5 ± 51.2 μm (range 69–342) for the LR at 8.5 and 186.5 ± 45.9 μm (range 75–269) at 10.5 mm, and for the MR, 158.1 ± 39.1 μm (range 69–273) at 7.2 mm and 193.7 ± 55.9 μm (range 105–386) at 9.2 mm. A correlation was observed between the AL and MR thickness (R = −0.255; p = 0.023) while no correlation was observed for the LR (p ≥ 0.203). No correlations were found between thickness and gender or thickness and age (p ≥ 0.125). Conclusions The reference ranges of the horizontal rectus muscles thickness was described using SD-OCT, observing an association between the AL and the MR thickness.

Purpose Retinal hemorrhages are observed frequently in patients with leukemia. However, little is known about the impact and natural history of these hemorrhages. The purpose of this study was to describe leukemic retinal hemorrhages using multimodal imaging and to monitor their evolution longitudinally. Design Retrospective case series. Participants A total of 11 eyes of 7 symptomatic leukemic patients with posterior segment hemorrhages. Methods Single-center study performed at the Johns Hopkins Hospital. Symptomatic leukemic patients with posterior segment hemorrhages underwent serial dilated fundus examinations. The hemorrhages were documented longitudinally with color fundus photographs and spectral-domain (SD) OCT. Main Outcomes Measures Microanatomic locations of leukemic retinal hemorrhages and their impact on vision and evolution over time. Results A total of 7 patients (71.4% men; 57.1% white, 28.6% black, and 14.3% Hispanic) were included, with 11 eyes showing posterior segment hemorrhages. The median age at presentation was 49.8 years. All patients had intraretinal hemorrhages; these involved the vitreous and sub–internal limiting membrane (ILM) space in 1 and 3 patients, respectively. The median total follow-up duration was 4.0 months. At the final follow-up visits, 4 of 6 patients showed complete resolution of hemorrhages on examination and color fundus photographs. The final SD-OCT images of all patients did not show any retinal thinning, disruption of the ellipsoid zone, disorganization of the retinal layers, intraretinal fluid, or subretinal fluid. Conclusions Symptomatic leukemic retinal hemorrhages are associated with anemia and thrombocytopenia. These hemorrhages, including visually significant central sub-ILM hemorrhages, tend to be self-limiting and resolve within a few months with treatment of the underlying disease.

Summary Purpose To assess the value of a monthly injection of Lucentis® until stable visual acuity (VA) is obtained for three consecutive months without exudation in patients with neovascular age macular degeneration (AMD). Methods Prospective, single-center, non-controlled trial including naive AMD patients with neovascularization. An assessment of VA and a spectral domain optical coherence tomography (SD-OCT) were performed at baseline and every month. Monthly injections of Lucentis® were performed over three months. The monthly injections were then continued until three consecutive stable VA results were obtained with no signs of exudation. Results Fifteen out of the 21 patients included were anatomically good responders. A mean gain of +14Le (9) was obtained up to the point at which there was no exudation. There was no additional gain from this point until 3 consecutive stable VA results were obtained. During the PRN phase, an additional mean gain of +3.2Le (7.7) was obtained. Conclusion This initial VA-guided regimen with ranibizumab might prevent the slight decrease in VA observed during the first year of PRN studies.

Purpose To report a deviation in the position of the foveal bulge (FB) from the foveal center and to analyze its relationship with the foveal shape in normal subjects using spectral-domain (SD) OCT. Design Cross-sectional study. Participants A total of 146 clinically normal subjects. Methods Macular Cube 512 × 128 was used to obtain the cross-sectional images of the macula in Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). The foveal center was identified manually as the deepest point within the foveal dip, which was termed the “manually identified foveal center” (MFC). The position of the FB with respect to the MFC was noted, and the radial distance between them was measured. The foveal center detected by the inbuilt auto-fovea finder algorithm was considered as the automatically detected foveal center (AFC), and the distance between the AFC and the FB was measured. The radial distances of the FB from the MFC and the AFC were compared, and its direction of deviation from the foveal center was noted. All OCT measurements were adjusted for the ocular magnification factor. The amount of deviation was correlated with the foveal shape parameters, such as foveal radius. Main Outcome Measures Radial distance between FB and foveal center and its direction of deviation. Results Mean age of the subjects was 43.9±14.4 years. The position of the FB was deviated from the foveal center in 125 subjects (85.6%). Median radial distance between the FB and the MFC was 58.6 μm (35.16–75.04 μm) with the maximum separation of 222.68 μm. From the AFC, the FB was separated by a median of 58.6 μm (46.88–84.51 μm), maximum separation being 181.94 μm. The direction of deviation of the FB from foveal center was nasal in a majority of subjects (n = 75, 51% in MFC). The separation between the FB and the foveal center was not associated with age (P = 0.149), gender (P = 0.762), or axial length (P = 0.25). Conclusions The position of the FB did not coincide with the foveal center and was deviated in the direction of the optic disc in a majority of normal subjects. Further studies are required to correlate this anatomic deviation with the fixation locus of the individuals.

Everolimus is an inhibitor of the mammalian target of rapamycin (mTOR) that has been approved by the US Food and Drug Administration for the treatment of subependymal giant cell astrocytoma (SEGA) in patients with tuberous sclerosis complex (TSC). Retinal hamartomas, which are one of the major diagnostic features of TSC, tend to remain stable or gradually progress in the natural history of the disease. We report 2 patients with TSC treated with everolimus for SEGA in whom fundus photographs and spectral domain optical coherence tomography demonstrated regression of previously documented multiple retinal hamartomas in all 4 eyes.

In this paper, we introduce a novel time-averaged sampling method that can be used in a low-cost, camera-based, line-field, spectral domain optical coherence tomography (SD-OCT) device. We demonstrate that when used with an automated subtraction and magnitude based averaging scheme that is analogous to lock-in detection, this method can enhance the usually poor dynamic range and SNR. The technique is unique as it effectively eliminates arbitrarily located, arbitrarily strong autocorrelation artifacts, and is robust against blemishes in the camera or the reference mirror. We show through experiment, theory and simulations that a judicious choice of the Fourier transform window function, and one of the two proposed variants of the averaging scheme can enhance the final image. B-scan images of a variety of samples, and facile 3D tomograms, acquired with a device built from off-the-shelf components, demonstrate the potential of making OCT devices for niche applications, at much reduced costs.

Anthracnose and gray mold are two most devastating diseases of strawberries which can spread to healthy plants in short time and can cause large-scale yield losses worldwide. However, early identification of anthracnose and gray mold in strawberries is challenging due to that they rise fast and their course is short. Early identification of anthracnose and gray mold in strawberries is of great significance for managing strawberry production, achieving precise target spraying, avoiding the large-scale spread of disease as well as improving the yield and quality of strawberries. In this study, six machine learning-aided methods were developed based on the selected spectral fingerprint features for early identification of anthracnose and gray mold in strawberries using a hyperspectral imaging system. First, infection strawberry leaf dataset was artificially prepared by an expert, and the hyperspectral images (during the spectrum range of 400–1000 nm) of heathy, anthracnose-infected and gray-mold-infected leaves (149 of each type), and fungus-infected leaves respectively had three stages of infection (24 h:43; 48 h:47; 72 h:59). Second, the full spectra of ROI were extracted, and chemometric methods in spectral domain were used to explore the spectral fingerprint features for early identification of anthracnose and gray mold with machine learning. Third, six classification models for identification of anthracnose and gray mold in strawberries were developed, and the classification performance were evaluated and compared. For early detection of anthracnose and gray mold in strawberries, most classification models obtain relatively good accuracy (100%) and robust performance, recognizing the asymptomatic fungus infections classes before the obvious signs of disease appear notably in the strawberry. This study provides a foundational basis for the development of the rapid online inspection as well as the real-time monitoring system for field plant disease detection.

Conjunctival infestation of ticks is not a common event, even in endemic regions. We presented a case of conjunctival tick attachment treatment guided by spectral domain optical coherence tomography (SD-OCT). This patient experienced a two-day history of pain, itching and redness in the right eye. Anterior segment examination revealed a tick body in the lower bulbar conjunctiva. No invasion of the sclera was confirmed with anterior segment SD-OCT. Tick was removed with conjunctival excision. We would like to state that the use of SD-OCT can be useful in clinical practice for safe and complete removal of conjunctival ticks.

PURPOSE: We aimed to show the changes in choroidal thickness (CT) with spectral domain optical coherence tomography (SD-OCT) after prolonged use of N95 mask. METHOD: The healthcare workers who use the N95 face-mask, between 30-50 years of age who have best corrected visual acuity (BCVA) ≥10/10, spherical or cylindrical refraction errors less than 2 diopters, with normal intra ocular pressure (IOP), axial length (AL) between 22-24 mm included in the study. The choroid was imaged with enhanced depth imaging (EDI) techniques using SD-OCT. CT was measured, subfoveal, at 1000 µm nasal and temporal of the center of the fovea. Measurements were first made after wearing the N95 mask for at least 2 h without removing it and repeated 15 min after removing. RESULTS: After 2 h of the N95 mask using without removal, the mean subfoveal CT was 293.56 ± 76.12(min:185, max:479), the mean temporal CT was 253.81 ± 63.48(min:172, max:384), the mean nasal CT was 239.18 ± 53.92(min:139, max:356). Fifteen minutes after removal of the N95 mask, the mean subfoveal CT was 250.56 ± 52.48(min:172, max:397), the mean temporal was 218.40 ± 53.58(min:129, max:354), the mean nasal CT was 210.67 ± 53.31(min:132, max:366). The differences in subfoveal, temporal and nasal CT between 2 h of N95 mask use and 15 min after removal of the mask were statistically significant (p < 0.05 for each). CONCLUSION: Hypercapnia due to prolonged use of the N95 mask may cause choroidal hemodynamic changes and transient increased choroidal thickness.

We demonstrate a simple polarization-sensitive spectral-domain optical coherence tomography implement by using a single line-scan camera based on time divided detection. Two light shutters were placed on the dual assembly reference arm that provides a divided detection between the orthogonal vertical and horizontal polarized lights. The relative reflectivity and the retardance information were available by recombining the two orthogonal polarization images. This system can be employed to implement high speed polarization-sensitive OCT images.

Presbyacusis reflects dysfunctions present along the central auditory pathway. Given that the topographic representation of the auditory directional spatial map is deteriorated in the superior colliculus of aged animals, therefore, are spectral and temporal auditory processes altered with aging in the rat's superior colliculus? Extracellular single-unit recordings were conducted in the superior colliculus of anesthetized Sprague-Dawley adult (10 months) and aged (22 months) rats. In the spectral domain, level thresholds in aged rats were significantly increased when superior colliculus auditory neurons were stimulated with pure tones or Gaussian noise bursts. The sharpness of the frequency response tuning curve at 10 dB SPL above threshold was also significantly broader among the aged rats. Furthermore, in the temporal domain, the minimal silent gap thresholds to Gaussian noises were significantly longer in aged rats. Hence, these results highlight that spectral and temporal auditory processing in the superior colliculus are impaired during aging.

In recent years many optoelectronic techniques have been developed for improvement and the development of devices for tissue analysis. Spectral-Domain Optical Coherence Tomography (SD-OCT) is a new medical interferometric imaging modality that provides depth resolved tissue structure information with resolution in the μm range. However, SD-OCT has its own limitations and cannot offer the biochemical information of the tissue. These data can be obtained with hyperspectral imaging, a non-invasive, sensitive and real time technique. In the present study we have combined Spectral-Domain Optical Coherence Tomography (SD-OCT) with Hyperspectral imaging (HSI) for tissue analysis. The Spectral-Domain Optical Coherence Tomography (SD-OCT) and Hyperspectral imaging (HSI) are two methods that have demonstrated significant potential in this context. Preliminary results using different tissue have highlighted the capabilities of this technique of combinations.

Objective To describe optical coherence tomography angiography (OCTA) reflectance artifacts secondary to retinal pigment epithelial detachment (RPED). Design Retrospective review. Methods Four eyes from 4 subjects were included. Three presented with RPED and 1 eye was a normal control. Two eyes diagnosed with RPED and the normal eye were evaluated using en face OCTA centred at the fovea acquired using the RTVue XR Avanti (Optovue Inc). In the third eye with RPED, OCTA imaging was performed using a CIRRUS 5000 prototype modified to do OCTA imaging on a spectral domain OCT platform provided by Carl Zeiss Meditec, Inc. The segmented OCTA angiograms were overlaid to determine if the flow patterns seen at the edge of the RPEDs were due to reflectance from the inner retinal vessels, also known as “decorrelation tails.” Results OCTA projection artifacts were noted when segmentation lines intersected with the boundary of the RPED. The overlaid segmented OCTA from the 3 RPED eyes imaged using each system revealed the same vasculature pattern at the edges of the RPED as that of the inner retina, demonstrating the “decorrelation tails” artifact, which caused the RPED to appear as a bright ring on the segmented OCTA. Conclusions OCTA images are susceptible to various known artifacts. This series describes the impact of the projection artifact seen at the edges of an RPED that simulates appearance of flow but is actually due to reflectance of the inner retinal vasculature on the RPED.

Purpose To determine the sensitivity and specificity of OCT angiography (OCTA) in the detection of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). Design Prospective case series. Subjects A prospective series of 72 eyes were studied, which included eyes with treatment-naive CNV due to AMD, non-neovascular AMD, and normal controls. Methods All eyes underwent OCTA with a spectral domain OCT. The 3-dimensional angiogram was segmented into separate en face views including the inner retinal angiogram, outer retinal angiogram, and choriocapillaris angiogram. Detection of abnormal flow in the outer retina served as candidate CNV with OCTA. Masked graders reviewed structural OCT alone, en face OCTA alone, and en face OCTA combined with cross-sectional OCTA for the presence of CNV. Main Outcome Measure The sensitivity and specificity of CNV detection compared to the gold standard of fluorescein angiography and OCT was determined for structural spectral domain OCT alone, en face OCTA alone, and with en face OCTA combined with cross-sectional OCTA. Results Of 32 eyes with CNV, both graders identified 26 true positives with en face OCTA alone, resulting in a sensitivity of 81.3%. Four of the 6 false negatives had large subretinal hemorrhage and sensitivity improved to 94% for both graders if eyes with subretinal hemorrhage were excluded. The addition of cross-sectional OCTA along with en face OCTA improved the sensitivity to 100% for both graders. Structural OCT alone also had a sensitivity of 100%. The specificity of en face OCTA alone was 92.5% for grader A and 97.5% for grader B. The specificity of structural OCT alone was 97.5% for grader A and 85% for grader B. Cross-sectional OCTA combined with en face OCTA had a specificity of 97.5% for grader A and 100% for grader B. Conclusions Sensitivity and specificity for CNV detection with en face OCTA combined with cross-sectional OCTA approaches that of the gold standard of fluorescein angiography with OCT, and it is better than en face OCTA alone. Structural OCT alone has excellent sensitivity for CNV detection. False positives from structural OCT can be mitigated with the addition of flow information with OCTA.

Purpose To describe the appearance of the superficial and deep retinal capillary plexi in three patients with fovea plana of differing severity using spectral-domain optical coherence tomography angiography (OCTA). Observations In the first case of grade 1 fovea plana (a patient with 20/25 vision), OCTA showed an orderly branching pattern of vessels from the superficial and deep retinal plexi extending to the center of the fovea. The second case of grade 3 fovea plana (20/30 vision) showed some disruption of the orderly vascular pattern with small caliber vessels from both superficial and deep layers densely covering the fovea center. Case 3 represented a patient with grade 4 fovea plana associated with PAX6 mutation and poor visual acuity. OCTA revealed a disorganized pattern of large and small caliber vessels from the superficial capillary network extending into the center of the fovea. Conclusions and importance Previously available imaging modalities were unable to specifically target different layers of the retinal vasculature. Using OCTA we have been able to show progressive changes in the vascular pattern in the deep and superficial retinal layers of patients with different grades of fovea plana. This novel imaging technique may play a role in the classification and assessment of patients with fovea plana.

Objective To evaluate the agreement, reproducibility, and repeatability of 2 spectral domain optical coherence tomography (SD-OCT) devices in Schwalbe's line (SL)–based anterior chamber angle parameters. Methods The inferior anterior chamber angle of 65 eyes from 65 participants (33 right eyes and 32 left eyes) were scanned twice with the Nidek RS 3000 Advanced SD-OCT and Cirrus SD-OCT. SL angle opening distance (SL-AOD) and SL trabecular-iris-space area (SL-TISA) were graded by masked certified graders at the Doheny Image Reading Center. Results The mean SL-AOD/SL-TISA was 617.3 ± 237.9 µm/0.211 ± 0.086 mm 2 for the Cirrus and 633.7 ± 219.3 µm/0.218 ± 0.080 mm 2 for the Nidek RS 3000 Advanced SD-OCT. The repeatability (intraclass correlation coefficients [ICCs] >0.936) and intergrader reproducibility (ICCs >0.915) in SL-AOD and SL-TISA with Cirrus OCT were excellent. The repeatability (ICCs >0.948) and intergrader reproducibility (ICCs >0.709) in SL-AOD and SL-TISA with the Nidek RS 3000 Advanced SD-OCT were moderate to good. Moderate agreement between the 2 devices was also documented with a mean difference of −15.3 (limits of agreement [LoA] −246.5 to 277.1) mm for SL-AOD and 0.006 (LoA −0.096 to 0.108) mm in SL-TISA. Conclusion Both devices were able to provide consistent angle measurements, but repeatability and reproducibility were better in Cirrus SD-OCT than in Nidek RS 3000 Advanced SD-OCT.

Objective To compare idiopathic full-thickness macular hole (FTMH) closure rates and postoperative best-corrected visual acuity (BCVA) between spectral domain optical coherence tomography (SD-OCT)–guided facedown posturing and conventional 1-week facedown posturing after macular hole surgery. Design A retrospective comparative study. Participants Thirty-one consecutive eyes that underwent surgery for FTMH between July 2013 and September 2014 were divided into 2 groups. Methods In the SD-OCT-guided group, SD-OCT was performed on the first day after surgery. If the macular hole was closed, the patient could assume any position but supine. If the hole was not closed on postoperative day 1, SD-OCT was performed daily for 1 week until the hole was closed, at which point the patient was asked to stop positioning. For the control group, patients were asked to keep facedown posturing for 1 week after surgery. Results Mean length of follow-up for the SD-OCT-guided group and the control group was 188.3 (SD = 74.6) days and 216.7 (SD = 71.2) days, respectively. FTMH closure rate was 100% for both groups. Mean time for FTMH closure in the SD-OCT group was 1.2 days. There was no statistical difference in postoperative BCVA at the last visit between SD-OCT-guided (0.49 ± 0.3 logMAR) and control (0.50 ± 0.4 logMAR; p = 0.9422) groups. Conclusions No difference in FTMH closure rates was detected between the SD-OCT-guided facedown posturing group and the control group. SD-OCT-guided posturing may be used to shorten facedown positioning while maintaining a high success rate.

Objective To assess the agreement between intraoperative measurements of the limbus-insertion distance of the extraocular muscles with those measured by spectral domain optical coherence tomography. Methods An analysis was made of a total of 67 muscles of 21 patients with strabismus. The limbus-insertion distance of the horizontal rectus muscles were measured using pre-operative SD-OCT and intra-operatively in 2 ways: (1) direct, after a conjunctival dissection in patients who underwent surgery, or (2) transconjunctival in patients who were treated with botulinum toxin, or in those who were not going to be operated. The intraclass correlation coefficient and Bland–Altman plots were calculated to determine the concordance between the 2 methods. Results The mean age was 45.9 ± 20.9 years (range 16 to 85), with 52% being women. The percentage of identification by direct intraoperative measurement was 95.6% (22/23), by transconjunctival intraoperative measurement 90.9% (40/44), and by OCT 85% (57/67), with 22 muscles finally being analyzed for the agreement study between direct intraoperative measurement and OCT measurements, and 35 muscles for the agreement between transconjuctival intraoperative measurement and OCT. The intraclass correlation coefficient showed good agreement with OCT and direct intraoperative measurements (0.931; 95% confidence interval (95% CI): 0.839–0.972; P

Ixodidae tick, also known as a hard tick, is one of the major vectors of various tick-borne diseases. Studying its anatomy is the fundamental approach for diverse acarological studies and the key to understanding tick morphology. However, the conventional methods of observing internal organs rely primarily on dissection, which damages specimens irrecoverably. In this study, we developed an optical coherence tomography (OCT) system to non-invasively investigate the morphological characteristics of the hard tick. Herein, OCT imaging was conducted by the developed spectral-domain OCT (SD-OCT) system with two different objective lenses. The developed system provides an axial resolution (in the air) of 6.2 µm and a maximum lateral resolution of 2.46 µm as an objective lens with a high numerical aperture (NA) and 10× magnification was employed. Using the developed SD-OCT system, internal organs of tick specimens, such as salivary glands, midgut, genital orifice, and ovary, were identified without inflicting damage. The study suggests the feasibility of the optical coherence imaging for the acarological study of the fundamental morphological inspection and for possible future studies, such as verifying the potential morphological differences among virus transmitted hard tick specimens.