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Primary angle closure glaucoma (PACG) is a major cause of visual impairment, particularly in Asia. Although effective screening tools are necessary, the current gold standard is complex and time-consuming, requiring extensive expertise. Artificial intelligence has introduced new opportunities for innovation in ophthalmic imaging. Anterior chamber depth (ACD) is a key risk factor for angle closure and has been suggested as a quick screening parameter for PACG. This study aims to develop an AI algorithm to quantitatively predict ACD from anterior segment photographs captured using a portable smartphone slit-lamp microscope. We retrospectively collected 204,639 frames from 1586 eyes, with ACD values obtained by anterior-segment OCT. We developed two models, (Model 1) diagnosable frame extraction and (Model 2) ACD estimation, using SWSL ResNet as the machine learning model. Model 1 achieved an accuracy of 0.994. Model 2 achieved an MAE of 0.093 ± 0.082 mm, an MSE of 0.123 ± 0.170 mm, and a correlation of R = 0.953. Furthermore, our model's estimation of the risk for angle closure showed a sensitivity of 0.943, specificity of 0.902, and an area under the curve (AUC) of 0.923 (95%CI: 0.878–0.968). We successfully developed a high-performance ACD estimation model, laying the groundwork for predicting other quantitative measurements relevant to PACG screening. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the use of anterior-segment OCT (AS-OCT) to visualize the aqueous outflow pathway and patency of the scleral flap in glaucoma filtration surgery blebs. Design: Cross-sectional study. Subjects: Two hundred five filtering blebs of 112 patients with glaucoma who had undergone trabeculectomy (Trab, n = 97) or deep sclerectomy (DS, n = 108) surgery with/without mitomycin-C (MMC). Methods: Swept-source AS-OCT raster slices were used to image the Trab and DS blebs in sagittal and coronal planes using a standardized protocol. Bleb appearances were classified into 4 categories based on the scleral flap and sclerostomy/trabeculo-descemet window (TDW) appearance: A—sclerostomy/TDW not visible; B—sclerostomy/TDW visible but scleral flap indiscriminate from sclera; C—scleral flap distinct but edges adherent to surrounding sclera; D—scleral flap edges non adherent to surrounding sclera. Main Outcome Measures: Surgical outcomes were classified into complete success (CS) (intraocular pressure [IOP] ≤18 mmHg with no medications), qualified success (QS) (IOP ≤18 with medications), and failure (F) (IOP >18 mmHg). Results: The proportions of CS, QS, and F in the Trab and DS cohorts were 45.0% and 29.6%, 33.0% and 31.5%, 22.0% and 38.9% respectively, with a median postoperative follow-up of 8.4 years (standard deviation 7.9; interquartile range 3.2–9.0). In QS and failed blebs, category C (Trab, 53.7%; DS, 52.5%) accounted for the majority of scleral flap appearances, followed by categories A and B. Category D (86.0%; 71.9%) accounted for the majority of appearances in Trab and DS blebs with CS. There was a significantly greater proportion of MMC use in categories C and D compared with categories A and B in both Trab (P < 0.0001) and DS (P = 0.02) cohorts, demonstrating the association of intraoperative MMC use with increased patency of the scleral flap. Conclusions: Swept-source AS-OCT may be used to visualize the position and patency of the sclerostomy/TDW and scleral flap in relation to surrounding structures in both sagittal and coronal planes. Although free scleral flap edges are primarily correlated with MMC use, it may also correlate with surgical success. Anterior-segment OCT may be used to complement subjective bleb grading at the slit lamp in the assessment of filtering blebs. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Pedro Carreira, Tomás Loureiro, Ana Rita Carreira, Filipe Gouveia-Moraes, Ana Cardoso, Audrey Sampaio, Paul Campos, Sandra Rodrigues-Barros, Ines Machado, Nuno Campos Centro de Responsabilidade Integrada de Oftalmologia, Hospital Garcia de Orta, Almada, PortugalCorrespondence: Tomás Loureiro, Centro de Responsabilidade Integrada de Oftalmologia, Hospital Garcia de Orta, E.P.E, Av. Torrado da Silva, Almada, 2805-267, Portugal, Email loureiro.tomas@gmail.comIntroduction: Upper tarsal mechanical forces influence corneal epithelial thickness profile, which could modulate corneal astigmatism. Upper eyelid blepharoplasty reduces upper tarsal strength and may have an impact on ocular surface. The aim of this study is to evaluate the effect of upper eyelid blepharoplasty on corneal epithelial thickness profile, astigmatism and aberrations.Methods: Patients with dermatochalasis underwent bilateral upper eyelid blepharoplasty. Anterior segment optical coherence tomography (AS-OCT) (Zeiss Cirrus 5000 HD-OCT) and Pentacam (Oculus, Wetzlar Germany) were performed before surgery and in the 8th postoperative week. Corneal epithelial thickness, keratometry, aberrations and asphericity were considered for statistical purposes. Only right eyes were considered. A p-value lower than 0.05 was considered significant.Results: Thirty eyes of 30 patients were included. The degree of astigmatism did not change after surgery (0.95D vs 0.83D, p=0.23). The difference between preoperative and postoperative steepest axis was 3.1° (p=0.04) with a tendency to change toward the vertical meridian. Mean epithelial thickness was higher in the inferior region both pre- and postoperatively and did not change. ET in the superior octant was lower (42 μm vs 45 μm, p< 0.01) and the difference between inferior and superior octants (I-S) was higher (7 μm vs 3 μm, p< 0.001) before surgery. There were no statistically significant changes in corneal aberrations (p=0.52) and asphericity (p=0.41) after surgery.Conclusion: Our results support that upper tarsus pressure influences epithelial thickness profile and, consequently, the corneal steepest keratometry. These results lead us to postulate that upper eyelid blepharoplasty may influence biometric and keratometric measurements.Keywords: Blepharoplasty, Epithelial Thickness, Corneal Tomography, Anterior-Segment Optical Coherence Tomography

Primary angle closure glaucoma (PACG) is a major cause of visual impairment, particularly in Asia. Although effective screening tools are necessary, the current gold standard is complex and time-consuming, requiring extensive expertise. Artificial intelligence has introduced new opportunities for innovation in ophthalmic imaging. Anterior chamber depth (ACD) is a key risk factor for angle closure and has been suggested as a quick screening parameter for PACG. This study aims to develop an AI algorithm to quantitatively predict ACD from anterior segment photographs captured using a portable smartphone slit-lamp microscope. We retrospectively collected 204,639 frames from 1586 eyes, with ACD values obtained by anterior-segment OCT. We developed two models, (Model 1) diagnosable frame extraction and (Model 2) ACD estimation, using SWSL ResNet as the machine learning model. Model 1 achieved an accuracy of 0.994. Model 2 achieved an MAE of 0.093 ± 0.082 mm, an MSE of 0.123 ± 0.170 mm, and a correlation of R = 0.953. Furthermore, our model’s estimation of the risk for angle closure showed a sensitivity of 0.943, specificity of 0.902, and an area under the curve (AUC) of 0.923 (95%CI: 0.878–0.968). We successfully developed a high-performance ACD estimation model, laying the groundwork for predicting other quantitative measurements relevant to PACG screening.

Introduction: In this work, we provide a detailed characterization of a rare complication—subconjunctival cyst formation after strabismus surgery—in a large German cohort. Methods: We conducted a retrospective analysis of 822 consecutive patients who underwent strabismus surgery between 2015 and 2022. The patients received comprehensive eye and orthoptic examinations preoperatively, at 1 day, and at 3 months postoperatively. Cysts were analyzed with slit-lamp examination, anterior segment optical coherence tomography (AS-OCT), and histopathological subsumption. Results: Nineteen cases of postoperative cysts were observed (2.3%), 12 of which underwent surgical revision. Clinical evaluation including slit-lamp and AS-OCT as well as histological analysis resulted in a classification of three types of cysts: type 1, which is a single hyporeflective cyst, type 2, which is a multilobular hyporeflective cyst, and type 3, a dense hyperreflective granulomatous-like cyst. Eta (η) correlation ratio analysis could show a correlation between time of clinical appearance and type of cyst (Eta = 0.63). Most cysts developed within 20 days after surgery. Not only did cysts more frequently affect the medial rectus muscle, which in most cases underwent a shortening procedure (11/19 tucks, 4/19 resections) for intermittent exotropia (X(T)), but the cyst also formed earlier than in the lateral rectus muscle (Eta = 0.45). No correlation could be shown between the type of surgical procedure and time of cyst occurrence (Eta = 0.1). Patient age and cyst type correlated strongly (Eta = 0.47). The underlying type of strabismus did not correlate with the type of cyst observed. Conclusions: Our cases showed a strong positive correlation to the type of strabismus (X(T)), age (young patients), and the procedure (tuck/resection). We introduce a grading system for postoperative cysts after strabismus surgery, complementing histopathology and slit-lamp aspects with AS-OCT information. [ABSTRACT FROM AUTHOR]

Abstract Introduction In this work, we provide a detailed characterization of a rare complication—subconjunctival cyst formation after strabismus surgery—in a large German cohort. Methods We conducted a retrospective analysis of 822 consecutive patients who underwent strabismus surgery between 2015 and 2022. The patients received comprehensive eye and orthoptic examinations preoperatively, at 1 day, and at 3 months postoperatively. Cysts were analyzed with slit-lamp examination, anterior segment optical coherence tomography (AS-OCT), and histopathological subsumption. Results Nineteen cases of postoperative cysts were observed (2.3%), 12 of which underwent surgical revision. Clinical evaluation including slit-lamp and AS-OCT as well as histological analysis resulted in a classification of three types of cysts: type 1, which is a single hyporeflective cyst, type 2, which is a multilobular hyporeflective cyst, and type 3, a dense hyperreflective granulomatous-like cyst. Eta (η) correlation ratio analysis could show a correlation between time of clinical appearance and type of cyst (Eta = 0.63). Most cysts developed within 20 days after surgery. Not only did cysts more frequently affect the medial rectus muscle, which in most cases underwent a shortening procedure (11/19 tucks, 4/19 resections) for intermittent exotropia (X(T)), but the cyst also formed earlier than in the lateral rectus muscle (Eta = 0.45). No correlation could be shown between the type of surgical procedure and time of cyst occurrence (Eta = 0.1). Patient age and cyst type correlated strongly (Eta = 0.47). The underlying type of strabismus did not correlate with the type of cyst observed. Conclusions Our cases showed a strong positive correlation to the type of strabismus (X(T)), age (young patients), and the procedure (tuck/resection). We introduce a grading system for postoperative cysts after strabismus surgery, complementing histopathology and slit-lamp aspects with AS-OCT information.

We investigated the internal morphology of filtration blebs after XEN gel stent implantation using anterior segment optical coherence tomography (AS-OCT) and identified factors related to intraocular pressure (IOP) postoperatively. Eighteen eyes of 18 patients who had undergone XEN gel stent implantation were analyzed. Blebs were imaged using Visante OCT (Carl Zeiss Meditec AG, Germany) at 6 months and 1 year after surgery and evaluated for quantitative parameters including bleb height, maximum height of internal cavity, maximum bleb wall thickness, and maximum bleb epithelial thickness. Subjects were classified into two groups according to the presence or absence of a definite internal cavity between the conjunctiva and sclera using AS-OCT imaging. Nine eyes (50%) were assigned to the internal cavity group and 9 (50%) to the uniform group. Postoperative IOP was significantly lower in the internal cavity group than in the uniform group both at 6 months and 1 year after surgery (p = 0.024 and p = 0.040). Postoperative IOP showed statistically significant negative correlations with bleb height and the height of the internal cavity (Spearman correlation coefficient r = −0.518, p = 0.028 and r = −0.453, p = 0.034, respectively). AS-OCT facilitates analysis of bleb morphology after XEN gel stent implantation. A larger height of the internal cavity of the bleb appeared to correlate with lower IOP after XEN implantation. [ABSTRACT FROM AUTHOR]

(1) Background: Cell injection therapy is an emerging treatment for bullous keratopathy (BK). Anterior segment optical coherence tomography (AS-OCT) imaging allows the high-resolution assessment of the anterior chamber. Our study aimed to investigate the predictive value of the visibility of cellular aggregates for corneal deturgescence in an animal model of bullous keratopathy. (2) Methods: Cell injections of corneal endothelial cells were performed in 45 eyes in a rabbit model of BK. AS-OCT imaging and central corneal thickness (CCT) measurement were performed at baseline and on day 1, day 4, day 7 and day 14 following cell injection. A logistic regression was modelled to predict successful corneal deturgescence and its failure with cell aggregate visibility and CCT. Receiver-operating characteristic (ROC) curves were plotted, and areas under the curve (AUC) calculated for each time point in these models. (3) Results: Cellular aggregates were identified on days 1, 4, 7 and 14 in 86.7%, 39.5%, 20.0% and 4.4% of eyes, respectively. The positive predictive value of cellular aggregate visibility for successful corneal deturgescence was 71.8%, 64.7%, 66.7% and 100.0% at each time point, respectively. Using logistic regression modelling, the visibility of cellular aggregates on day 1 appeared to increase the likelihood of successful corneal deturgescence, but this did not reach statistical significance. An increase in pachymetry, however, resulted in a small but statistically significant decreased likelihood of success, with an odds ratio of 0.996 for days 1 (95% CI 0.993–1.000), 2 (95% CI 0.993–0.999) and 14 (95% CI 0.994–0.998) and an odds ratio of 0.994 (95% CI 0.991–0.998) for day 7. The ROC curves were plotted, and the AUC values were 0.72 (95% CI 0.55–0.89), 0.80 (95% CI 0. 62–0.98), 0.86 (95% CI 0.71–1.00) and 0.90 (95% CI 0.80–0.99) for days 1, 4, 7 and 14, respectively. (4) Conclusions: Logistic regression modelling of cell aggregate visibility and CCT was predictive of successful corneal endothelial cell injection therapy. [ABSTRACT FROM AUTHOR]

The purpose was to assess the profile of subconjunctival oblique limbus incision (SCOLI) design by using anterior-segment optical coherence tomography (AS-OCT) and try to emphasize the proper technique of wound construction. The structural dimensions and integrity of the wound were acquired from the patients, who had undergone manual small-incision cataract surgery with SCOLI techniques, using a Canon OCT anterior-segment imaging system on the first postoperative day. The use of AS-OCT allowed for an in vivo evaluation of SCOLI in high definition. The radial OCT scan image showed three staggered incisions, including conjunctiva incision, scleral entrance, and inner corneal lip. A tangential scan demonstrated that the internal lip is parallel to the curvature of the peripheral cornea. The en face image showed an asymmetric 4 arc-shaped configuration rather than a symmetrical one. In conclusion, AS-OCT could be used to analyze SCOLI to determine optimal wound construction and geometry. The results of this study indicated that an asymmetric 4 arc-shaped limbus tunnel incision was superior to the conventional linear equivalent in stability and nucleus delivery.

Limbal stem cells (LSCs) maintain the normal homeostasis and wound healing of corneal epithelium. Limbal stem cell deficiency (LSCD) is a pathologic condition that results from the dysfunction and/or an insufficient quantity of LSCs. The diagnosis of LSCD has been made mainly based on medical history and clinical signs, which often are not specific to LSCD. Methods to stage the severity of LSCD have been lacking. With the application of newly developed ocular imaging modalities and molecular methods as diagnostic tools, standardized quantitative criteria for the staging of LSCD can be established. Because of these recent advancements, effective patient-specific therapy for different stages of LSCD may be feasible.

The purpose was to assess the profile of subconjunctival oblique limbus incision (SCOLI) design by using anterior-segment optical coherence tomography (AS-OCT) and try to emphasize the proper technique of wound construction. The structural dimensions and integrity of the wound were acquired from the patients, who had undergone manual small-incision cataract surgery with SCOLI techniques, using a Canon OCT anterior-segment imaging system on the first postoperative day. The use of AS-OCT allowed for an in vivo evaluation of SCOLI in high definition. The radial OCT scan image showed three staggered incisions, including conjunctiva incision, scleral entrance, and inner corneal lip. A tangential scan demonstrated that the internal lip is parallel to the curvature of the peripheral cornea. The en face image showed an asymmetric 4 arc-shaped configuration rather than a symmetrical one. In conclusion, AS-OCT could be used to analyze SCOLI to determine optimal wound construction and geometry. The results of this study indicated that an asymmetric 4 arc-shaped limbus tunnel incision was superior to the conventional linear equivalent in stability and nucleus delivery. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the repeatability of corneal epithelial thickness (CET) measurements in normal eyes and eyes diagnosed with corneal disease using the epithelial thickness map (ETM) of anterior segment optical coherence tomography (OCT)., Methods: In this retrospective study, patients with 3 OCT scans using the ETM mode of Cirrus OCT (Carl Zeiss Meditec AG, Jena, Germany) between October 2021 and January 2024 were reviewed. Two groups of subjects were included: (1) normal subjects with no history of ophthalmic surgery, corneal diseases, and topical antiglaucoma medication uses; and (2) subjects with corneal diseases including dry eye syndrome, recurrent corneal erosion, pterygium, and others. 57 eyes of 57 normal subjects and 106 eyes of 76 patients with corneal disease were included. ETM was analyzed in 25 zones (1 zone within 0-2 mm diameter, 8 zones within 2-5 mm diameter, 8 zones within 5-7 mm diameter, and 8 zones within 7-9 mm diameter). Repeatability was evaluated by calculating intraclass correlation coefficient (ICC), coefficient of variation (CoV), within-subject standard deviation (Sw), and Bland-Altman plot., Results: Among a total of 25 sectors, the normal eyes showed high repeatability (ICC > 0.75, CoV 2.17%-5.29%, and Sw 0.76-1.65 μm) in 23 sectors, and in corneal diseases patients also showed high repeatability (ICC >0.75, CoV 4.17%-9.61%, and Sw 1.29-3.34 μm) in 22 sectors. However, the wide range of 95% limit of agreement (LoA) width of Bland-Altman plot presented in corneal disease group and some peripheral zones in normal eyes indicates some variability of CET measurements., Conclusion: Except for a few peripheral sectors, ETM of Cirrus OCT provides repeatable CET measurements in normal eyes, however in corneal disease group, repeatability was not consistently high. To measure CET accurately, performing multiple measurements is advised especially in patients with corneal disease and patients in whom peripheral CET values.

Purpose: To compare changes in the swept-source (SS) anterior-segment optical coherence tomography (AS-OCT) parameters and intraocular pressure (IOP) control after lens extraction in various spectra of primary angle-closure disease (PACD)., Methods: A total 92 eyes from 92 patients with PACD who underwent lens extraction were included in the study. All patients underwent IOP measurement preoperatively and at 1 day, 1 week, and 1, 3, and 6 months postoperatively. SS AS-OCT was performed in all subjects preoperatively and 1 month postoperatively. All participants were divided into two groups depending on the presence of glaucomatous optic disc or visual field damage (group A, PAC suspect or PAC; group B, PAC glaucoma). The changes in IOP and anterior chamber angle parameters of SS AS-OCT of each group were compared. Regression analysis was performed to find factors associated with the degree of IOP reduction after lens extraction., Results: Preoperatively, there was no significant difference in IOP between the two groups (16.3 ± 2.5 mmHg vs. 16.9 ± 3.2 mmHg, p = 0.297), but the number of glaucoma medications used was greater in group B (0.6 ± 1.0 vs. 2.0 ± 0.9, p < 0.001). Postoperatively, IOP was not significantly different, but the number of medications used was greater in group B (0.2 ± 0.7 vs. 0.9 ± 0.8, p < 0.001). Anterior chamber angle parameters including angle opening distance and trabecular-iris angle had a greater increase in group B after lens extraction. However, the residual iridotrabecular contact (ITC) index was significantly greater in group B (5.6 ± 7.0 vs 10.7 ± 12.1, p = 0.014). A greater change in the ITC index was related to a greater degree of IOP reduction (β coefficient, 0.429; p < 0.001)., Conclusions: Eyes with PAC glaucoma had a greater residual ITC index after lens extraction compared with eyes of other PACD spectrum and required a greater number of glaucoma medications to maintain a similar level of IOP.

An 80-year-old Japanese man presented with decreased vision in his right eye (OD) after every hemodialysis (HD) session beginning several months previously. His local ophthalmologist prescribed antiglaucoma medications because of high intraocular pressure (IOP) (38 mm Hg) OD 4 months previously; with treatment, the IOP fluctuated between 6 and 34 mm Hg OD. When hospitalized, the IOP was measured, and the anterior chamber was observed by anterior-segment optical coherence tomography (AS-OCT) before and after HD. Before HD, the IOP levels were 7 mm Hg OD and 8 mm Hg in the left eye (OS). AS-OCT showed marked anterior iris bowing due to circumferential posterior synechia OD. The scan showed irido-trabecular contact (ITC) in the nasal angle and not the temporal angle OD. Immediately after HD, the IOP levels were 28 mm Hg OD and 12 mm Hg OS; AS-OCT showed ITC in the nasal and temporal angles OD. Since the iris bombe and HD-induced increase in the ITC were expected to have caused the IOP spike and blurred vision, posterior synechialysis and goniosynechialysis were performed OD. Postoperatively, the iris plane flattened; no IOP spike was recorded, and the blurred vision after HD resolved. At 22 months postoperatively, the IOP was 7 mm Hg in both eyes (OU). No deterioration of visual acuity and visual field was recorded during the follow-up period OU. IOP spikes can occur during and after HD because of transient anterior chamber angle obstruction in cases with narrow angles. AS-OCT is useful for detecting minor morphologic changes in the anterior chamber angle during HD.

A 61-year-old Japanese woman presented to our hospital for treatment of systemic serositis associated with systemic lupus erythematosus (SLE). At the initial ophthalmologic examination, her best-corrected visual acuity was 1.2 and 0.6 in her right and left eyes, respectively. Slit-lamp examination showed marked chemosis in both eyes (OU). Swept source-based, anterior-segment optical coherence tomography (AS-OCT) clearly showed conjunctival elevations corresponding to the chemosis in all scan directions OU. In some scans, hyporeflective spaces with luminal structures corresponding to dilated lymphatic channels and nonluminal structures corresponding to interstitial fluid accumulation were seen clearly under the conjunctival epithelium and/or in the parenchyma. In all scan directions, the supraciliary space was seen clearly, suggesting the presence of an annular ciliochoroidal detachment. Fundus examinations showed retinal edema temporal to the optic nerve head and subfoveal serous retinal detachments OU. Ocular effusions resolved by 2 weeks after the start of steroid pulse therapy, and pleural effusions and ascites resolved and pericardial effusion decreased by 2 months. AS-OCT can be useful for understanding the mechanism(s) of the less common anterior-segment ocular manifestations of SLE.

Purpose: To investigate the use of anterior-segment OCT (AS-OCT) to visualize the aqueous outflow pathway and patency of the scleral flap in glaucoma filtration surgery blebs., Design: Cross-sectional study., Subjects: Two hundred five filtering blebs of 112 patients with glaucoma who had undergone trabeculectomy (Trab, n = 97) or deep sclerectomy (DS, n = 108) surgery with/without mitomycin-C (MMC)., Methods: Swept-source AS-OCT raster slices were used to image the Trab and DS blebs in sagittal and coronal planes using a standardized protocol. Bleb appearances were classified into 4 categories based on the scleral flap and sclerostomy/trabeculo-descemet window (TDW) appearance: A-sclerostomy/TDW not visible; B-sclerostomy/TDW visible but scleral flap indiscriminate from sclera; C-scleral flap distinct but edges adherent to surrounding sclera; D-scleral flap edges non adherent to surrounding sclera., Main Outcome Measures: Surgical outcomes were classified into complete success (CS) (intraocular pressure [IOP] ≤18 mmHg with no medications), qualified success (QS) (IOP ≤18 with medications), and failure (F) (IOP >18 mmHg)., Results: The proportions of CS, QS, and F in the Trab and DS cohorts were 45.0% and 29.6%, 33.0% and 31.5%, 22.0% and 38.9% respectively, with a median postoperative follow-up of 8.4 years (standard deviation 7.9; interquartile range 3.2-9.0). In QS and failed blebs, category C (Trab, 53.7%; DS, 52.5%) accounted for the majority of scleral flap appearances, followed by categories A and B. Category D (86.0%; 71.9%) accounted for the majority of appearances in Trab and DS blebs with CS. There was a significantly greater proportion of MMC use in categories C and D compared with categories A and B in both Trab ( P < 0.0001) and DS ( P  = 0.02) cohorts, demonstrating the association of intraoperative MMC use with increased patency of the scleral flap., Conclusions: Swept-source AS-OCT may be used to visualize the position and patency of the sclerostomy/TDW and scleral flap in relation to surrounding structures in both sagittal and coronal planes. Although free scleral flap edges are primarily correlated with MMC use, it may also correlate with surgical success. Anterior-segment OCT may be used to complement subjective bleb grading at the slit lamp in the assessment of filtering blebs., Financial Disclosures: The author(s) have no proprietary or commercial interest in any materials discussed in this article., (© 2024 by the American Academy of Ophthalmology.)

An 80-year-old Japanese man presented with decreased vision in his right eye (OD) after every hemodialysis (HD) session beginning several months previously. His local ophthalmologist prescribed antiglaucoma medications because of high intraocular pressure (IOP) (38 mm Hg) OD 4 months previously; with treatment, the IOP fluctuated between 6 and 34 mm Hg OD. When hospitalized, the IOP was measured, and the anterior chamber was observed by anterior-segment optical coherence tomography (AS-OCT) before and after HD. Before HD, the IOP levels were 7 mm Hg OD and 8 mm Hg in the left eye (OS). AS-OCT showed marked anterior iris bowing due to circumferential posterior synechia OD. The scan showed irido-trabecular contact (ITC) in the nasal angle and not the temporal angle OD. Immediately after HD, the IOP levels were 28 mm Hg OD and 12 mm Hg OS; AS-OCT showed ITC in the nasal and temporal angles OD. Since the iris bombe and HD-induced increase in the ITC were expected to have caused the IOP spike and blurred vision, posterior synechialysis and goniosynechialysis were performed OD. Postoperatively, the iris plane flattened; no IOP spike was recorded, and the blurred vision after HD resolved. At 22 months postoperatively, the IOP was 7 mm Hg in both eyes (OU). No deterioration of visual acuity and visual field was recorded during the follow-up period OU. IOP spikes can occur during and after HD because of transient anterior chamber angle obstruction in cases with narrow angles. AS-OCT is useful for detecting minor morphologic changes in the anterior chamber angle during HD. [ABSTRACT FROM AUTHOR]

Polarization-sensitive anterior-segmental optical coherence tomography (PS-OCT) is useful to evaluate the filtering blebs after trabeculectomy. However, the attenuation phenomenon of OCT signal disturbs the visibility of intra-bleb's structure and distribution of birefringence; a specific parameter of PS-OCT. This study aimed to evaluate the effectiveness of the attenuation-coefficient image of the filtering blebs. This study included 25 eyes 6 months after TLE. The attenuation-coefficient image of blebs was calculated from OCT intensity signal information. The contrast level of the image (reflectivity of bleb's surface wall/reflectivity of scleral flap) in both attenuation-coefficient image and intensity image and the height of the bleb's wall were calculated. The improvement extent of contrast was defined as the ratio of contrast (attenuation-coefficient image's contrast/intensity image's contrast). We compared the contrast of attenuation-coefficient image and intensity image and investigated the relationship between improvement extent of contrast and height of bleb's wall. The contrast of the attenuation-coefficient image (317.7 ± 255.4%) was significantly higher than that of the intensity image (39.1 ± 24.5%) (P <.01) and the improvement extent of contrast was 9.5 ± 4.6 times. Furthermore, there was a positive correlation between the improvement extent of contrast and the height of the bleb's wall (r = 0.44, P =.03). The contrast of the image at depth of filtering blebs was improved by attenuation-coefficient image. It is suggested that the attenuation-coefficient image may improve the visibility of the structure and distribution of birefringence in the blebs compared to the intensity image. [ABSTRACT FROM AUTHOR]

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 anteriorsegment 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 trabeculariris 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. [ABSTRACT FROM AUTHOR]

A 61-year-old Japanese woman presented to our hospital for treatment of systemic serositis associated with systemic lupus erythematosus (SLE). At the initial ophthalmologic examination, her best-corrected visual acuity was 1.2 and 0.6 in her right and left eyes, respectively. Slit-lamp examination showed marked chemosis in both eyes (OU). Swept source-based, anterior-segment optical coherence tomography (AS-OCT) clearly showed conjunctival elevations corresponding to the chemosis in all scan directions OU. In some scans, hyporeflective spaces with luminal structures corresponding to dilated lymphatic channels and nonluminal structures corresponding to interstitial fluid accumulation were seen clearly under the conjunctival epithelium and/or in the parenchyma. In all scan directions, the supraciliary space was seen clearly, suggesting the presence of an annular ciliochoroidal detachment. Fundus examinations showed retinal edema temporal to the optic nerve head and subfoveal serous retinal detachments OU. Ocular effusions resolved by 2 weeks after the start of steroid pulse therapy, and pleural effusions and ascites resolved and pericardial effusion decreased by 2 months. AS-OCT can be useful for understanding the mechanism(s) of the less common anterior-segment ocular manifestations of SLE. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate variability in measured intraocular pressure (IOP) values when correlated with central corneal thickness measurements obtained by both ultrasonic and optical tools. Patients and Methods: We included 46 eyes of 46 healthy subjects (age range 35– 76 years). Exclusion criteria for the current study were patients with confirmed diagnosis of glaucoma, glaucoma suspect patients and those having corneal opacities, scars or prior cornea-based laser vision correction. Central corneal thickness (CCT) was measured using two methods: ultrasonically (CCT1) by pachymeter and optically (CCT2) using anterior-segment optical coherence tomography (AS-OCT). The IOP was measured in all subjects using Goldmann applanation tonometry (GAT). Results: No significant difference was detected comparing intraocular pressure values and CCT-corrected intraocular pressure (IOPcc1 and IOPcc2) (P=0.47 and P=0.06, respectively) among the study participants. A significant negative correlation was found between corneal thickness-corrected IOP values and the measured central corneal thickness by both optical and ultrasonic tools (P=0.004 and P=0.001, respectively). Conclusion: Intraocular pressure appears to be dependent and positively correlated with CCT changes. However, this does not appear to depend largely on methods used for measuring the CCT in the current study. Corrected intraocular pressure is negatively correlated to both ultrasonically and optically measured central corneal thickness. [ABSTRACT FROM AUTHOR]

Abstract Background The prospective observation study aimed to evaluate changes in corneal higher-order aberrations induced by advancement of pterygium using an anterior-segment optical coherence tomography (AS-OCT) and Zernike aberration analysis. Methods The corneal topography of 284 eyes with primary pterygia originating from the nasal region was measured using an AS-OCT (SS-1000, Tomey). With anterior corneal elevation data, Zernike polynomial coefficients were calculated in diameters of 1.0, 3.0, and 5.0 mm, and the coma, spherical, coma-like, spherical-like, and total higher-order aberrations were obtained. Pterygium size was also measured as a ratio of positions of the pterygium end with respect to the corneal diameter and categorized in eight classes: less than 15%, 15–20%, 20–25%, 25–30%, 30–35%, 35–40%, 40–45, and 45% or larger. Increases in the aberrations were analyzed with reference to those in eyes with pterygium size

Keywords: Acanthamoeba keratitis; anterior-segment optical coherence tomography; bilateral keratitis; case report; radial keratoneuritis EN Acanthamoeba keratitis anterior-segment optical coherence tomography bilateral keratitis case report radial keratoneuritis 871 873 3 11/03/21 20211215 NES 211215 Introduction Acanthamoeba keratitis (AK) is a rare but vision-threatening keratitis that is usually unilateral; however, it has been reported to be bilateral with the use of contact lenses or orthokeratology.[1] Apart from contact lens use, in developing countries, AK is also associated with trauma to the eye, exposure to contaminated soil or water, warmer climates, and poor socio-economic conditions.[2] AK can present as patchy stromal infiltrates, stromal ring infiltrate, epithelial haze, and radial keratoneuritis. This report documents a case of microbiologically proven contact lens-related bilateral AK with radial keratoneuritis in which AS-OCT was used to objectively visualise the radial keratoneuritis and monitor treatment course. Fiest et al.[10] showed pseudomonas on peripheral keratitis secondary to extended wear lenses with an infiltrate running from the edge of the infiltrate to the limbus like a radial keratoneuritis. [Extracted from the article]

Purpose: To compare the clinical characteristics of acute hydrops between eyes with recurrent keratoconus and eyes with treatment-naïve keratoconus. Methods: Six eyes with acute hydrops caused by recurrent keratoconus (recurrent group) and 29 eyes with acute hydrops due to treatment-naïve keratoconus (naïve group) were included. We collected data from anterior-segment optical coherence tomography (AS-OCT), corneal topography and medical records. With AS-OCT, we investigated the location of Descemet's membrane break, the length and frequency of Descemet's membrane detachment, and the speed of corneal thinning before acute hydrops. Results: Descemet's membrane breaks were detectable in 6 cases in the recurrent group (100%) and 7 cases in the naïve group (70%). Distance from the break to the central line was 2–3 mm in the recurrent group, and less than 1 mm in the naïve group (p <.001). Detachment length was significantly greater in the recurrent group than in the naïve group (p =.003). Steep corneal power values tended to increase before acute hydrops in the recurrent group, but the difference between groups was not significant (observation period; 6.03 ± 2.67, 7.36 ± 5.53 years, respectively). Penetrating keratoplasty was required in 5 cases (83%) in the recurrent group, and 8 cases (28%) in the naïve group (p =.02). Conclusions: Acute hydrops due to recurrent keratoconus occurred around graft-host junctions and was more severe than that in eyes with treatment-naïve keratoconus. Severity assessment of Descemet's membrane detachment using AS-OCT provided clues not only for diagnosis, but also for predicting prognosis. [ABSTRACT FROM AUTHOR]

• Pigment dispersion is associated with various morphological changes. • Anterior Segment Optical Coherence Tomography (AS-OCT) shows the anterior chamber angle and iris-lens plane clearly. • With specular microscopy (SM), the effects of pigment dispersion on endothelial cells can be evaluated. To evaluate the differences of central corneal thickness (CCT), corneal endothelial cell morphology, and biometric parameters of the anterior chamber and iridocorneal angle in pigment dispersion syndrome (PDS), pigmentary glaucoma (PG), primary open-angle glaucoma (POAG), and healthy group. Twenty- three eyes in the PDS group, 39 eyes in the PG group, 33 eyes in the POAG group, and 45 eyes in the healthy control group were included in this cross-sectional retrospective study. Corneal endothelial cell density, the coefficient of variation in the cell area, hexagonality, and central corneal thickness (CCT) were obtained by specular microscopy (CEM 530, NIDEK, Japan). Anterior chamber depth (ACD), iridocorneal angle parameters and CCT were measured by anterior segment optical coherence tomography (AS-OCT) (Visante OCT, Carl Zeiss AG, Germany). The mean CCT via specular microscopy (SM-CCT) was measured at the thinnest value in the PG group (531.20 ± 34.91 µm) and the thickest in the control group (569.13 ± 37.52 µm). CV value was higher in PG (34.65 ± 6.84) and POAG group (34.27 ± 9.93) and lower in control group (28.82 ± 5.18) (p = 0,005). The mean AS-OCT-CCT was the thinnest in the PG group (513.61 ± 39.94 µm), and the thickest in the control group (547.04 ± 36.72 µm) (p = 0.001). All parameters of the iridocorneal angle were larger in the PDS and PG groups (p < 0.001). In the correlation analysis of the glaucomatous eyes, a negative correlation between the C/D ratio and SM-CCT and AS-OCT-CCT (p = 0.037, p = 0.017, respectively) and a positive correlation between the pRNFL thickness and AS-OCT- CCT (p = 0.002). CCT values obtained with both SM and AS-OCT were found to be significantly thinner in PG cases. CV, which is the measure of polymegatism, was found to be significantly higher in PG cases. [ABSTRACT FROM AUTHOR]

Purpose: To investigate epithelial thickness-distribution characteristics in a large group of keratoconic patients and their correlation to normal eyes employing anterior-segment optical coherence tomography (AS-OCT). Materials and methods: The study group (n=160 eyes) consisted of clinically diagnosed keratoconus eyes; the control group (n=160) consisted of nonkeratoconic eyes. Three separate, three-dimensional epithelial thickness maps were obtained employing AS-OCT, enabling investigation of the pupil center, average, mid-peripheral, superior, inferior, maximum, minimum, and topographic epithelial thickness variability. Intraindividual repeatability of measurements was assessed. We introduced correlation of the epithelial data via newly defined indices. The epithelial thickness indices were then correlated with two Scheimpflug imaging-derived AS-irregularity indices: the index of height decentration, and the index of surface variance highly sensitive to early and advancing keratoconus diagnosis as validation. Results: Intraindividual repeatability of epithelial thickness measurement in the keratoconic group was on average 1.67 µm. For the control group, repeatability was on average 1.13 µm. In the keratoconic group, pupil-center epithelial thickness was 51.75±7.02 µm, while maximum and minimum epithelial thickness were 63.54±8.85 µm and 40.73±8.51 µm. In the control group, epithelial thickness at the center was 52.54±3.23 µm, with maximum 55.33±3.27 µm and minimum 48.50±3.98 µm epithelial thickness. Topographic variability was 6.07±3.55 µm in the keratoconic group, while for the control group it was 1.59±0.79 µm. In keratoconus, topographic epithelial thickness change from normal, correlated tightly with the topometric asymmetry indices of IHD and ISV derived from Scheimpflug imaging. Conclusion: Simple, OCT-derived epithelial mapping, appears to have critical potential in early and advancing keratoconus diagnosis, confirmed with its correlation with established Scheimpflug-derived asymmetry topometric indices. [ABSTRACT FROM AUTHOR]

Purpose: To compare lens vault between open-angle and narrow-angle eyes in African-, Caucasian-, Hispanic-, Chinese- and Filipino-Americans. Methods: In this prospective study, 436 patients with open angle and narrow angle based on the Shaffer gonioscopic grading classification underwent anterior-segment optical coherence tomography. The Zhongshan Angle Assessment Program was used to calculate lens vault. The narrow-angle group included 32 Chinese-Americans, 22 Filipino-Americans, 26 African-Americans, 24 Hispanic-Americans and 73 Caucasian-Americans. The open-angle group included 56 Chinese-Americans, 29 Filipino-Americans, 45 African-Americans, 27 Hispanic-Americans and 102 Caucasian-Americans. Linear mixed effect regression models, accounting for the use of both eyes and adjusting for age, sex, pupil diameter and spherical equivalent, were used to test for the ethnicity and angle coefficients. Tukey's multiple comparison test was used for pairwise comparisons among the open-angle racial groups. Results: Significant difference in lens vault was found among the open-angle racial groups ( P = 0.022). For the open-angle patients, mean values for the lens vault measurements were 265 ± 288 µm for Chinese-Americans, 431 ± 248 µm for Caucasian-Americans, 302 ± 213 µm for Filipino-Americans, 304 ± 263 µm for Hispanic-Americans and 200 ± 237 µm for African-Americans. Using Tukey's multiple comparison for pairwise comparisons among the open-angle racial groups, a significant difference was found between African-American and Caucasian-Americans groups ( P < 0.001). P values for the rest of the pairwise comparisons were not statistically significant. No significant difference was found among the narrow-angle racial groups ( P = 0.14). Comparison between the open angle and narrow angle within each racial group revealed significant difference for all racial groups ( P < 0.05). Conclusion: Among all the ethnicities included in this study, narrow-angle eyes have greater lens vault compared to open-angle eyes. With the exception of the comparison between African-Americans and Caucasian-Americans, differences in lens vault measurements among the racial groups with open angle were statistically insignificant. Our data suggest that other factors may play a greater role in predisposing Asian races to angle closure. [ABSTRACT FROM AUTHOR]

We report a case of a giant iris cyst treated with neodymium-doped yttrium aluminum garnet laser cystotomy. A 33-year-old woman presented with nanophthalmos and ocular hypertension secondary to a giant iris cyst after congenital cataract surgery in the left eye. Examination with a rotating Scheimpflug camera and anterior-segment optical coherence tomography revealed a large iris cyst surrounding the pupillary region. She underwent laser iridocystotomy and irrigation of the anterior chamber. No recurrence of the iris cyst has been noted after 18 months and the IOP is normal. The cyst was treated successfully by laser cystotomy without other ocular tissue damage. Examination with a rotating Scheimpflug camera and anterior-segment optical coherence tomography proved to be simple and quick methods for assessing the iris cyst. [ABSTRACT FROM AUTHOR]

To correlate the cross-sectional features of filtering blebs on anterior-segment optical coherence tomography (AS-OCT) 2 weeks after trabeculectomy with bleb function at 6 months. Forty-eight eyes followed for 6 months or more after trabeculectomy with mitomycin C were included. Bleb wall reflectivity of developing blebs on AS-OCT 2 weeks postoperatively was correlated with mature bleb function at 6-month postoperative visit. Developing bleb walls at 2 weeks were classified as uniform in 10/48 eyes (20.8%) and multiform in 38/48 eyes (79.2%). Blebs with uniform reflectivity were significantly more likely to have worse function at 6 months ( P < 0.001). Multiform bleb walls had hyporeflective areas seeming to represent loosely-arranged connective tissue (multiple-layer structures), subconjunctival separation, and microcysts. Blebs with multiple-layer structures at 2 weeks were associated with better bleb function at 6 months ( P = 0.025). Intraocular pressure (IOP) of developing blebs at 2 weeks did not correlate with bleb function at 6 months ( P = 0.471). Bleb wall reflectivity on AS-OCT 2 weeks after surgery may predict bleb function at 6 months, whereas IOP of developing blebs may not. [ABSTRACT FROM AUTHOR]

The corneal epithelium represents one of the main structures that undergo degenerative alterations due to antiglaucomatous therapy. Chronic glaucoma therapy containing benzalkonium chloride induces epithelial cellular changes and inflammatory infiltration that in turn causes ocular surface changes resulting in ocular discomfort. Also, age‐related changes can involve the tear film stability and the corneal epithelium surface with reduction of microvilli. The objective of this study is to gain insights about the changes in corneal epithelium in glaucomatous patients divided according to age, type and duration of therapy using anterior‐segment optical coherence tomography (AS‐OCT). This study evaluated a total of 81 eyes of 42 patients for whom corneal epithelium thickness (CET) was measured in different sectors of the cornea. Our results showed no significant differences in CET among patients divided according to type and duration of treatment, while younger patients showed a thinner CET in comparison with older patients. AS‐OCT results demonstrated that the physiological age‐related alterations contributed to corneal epithelium changes in patients undergo chronic antiglaucoma therapy. [ABSTRACT FROM AUTHOR]

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.

Purpose: Assess epidermolysis bullosa (EB)-related corneal pathology using anterior segment optical coherence tomography (AS-OCT) and correlate imaging with clinical metrics in EB patients versus age-matched controls., Methods: EB patients and controls were recruited during an EB conference (July 2018) and at Tufts Medical Center (June-August 2019). Subjects completed a questionnaire, had best corrected visual acuity (BCVA) tested, and underwent AS-OCT scanning. Stromal and epithelial thickness were measured. Depth, length, and type of the three largest lesions were assessed by a masked examiner using a novel pathology grading system. Multivariate analysis of AS-OCT findings and clinical metrics was performed., Results: 62 EB patients and 60 age-matched controls were enrolled. Mean BCVA was 1.8 lines worse in patients (p < 0.001). Vision loss was associated with increased stromal thickness. Discrete lesions were seen in 60.2% of patient eyes, averaging 1.71 ± 1.75 lesions in patients and 0.14 ± 0.42 in controls (p < 0.001). Mean primary lesion depth was 151.88 ± 97.49 μm in patients. Patients showed significant stromal thickening versus controls and lesions were most common in the periphery and inferiorly. Differences in frequency and duration of abrasions and severity of pain were all statistically and clinically significant in patients versus controls (p < 0.001)., Conclusions: AS-OCT can visualize and quantify differences in the corneas of EB patients compared with age-matched controls. Novel findings include quantification of average depth, length, and severity of discrete lesions, and sparing of the superior quadrant from stromal thickening in EB patients. These results support use of AS-OCT and a questionnaire in clinical trials for new EB therapies., (Copyright © 2020. Published by Elsevier Inc.)

Purpose: To investigate the relation between the quantitative iris parameters and iridotrabecular contact (ITC) in patients with primary angle-closure (PAC) and PAC glaucoma (PACG)., Materials and Methods: PAC and PACG with laser peripheral iridotomy were recruited prospectively. Anterior-segment optical coherence tomography (ASOCT) was performed under light and dark conditions, and scans were taken along the vertical and horizontal axes. Iris thickness at 500 μm (IT500) and 750 μm (IT750) from the scleral spur, maximal iris thickness (MIT), and cross sections of the iris area (I-Area) were measured by using software. ITC was defined by the ASOCT as the contact between the peripheral iris and angle wall anterior to the scleral spur. The ITC(+) and ITC(-) groups were defined as eyes that had ITC in two or more quadrants and in no or one quadrant, respectively., Results: A total of 79 eyes of 60 patients (consisting of 48 PAC and 31 PACG) were recruited. The prevalence of superior, inferior, temporal, and nasal ITC was 44 eyes (55.7%), 48 eyes (60.8%), 18 eyes (22.8%), and 16 eyes (20.2%), respectively. These iris parameters of the inferior quadrant, which had the highest prevalence of all the quadrants, were used for the analysis. After adjusting for age, sex, pupil size, and central anterior chamber depth, mean values of IT500 and IT750 were significantly greater in the ITC(+) group than the ITC(-) group (P<0.05). Multivariate-adjusted odds ratios of parameters for the ITC(+) group compared with the ITC(-) group were: IT500, 1.9 (P=0.029); IT750, 2.0 (P=0.011), MIT, 1.4 (P=0.244), and I-Area, 0.97 (P=0.406), respectively, per 0.1-unit increase., Conclusion: Peripheral iris thickness is associated with ITC in patients with angle closure.

Purpose: The aim of the study reported here was to evaluate characteristics of the anterior-segment via anterior-segment optical coherence tomography (AS-OCT) and corneal biomechanical properties using an ocular response analyzer and their changes by peripheral laser iridotomy (PI) in patients with pigmentary glaucoma (PG)., Materials and Methods: Seventeen eyes with PG were included consecutively. AS-OCT and ocular response analyzer measurements were taken before and 3 months after PI. Baseline morphology and change in morphology were analyzed by correlation and multiple linear regression analysis. The main parameters assessed were anterior-chamber (AC) angles and volume as well as corneal hysteresis (CH) and corneal resistance factor., Results: AC angles were found to have decreased significantly in each quadrant after PI (P<0.001), with the highest effect seen in the temporal quadrant, which decreased from 57.0°±9.6° to 44.1°±5.2° (± standard deviation). Mean AC volume decreased significantly from 213.1±36.4 to 187.0±23.4 mm(3) (P<0.001). CH and corneal resistance factor did not change after PI. CH was found to correlate with the preoperative superior and inferior angle width (Spearman's rho 0.553 and 0.615, respectively, P<0.05). Biomechanical parameters showed no predictive value on the change of AC angles or volume., Conclusion: PI in eyes with PG results in a highly significant reduction in the AC angles and volume as visualized by AS-OCT, with the largest effect seen in the temporal quadrant. CH is strongly positively correlated with the superior and inferior preoperative AC angles, emphasizing the importance of the biomechanical properties of the cornea for glaucoma pathogenesis in PG, but corneal biomechanical properties cannot predict PI-related AC changes.