scholarly journals Machine Learning-Guided Prediction of Central Anterior Chamber Depth Using Slit Lamp Images from a Portable Smartphone Device

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 182
Author(s):  
David Chen ◽  
Yvonne Ho ◽  
Yuki Sasa ◽  
Jieying Lee ◽  
Ching Chiuan Yen ◽  
...  
Keyword(s):  
Machine Learning ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Training Data ◽  
Portable Devices ◽  
Anatomical Landmarks ◽  
Strong Positive Correlation ◽  
Slit Lamp ◽  
History Of

There is currently no objective portable screening modality for narrow angles in the community. In this prospective, single-centre image validation study, we used machine learning on slit lamp images taken with a portable smartphone device (MIDAS) to predict the central anterior chamber depth (ACD) of phakic patients with undilated pupils. Patients 60 years or older with no history of laser or intraocular surgery were recruited. Slit lamp images were taken with MIDAS, followed by anterior segment optical coherence tomography (ASOCT; Casia SS-1000, Tomey, Nagoya, Japan). After manual annotation of the anatomical landmarks of the slit lamp photos, machine learning was applied after image processing and feature extraction to predict the ACD. These values were then compared with those acquired from the ASOCT. Sixty-six eyes (right = 39, 59.1%) were included for analysis. The predicted ACD values formed a strong positive correlation with the measured ACD values from ASOCT (R2 = 0.91 for training data and R2 = 0.73 for test data). This study suggests the possibility of estimating central ACD using slit lamp images taken from portable devices.

scholarly journals A Study Validating the Estimation of Anterior Chamber Depth and Iridocorneal Angle with Portable and Non-Portable Slit-Lamp Microscopy

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1436
Author(s):  
Eisuke Shimizu ◽  
Hiroyuki Yazu ◽  
Naohiko Aketa ◽  
Ryota Yokoiwa ◽  
Shinri Sato ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Strong Correlation ◽  
Objective Assessment ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Japanese Patients ◽  
Slit Lamp ◽  
Retrospective Case ◽  
Iridocorneal Angle ◽  
Kappa Value

This study assessed the anterior chamber depth (ACD) and iridocorneal angle using a portable smart eye camera (SEC) compared to the conventional slit-lamp microscope and anterior-segment optical coherence tomography (AS-OCT). This retrospective case-control study included 170 eyes from 85 Japanese patients. The correlation between the ACD evaluations conducted with the SEC and conventional slit-lamp was high (r = 0.814). The correlation between the Van-Herick Plus grade obtained using two devices was also high (r = 0.919). A high kappa value was observed for the Van-Herick Plus grading (Kappa = 0.757). A moderate correlation was observed between the ACD measured using AS-OCT and the slit-lamp image acquired with the conventional slit-lamp microscope and SEC (r = 0.609 and 0.641). A strong correlation was observed between the trabecular-iris angle (TIA) measured using AS-OCT and Van-Herick Plus grade obtained with the conventional slit-lamp microscope and SEC (r = 0.702 and 0.764). Strong correlations of ACD evaluation and high kappa value of the Van-Herick Plus grading indicated the adequate subjective assessment function of the SEC. Moderate correlations between the ACD objective measurement and evaluation and strong correlation between the TIA and Van-Herick Plus grade suggested the good objective assessment function of the SEC. The SEC demonstrated adequate performance for ACD evaluation and angle estimation.

scholarly journals Changes in anterior segment optical coherence tomography following pars plana vitrectomy without tamponade

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Alireza Khodabande ◽  
Massood Mohammadi ◽  
Hamid Riazi-Esfahani ◽  
Shahab Karami ◽  
Massood Mirghorbani ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Pars Plana Vitrectomy ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Optical Coherence ◽  
Mean Values ◽  
Iop Measurement ◽  
Pars Plana ◽  
The Mean

Abstract Background To evaluate changes in anterior segment morphology on anterior segment optical coherence tomography (AS-OCT) following pars plana vitrectomy (PPV) without tamponade. Methods Patients who underwent PPV without tamponade for epiretinal membrane were evaluated. Eligible patients underwent intraocular pressure (IOP) measurement and AS-OCT preoperatively as well as 1 month and 6 months post-operatively. Anterior chamber width (ACW), anterior chamber depth (ACD), trabecular iris angle (TIA), angle opening distance at 500 and 750 µm (AOD), and trabecular iris space area at 500 and 750 µm (TISA) at four quadrants were recorded and analyzed. Additionally, the mean values of TIA (MTIA), AOD (MAOD), and TISA (MTISA) for each eye (mean of four quadrants) were analyzed. Results 23 patients completed the study. The mean age of participants was 56.4 ± 3.6 years of age and 13/23 (56%) were female. Mean IOP of patients was 18.1 ± 1.1, 18.3 ± 1.1, and 18.1 ± 1.2 preoperatively,1 month post-operatively, and 6 months post-operatively, respectively. (p = 0.83). No difference was detected post-operatively in measurements of ACW, ACD, MTIA, MAOD500, MAOD750, MTISA500, and MTISA750. Conclusion Pars plana vitrectomy without tamponade was not associated with changes in anterior chamber morphology.

Effect of light backscattering from anterior segment structures on automated flare meter measurements

2021 ◽  
pp. 112067212110393
Author(s):  
Murat Hasanreisoglu ◽  
Cem Kesim ◽  
Duygu Yalinbas ◽  
Mervenur Yilmaz ◽  
Nur Sena Uzunay ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Scattered Light ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Laser Flare Photometry ◽  
Aqueous Flare ◽  
Group I ◽  
Lens Density ◽  
Laser Flare ◽  
Group Ii

Background: To evaluate effect of maximal anterior cortical lens density, iris scatter and anterior chamber depth on laser flare photometry. Methods: Patients diagnosed with clinical uveitis were enrolled in the study. Clinical flare gradings were recorded upon the Standardization of Uveitis Nomenclature. Aqueous flare was measured with an automated device (Kowa FM-700). Back-scattering from anterior cortical lens and anterior iris surface was calculated from Scheimpflug images. A curvilinear regression model was used to calculate estimated values for each clinical grade. These values were used to split cases in Group I (laser flare photometry lower than estimated) and Group II (laser flare photometry higher than estimated). Mean anterior chamber depth, pupil aperture, maximal anterior cortical lens density and iris scatter values were compared between two groups. A stepwise multiple regression analysis was performed to determine the effect of clinical flare gradings and ocular parameters on aqueous flare measurements. Results: The study included 228 eyes of 114 cases. Scheimpflug images were obtained from 105 eyes. Estimated aqueous flare measurements (in photons/milliseconds) were 4.87, 8.50, 14.81, 25.83, 45.04 and 136.93 for 0, 0.5+, 1+, 1.5+, 2+ and 3+ clinical flare respectively. Group II had higher maximal anterior cortical lens density than Group I (96.6 ± 37.1 vs 77.9 ± 17.1 pixel unit, p = 0.001). The measured aqueous flare was significantly related to clinical flare, maximal anterior cortical lens density and pupil aperture (adjusted R2: 0.480, p < 0.001). Conclusion: The back-scattered light from anterior cortical lens could affect laser flare photometry measurements. This effect might be quantified by Scheimpflug imaging.

scholarly journals Anatomical and Visual Effects of Implantable Phakic Contact Lens on Correction of Myopia

2022 ◽  
Author(s):  
Mahmoud Ekram ◽  
Ahmed Mohamed Kamal Elshafei ◽  
Asmaa Anwar Mohamed ◽  
Mohamed Farouk Sayed Othman Abdelkader
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Contact Lens ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Case Series ◽  
Care Group ◽  
Case Series Study ◽  
Significant Difference ◽  
The Mean

Abstract Purpose: To evaluate the anatomical effects of implantable phakic contact lens (IPCL) (Care Group, India) on anterior segment and its visual outcomes .Patients and methods: In a prospective interventional case series study, 60 highly myopic eyes of 32 patients were subjected to IPCL implantation in the Ophthalmology Department of Minia University Hospital, Egypt from January 2019 to June 2021. All patients had complete ophthalmic examination and were followed up for 1 year. Pentacam was used for preoperative and postoperative estimation of anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV) and IPCL vault in the 1st, 3rd, and 12th months. Assessment of corneal endothelium was done using specular microscope preoperatively and after 12 months. Preoperative and postoperative refraction and visual acuity were measured. Results: There was a statistically significant decrease in ACD, ACA, and ACV. There was no significant difference between preoperative and postoperative mean intraocular pressure (IOP) by the 12th month (P=0.163). The mean preoperative endothelial cell count (ECD) was significantly reduced from 2929.3±248 cells/mm2 to 2737.9±303 cells/mm2 at the 12th month (P<0.001). with a statistically highly significant improvement of mean Log Mar uncorrected visual acuity (UCVA) from 1.48±0.19 preoperatively to 0.46±0.11 by the end of follow up (P<0.001) with insignificant difference between preoperative best corrected visual acuity (BCVA) and postoperative UCVA (P=0.209). In the 12th month, the mean vault was 240±540 μm. No sight threatening complications occurred.Conclusion: Although IPCL induced anatomical changes, it was safe and effective for correction of high myopia.

scholarly journals Anterior Chamber Angle Assessment Techniques: A Review

2020 ◽  
Vol 9 (12) ◽  
pp. 3814
Author(s):  
Ivano Riva ◽  
Eleonora Micheletti ◽  
Francesco Oddone ◽  
Carlo Bruttini ◽  
Silvia Montescani ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Anterior Chamber ◽  
Imaging Techniques ◽  
Anterior Segment ◽  
Standard Technique ◽  
Qualitative Assessment ◽  
Ophthalmological Examination ◽  
Slit Lamp ◽  
Anterior Chamber Angle ◽  
Chamber Angle

Assessment of the anterior chamber angle (ACA) is an essential part of the ophthalmological examination. It is intrinsically related to the diagnosis and treatment of glaucoma and has a role in its prevention. Although slit-lamp gonioscopy is considered the gold-standard technique for ACA evaluation, its poor reproducibility and the long learning curve are well-known shortcomings. Several new imaging techniques for angle evaluation have been developed in the recent years. However, whether these instruments may replace or not gonioscopy in everyday clinical practice remains unclear. This review summarizes the last findings in ACA evaluation, focusing on new instruments and their application to the clinical practice. Special attention will be given to the comparison between these new techniques and traditional slit-lamp gonioscopy. Whereas ultrasound biomicroscopy and anterior segment optical coherence tomography provide quantitative measurements of the anterior segment’s structures, new gonio-photographic systems allow for a qualitative assessment of angle findings, similarly to gonioscopy. Recently developed deep learning algorithms provide an automated classification of angle images, aiding physicians in taking faster and more efficient decisions. Despite new imaging techniques made analysis of the ACA more objective and practical, the ideal method for ACA evaluation has still to be determined.

scholarly journals Anterior Chamber Angle and Volume Do Not Change after Myopic Laser-Assisted In Situ Keratomileusis in Young Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Ertuğrul Tan Yassa ◽  
Cihan Ünlü
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Young Patients ◽  
Anterior Chamber Depth ◽  
Ablation Depth ◽  
Anterior Chamber Angle ◽  
Chamber Volume ◽  
The Mean ◽  
Chamber Angle

Purpose. We aimed to investigate whether anterior chamber angle, depth, and volume change after myopic laser-assisted in situ keratomileusis (LASIK) in young patients. Methods. This retrospective study included 29 eyes of 29 patients (15 females and 14 males) between the ages of 18 and 39 years who underwent LASIK for the treatment of myopia. In addition to complete ophthalmic examination, anterior chamber angle (ACA), central anterior chamber depth (ACD), and anterior chamber volume (ACV) were measured by using a Sirius rotating Scheimpflug camera combined with Placido disc corneal topography (CSO, Florence, Italy). Preoperative and postoperative values were compared using paired t-tests. Linear regression was used to evaluate the relationship between changes in refraction and changes in ACA, ACD, and ACV as well as between attempted maximum ablation depth and changes in ACA, ACD, and ACV. Results. The mean age of the study population was 25.5 ± 6.2 years. The mean preoperative and postoperative spherical equivalent values were −3.30 ± 1.92 D and −0.18 ± 0.29 D, respectively. ACV and ACA were not significantly changed after surgery; however, central ACD was significantly decreased (preoperatively = 3.366 ± 0.316 mm vs postoperatively = 3.3 ± 0.298 mm) with a mean difference of 0.066 ± 1.121 mm. There were no significant relationships between changes in refraction and anterior segment dimensions or between attempted maximum ablation depth and anterior segment dimensions. Conclusion. Measurements with Sirius showed that ACA and ACV did not change; however, central ACD significantly decreased after myopic LASIK in young patients, indicating that the preoperative central ACD value should not be used interchangeably with the postoperative central ACD value.

scholarly journals Evaluation of Anterior Segment’s Structures in Tilted Disc Syndrome

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Ercan Ozsoy ◽  
Abuzer Gunduz ◽  
Ersin Ersan Demirel ◽  
Tongabay Cumurcu
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Control Group ◽  
Tilted Disc Syndrome ◽  
Chamber Volume ◽  
Significant Difference ◽  
Tilted Disc

Purpose. To evaluate anterior segment’s structures by Pentacam in patients with tilted disc syndrome (TDS).Methods. Group 1 included forty-six eyes of forty-six patients who have the TDS. Group 2 including forty-six eyes of forty-six cases was the control group which was equal to the study group in age, gender, and refraction. A complete ophthalmic examination was performed in both groups. All cases were evaluated by Pentacam. The axial length (AL) of eyes was measured by ultrasound. Quantitative data obtained from these measurements were compared between two groups.Results. There was no statistically significant difference for age, gender, axial length, and spherical equivalent measurements between two groups (p=0.625,p=0.830,p=0.234, andp=0.850). There was a statistically significant difference for central corneal thickness (CCT), corneal volume (CV), anterior chamber angle (ACA), and pupil size measurements between two groups (p=0.001,p=0.0001,p=0.003, andp=0.001). Also, there was no statistically significant difference for anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness (LT) measurements between two groups (p=0.130,p=0.910, andp=0.057).Conclusion. We determined that CCT was thinner, CV was less, and ACA was narrower in patients with TDS. There are some changes in the anterior segment of the eyes with tilted disc.

The effect of mydriasis on moderate-to-high myopic eyes with implantable collamer lenses V4 and V4c

2019 ◽  
Vol 30 (3) ◽  
pp. 462-468 ◽  
Author(s):  
Yi Zhu ◽  
Jing Zhang ◽  
Haobin Zhu ◽  
Jili Chen ◽  
Jibo Zhou
Keyword(s):  
Observational Study ◽  
Anterior Chamber ◽  
Corneal Endothelium ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Central Hole ◽  
Pressure Equilibrium ◽  
Before And After ◽  
Icl V4c

Purpose:To evaluate the vault change and anterior segment movement induced by mydriasis in moderate-to-high myopic eyes with implantable collamer lenses (ICL).Setting:Shanghai, ChinaDesign:A prospective consecutive observational study.Methods:A total of 45 eyes of 24 patients with ICL V4 implantation and 128 eyes of 65 patients with ICL V4c implantation were included and analyzed. Anterior chamber depth, posterior corneal endothelium-to-ICL distance, and vault before and after mydriasis were measured by Pentacam (Oculus, Wetzlar, Germany) at 1, 3, and 6 months after surgery.Results:Significant vault increases and anterior chamber depth increases induced by mydriasis were noted in both ICL V4 and V4c groups at 1, 3, and 6 months postoperatively. The corneal endothelium-ICL distance increased significantly in eyes with implanted ICL V4c after mydriasis at 3 and 6 months. Moreover, mydriasis-induced vault increases were greater in the ICL V4 group than in the ICL V4c group at 3 and 6 months. In eyes with implanted ICL V4c, mydriasis-induced vault increases were significantly greater at 1 month than at 3 and 6 months.Conclusion:Mydriasis results in a general vault increase in eyes with implanted ICLs. The adjustment of the pressure equilibrium via the central hole of the ICL V4c has an important role in vault change. The mydriasis-induced vault increases tend toward stability after 3 months postoperatively. Mydriasis is relatively safe in eyes with ICL implantation.

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