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Background: The aim of this study is evaluate the accuracy of AS-OCT as a pre-operative tool to measure extra-ocular muscles insertion distance prior to strabismus surgery. Methods: It was a cross sectional observational study including 35 patients were imaged by AS-OCT and operated upon, intraoperative measurment of MR and LR muscles insertion distance was done. Results: There was a statically significant difference between AS-OCT and intra-operative measurements in case of LR muscle. Conclusion: AS-OCT is a useful non-contact tool in measuring MR muscle insertion distance.

Purpose: To evaluate graft detachment after Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic eyes and DMEK combined with cataract surgery (triple DMEK). Design: Analysis of 3 single-center prospective cohort studies and 1 randomized controlled trial. Participants: Participants with Fuchs’ endothelial corneal dystrophy. Methods: A validated neural network for image segmentation quantified graft detachment on anterior segment OCT (AS-OCT) images 3 days after DMEK and at the 2-week postoperative visit. Area and volume of graft detachment were compared between DMEK only and triple DMEK using generalized estimating equation models and adjusting for participant age and the size of the air bubble. Main Outcome Measures: Area and volume of DMEK graft detachment. Results: Among 207 participants with 270 eyes included, 75 pseudophakic eyes had DMEK only and 195 eyes had triple DMEK. A total of 147 eyes had less than one third of detachment at day 3. In 139 of these eyes (95%), detachment was still less than one third at the 2-week scan, indicating that postoperative graft detachment at 2 weeks occurred mainly in eyes with early detachment. When superimposing all 3-dimensional maps from 2 weeks after surgery, the central graft was mainly attached and detachment was located at the graft margin. The mean area of graft detachment decreased from 28% in DMEK only and 38% in triple DMEK to 16% in DMEK only and 25% in triple DMEK at the 2-week postoperative visit. At 2 weeks, the mean area of detachment was 1.85-fold higher (95% confidence interval [CI], 1.34–2.56) and the mean volume was 2.41-fold higher (95% CI, 1.51–3.86) in triple DMEK compared with DMEK. A total of 46 eyes received rebubbling procedures, with 7 eyes (9%) in the DMEK group and 39 eyes (20%) in the triple DMEK group (adjusted risk ratio, 3.1; 95% CI, 1.3–7.1), indicating that rebubbling was more common in eyes undergoing triple DMEK. Conclusions: Automated segmentation of AS-OCT images allowed precise quantification of graft detachment over time and identified DMEK combined with cataract surgery as a risk factor. Frequency of operative follow-up might be guided by extent of detachment in the first postoperative days after DMEK.

The purpose of this study is to quantitatively assess lens opacity, using a swept-source optical coherence tomography (SS-OCT) device for anterior segment assessment, and establish the correlation with Scheimpflug imaging, corrected distance visual acuity (CDVA) and cumulative dissipated energy (CDE). This prospective cross-sectional single-center study enrolled 51 patients (51 eyes) with crystalline lens opacity. Patients with previous ocular surgery, pathologies or general disorders affecting vision were excluded. Eyes were scanned with an SS-OCT device, and lens densitometry was automatically analyzed using a custom MATLAB script which examined lens density, nuclear density and linear density. The same analyses were performed on Scheimpflug images. Preoperative CDVA and CDE during phacoemulsification were recorded. Spearman's (ρ) and Pearson's (r) correlation coefficients were assessed according to data normality. Statistically significant correlations were established between SS-OCT and Scheimpflug imaging using lens analysis (ρ = 0.47, p < 0.001), nuclear analysis (ρ = 0.73, p < 0.001) and linear analysis (r = 0.44, p < 0.001). A significant correlation with CDE was found with all the SS-OCT methods (r = 0.57, p < 0.001). Only the nuclear analysis of the SS-OCT scans (Tb = −0.33, p < 0.01) and Pentacam Nucleus Staging (Tb = −0.26, p < 0.05) showed a statistically significant correlation with CDVA. Good inter-device agreement in lens densitometry was found. However, SS-OCT yielded improved lens imaging compared with the Scheimpflug device and a higher correlation with clinical parameters. Thus, high-resolution SS-OCT has the potential to become a preferable option for automatic cataract grading and preoperative planning. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is evaluate the accuracy of AS-OCT as a pre-operative tool to measure extra-ocular muscles insertion distance prior to strabismus surgery. Methods: It was a cross sectional observational study including 35 patients were imaged by AS-OCT and operated upon, intraoperative measurment of MR and LR muscles insertion distance was done. Results: There was a statically significant difference between AS-OCT and intra-operative measurements in case of LR muscle. Conclusion: AS-OCT is a useful non-contact tool in measuring MR muscle insertion distance. [ABSTRACT FROM AUTHOR]

PurposeTo evaluate the anterior segment in children with an R124L mutation corneal dystrophy (CD) using anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM).MethodsWe investigated a family with prevalent CD and an R124L mutation; 59 individuals (14 patients; 6 male and 8 female, aged 2–69 years, 6 children, 2:4 male: female ratio) from four generations were included. We observed corneal lesions through ophthalmologic examinations, AS-OCT, and IVCM. The mean follow-up was 4.60 ± 3.91 years.ResultsThe mean age for childhood CD onset was 0.90 ± 0.61 years. An Avelino DNA test revealed a heterozygous R124L mutation. Clinical manifestations included recurrent photophobia, tearing, and a foreign body sensation. Recurrence frequency decreased with age. Slit lamp microscopy revealed a rough corneal epithelium. The anterior matrix under the corneal epithelium and the anterior elastic layer were scattered with gray and white opacity. From onset to follow-up, the children’s visual acuity decreased from 0.34 ± 0.12 to 0.55 ± 0.17 LogMAR units. AS-OCT showed uneven corneal epithelial thickness. The Bowman’s layer was replaced by abnormal substances in the anterior segment. Corneal deposits became increasingly thicker; the average thickness at the last follow-up was 102.78 ± 10.13 μm. IVCM revealed uneven and reflective signals in the corneal upper cortex and subepithelium, with unclear boundaries and a loss of normal cell morphology.ConclusionWe report an early age of onset in a family with prevalent CD due to R124L mutations. AS-OCT is a convenient, quick, and non-contact tool for screening and monitoring the pathological process of CD.

Background: Dry eye is a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film and accompanied by ocular symptoms. Tear film instability and hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities play important role in the etiology of dry eye. Objective: To correlate the corneal epithelial thickness and grades of dryness using optical coherence tomography (OCT) in dry eye patients versus normal eye patients. Patients and Methods: A prospective case control study was conducted on patients of the outpatient clinic at Ophthalmology department, Faculty of Medicine, Ain Shams University. The study was conducted on patients in middle age group (from 20 to 50 years old of both sexes). The sample size was 30 dry eyes and 30 normal eyes. Results: Regarding the AS/OCT-C 5mm results among the studied patients, we found that Avg. of superior quadrants in Dry eyes group ranged from 47 to 59.6 with mean 6 SD=53.63 6 3.7 while in Normal eyes group the Avg. of superior quadrants ranged from 49 to 56 with mean 6 SD=52.7 6 1.93 with no statistical significant difference (p=0.227) between the two groups. Avg. of inferior quadrants in Dry eyes group ranged from 49 to 65.6 with mean 6 SD=55.62 6 4.35 while in Normal eyes group the Avg. of inferior quadrants ranged from 49 to 56 with mean 6 SD=52.7 6 1.93 with statistical significant difference (p=0.002) between the two groups. Regarding Comparison, there was a highly significant difference between the two studied groups (p=<.001). Conclusion: There was significant difference Fundus examination, AS/OCT-C 5mm, highest thickness, AS/OCT-C 2mm and AS/OCT-P 9mm results between dry eye patients and normal subjects. [ABSTRACT FROM AUTHOR]

Background: The introduction of non-invasive diagnostic tools in ophthalmology has significantly reshaped current clinical practice in different settings. Recently, different anterior segment (AS) intraoperative optical coherence tomography (i-OCT) systems have been employed for different interventional procedures including cataract surgery. Materials and Methods: A review on the use of AS i-OCT in the management of cataract surgery, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). The level of evidence according to the Oxford Centre for Evidence-Based Medicine (OCEM) 2011 guidelines, and the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system were assessed for all included articles. Results: Out of 6302 articles initially extracted, 6302 abstracts were identified for screening and 32 of these met the inclusion/exclusion criteria for full-text review; 19 articles were excluded. Conclusions: The use of AS i-OCT in cataract surgery, even if only a few studies have a high level or grade of evidence, may represent a useful tool for novel surgeons approaching phacoemulsification but also for expert ones for teaching purposes and to plan and manage complicated cases. [ABSTRACT FROM AUTHOR]

Background: Information on the centration and tilt of iris-claw intraocular lenses (IC-IOLs) is limited. In this study, we tested the capacity of an anterior segment optical coherence tomography (AS-OCT) instrument to measure decentration and tilt of anterior and posterior IC-IOLs through an integrated software.Methods: The present observational, cross-sectional study was conducted at University Eye Clinic of Parma (Parma, Italy). The CASIA2 swept-source AS-OCT (Tomey Corp.) was used to measure the tilt and decentration of posterior and anterior IC-IOLs in patients implanted at least 6 months in advance. After failure with full-automation, semi-manual IOL tracing was applied. In-the-bag (IB) contralateral IOLs, when present, were measured automatically. The Bland-Altman method was used to evaluate the agreement between repeated measurements (2 images for each study eye). The amount and direction of tilt and decentration were recorded and plotted into polar charts for evaluation.Results: A total of 21 patients were included: 14 with posterior and 7 with anterior IC-IOL fixation. In 17 eyes (81%), the AS-OCT provided a repeatable measurement of tilt and decentration. All contralateral eyes with IB IOL were automatically measured. The median decentration was 0.67 mm, 0.24 mm, and 0.24 mm in posterior IC-IOLs, anterior IC-IOLs, and IB IOLs group, respectively. The median tilt was 5.0°, 5.6°, and 5.6° for posterior IC-IOLs, anterior IC-IOLs, and IB IOLs, respectively. Tilt direction was mainly temporal, while decentration was inferior-temporal with posterior IC-IOLs and scattered with anterior IC-IOLs and IB IOLs.Conclusions: The semi-manual tracing function of the CASIA2 AS-OCT provides repeatable and affordable measurements of the decentration and tilt of IC-IOLs in both the anterior and posterior chamber. Data from the former group were similar to the IB group. [ABSTRACT FROM AUTHOR]

To demonstrate the value of "smoothness index (SI)" as a novel tool for quantitative analysis of iris surface findings in unilateral Fuchs' uveitis (FU). Both phakic eyes from patients with unilateral FU as well as healthy control subjects underwent anterior segment optical coherence tomography (AS-OCT). The ImageJ software was used for calculating the SI. Forty eyes from 20 patients with unilateral FU and 40 eyes from 20 healthy subjects were enrolled. In FU eyes, mean overall SI (0.876 ± 0.030) was significantly higher than fellow control eyes (0.841 ± 0.041) (p =.001). Mean inter-eye difference for overall SI in the FU patients (0.037 ± 0.030) was significantly larger than the healthy control subjects (0.018 ± 0.014) (p =.033). Iris "smoothness index" can be used to quantitatively assess iris surface smoothness and may facilitate the diagnosis of subtle iris atrophic changes in eyes affected by FU especially in the absence of heterochromia. [ABSTRACT FROM AUTHOR]

Purpose: : To analyze the ocular biometric parameters of eyes with acute primary angle closure (APAC) as compared to fellow eyes.Methods: : A cross-sectional study was conducted on 27 patients presenting with recent onset APAC to a tertiary eye institute in India. Anterior and posterior ocular biometric parameters were measured simultaneously by anterior segment optical coherence tomography (AS-OCT), A-scan, ultrasound biomicroscopy (UBM), and B-mode ultrasonogram (USG). The parameters measured were anterior chamber depth (ACD), anterior chamber angle (ACA), angle opening distance (AOD500, AOD750), lens vault (LV), axial length (AL), ciliary body thickness maximum (CBTmax) and at the point of scleral spur (CBT0), anterior placement of the ciliary body (APCB), and retinochoroidal thickness (RCS).Results: Mean age ± SD of patients with APAC was 55.66 ± 7.2 years with female preponderance (21:6 patients). Mean presenting IOP ± SD of the affected eye and fellow eye were 54.74 ± 11.67 mm Hg and 18.7 ± 11.67 mm Hg, respectively. Eyes with APAC had statistically significant narrower anterior ocular biometric parameters, higher LV, decreased ciliary body thickness, more APCB, and longer AL than the fellow eyes. CBTmax is the only variable that had significance (β = -0.421,95% CI: -0.806 to - 0.035, P = 0.034) in the univariate analysis with RCS thickness in APAC eyes. Further, there was a correlation between CBT0 and APCB with CBTmax both in univariate (β = 0.894, P < 0.0001 and β = -0.351, P = 0.039) and multivariable analysis (β = 0.911, P < 0.0001 and β = -0.416, P = 0.016).Conclusion: Compared to the fellow eyes, APAC eyes had different ocular biometric parameters. In addition to known biometric parameters associated with pupillary block (narrower anterior biometric parameters-ACA, ACD, and AOD), our study found multiple nonpupillary block factors such as higher lens vault and thinner and more anteriorly placed ciliary body to be associated with APAC. [ABSTRACT FROM AUTHOR]

To describe the changes in corneal epithelial thickness and reflectivity following simple limbal epithelial transplantation (SLET) using anterior segment optical coherence tomography (ASOCT). This was a prospective imaging study of 31 eyes of 29 patients who had undergone autologous or allogeneic SLET for limbal stem cell deficiency and had stable, avascular surfaces postoperatively. ASOCT scans of all four quadrants were taken preoperatively and at 1-week, 1-month, 3-month, 6-month, and 1-year postoperative time points in the eyes undergoing SLET. Baseline scans were also taken from the normal eye in unilateral cases. The following parameters were obtained from the scans: (i) epithelial thickness (ET), (ii) stromal thickness, (iii) total corneal thickness, (iv) epithelial reflectivity (ER), (v) stromal reflectivity, and (vi) epithelial/stromal (ES) reflectivity ratio. Chemical injury (24 eyes, 77.4%) was the most common indication for surgery. There was a significant improvement in the ET (184.8 ± 117.1 vs 60.3 ± 10 µm, p <.0001) and ER (144.5 ± 26.4 vs 120.9 ± 28.9, p <.0001) within the initial postoperative period following SLET, which remained stable at the end of 1 year follow-up. There was no difference in the ET of the post-SLET and normal eyes after the 3-month timepoint and this normalization was maintained until the end of the first year. A significant normalization was also noted in the ES reflectivity ratio at the end of 1 year (2.1 ± 0.8 vs 1 ± 0.2, p <.001). A significant correlation was found between the final visual acuity and the total corneal thickness (r = 0.942, p =.005). There is a significant improvement in the epithelial thickness and reflectivity of the cornea in eyes undergoing SLET. ASOCT provides a reliable objective measure of these changes and can be used to monitor the outcomes in these eyes postoperatively. [ABSTRACT FROM AUTHOR]

To assess baseline ocular biometric risk factors for progression from primary angle closure suspect (PACS) to primary angle closure (PAC) or acute angle closure (AAC). Prospective, observational study. Six hundred forty-three mainland Chinese with untreated PACS. Participants underwent baseline clinical examinations, including gonioscopy, anterior segment OCT (AS-OCT) imaging, and A-scan ultrasound biometry as part of the Zhongshan Angle Closure Prevention (ZAP) Trial. Primary angle closure suspect was defined as an inability to visualize pigmented trabecular meshwork in 2 or more quadrants based on static gonioscopy. Primary angle closure was defined as development of intraocular pressure above 24 mmHg or peripheral anterior synechiae. Progression was defined as development of PAC or an AAC attack. Multivariable logistic regression models were developed to assess biometric risk factors for progression. Six-year progression from PACS to PAC or AAC. Six hundred forty-three untreated eyes (609 nonprogressors, 34 progressors) of 643 participants were analyzed. In a multivariable model with continuous parameters, narrower horizontal angle opening distance of 500 μm from the scleral spur (AOD 500 ; odds ratio [OR], 1.10 per 0.01-mm decrease; P = 0.03), flatter horizontal iris curvature (IC; OR, 1.96 per 0.1-mm decrease; P = 0.01), and older age (OR, 1.11 per 1-year increase; P = 0.01) at baseline were associated significantly with progression (area under the receiver operating characteristic curve [AUC], 0.73). Smaller cumulative gonioscopy score was not associated with progression (OR, 1.03 per 1-modified Shaffer grade decrease; P = 0.85) when replacing horizontal AOD 500 in the multivariable model. In a separate multivariable model with categorical parameters, participants in the lowest quartile of horizontal AOD 500 (OR, 3.10; P = 0.002) and IC (OR, 2.48; P = 0.014) measurements and 59 years of age or older (OR, 2.68; P = 0.01) at baseline showed higher odds of progression (AUC, 0.72). Ocular biometric measurements can help to risk-stratify patients with early angle closure for more severe disease. Anterior segment OCT measurements of biometric parameters describing the angle and iris are predictive of progression from PACS to PAC or AAC, whereas gonioscopy grades are not. [ABSTRACT FROM AUTHOR]

An 81-year-old patient was referred for an intraocular lens (IOL) exchange surgery because of a presumed IOL opacification. Using diagnostic imaging techniques such as anterior segment optical coherence tomography (OCT) and Scheimpflug imaging, we revealed that the presumed IOL opacification was in fact a liquefied aftercataract. As a result, an intraocular surgery was avoided and the patient was successfully treated with a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy.

Purpose: This study aims to evaluate the repeatability of anterior segment optical coherence tomography (AS-OCT) in diverse ocular surface disorder (OSD) cohorts, exploring various anterior segment parameters and their accuracy in different disease groups., Methods: A total of 239 participants across six distinct OSD groups and healthy controls underwent nonmydriatic AS-OCT imaging using the Tomey CASIA 2 device. Anterior segment parameters including anterior chamber depth, width, angle metrics, corneal thickness, keratometry, lens vault, and others were meticulously assessed. Statistical analyses determined repeatability limits and coefficients of variation for each parameter within the different OSD cohorts., Results: Repeatability for anterior chamber and corneal parameters remained consistent across all OSD groups, indicating minimal impact of ocular surface disease on accuracy. The coefficient of variation (CoV) for the trabecular iris-space area was about 20% for all cohorts. Ocular surface inflammation emerged as a key factor in dry eye, affecting immune-mediated and non-immune conditions alongside age-related ocular surface changes. While anterior chamber depth measurements showed variations, particularly in immune (CoV = 2.5%) and non-immune (CoV = 3.8%) OSD groups, parameters like anterior chamber width and angle to angle showed similar values among the cohorts. Keratometry measures remained stable despite OSD (CoV lower than 1%)., Conclusion: The Tomey CASIA 2 demonstrated reliable repeatability for measuring anterior segment parameters in diverse OSD cohorts. Despite challenges posed by dry eye conditions, this technology holds promise in assessing OSD, suggesting potential clinical protocols similar to those in healthy controls., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Recchioni, Venkataraman, Rauz and Domínguez-Vicent.)

To develop and evaluate the performance of a 3-dimensional (3D) deep-learning–based automated digital gonioscopy system (DGS) in detecting 2 major characteristics in eyes with suspected primary angle-closure glaucoma (PACG): (1) narrow iridocorneal angles (static gonioscopy, Task I) and (2) peripheral anterior synechiae (PAS) (dynamic gonioscopy, Task II) on OCT scans. International, cross-sectional, multicenter study. A total of 1.112 million images of 8694 volume scans (2294 patients) from 3 centers were included in this study (Task I, training/internal validation/external testing: 4515, 1101, and 2222 volume scans, respectively; Task II, training/internal validation/external testing: 378, 376, and 102 volume scans, respectively). For Task I, a narrow angle was defined as an eye in which the posterior pigmented trabecular meshwork was not visible in more than 180° without indentation in the primary position captured in the dark room from the scans. For Task II, PAS was defined as the adhesion of the iris to the trabecular meshwork. The diagnostic performance of the 3D DGS was evaluated in both tasks with gonioscopic records as reference. The area under the curve (AUC), sensitivity, and specificity of the 3D DGS were calculated. In Task I, 29.4% of patients had a narrow angle. The AUC, sensitivity, and specificity of 3D DGS on the external testing datasets were 0.943 (0.933–0.953), 0.867 (0.838–0.895), and 0.878 (0.859–0.896), respectively. For Task II, 13.8% of patients had PAS. The AUC, sensitivity, and specificity of 3D DGS were 0.902 (0.818–0.985), 0.900 (0.714–1.000), and 0.890 (0.841–0.938), respectively, on the external testing set at quadrant level following normal clinical practice; and 0.885 (0.836–0.933), 0.912 (0.816–1.000), and 0.700 (0.660–0.741), respectively, on the external testing set at clock-hour level. The 3D DGS is effective in detecting eyes with suspected PACG. It has the potential to be used widely in the primary eye care community for screening of subjects at high risk of developing PACG. [ABSTRACT FROM AUTHOR]

Purpose: To develop and apply a neural network for quantification of endothelial corneal graft detachment using anterior segment (AS) OCT. Design: Training and validation of a neural network and application within a prospective cohort. Participants: Patients two weeks after Descemet membrane endothelial keratoplasty. Methods: Investigators manually labeled the posterior cornea and the graft in cross-sectional images of rotational AS OCT scans. Neural networks for image segmentation were trained to identify the area of graft detachment on cross-sectional images. The best-performing neural network with the lowest misclassification (Youden index) and highest spatial overlap with the ground truth (Dice coefficient) was selected and evaluated in a separate dataset. Three-dimensional maps of the area and volume of graft detachment were calculated. For application, the neural network’s rating on the detachment was compared with slit-lamp–based ratings of cornea specialists on the same day as the AS OCT imaging took place. Main Outcome Measures: Youden index and Dice coefficient. Results: Neural networks were trained on 27 AS OCT scans with 6912 labeled images. Among 48 combinations of probability thresholds and epoch states, the best-performing neural network showed a Youden index of 0.99 and a Dice coefficient of 0.77, indicating low misclassification and good spatial overlap on individual image segmentation. In the validation set unknown to the neural network with 20 scans (5120 images), the Youden index was 0.85 and the Dice coefficient was 0.73, and a high overall performance compared with the manually labeled ground truth (R2 = 0.90). In the application set with 107 eyes, the neural network estimated the mean percent detachment larger than the cornea specialist (mean difference, 8.2 percentage points; 95% confidence interval, 6.2–10.2). Masked review of 42 AS OCTs with more than ±10 percentage points difference in ratings showed that clinicians underestimated the true detachment in cases with significant detachment requiring intervention. Conclusions: Deep learning-based segmentation of AS OCT images quantified the percent and the volume of DMEK graft detachment with high precision. Fully automated 3-dimensional quantification of graft detachment is highly sensitive, particularly in corneas with a significant amount of detachment, and may support decision making.

Background: Despite its proven effectiveness and safety profile, the XEN gel stent (Allergan Inc., CA, USA) for minimally invasive glaucoma surgery (MIGS) has a probability of postoperative complications, including postoperative hypotony, hyphema, stent migration, stent obstruction, bleb fibrosis, and fibrin formation. In particular, the use of adjunctive Mitomycin-C (MMC) might be associated with bleb-related complications, including conjunctival erosion, XEN gel stent exposure, and blebitis. However, there are few studies on XEN gel stent exposure and its management. We describe a case of XEN gel stent exposure with conjunctival erosion 18 months postoperatively, which resolved effectively after combination treatment with a rotational conjunctival flap and amniotic membrane transplantation. Case presentation: A 74-year-old Korean male patient with diabetes and hypertension underwent uncomplicated ab interno XEN gel stent implantation with a subconjunctival injection of 0.1 cc of 0.02% MMC and presented with low intraocular pressure (IOP) with a well-functioning filtering bleb. Periocular pain and tearing developed 18 months after the initial operation, with mild deterioration of visual acuity to 20/100. Despite conservative medical treatment, the conjunctival erosion was not relieved. Anterior segment optical coherence tomography (AS-OCT) revealed an exposed XEN gel stent with conjunctival erosion. We performed bleb revision surgery using a rotational conjunctival flap and amniotic membrane transplantation. Slit-lamp examination and AS-OCT showed a well-formed moderate bleb without leakage, and IOP continued to be well controlled (14 mm Hg with latanoprost) until six months after bleb revision. Conclusions: This case report highlights the importance of careful examination, including slit-lamp examination, the Seidel test, and AS-OCT, to identify accurate anatomical positioning and to monitor ocular surface changes after XEN gel stent implantation with MMC or 5-FU. Combination treatment (rotational conjunctival flap and amniotic membrane transplantation) may be relatively safe for persistent XEN gel stent exposure.

Purpose: to report the utility of Anterior Segment Optical Coherence Tomography (AS OCT) for planning superficial sclerectomy in a patient with nevus of Ota. Observations: Oculodermal melanocytosis, also called nevus of Ota, is a benign pigmentary disorder that involves the skin innervated by the first and second branches of the trigeminal nerve. To reduce these black or brownish lesions, different surgical treatments have been reported, such as flipped scleral flap, sclera allograft and the grabbing method. Superficial sclerectomy is a recent technique that has proven effective in improving scleral pigmentation. Although this procedure allows the operating time to be reduced and results in a smoother scleral bed surface, it has a limitation, represented by the difficulty of estimating the depth of the sclerectomy: an inaccurate estimate or incorrect depth could cause an inadequate deep scleral dissection with excessive weakening of the sclera. We report a case of a 27-year-old patient with nevus of Ota undergoing superficial sclerectomy. The depth of scleral pigmentation was evaluated with AS OCT images before the surgery, allowing a superficial sclerectomy to be performed with a precalibrated diamond blade. Conclusions and Importance: In oculodermal melanocytosis (nevus of Ota) the use of AS OCT images showing the depth of scleral pigmentation could lead to the most effective and safest surgical choice for each case.

To assess anatomic changes after laser peripheral iridotomy (LPI) and predictors of angle widening based on anterior segment (AS) OCT and angle opening based on gonioscopy. Prospective observational study. Primary angle-closure suspects (PACSs) 50 to 70 years of age. Participants of the Zhongshan Angle Closure Prevention (ZAP) Trial underwent gonioscopy and AS-OCT imaging at baseline and 2 weeks after LPI. Primary angle-closure suspect was defined as the inability to visualize pigmented trabecular meshwork in 2 or more quadrants on static gonioscopy. Laser peripheral iridotomy was performed on 1 eye per patient in superior (between 11 and 1 o'clock) or temporal or nasal locations (at or below 10:30 or 1:30 o'clock). Biometric parameters in horizontal and vertical AS-OCT scans were measured and averaged. Linear and logistic regression modeling were performed to determine predictors of angle widening, defined as change in mean angle opening distance measured at 750 μm from the scleral spur (AOD 750); poor angle widening, defined as the lowest quintile of change in mean AOD 750 ; and poor angle opening, defined as residual PACS after LPI based on gonioscopy. Anatomic changes and predictors of angle widening and opening after LPI. Four hundred fifty-four patients were included in the analysis. Two hundred nineteen underwent superior LPI and 235 underwent temporal or nasal LPI. Significant changes were found among most biometric parameters (P < 0.006) after LPI, including greater AOD 750 (P < 0.001). One hundred twenty eyes (26.4%) showed residual PACS after LPI. In multivariate regression analysis, superior LPI location (P = 0.004), smaller AOD 750 (P < 0.001), and greater iris curvature (P < 0.001), were predictive of greater angle widening. Temporal or nasal LPI locations (odds ratio [OR], 2.60, P < 0.001) was predictive of poor angle widening. Smaller mean gonioscopy grade (OR, 0.34, 1-grade increment) was predictive of poor angle opening. Superior LPI location results in significantly greater angle widening compared with temporal or nasal locations in a Chinese population with PACS. This supports consideration of superior LPI locations to optimize anatomic changes after LPI. [ABSTRACT FROM AUTHOR]

AIM: To investigate the clinical application value of anterior segment OCT(AS-OCT)in diagnosis and treatment of descemet's membrane detachment(DMD)after intraocular surgery. METHODS: Totally 23 eyes of 21 patients with corneal edema after intraocular surgery in our hospital from June 2016 to April 2019 were analyzed retrospectively. The degree of corneal edema and the descemet's membrane detachment(DMD)were observed by AS-OCT. The patients with mild or above descemet's membrane detachment were treated with anterior chamber gas tamponade, the patients with other corneal edema were treated with drug conservative treatment, and the corneal edema and adhesion of descemet's membrane were observed.RESULTS: In this study, 21 patients(23 eyes)had corneal edema of different degrees, 14 eyes with descemet's membrane detachment,11 eyes with mild or above descemet's membrane detachment were re-examined by AS-OCT one day after anterior chamber gas tamponade. 10 eyes had good adhesion, 1 eye had poor adhesion, and the adhesion was good after anterior chamber gas tamponade again. After 1mo follow-up, the cornea of all the patients recovered to be transparent and their vision recovered well.CONCLUSION:AS-OCT can timely and accurately diagnose and evaluate descemet's membrane detachment and its therapeutic effect.

Abstract Background Primary vitreoretinal lymphoma (VRL) is a rare disease with 30–380 new cases in the United States per year. Its insidious process and spread to the central nervous system (CNS) leads to a mean 5-year survival rate from 41.4 to 71%. Medical treatment of VRL has been summarized extensively in the literature and involves intraocular rituximab and methotrexate as first line agents in unilateral VRL, with systemic chemotherapy to be considered in bilateral or CNS-involving disease. In addition, therapeutic “debulking” vitrectomy has been reported in the literature, with some limited success. Despite this, recurrence rate is high and should always be suspected in the setting of new inflammation. Anterior segment optical coherence tomography (ASOCT) has not been previously used to image VRL recurrence in the anterior vitreous. Case presentation A 63-year-old man, with VRL was found to have cells and debris in the anterior vitreous, 10 months after his first vitrectomy, intravitreal rituximab and methotrexate. Since the patient was phakic at the time of initial vitrectomy, the anterior vitreous had not been removed. ASOCT confirmed the findings. Subsequent surgery removed the lens and debris. Both the patient’s vision and ASOCT improved. Conclusions We suggest that ASOCT of the anterior segment is a useful diagnostic tool to monitor for recurrence of VRL. In biopsy-proven VRL, phakic patients who undergo therapeutic vitrectomy, should also be considered for lens extraction and anterior vitrectomy to limit recurrences.

Abstract Background The object of this study is to investigate the effect of early bleb parameters measured by three-dimensional anterior-segment optical coherence tomography on the surgical success of trabeculectomy. Methods This retrospective study included 45 patients with 19 of exfoliation glaucoma, 17 of primary open angle glaucoma, 4 of neovascular glaucoma, 4 of uveitic glaucoma and 1 of glaucoma caused from familial amyloid polyneuropathy who underwent trabeculectomy. Bleb parameters, such as total bleb height, the position and the width of filtration openings on the scleral flap, bleb wall thickness, fluid-filled cavity height, and bleb wall intensity were assessed by three-dimensional anterior-segment optical coherence tomography 0.5 months after trabeculectomy, and were subjected to a Cox proportional hazard model as potential prognostic factors. Surgical success was defined as: IOP

AIM: To analyze the correlation and consistency of five corneal diameter measurements.METHODS: Totally 25 cases(50 eyes)who underwent ICL implantation in West China Hospital. The preoperative horizontal corneal diameter was measured using measuring caliper, SIRIUS anterior eye assay system, IOL Master500, anterior segment OCT and UBM. RESULTS: The mean WTW distances were 11.54±0.30 mm as obtained with measuring caliper, 11.77±0.33mm with SIRIUS anterior eye assay system, 11.98±0.33mm with IOL Master500, 11.63±0.35mm with anterior segment OCT and 11.53±0.34mm with UBM. No statistical difference was found between measuring caliper and UBM, measuring caliper and anterior segment OCT, UBM and anterior segment OCT. The linear correlation analysis found significant correlation between the measurements of the five measurements. The Bland-Altman analysis for the measuring caliper and SIRIUS, measuring caliper and UBM, measuring caliper and anterior segment OCT found that the absolute values of 95% LOA upper and lower limits were less than 0.5mm.CONCLUSION: The results of the four kinds of corneal horizontal diameter measurements can be interchanged including SIRIUS, UBM, anterior segment OCT and measuring caliper. IOL Master500 results are the largest, that cannot be used as a diagnostic basis for measuring the size of corneal horizontal diameter. The results of other measurement equipment should be combined with clinical practice.

Leopoldo Spadea, Emanuele Tonti, Rita Napolitano Eye Clinic, Department Sensory Organs, Policlinico “Umberto I”, “Sapienza” University of Rome, Rome, Italy Objective: To describe a very unique case of two Descemet stripping automated endothelial keratoplasty (DSAEK) surgeries performed in both eyes of the same patient with an extremely different graft thickness and overall corneal thickness but with the same corrected distance visual acuity (CDVA) 2 years after surgery.Case presentation: A 75-year-old woman with bilateral bullous keratopathy (BK) was submitted to DSAEK surgeries in both eyes, first in right and after 6 months in left eye. CDVA was 20/160 in the right eye and 20/63 in the left eye. Corneal thickness evaluated by anterior segment optical coherence tomography was 569 µm in the right eye and 560 µm in the left eye. The root mean square (RMS) was 2.1 in the right and left eyes. Endothelial cell densities were not detectable in both eyes. The estimated precut donor graft thickness from eye bank was 250 and 40 µm in the right and in the left graft, respectively. Two years after surgery CDVA was 20/25 in both eyes. Corneal thickness was 633 µm with a lenticule thickness of 206 µm in the right eye and 439 µm with a lenticule thickness of 48 µm in the left eye. The RMS was 1.7 in the right eye and 1.4 in the left eye. Endothelial cell density was 2.272 cells/mm2 in the right and 2.154 cells/mm2 in the left eye.Conclusion: DSAEK was safe and effective in the treatment of BK. In our report, the visual outcome resulted to be poorly related either to donor graft thickness or to postoperative corneal thickness. Keywords: anterior segment OCT, bullous keratopathy, Descemet stripping endothelial keratoplasty, graft thickness, visual acuity

The purpose of this study is to quantitatively assess lens opacity, using a swept-source optical coherence tomography (SS-OCT) device for anterior segment assessment, and establish the correlation with Scheimpflug imaging, corrected distance visual acuity (CDVA) and cumulative dissipated energy (CDE). This prospective cross-sectional single-center study enrolled 51 patients (51 eyes) with crystalline lens opacity. Patients with previous ocular surgery, pathologies or general disorders affecting vision were excluded. Eyes were scanned with an SS-OCT device, and lens densitometry was automatically analyzed using a custom MATLAB script which examined lens density, nuclear density and linear density. The same analyses were performed on Scheimpflug images. Preoperative CDVA and CDE during phacoemulsification were recorded. Spearman’s (ρ) and Pearson’s (r) correlation coefficients were assessed according to data normality. Statistically significant correlations were established between SS-OCT and Scheimpflug imaging using lens analysis (ρ = 0.47, p < 0.001), nuclear analysis (ρ = 0.73, p < 0.001) and linear analysis (r = 0.44, p < 0.001). A significant correlation with CDE was found with all the SS-OCT methods (r = 0.57, p < 0.001). Only the nuclear analysis of the SS-OCT scans (Tb = −0.33, p < 0.01) and Pentacam Nucleus Staging (Tb = −0.26, p < 0.05) showed a statistically significant correlation with CDVA. Good inter-device agreement in lens densitometry was found. However, SS-OCT yielded improved lens imaging compared with the Scheimpflug device and a higher correlation with clinical parameters. Thus, high-resolution SS-OCT has the potential to become a preferable option for automatic cataract grading and preoperative planning.

To investigate the corneal epithelial and limbal epithelial alterations in patients under topical glaucoma treatment using anterior segment-OCT (AS-OCT) and to determine the changes of the limbal region due to the preservatives and glaucoma drugs, that can progress to limbal stem cell deficiency (LSCD). Limbal thickness was measured by AS-OCT to evaluate limbal cell deficiency. Forty-seven patients using topical medication for glaucoma, and 48 control subjects were enrolled in this matched case-control study. The patients were divided into four groups according to the treatment regimens. Group 1: One-drug regimen, Group 2: Two-drug regimen, Group 3: Three-drug regimen, Group 4: Four-drug regimen For the ocular surface evaluation; tear break-up time with standard fluorescein sodium sterile strip application, Schirmer test-I, Ocular Surface Disease Index Questionnaire, and AS-OCT were performed. A total of 95 subjects were included: 47 eyes of 47 patients with glaucoma medication and 48 eyes of 48 healthy subjects. There was a statistically significant difference between patients and controls according to BUT, SCH, and OSDI (p < 0.001). The mean central corneal epithelium thickness was 48.5 ± 5.3 in patients and 54.5 ± 5.9 in controls (p < 0.001). The mean central total corneal thickness was 529.2 ± 41.2 in patients and 536 ± 35.3 in controls (p = 0.335). The mean limbal epithelium thickness was 64.1 ± 9.1 in patients and 76 ± 11.5 in controls (p < 0.001). Using at least one glaucoma drug caused limbal area injury, changed ocular surface measurements, and significantly reduced the limbal epithelial thickness where the stem cells reside. The limbal epithelial thickness measurement by AS-OCT seems to be an innovative, non-invasive, and promising technique for detecting and staging corneal damage in topical glaucoma therapy. [ABSTRACT FROM AUTHOR]

To discuss and evaluate new technologies for a better diagnosis of corneal diseases and limbal stem cell deficiency, the outcomes of a consensus process within the European Vision Institute (and of a workshop at the University of Cologne) are outlined. Various technologies are presented and analyzed for their potential clinical use also in defining new end points in clinical trials. The disease areas which are discussed comprise dry eye and ocular surface inflammation, imaging, and corneal neovascularization and corneal grafting/stem cell and cell transplantation. The unmet needs in the abovementioned disease areas are discussed, and realistically achievable new technologies for better diagnosis and use in clinical trials are outlined. To sum up, it can be said that there are several new technologies that can improve current diagnostics in the field of ophthalmology in the near future and will have impact on clinical trial end point design. [ABSTRACT FROM AUTHOR]

Purpose: To demonstrate that rifabutin-related corneal deposits are localized to the deep stroma using anterior segment optical coherence tomography (OCT) and confocal microscopy. Observations: A 55-year-old male with a history of human immunodeficiency virus (HIV) and disseminated mycobacterium avium complex on rifabutin treatment for 3 years presented with bilateral corneal deposits. Confocal microscopy and anterior segment OCT confirm that rifabutin-related corneal deposits are located in the deep stroma, rather than in the endothelium. Conclusions: And Importance: Rifabutin deposits localize to the deep corneal stroma, and can be seen with both confocal microscopy and anterior segment OCT. Anterior segment OCT is a widely available and easily used diagnostic tool, and can provide utility in the diagnosis of corneal deposits.

An 18-year-old girl who had undergone deep anterior lamellar keratoplasty in her left eye for keratoconus a year back presented with inferonasal graft dehiscence with intact host Descemet's membrane and intact anterior chamber after sustaining blunt injury a week prior. The graft was sutured to the host bed, and complete resolution of graft edema was seen in 4 weeks. One year later, she underwent cataract surgery with foldable intraocular lens implantation. At her final follow-up, the best-corrected visual acuity in her left eye was 20/40 with a clear corneal graft and a stable posterior chamber intraocular lens implantation.

Introduction: As various pterygium morphologies have been advocated as contributing factor on corneal astigmatism, little support in the literature available in establishing techniques in measuring pterygium thickness as clinical indicator. Objective: The aim of this study was to describe a quantitative method in determining pterygium thickness using anterior segment optical coherence tomography (AS-OCT). Methods: Anterior segment imaging was performed using enhanced high resolution cornea (EHRC) of Visante™ AS-OCT in 120 primary pterygium eyes. Prior to imaging, corneal topography assessment was performed on each pterygium eye in order to identify its topographic location. Based on topography mapping, three meridians (in degrees) were selected as close as possible to the pterygium border, which signify the demarcation of pterygium from the cornea. Reliability testing between intra and inter-observer of AS-OCT imaging modality was examined using intraclass correlation and scatter plot. Results: The overall (n = 120) mean and standard deviation of pterygium thickness EHRC of AS-OCT modality were 0.48 ± 0.10 mm (confidence interval: 0.45 – 0.50). EHRC of AS-OCT also showed excellent intra and intergrader reliability in measuring pterygium thickness with intraclass correlation of 0.997 (confidence interval: 0.994 – 0.998). Conclusions: EHRC of AS-OCT imaging modality is a better choice in assessing pterygium compared to traditional slit-lamp biomicroscopy. This tool is applicable for future work related to better understanding on the role thickness in pterygium morphology, its progression and prediction of induced corneal astigmatism and visual impairment due to pterygium.

Ryo Yomoda, Hiroki Sasaki, Jiro Kogo, Akira Shiono, Tatsuya Jujo, Reio Sekine, Naoto Tokuda, Yasushi Kitaoka, Hitoshi Takagi Department of Ophthalmology, St Marianna University School of Medicine, Kawasaki, Kanagawa, Japan Purpose: The purpose of this study was to compare straight and angled incisions in 27-gauge microincision vitrectomy in patients with epiretinal membrane (ERM).Methods: Seventy-three eyes of 68 patients with ERM who underwent straight (35 eyes) or angled incision (38 eyes) for 27-gauge microincision vitrectomy were retrospectively evaluated.Results: No statistically significant difference was found between the two groups in postoperative logarithm of minimal angle of resolution best-corrected visual acuity. The intraocular pressure and rate of hypotony 1 day postoperatively did not differ between the straight- and angled-incision groups (intraocular pressure: 11.5 vs 13.4 mmHg, respectively; rate of hypotony: 20% vs 8%, respectively). Surgical wound closing occurred by postoperative day 10 in both groups.Conclusion: A straight incision is as safe and useful in ERM vitrectomy as an angled one. Keywords: 27-gauge vitrectomy, MIVS, epiretinal membrane, straight incision, angled incision, anterior segment OCT

Purpose: To investigate the agreement and reliability of anterior segment optical coherence tomography (AS-OCT) and Scheimpflug imaging in measuring the distance from the anterior edge of an iris-fixated phakic intraocular lens (IF-pIOL) to the corneal endothelium. Methods: Anterior segment configuration was assessed in a total of 62 eyes of which 25 hyperopic and 37 myopic eyes, all corrected with an IF-pIOL. Measurements were performed by two independent observers using AS-OCT (Visante, Model 1000, Carl Zeiss Meditec Inc.) and Scheimpflug imaging (Pentacam HR, Oculus Optikgerate). The distance from the anterior edge of the pIOL to the endothelium was measured in five different positions using both modalities with their corresponding pIOL software. The measurements as well as the inter- and intra-observer reliability of the two imaging modalities were then compared. Results: Distance measurements for all positions performed by AS-OCT were found to be significantly larger than those performed by Scheimpflug imaging, with mean differences ranging from 0.11 to 0.22 mm. Both instruments exhibited good inter- and intra-observer reliability. Conclusion: Anterior pIOL edge to endothelium distance measurements by AS-OCT and Scheimpflug imaging have good intra- and inter-observer reliability. However, as AS-OCT provides larger measurements, these two modalities cannot be used interchangeably. Correction of this difference might be essential for proper decision-making during pre-operative screening for pIOL implantation and post-operative safety monitoring. [ABSTRACT FROM AUTHOR]

The crystalline lens plays an important role in the pathophysiology of primary angle closure and primary angle-closure glaucoma. The aging process is associated with a progressive enlargement of the lens, resulting in greater iridolenticular and iridotrabecular contact, which exacerbates both pupillary block and appositional angle closure, irrespective of the cataract status of the lens. Cataract surgery has been shown to widen the angle and reduce intraocular pressure in eyes with primary angle closure or primary angle-closure glaucoma. Recently, clear lens phacoemulsification has been suggested as a treatment modality in such eyes. We review the literature on clear lens extraction in eyes with angle closure and discuss its efficacy, safety, and indications. Although it is evident that clear lens extraction is beneficial in eyes with primary angle closure and primary angle-closure glaucoma, it is technically challenging and should be performed by experienced surgeons who not only master the procedure but are also able to deal with potential complications. Since the follow-up of the reviewed studies is relatively short, long-term follow-up (>10 years) of patients who undergo this procedure is needed to evaluate the safety and confirm the early benefits reported. [ABSTRACT FROM AUTHOR]

Purpose: To examine the influence of anterior segment optical coherence tomography imaging protocols on the intraobserver and intrasession repeatability of epithelial, stromal, and total corneal thickness measurements.Methods: Repeated anterior segment optical coherence tomography (AS-OCT) images (Spectralis, Heidelberg) were obtained from 15 adults using single 8.3 mm wide horizontal line scans with an average of 2, 10, 20, 30, 50 and 100 B-scans. Volumetric scans consisting of nine 8.3 mm horizontal line scans encompassing a 1.3 mm vertical region were also captured (with 20 B-scans per line scan). Single point thickness measures (at the normal to the tangent of the anterior corneal surface) were compared with thickness measures averaged over the central 6 mm. The impact of B-scan averaging and intraobserver variability were examined for single line scans. For volumetric scans, the impact of the number of line scans upon intraobserver and intrasession variability were calculated.Results: Intraobserver repeatability did not vary significantly as a function of the number of averaged B-scans per line scan, but was lowest for 20-30 averaged B scans. For volumetric scans, increasing the number of line scans did increase scan duration (p < 0.001), with minimal impact upon the average scan quality index (p = 0.06). Averaging more than 3 line scans did not significantly improve intraobserver or intrasession repeatability for either single point or average thickness measurements.Conclusion: AS-OCT volumetric scans with 3 lines each consisting of 20 B-scans with measurements averaged over a central 6 mm of the cornea provide highly repeatable measures of epithelial, stromal and total corneal thickness (95 % LoA ≤ ±3.2 μm for intraobserver repeatability and ≤ ±3.7 μm for intrasession repeatability). This scanning protocol can provide reliable information when monitoring subtle changes in corneal thickness. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of scleral-fixated intraocular lens (IOL) tilt on visual outcomes. Methods: Ninety-four eyes of consecutive 94 patients who underwent scleral-fixated IOL implantation with Z-suture technique were included in this prospective study. The values of pre- and postoperative 12th month uncorrected visual acuity (UCVA), cylindrical refractive error, best-corrected visual acuity (BCVA) and corneal and lenticular astigmatism were recorded. The position of the implanted IOL was evaluated with anterior segment optical coherence tomography (AS-OCT). The relationships between the AS-OCT measurements and the visual acuity or refractive errors were investigated. Results: The IOL position was evaluated as tilted in 68 (72.3%) patients: 29 (30.8%) in both vertical + horizontal axes, 30 (31.9%) in the horizontal axis and 9 (9.6%) in the vertical axis. There were no significant differences between patients with and without tilt IOL position in terms of the UCVA, BCVA, cylindrical refractive error and lenticular astigmatism (p > 0.05, for each). The mean BCVA was significantly higher in the no-tilt group than in the both horizontal + vertical tilt and the vertical tilt groups (p = 0.03, p = 0.04, respectively). The mean lenticular astigmatism was significantly higher in the vertical tilt group than the other groups (p = 0.04). Conclusion: Tilting in IOL position occurs commonly; however, IOLs with tilting on any of the axes do not have significantly worse outcomes when compared with IOLs with no tilt, in terms of visual results and refractive errors. On the other hand, tilting on the vertical axis is observed less commonly, yet is more effective on visual results and refractive errors, when compared with tilting on the horizontal axis. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the performance of deep learning algorithms in the opportunistic screening for primary angle-closure disease (PACD) using combined anterior segment parameters., Methods: This was an observational, cross-sectional hospital-based study. Patients with PACD and healthy controls who underwent comprehensive eye examinations, including gonioscopy and anterior segment optical coherence tomography (ASOCT) examinations under both light and dark conditions, were consecutively enrolled from the Department of Ophthalmology at the Beijing Tongren Hospital between November 2020 and June 2022. The anterior chamber, anterior chamber angle, iris, and lens parameters were assessed using ASOCT. To build the prediction models, backward logistic regression was utilized to select the variables to discriminate patients with PACD from normal participants, and the area under the receiver operating characteristic curve was used to evaluate the efficacy of the opportunistic screening., Results: The data from 199 patients (199 eyes) were included in the final analysis and divided into two groups: PACD (109 eyes) and controls (90 eyes). Angle opening distance at 500 μm, anterior chamber area, and iris curvature measured in the light condition were included in the final prediction models. The area under the receiver operating characteristic curve was 0.968, with a sensitivity of 91.74 % and a specificity of 91.11 %., Conclusion: ASOCT-based algorithms showed excellent diagnostic performance in the opportunistic screening for PACD. These results provide a promising basis for future research on the development of an angle-closure probability scoring system for PACD screening., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

The accurate segmentation of AS-OCT images is a prerequisite for the morphological details analysis of anterior segment structure and the extraction of clinical biological parameters, which play an essential role in the diagnosis, evaluation, and preoperative prognosis management of many ophthalmic diseases. Manually marking the boundaries of the anterior segment tissue is time-consuming and error-prone, with inherent speckle noise, various artifacts, and some low-quality scanned images further increasing the difficulty of the segmentation task. In this work, we propose a novel model called SeqCorr-EUNet with a dual-flow architecture based on convolutional gated recursive sequence correction for semantic segmentation and quantification of AS-OCT images. An EfficientNet encoder is employed to enhance the intra-slice features extraction ability of semantic segmentation flow. The sequence correction flow based on ConvGRU is introduced to extract inter-slice features from consecutive adjacent slices. Spatio-temporal information is fused to correct the morphological details of pre-segmentation results. And the channel attention gate is inserted into the skip-connection between encoder and decoder to enrich the contextual information and suppress the noise of irrelevant regions. Based on the segmentation results of the anterior segment structures, we achieved automatic extraction of essential clinical parameters, 3D reconstruction of the anterior chamber structure, and measurement of anterior chamber volume. The proposed SeqCorr-EUNet has been evaluated on the public AS-OCT dataset. The experimental results show that our method is competitive compared with the existing methods and significantly improves the segmentation and quantification performance of low-quality imaging structures in AS-OCT images., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To analyze differences in refractive outcome Δ (difference between postoperative and expected refractive error) and in anterior segment changes between cataract surgery patients and combined phacovitrectomy patients. We also aimed to provide a corrective formula allowing to minimise the refractive outcome Δ in combined surgery patients., Methods: Candidates for phacoemulsification and combined phacovitrectomy (respectively PHACO and COMBINED groups) were prospectively enrolled in two specialised centres. Patients underwent best corrected visual acuity (BCVA) assessment, ultra-high speed anterior segment optical coherence tomography (OCT), gonioscopy, retinal OCT, slit lamp examination and biometry at baseline, 6 weeks postoperatively and 3 months postoperatively., Results: No differences in refractive Δ, refractive error and anterior segment parameters were noted between PHACO and COMBINED group (109 and 110 patients respectively) at 6 weeks. At 3 months, COMBINED group showed a spherical equivalent of -0.29 ± 0.10 D versus -0.03 ± 0.15 D in PHACO group (p = 0.023). COMBINED group showed a significantly higher Crystalline Lens Rise (CLR), angle-to-angle (ATA) and anterior chamber width (ACW) and a significantly lower anterior chamber depth (ACD) and refractive Δ with all 4 considered formulas at 3 months. For IOL power lower than 15, a hyperopic shift was observed instead., Conclusions: Anterior segment OCT suggests anterior displacement of the effective lens position in patients undergoing phacovitrectomy. A corrective formula can be applied to IOL power calculation to minimize undesired refractive error., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To describe the clinical and Anterior Segment Swept-Source Optical Coherence Tomography (AS-SS OCT) findings in Bilateral Acute Depigmentation of the Iris (BADI).Design: Retrospective descriptive study of three clinical cases.Results: Three women diagnosed with BADI shared a history of bacterial infections treated with moxifloxacin. The AS-SS OCT showed damage from the collarette to the root of the iris, without affecting the pupillary area. In the affected areas, the anterior edge had lost its homogeneous hyper-reflectivity. The stroma was thinned and showed a patchy and diffused hyper-reflectivity. The pigmentary epithelium appeared unaffected.Conclusions: AS-SS OCT findings, not previously described, locate the damage in BADI in the anterior edge and iridian stroma, areas which are rich in melanocytes and permeable to aqueous humor. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to describe findings demonstrated by anterior segment spectral domain optical coherence tomography (AS-OCT) in various types of deeply embedded corneal foreign bodies. Methods: In this experimental study, an ex vivo model of calf eyes was used and seven different foreign bodies were deeply embedded in the cornea, consisting of five different materials: glass, plastic, metal, wood, and pencil graphite. The eyes were photographed and then scanned by AS-OCT. The images were analyzed to determine distinguishing characteristics for each material. Results: Various materials presented unique characteristics in AS-OCT. The opaque materials (pencil graphite, metals, and wood) demonstrated a hyper-reflective anterior border, whereas the posterior border signal could not be clearly identified due to the shadowing effect. Moreover, a chain of signals was characteristic of both pencil graphite and metals though a "mirroring effect" was unique for metals. Wood, as an opaque material, appears as a hyper-reflective mass with a spectrum of penetrability depending on the degree of concentration. Transparent materials demonstrated hyper-reflective sharp borders when surrounded by air or fluid, as opposed to when being embedded purely in the corneal stroma. Conclusions: This study shows that AS-OCT was used to systematically define a novel set of distinguishing characteristics specific to various materials extruding from the cornea, fully embedded in the cornea, and intruding into the anterior chamber. Hopefully, the described characteristics of each material can aid clinicians in diagnosing the type of the material embedded and the depth of its involvement in ocular injury. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to use Triton® SweptSource OCT to evaluate the morphology of blebs formed when eyes are treated with XEN® implants and to compare these with the blebs in successfully functioning eyes after trabeculectomy (TB) and with eyes of healthy controls. Methods: A cross-sectional, observational study. We analyzed 25 eyes, 15 after TB and 10 with XEN® implants, comparing them with 23 healthy eyes (controls). We evaluated the conjunctival morphology of the eyes using AS-OCT. The main parameters evaluated were bleb height, sub-epithelial fibrosis, epithelial thickness, and changes in intraocular pressure (IOP). Results: We found that the filtering blebs formed in eyes in which a XEN® stent was implanted were significantly flatter (bleb height 417 ± 183 μm) than the blebs formed in TB eyes (bleb height 618 ± 256 μm, p < 0.05). Moreover, sub-epithelial fibrosis did not develop in any of the blebs produced by the XEN stent, whereas some fibrosis was evident in 40% of the blebs that formed after TB (p < 0.05). The epithelium was thicker when the XEN implant was used (65 ± 18.5 μm) than when eyes underwent TB (60 ± 17.7 μm), and it was thicker than in control eyes (51 ± 9.7 μm, p < 0.05). Moreover, the decrease in the IOP induced by the XEN® stent (− 8.5 ± 5.3 mmHg) was similar to that produced by TB (− 8.8 ± 5.2 mmHg, p > 0.05). Conclusions: Filtering blebs obtained after the introduction of a XEN® stent were morphologically distinct to those produced by TB, and they are more similar to the healthy conjunctiva. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the incidence of transient dry eye associated with LASIK for myopia and the efficacy of topical cyclosporine A administration. Methods: Group A was formed from 145 (82 female, 63 male) eyes that developed clinically significant dry eye within 1 month post-LASIK and were subjected to cyclosporine A treatment. A "non-symptomatic for dry eye" and age- and gender-matched group (group B) was formed from the same pool of patients to serve as control. Schirmer's, tear film break-up time (TBUT) and Ocular Surface Disease Index (OSDI) questionnaire were evaluated. Central corneal epithelial thickness (CET) and topographic epithelial thickness variability (TVT) were evaluated as quantitative dry eye objective markers. Subjective patient survey was also assessed. Results: Mean age was 39.7±6.2 years for the female and 47.67±9.5 years for the male patients, in group A. Schirmer's test mean preoperative value was 8.4±3.1 mm; and 4.5±3.6 mm at 1 month post-LASIK. Statistically significant decrease from 1 month post-LASIK baseline was found at 12 months (8.2±2.1 mm; P=0.02). Mean preoperative TBUT value was 7.5±2.5 seconds, 6.5±3.1 seconds at 1 month postoperatively, and 7.6±2.0 seconds at 12 months postoperatively, statistically significant to baseline (P=0.04). Preoperatively, CET was 52.37±3.40 µm and TTV was 1.24±0.57 µm, 59.87±3.89 µm, and 2.74±0.57 µm at 1 month post-LASIK respectively and at 12 months, 55.42±2.75 µm and 1.39±0.96 µm. The differences in CET between 12 months post-LASIK vs baseline were statistically significant (P=0.007). The mean preoperative OSDI scores were 11.47±9.97 for group A and 11.79±10.31 for group B (P=0.782), which changed to 23.03±10.17 and 15.13±9.49 at 12 months postoperatively (P<0.05), respectively. Following commencement of cyclosporine A treatment in group A, statistically significant improvement was noted, greater than the one in group B, in all metrics at the 12-month examination in comparison to the 1-month baseline. Conclusion: Topical cyclosporine A treatment is an effective alternative in the management of LASIK for myopia-related transient dry eye. Optical coherence tomography epithelial mapping may provide an objective benchmark in diagnosing and monitoring this significant disorder and its correlation with visual symptoms. [ABSTRACT FROM AUTHOR]