scholarly journals Automated measurement of iris surface smoothness using anterior segment optical coherence tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Zarei ◽  
Tahereh Mahmoudi ◽  
Hamid Riazi-Esfahani ◽  
Behnam Mousavi ◽  
Nazanin Ebrahimiadib ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Correlation Coefficient ◽  
Anterior Segment ◽  
Control Group ◽  
Optical Coherence ◽  
Actual Length ◽  
Interclass Correlation Coefficient ◽  
Interclass Correlation ◽  
Automated Measurements ◽  
Fellow Eyes

AbstractFuchs uveitis (FU) is a chronic and often unilateral ocular inflammation and characteristic iris atrophic changes, other than heterochromia, are common in FU and are key to the correct diagnosis in many cases. With the advent of anterior segment optical coherence tomography (AS-OCT), some investigators attempted to quantitatively study these atrophic changes; mostly by introducing various methods to measure iris thickness in AS-OCT images. We aimed to present an automated method in an observational case series to measure the smoothness index (SI) of the iris surface in AS-OCT images. The ratio of the length of the straight line connecting the most peripheral and central points of the anterior iris border (in nasal and temporal sides) to the actual length of this border on AS-OCT images, was defined as SI. In a uveitis referral center, twenty-two eyes of 11 patients with unilateral Fuchs uveitis (FU) (7 female) and 22 eyes of 11 healthy control subjects underwent AS-OCT imaging. Image J and a newly developed MATLAB algorithm were used for manual and automated SI measurements, respectively. Agreement between manual and automated measurements was evaluated with Bland–Altman analysis and interclass correlation coefficient. The inter-eye difference of SI was compared between the FU group and the control group. Automated mean overall SI was 0.868 ± 0.037 and 0.840 ± 0.039 in FU and healthy fellow eyes, respectively (estimated mean difference =  − 0.028, 95% CI [− 0.038, − 0.018], p < 0.001). Bland- Altman plots showed good agreement between two methods in both healthy and FU eyes. The interclass correlation coefficient between the manual and automated measurements in the FU and healthy fellow eyes was 0.958 and 0.964, respectively. The inter-eye difference of overall SI was 0.029 ± 0.015 and 0.012 ± 0.008 in FU group and control group, respectively (p = 0.01). We concluded that the automated algorithm can rapidly and conveniently measure SI with results comparable to the manual method.

scholarly journals Automated Measurement of Iris Surface Smoothness Using Anterior Segment Optical Coherence Tomography  

2021 ◽  
Author(s):  
Mohammad Zarei ◽  
Tahereh Mahmudi ◽  
Hamid Riazi-Esfahani ◽  
Behnam Mousavi ◽  
Nazanin Ebrahimiadib ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Correlation Coefficient ◽  
Anterior Segment ◽  
Control Group ◽  
Optical Coherence ◽  
Interclass Correlation Coefficient ◽  
Interclass Correlation ◽  
Automated Measurements ◽  
And Control ◽  
Fellow Eyes

Abstract Fuchs uveitis (FU) is a chronic and often unilateral ocular inflammation and characteristic iris atrophic changes, other than heterochromia, are common in FU and are key to the correct diagnosis in many cases. With the advent of anterior segment optical coherence tomography (AS-OCT), some investigators attempted to quantitatively study these atrophic changes; mostly by introducing various methods to measure iris thickness in AS-OCT images. We aimed to present an automated method in a observational case series to measure the smoothness index (SI) of iris surface in AS-OCT images. The ratio of the length of the straight line connecting the most peripheral and central points of the anterior iris border (in nasal and temporal sides) to the actual length of this border on AS-OCT images, was defined as SI. In a uveitis referral center twenty-two eyes of 11 patients with unilateral Fuchs uveitis (FU) (7 female) and 22 eyes of 11 healthy control subjects underwent AS-OCT imaging. Image J and a newly developed MATLAB algorithm were used for manual and automated SI measurements, respectively. Agreement between manual and automated measurements was evaluated with Bland-Altman analysis and interclass correlation coefficient. The inter-eye difference of SI was compared between FU group and control group. Automated mean overall SI was 0.868 ± 0.037 and 0.840 ± 0.039 in FU and healthy fellow eyes, respectively (estimated mean difference = -0.028, 95% CI [-0.038, -0.018], p<0.001). Bland- Altman plots showed good agreement between two methods in both healthy and FU eyes. Interclass correlation coefficient between the manual and automated measurements in the FU and healthy fellow eyes was 0.958 and 0.964, respectively. Inter-eye difference of overall SI was 0.029 ± 0.015 and 0.012 ± 0.008 in FU group and control group, respectively (p=0.01). We concluded that he automated algorithm can rapidly and conveniently measure SI with results comparable to manual method.

scholarly journals Quantitative analysis of the iris surface smoothness by spectral domain optical coherence tomography in Fuchs uveitis

2020 ◽  
Author(s):  
Mohammad Zarei ◽  
Elias Khalili Pour ◽  
Nazanin Ebrahimiadib ◽  
Hamid Riazi-Esfahani
Keyword(s):  
Optical Coherence Tomography ◽  
Quantitative Analysis ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Actual Length ◽  
Straight Line ◽  
Smoothness Index ◽  
The Mean ◽  
Imagej Software ◽  
Fellow Eyes

AbstractPurposeTo demonstrate the value of “smoothness index” as a novel tool for quantitative analysis of iris surface findings in unilateral Fuchs’ uveitis (FU).MethodsIn this observational study, both phakic eyes from patients with the diagnosis of unilateral FU were enrolled. All eyes underwent a complete ophthalmic examination and anterior segment optical coherence tomography(AS-OCT). The images were extracted and exported to the ImageJ software for calculating the “smoothness index (SI)”. The SI was defined as ratio of length of the straight line connecting the most peripheral and the most central points of anterior iris surface to actual length of this boundary.ResultsForty eyes from 20 patients with unilateral FU were enrolled. Mean age of patients was 40±10 years. Mean overall SI was 0.876± 0.030 in eyes with FU that was significantly more than fellow control eyes (0.841± 0.041). (p=0.005) The mean temporal and nasal SI were 0.878± 0.035 and 0.874± 0.033 in eyes with FU, compared to 0.843± 0.041 and 0.838± 0.047 in control fellow eyes, respectively. (p = 0.008 and p = 0.009, respectively)ConclusionIris “smoothness index” is a novel index to quantitatively document diffuse smoothness of iris anterior surface in eyes with FU. This index may facilitate diagnosis of subtle iris atrophic changes in these eyes, especially when heterochromia is absent.

scholarly journals A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yun Ji Lee ◽  
Yeon Jeong Lee ◽  
Jae Yeon Lee ◽  
Suhwan Lee
Keyword(s):  
Optical Coherence Tomography ◽  
Central Serous Chorioretinopathy ◽  
Anterior Segment ◽  
Venous Drainage ◽  
Enhanced Depth Imaging ◽  
Control Group ◽  
Study Group ◽  
Optical Coherence ◽  
Swept Source ◽  
Significant Difference

AbstractThe aim of this study is to compare the scleral thickness of central serous chorioretinopathy (CSC) eyes with controls using anterior segment optical coherence tomography (AS OCT). This prospective case control study included 15 patients (15 eyes) with CSC and 15 age and gender matched healthy subjects. All subjects underwent spectral domain OCT with enhanced depth imaging and swept source AS OCT of temporal sclera. We investigated difference in scleral thickness between the two groups and relationship between choroidal and scleral thickness. Among the 15 eyes in the study group, 1 eye had acute CSC, 4 had recurrent CSC, 7 had inactive CSC, and 3 had chronic CSC. There was no significant difference in terms of age, gender, axial length and spherical equivalent between the two groups. The choroidal and scleral thickness of the study group were significantly greater than those of the control group (P < 0.001, P = 0.034). Choroidal thickness was positively correlated with scleral thickness (P = 0.031). A thick sclera along with a thick choroid were demonstrated in CSC eyes using AS OCT. Scleral characteristics might be involved in the pathogenesis of CSC by affecting outflow resistance of venous drainage in choroidal circulation.

Corneal optical density in Fuchs endothelial dystrophy determined by anterior segment optical coherence tomography

2020 ◽  
pp. 112067212094479
Author(s):  
Christian M Wertheimer ◽  
Carolin Elhardt ◽  
Andreas Wartak ◽  
Nikolaus Luft ◽  
Stefan Kassumeh ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Density ◽  
Anterior Segment ◽  
Corneal Edema ◽  
Diagnostic Tools ◽  
Control Group ◽  
Distilled Water ◽  
Optical Coherence ◽  
Corneal Surgery ◽  
Disease Characteristics

Purpose: In this study, we propose a method to grade corneal stromal opacity using optical density measurements by anterior segment optical coherence tomography (AS-OCT) and validate the approach in Fuchs endothelial corneal dystrophy (FECD). Methods: A retrospective analysis of human corneal OCT scans was performed on 48 eyes of 32 patients with FECD and 33 control eyes of 21 patients using the Carl Zeiss Cirrus HD-OCT 5000. In addition, corneal edema in fresh rabbit cadaver eyes was artificially induced by distilled water and imaged with the Thorlabs TELESTO-II spectral domain OCT at different time points during saturation. The increase of opacity due to corneal edema was proposed to directly correlate with enhanced reflectivity sites in the OCT images, corresponding to higher optical density. The increase was determined as the image area above a statistically established gray-scale value using ImageJ and correlated with other disease characteristics. Results: Optical densities in human corneas showed significant differences between FECD patients and the control group ( p = 0.002). The increased optical densities determined in FECD corneas correlated well with other disease characteristics such as corneal pachymetry or visual acuity. Likewise, rabbit corneas showed a time dependent increase in thickness and in corneal optical density during soaking in distilled water. Conclusion: This study presents corneal optical density by AS-OCT as an objective value for corneal changes in FECD. Complementing other diagnostic tools in FECD the assessment of corneal optical density may identify progression of FECD, gauge novel therapeutic strategies and support risk and benefit analyses for corneal surgery.

Changes in Langerhans cells and the structure of corneal nerve fibers in patients with glaucoma according in vivo confocal microscopy

2021 ◽  
pp. 30-32
Author(s):  
S.E. Avetisov ◽  
◽  
V.V. Strahov ◽  
Z.V. Surnina ◽  
A.A. Popova ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Confocal Microscopy ◽  
Langerhans Cells ◽  
Structural Changes ◽  
Open Angle Glaucoma ◽  
Anterior Segment ◽  
Nerve Fibers ◽  
Control Group ◽  
Optical Coherence ◽  
Corneal Nerve

The most important tasks of preventing blindness and low vision in primary open-angle glaucoma (POAG) are its early diagnosis and quality monitoring in order to stabilize the glaucoma process. Purpose. To analyze the state of Langerhans inflammatory cells and the structure of corneal nerve fibers in patients with POAG. Material and methods. The study included 46 patients. The main group - 26 patients (52 eyes) aged 39 to 80 years - diagnosed with POAG stages I-IV. Control group - 20 patients (40 eyes) - ophthalmologically healthy volunteers with a normal level of intraocular pressure (IOP) and no signs of POAG at the age from 36 to 72 years. Patients underwent: visometry, biomicroscopy of the anterior segment of the eye, ophthalmoscopy, gonioscopy, contour tonometry using the Pascal method, optical coherence tomography (OCT) of the optic nerve discs (Zeiss Stratus 3000) and confocal microscopy of the cornea (CMR) (HRT III, Rostock Cornea Module). Results. In patients with POAG, according to CMR data, structural changes were revealed in the layer of nerve fibers of the cornea, and abnormalities in the structure and number of inflammatory macrophages (Langerhans cells) were also identified. The interocular asymmetry of CNF was investigated in patients with different stages of glaucoma in paired eyes. Conclusion. Аnalyzing the structure of corneal nerve fibers and Langerhans cells can be used as a diagnostic algorithm in patients with POAG. Key words: glaucoma, confocal microscopy, corneal nerve fibers, Langerhans cells, optical coherence tomography.

Evaluation of acquired punctal stenosis using anterior segment optical coherence tomography

2019 ◽  
pp. 112067211987139
Author(s):  
Raafat Mohyeldeen Abdelrahman ◽  
Heba Radi AttaAllah ◽  
Ahmed A Abdelghany ◽  
Jorge L Alio
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Normal Subjects ◽  
Control Group ◽  
Optical Coherence ◽  
Diagnostic Modality ◽  
Normative Database ◽  
Group 2 ◽  
Group 1 ◽  
Punctal Stenosis

Background/objectives: The aim of this article was to study the lower punctum parameters in patients with acquired punctal stenosis using spectral-domain anterior segment optical coherence tomography. Subjects/methods: This was a prospective nonrandomized study that included two groups. Group 1 was composed of 32 puncta from 32 subjects (11 males and 21 females, aged 40–62 years) with epiphora and clinically diagnosed punctal stenosis. Group 2 (control group) included 30 puncta from 30 normal subjects (10 males and 20 females, aged 43–63 years). Anterior segment optical coherence tomography was employed to evaluate lower punctum parameters in all subjects; the inner and outer punctal diameters as well as punctal depth were measured. Results: External punctal diameter (mean: 466.1 ± 120.3 μm), internal punctal diameter (mean: 173.4 ± 55.6 μm) and punctal depth (mean: 188.4 ± 67 μm) values in Group 1 were statistically significantly lower than those in Group 2 (mean: 745.7 ± 156.9 μm, mean: 384 ± 119.1 μm, and mean: 284.9 ± 57.7 μm, respectively). Conclusion: Anterior segment optical coherence tomography could possibly be used as a noncontact and noninvasive diagnostic modality for evaluating and measuring the lower punctum in patients with punctal stenosis. Further research is required to develop a normative database and grading system for stenosed puncta and to correlate the degree of stenosis with the severity of epiphora.

scholarly journals Iris Morphological Features in Patients with 360° Angle-Closure Neovascular Glaucoma: An Anterior Segment Optical Coherence Tomography Study

2018 ◽  
Vol 9 (3) ◽  
pp. 449-456 ◽  
Author(s):  
Yui Kobayashi ◽  
Shunsuke Nakakura ◽  
Etsuko Terao ◽  
Yuki Fujio ◽  
Kanae Matsuya ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Trabecular Meshwork ◽  
Pupil Diameter ◽  
Anterior Segment ◽  
Neovascular Glaucoma ◽  
Morphological Features ◽  
Angle Closure ◽  
Control Group ◽  
Optical Coherence ◽  
Swept Source

Purpose: To investigate iris morphological features in 360° angle-closure neovascular glaucoma (NVG) by swept-source anterior segment optical coherence tomography (ASOCT). Patients and Methods: In this retrospective, clinic-based, comparative study, 14 patients with 360° angle-closure NVG and 14 healthy age-matched control subjects were enrolled. All patients enrolled had no prior glaucoma surgery but underwent cataract surgery with intraocular lens implantation. Horizontal scanning images of swept-source ASOCT were analyzed using software calipers in temporal and nasal angle areas. The iris thickness at 1 and 2 mm from the pupil edge, iris length, trabecular meshwork length, peripheral anterior synechia (PAS) length, PAS height ratio (PAS length/trabecular meshwork length), and pupil diameter were measured. Results: Between the groups, there were no statistically significant differences in iris length, trabecular meshwork length, and pupil diameter (p > 0.05). However, the iris thickness was significantly reduced in the NVG group compared with the control group in the temporal and nasal areas (0.306 vs. 0.563 mm/0.326 vs. 0.645 mm at 1 mm, 0.278 vs. 0.523 mm/0.282 vs. 0.546 mm at 2 mm, respectively) (mean, all p < 0.001). In the NVG group, PAS height ratios were 1.55 ± 0.45 (mean ± standard deviation) (range, 0.58–2.30) and 1.55 ± 0.78 (range, 0.68–3.68) at the temporal and nasal angles, respectively. Conclusions: In patients with 360° angle-closure NVG, the iris thickness decreased to about 50% of that in healthy subjects, and the PAS length exceeded the trabecular meshwork length by about 1.5 times.

scholarly journals Evaluation of radiation maculopathy after treatment of choroidal melanoma with ruthenium-106 using optical coherence tomography angiography

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ali Torkashvand ◽  
Hamid Riazi-Esfahani ◽  
Fariba Ghassemi ◽  
Elias Khalili Pour ◽  
Babak Masoomian ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Choroidal Melanoma ◽  
Case Series ◽  
Foveal Avascular Zone ◽  
Control Group ◽  
Optical Coherence ◽  
Capillary Plexus ◽  
The Impact ◽  
Fellow Eyes

Abstract Background To assess the impact of brachytherapy on macular microvasculature utilizing optical coherence tomography angiography (OCTA) in treated choroidal melanoma. Methods In this retrospective observational case series, we reviewed the recorded data of the patients with unilateral extramacular choroidal melanoma treated with ruthenium − 106 (106Ru) plaque radiotherapy with a follow-up period of more than 6 months. Automatically measured OCTA retinal parameters were analysed after image processing. Results Thirty-one eyes of 31 patients with the mean age of 51.1 years were recruited. Six eyes had no radiation maculopathy (RM). From 25 eyes with RM, nine eyes (36%) revealed a burnout macular microvasculature with imperceptible vascular details. Twenty-one non-irradiated fellow eyes from the enrolled patients were considered as the control group. Foveal and optic disc radiation dose had the highest value to predict the burnout pattern (ROC, AUC: 0.763, 0.727). Superficial and deep foveal avascular zone (FAZ) were larger in irradiated eyes in comparison to non-irradiated fellow eyes (1629 μm2 vs. 428 μm2, P = 0.005; 1837 μm2 vs 268 μm2, P = 0.021; respectively). Foveal and parafoveal vascular area density (VAD) and vascular skeleton density (VSD) in both superficial and deep capillary plexus (SCP and DCP) were decreased in all irradiated eyes in comparison with non-irradiated fellow eyes (P < 0.001). Compared with non-irradiated fellow eyes, irradiated eyes without RM had significantly lower VAD and VSD at foveal and parafoveal DCP (all P < 0.02). However, these differences at SCP were not statistically significant. Conclusion The OCTA is a valuable tool for evaluating RM. Initial subclinical microvascular insult after 106Ru brachytherapy is more likely to occur in DCP. The deep FAZ area was identified as a more critical biomarker of BCVA than superficial FAZ in these patients.

Pediatric Free-floating Anterior Chamber Cyst of the Iris Pigment Epithelium

2018 ◽  
Vol 1 ◽  
pp. 3
Author(s):  
Joshua S Agranat ◽  
Yoshihiro Yonekawa
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Incidental Finding ◽  
Pigment Epithelium ◽  
Anterior Segment ◽  
Ultrasound Biomicroscopy ◽  
Optical Coherence ◽  
Visual Axis ◽  
Associated Malignancy ◽  
Anatomic Locations

Iris pigment epithelial (IPE) cysts are a subset of iris cysts that arise from the IPE. They are spontaneously erupting epithelial-lined cavities that are found in various anatomic locations of the iris, including the iris pupillary margin, midzone, periphery, and free floating in the vitreous or anterior chamber. We report the case of an asymptomatic 13-year-old boy with an incidental finding of a dislodged anterior chamber cyst diagnosed on routine examination. Modern multimodal image analysis of the cyst including anterior segment optical coherence tomography and ultrasound biomicroscopy (UBM) was utilized to characterize the microstructural anatomy of the lesion. The patient was managed conservatively without complications. Cysts of the IPE typically do not affect vision or ocular health and can be monitored and observed after ascertaining no associated malignancy. Initial diagnostic investigation can include UBM and anterior segment optical coherence tomography. Intervention should be reserved only for cases where the cyst growth leads to obstruction of the visual axis and/or other secondary complications.

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