Angle Opening Distance Research Articles

Ultrasound Biomicroscopy Might Predict the Outcome of Phacoemulsification-Visco Dissection in Medically Controlled Primary Angle-Closure Glaucoma Eye With Extensive Peripheral Anterior Synechia.

Objective: The treatment procedures of primary angle-closure glaucoma (PACG) with extensive peripheral anterior synechia (PAS) is a subject of debate. This study is to investigate the clinical features of phacoemulsification (Phaco)-visco dissection in medically controlled PACG patients with PAS > 180° and evaluate the predictability of Ultrasound Biomicroscopy (UBM) parameters on postoperative intraocular pressure (IOP).Methods: 48 eyes (48 patients) with acute angle-closure glaucoma (AACG) and 30 eyes (30 patients) with chronic angle-closure glaucoma (CACG) were prospectively included. All patients underwent phaco-viscogoniolysis and foldable lens implantation and were followed for 1 year after surgery. We analyzed preoperative and postoperative IOP, the numbers of anti-glaucoma medicine, the visual field value, the extent of PAS, and UBM parameters alterations, and evaluated the correlation between preoperative UBM parameters and one-year postoperative IOP.Results: IOP reduced significantly from 16.24 ± 4.33 to 14.49 ± 3.69 mmHg in AACG group and from 16.16 ± 3.69 mmHg to 14.31 ± 4.12 mmHg in CACG group, and PAS decreased significantly from 270 ± 60.33 to 171 ± 56.44° in AACG group and from 285 ± 70.46 to 168 ± 61.32° in CACG group, and the number of anti-glaucoma drugs decreased significantly in both groups. Several UBM parameters, including anterior chamber depth, trabecular iris angle, and peripheral iris thickness 500 increased while iris convex reduced considerably in the two groups, and angle opening distance 500 and trabecular-meshwork ciliary process angle increased significantly only in AACG group. One-year postoperative IOP correlated with preoperative angle opening distance 500 and trabecular iris angle negatively and iris convex positively.Conclusion: Phaco-visco dissection can effectively reduce IOP, the numbers of glaucomatous medications, and PAS in medically controlled PACG patients with extensive PAS. UBM parameters might be valuable for analyzing postoperative anterior segment structure and predicting postoperative IOP of Phaco-visco dissection in PACG patients with extensive PAS.

Repeatability and Reproducibility of Anterior Chamber Angle Measurement with Swept-Source Optical Coherence Tomography in Patients with Primary Angle Closure Suspect

ABSTRACT Purpose: To evaluate the inter- and intra-observer reliability of anterior chamber (AC) angle measurements obtained by swept-source optical coherence tomography (SS-OCT). Methods: Forty-eight consecutive patients diagnosed with primary angle closure suspect (PACS) were included. Three masked observers at different training levels (one glaucoma specialist, one ophthalmology resident, and one pre-medical college student) measured 192 SS-OCT images of the PACS patients. One observer (the glaucoma specialist) repeated measurements 1 week later. SS-OCT parameters included: Anterior segment volume, including corneal, AC, and iris volume; anterior segment dimensions, including AC depth and width (ACD, ACW), and lens vault (LV); and angle parameters, including angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), and the trabecular iris angle (TIA). Intraclass correlation coefficients (ICCs) were used to measure reliability. Results: For inter-observer reproducibility, ICCs of corneal, AC, and iris volumes were 0.952 to 0.998. ICCs of ACD at all axes were above 0.989. ICCs of ACW and LV were smallest in the 90°-270° axis (0.751 and 0.768) but not significantly different from other axes. ARA, TISA, and TIA at all angles had significantly smallest ICCs 250 µm from the scleral spur compared with 500 µm and 750 µm. The ICCs comparing observers with different training levels had similar ranges and followed similar trends. For intra-observer repeatability, the smallest ICC was 0.843. Decreasing AC depth correlated with increased inter-observer reproducibility. Conclusions: We found excellent intra-observer repeatability for all SS-OCT parameters. Angle measurements have more variation among the observers when taken 250 µm from the scleral spur. Shallow AC might lead to more variability for angle parameters. Non-expert observers may be recruited for high-quality image grading with standard training.

The effects of cyclopentolate 1% versus tropicamide 1% on anterior segment angle parameters in three refractive pediatric groups.

This study aims to assess the effects of topical tropicamide 1% versus cyclopentolate hydrochloride 1% on the main numerical anterior chamber angle parameters using anterior segment optical coherence tomography (AS-OCT) in myopic, emmetropic, and hyperopic pediatric populations. One hundred eight healthy and non-amblyopic children were enrolled in this prospective study. The children were assigned into three refractive groups of myopia, emmetropia, and hyperopia for both tropicamide and cyclopentolate administrations. Half of the children in three groups were instilled tropicamide 1%, and the remaining halves were instilled cyclopentolate hydrochloride 1%. AS-OCT measurements of the anterior chamber angle in three groups were performed at the temporal areas of the right eyes under similar conditions at baseline, 30min after tropicamide, and 45min after cyclopentolate instillations. Main measurements including the angle-opening distance at 500µm anterior to the scleral spur (AOD500), trabecular iris space area at 500µm anterior to the scleral spur (TISA500), and scleral spur angle (SSA) were compared between three refractive groups. The groups were age and gender-matched. The mean baseline spherical equivalents were similar in hyperopia groups of the tropicamide (+2.34 ± 0.44) and cyclopentolate (+2.18 ± 0.32) administrations (p = 0.284), as well as the myopic children administered with tropicamide (-2.68 ± 0.40) and cyclopentolate (-2.74 ± 0.38), (p = 0.406). All baseline measurements of AOD500, TISA500, and SSA measurements were similar in three refractive groups for both tropicamide and cyclopentolate as well as the final measurements and thus measurement changes between two sessions (P >0.05 for all). Both drops induced an increase of AOD500, TISA500, and SSA measurements in three refractive groups (p <0.05 for all). Cycloplegic effects of topical instillations of tropicamide and cyclopentolate lead to a significant increase in anterior chamber angle measurements of AS-OCT. This similar effect of the drops should be considered for proper clinical assessment in children.

Association of peripheral anterior synechiae with anterior segment parameters in eyes with primary angle closure glaucoma

To investigate the association of peripheral anterior synechiae (PAS) with intraocular pressure (IOP) and anterior-segment parameters in subjects with primary angle-closure glaucoma (PACG). A total of 267 subjects with PACG were recruited and underwent gonioscopy and anterior-segment optical coherence tomography (ASOCT). Customized software was used to measure ASOCT parameters, including angle opening distance (AOD750) and trabecular-iris-space-area (TISA750) at 750 µm from the scleral spur, anterior chamber depth, width, area and volume (ACD, ACW, ACA, ACV), iris thickness (IT750), iris area (IAREA), and lens vault (LV). Presenting IOP was defined as the first IOP reading before the initiation of IOP-lowering treatment. The mean age of the 267 subjects was 67.0 ± 8.9 years, 140 (52.4%) were male, and 246 (92.1%) were of Chinese ethnicity. PAS was present in 122 (45.7%) subjects, and was most frequently found in the superior quadrant (79.5%). Subjects with PAS had greater presenting IOP (28.7 ± 12.9 vs 22.4 ± 9.7 mmHg, p < 0.001), narrower AOD750 (p < 0.001), smaller TISA750 (p < 0.001), ACD (p = 0.04), ACA (p = 0.02), ACV (p = 0.01) and larger LV (p = 0.01) compared to PACG eyes without PAS. No significant differences were noted for iris parameters. A multivariate logistic regression analysis showed that higher presenting IOP (β = 0.20, p < 0.001), worse visual field mean deviation (β = − 0.20, p = 0.01) and narrower AOD750 (β = − 0.25, p = 0.03) were the only parameters that significantly correlated with the extent of PAS in clock hours. Almost one-half of the subjects with PACG demonstrated PAS; these eyes were associated with higher presenting IOP, smaller anterior segment dimensions and more severe disease.

Iridocorneal angle assessment in children with spontaneously regressed retinopathy of prematurity.

To assess anterior segment anatomic parameters in school-aged children with spontaneously regressed retinopathy of prematurity (sr-ROP) and in children born preterm without ROP history (preT). sr-ROP and preT children were compared with healthy, born at term children (control group). Biometric characteristics were measured with the IOLMaster. Iridocorneal angle structure was evaluated using Visante AS-OCT, and angle opening distance, trabecular iris space area and scleral spur angle were calculated. Best-corrected visual acuity (BCVA) was measured with the ETDRS chart. We examined 22 eyes of 11 children with sr-ROP, 26 eyes of 13 preT children and 24 eyes of 12 healthy controls, with a median age of 8years. sr-ROP children exhibited worse mean BCVA and reduced AL compared to controls (p = 0.001 and p = 0.007, respectively). A narrower iridocorneal angle was found in sr-ROP compared to the preT and the control groups. Preterm children were found to have similar anterior chamber angle metrics compared to the full-term control group. In this study, school-aged children with a history of sr-ROP had narrower angles compared to preterm- and term-born children. AS-OCT demonstrated structural differences of the iridocorneal angle in sr-ROP, possibly reflecting a mild developmental arrest of the anterior segment.

Analysis of Iris volume using swept-source optical coherence tomography in patients with type 2 diabetes mellitus.

To evaluate iris volume before and after pupil dilation using swept-source anterior segment optical coherence tomography (SS-ASOCT) and investigate the associated factors of iris volume and iris volume change after pupil dilation in patients with type 2 diabetes mellitus (T2DM). A cross-sectional study was conducted in Zhongshan Ophthalmic Center among T2DM registered patients in the community of Guangzhou, China. Anterior chamber volume (ACV), iris volume, anterior chamber depth (ACD), angle opening distance at 500 μm (AOD 500) and pupil diameter were estimated using SS-ASOCT (CASIA; Tomey, Nagoya, Japan). Venous blood was taken for the measurement of glycosylated haemoglobin A1c (HbAlc). All biometric measurements were performed before and after pharmacologic pupil dilation. A total of 117 subjects were included in the analysis. The mean age (±SD) was 64.96 ± 7.75 years, and 62.4% were females. After pupil dilation, iris volume decreased in all eyes. Shorter duration of diabetes (p = 0.035), longer axial length (p < 0.001) and smaller pupil diameter (p < 0.001) were associated with larger iris volume. The change in iris volume per millimetre change in pupil diameter was 1.35mm3 /mm. Smaller baseline iris volume (p = 0.002) and higher HbA1c level (p = 0.010) were associated with smaller change in iris volume per millimetre change in pupil diameter, after adjusting for other factors. Iris volume can be estimated by SS-ASOCT. Diabetic duration was associated with static anatomy of iris volume, while HbA1c level indicated the dynamic response of iris volume. It is likely that diabetic duration and HbA1c level could affect the macroscopic and microscopic composition of the iris in the diabetic population.

Effect of High Myopia on Dynamic Changes of Anterior Angle After Pharmacologic Mydriasis in Cataract Patients: A SS-ASOCT Study.

PurposeThe purpose of this study was to evaluate the effect of high myopia on anterior angle change after pharmacologic mydriasis in patients with cataract using swept-source anterior segment optical coherence tomography (SS-ASOCT).MethodsThis prospective cross-sectional study continuously recruited patients with cataract aged 40 years and older during the period August 2019 to August 2020. The anterior segment parameters, including central corneal thickness (CCT), anterior chamber depth (ACD), angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), trabecular-iris angle (TIA), angle to angle width (ATA), and anterior chamber volume (ACV), were obtained using SS-ASOCT at baseline and 30 minutes after mydriasis. Regression analyses were performed to identify the factors related to the relative change of AOD500 (ΔAOD500).ResultsA total of 938 patients (938 eyes) were included. The AOD500 decreased from 0.46 ± 0.22 mm to 0.40 ± 0.19 mm, with percent ΔAOD500 of −13.59% ± 37.73% (P = 0.005). The patients with high myopia had a smaller reduction of anterior angle parameters, with a percent ΔAOD500 of −22.74% ± 58.09%% in non-high myopic eyes and −0.84% ± 45.47% in high myopic eyes (P < 0.001). The stepwise multivariate regression demonstrated that the smaller reduction of AOD500 were independently associated with younger age (coefficient = −2.11, 95% confidence interval [CI] = −2.59 to −1.64, P < 0.001), presence of high myopia (coefficient = 15.35, 95% CI = 3.63 to 27.07, P = 0.010), greater baseline TISA500 (coefficient = 60.78, 95% CI = 8.75 to 112.82, P = 0.022), and ATA (coefficient = 11.21, 95% CI = 4.53 to 17.89, P = 0.001).ConclusionsThe anterior chamber angle decreased after pharmacologic mydriasis in these patients with cataract. Angle shallowing after pharmacologic mydriasis was significantly less pronounced in high myopic eyes than in non-high myopic eyes.Translational RelevanceThese findings are informative for the relative less risk of angle-closure glaucoma in highly myopic eyes.

Associations of lens thickness and axial length with outcomes of laser peripheral iridotomy

To investigate the association of axial length (AL), lens thickness (LT), and lens vault (LV) with postoperative anterior chamber angle metrics after laser peripheral iridotomy (LPI). Prospective observational study of 69 patients (97 eyes) were diagnosed as primary angle-closure suspect (PACS), primary angle closure (PAC) or primary angle-closure glaucoma (PACG). AL, LT, anterior central chamber depth (ACD), angle opening distance (AOD), trabecular iris angle (TIA), and angle recess area (ARA) were measured before and 1wk after LPI. The association between AL, LT, LV with ACD, AOD, TIA, ARA were analyzed by comparing the differences between preoperative and postoperative measurements for anterior segment biometric parameters. ACD, AOD, TIA, and ARA were significantly increased after LPI (all P<0.05). Greater LT was significantly associated with greater postoperative increases in ACD, AOD, TIA, and ARA (all P<0.05). AL was not significantly associated with changes of anterior segment biometric parameters. Greater LV was significantly associated with greater postoperative increases in ACD, AOD, and TIA (all P<0.05), but was not significantly associated with changes of ARA. Greater baseline LT and LV measurements are associated with greater increases in anterior segment biometric parameters after laser peripheral iridotomy. AL are not associated with the change of anterior segment biometric parameters.

Identification of peripheral anterior synechia with anterior segment optical coherence tomography.

To generate a model that evaluates the presence and extent of peripheral anterior synechia (PAS) based on anterior segment optical coherence tomography (AS-OCT). The extent of PAS involvement in the eyes of patients with angle closure was assessed by indentation gonioscopy, and the part of non-PAS and PAS were assigned into two groups (NPAS and PAS). Anterior chamber angles were then imaged by AS-OCT with light-emitting diode (LED) irradiation directly into the pupils, leading to pupillary constriction and increasing anterior chamber angle width. Parameters including the angle opening distance at 750μm anterior to the scleral spur (AOD750) and trabecular-iris space area at 750μm anterior to the scleral spur (TISA750) were then obtained. The differences before and after LED irradiation of AOD750 and TISA750 were calculated and used to generate a PAS model based on binary logistic regression. Validation data were then tested. A total of 258 AS-OCT images in 14 eyes were assigned to the modeling data, and 120 were assigned to the validation data. There were no differences in AOD750 and TISA750 in the dark between NPAS and PAS (PAOD750 = 0.258, PTISA750 = 0.486), whereas after LED light exposure, TISA750light was larger in NPAS than in PAS (P = 0.047). The light-dark differences of both parameters showed significant differences between the two groups (PAOD750dif = 0.019, PTISA750dif < 0.001). The area under the curve of the model performance was 0.841, and the overall correct rate was 80.8% based on the validation data. The present study demonstrates that the AS-OCT-based PAS model could be useful in the identifying of the presence of synechial angle closure and evaluating the extent of PAS in a single eye.

Anterior Chamber Measurements in Healthy Children: A Cross-Sectional Study Using Optical Coherence Tomography.

PurposeTo establish anterior chamber measurements in children and investigate the influence of demographic factors on anterior chamber development.MethodsHandheld optical coherence tomography was used to scan the anterior chamber of participants’ eyes, without sedation. ImageJ was used to generate quantitative anterior chamber measurements, including central corneal thickness (CCT), anterior chamber width, trabecular meshwork length (TML), Schwalbe's line–angle opening distance (SL-AOD), and trabecular iris surface area (SL-TISA). The average anterior chamber measurements per age group, with 95% prediction intervals, were estimated using fractional polynomial modeling. Mixed regression models were used to evaluate the influence of age, gender, eye, angle, and refractive error variation on anterior chamber measurements.ResultsScans from 223 healthy children (2 days to 15 years of age) and 59 adults (16 to 47 years of age) were included. The anterior chamber width, TML, Schwalbe's line–angle opening distance, and Schwalbe's line–trabecular iris surface area significantly increased, whereas CCT decreased with aging (all P < 0.001). The anterior chamber has a rapid phase of development during the first 18 months of age and reaches maturity by the age of 5 years. Girls have significantly smaller anterior chambers compared with boys (all P < 0.001). There was no difference between right and left eye development (all P > 0.05). The temporal TML development was significantly greater than the nasal TML (P < 0.05). CCT development was negatively correlated with refractive power.ConclusionsThis novel, non-invasive study describes the postnatal development of anterior chamber in newborn children.Translational RelevanceOur established quantitative measurements have potential clinical use in understanding anterior segment diseases.

Intraocular pressure changes after phacoemulsification in pseudoexfoliation versus healthy eyes

BackgroundPseudoexfoliation (PXF) syndrome is the most common cause of secondary glaucoma worldwide. This systemic disorder causes further damage to the optic nerve and ultimately increases the need for surgical interventions. Therefore, intraocular pressure (IOP) control is very important in these patients. The aim of this study was to compare IOP changes after phacoemulsification in subjects with PXF syndrome compared to those without this syndrome.Methods61 patients were enrolled in this prospective clinical study. Subjects were assigned into two groups based on presence or absence of PXF syndrome. IOP and anterior chamber angle parameters including: angle opening distance (AOD) and trabecular-iris surface area (TISA) measured one day preoperatively and 3 months postoperatively. Intraoperative metrics factors including: infusion fluid usage (IFU), cumulative dissipated energy (CDE) and aspiration time (AT) were obtained from the phacoemulsification machine at the end of each surgery. IOP changes, anterior chamber angle parameters and intraoperative metrics factors were compared between groups.ResultsMean IOP before surgery was significantly higher in the PXF group (14.70 mm Hg) compared to controls (12.87 mm Hg) (P-value < 0.01). Phacoemulsification decreased IOP in both, but to greater extent in the PXF group (p-value < 0.01). AOD and TISA also increased significantly following surgery in both groups. The results showed that postoperative IOP was negatively correlated with preoperative IOP in both groups (p-value < 0.01). Also, IOP after phacoemulsification was negatively correlated with IFU in the PXF group (p-value = 0.03).ConclusionsPatients with PXF syndrome exhibited a reduction in IOP and increase in anterior chamber angle parameters after phacoemulsification. We observed a greater IOP reduction in PXF subjects when it was compared to controls. Higher preoperative IOP and intraoperative IFU were associated with more IOP reduction in the PXF group.

Circumferential Assessment of Changes in Anterior Segment Characteristics and Baseline Predictors of Angle Widening After Laser Iridotomy in Caucasian Eyes.

Laser peripheral iridotomy (LPI) widened the iridocorneal angle and flattened the iris circumferentially in Caucasian eyes and baseline refractive error, lens vault, and iris volume play a significant role in the angle widening. The purpose of this study was to investigate circumferential angle widening and iris changes after LPI using swept-source optical coherence tomography (SS-OCT) in Caucasian eyes with the use of novel anterior segment parameters. A total of 130 eyes (68 primary angle-closure suspect, 34 primary angle closure, and 28 primary angle-closure glaucoma eyes) of 66 subjects underwent 360-degree SS-OCT (SS-1000 CASIA) angle imaging and gonioscopy in the dark before and 7, 30, 90 days after LPI. For each eye, 16 frames (11.25 degree apart) were selected for analysis from 128 cross-sectional images, and novel 2-dimensional and 3-dimensional anterior segment parameters namely angle opening distance area (AODA) and the trabecular-iris space volume (TISV) 750 µm from the scleral spur, as well as iris parameters such as iris thickness (IT750 and IT2000), iris curvature, and iris curvature area were measured for each image. AODA and TISV were significantly increased and the iris curvature and iris curvature area were significantly decreased at days 7, 30, and 90 after LPI when compared with their baseline (all P<0.001) but there was no significant change in the IT750 and IT2000 (all P>0.05). The multivariable linear regression model showed a significant association of ΔAODA with refractive error (β=-0.23, P=0.013), lens vault (β=2.8, P=0.007), and iris volume (β=-0.11, P=0.027) after adjusting for age and sex. LPI widened the iridocorneal angle and flattened the iris circumferentially in Caucasian eyes in this study. Baseline refractive error, lens vault, and iris volume play a significant role in the circumferential angle widening by LPI.

Vitreous Decompression Combined with Phacoemulsification for Medically Unresponsive Acute Angle Closure.

The management of acute angle closure combined with an extremely shallow anterior chamber and cataract remains complex. This study evaluated a technique of vitreous needle aspiration combined with phacoemulsification for the treatment of acute angle closure with continuous high intraocular pressure (IOP). We retrospectively reviewed the results of vitreous needle aspiration combined with phacoemulsification in 17 eyes (17 patients) with acute angle closure with continuous high IOP and coexisting visually significant cataracts between September 2018 and April 2020 at the glaucoma unit of the affiliated Changshu Hospital of Xuzhou Medical University. The main outcomes were the best corrected visual acuity (BCVA), IOP, anterior chamber depth (ACD), angle open distance 500 (AOD500), number of antiglaucoma medications, and surgery-associated complications. There were no complications during phacoemulsification and a foldable acrylic intraocular lens was implanted in the capsular bag in all 17 patients. For all patients, vitreous needle aspiration was successful at the first attempt. The BCVA improved from 2.02 ± 0.54 logMAR preoperatively to 0.73 ± 0.57 logMAR postoperatively at the final examination (p < 0.001). The mean IOP was 54.47 ± 5.33 mmHg preoperatively and 15.59 ± 2.35 mmHg at the final examination (p < 0.001) without any medication. The ACD was 1.70 ± 0.16 mm preoperatively and 3.35 ± 1.51 mm at the final examination (p < 0.001). The AOD500 was 0.07 ± 0.02 mm preoperatively and 0.51 ± 0.04 mm at the final examination (p < 0.001). Our vitreous needle aspiration technique can be performed safely in phacoemulsification for the management of acute angle closure with continuous high IOP.

Iridocorneal contact as a potential cause of corneal decompensation following laser peripheral iridotomy.

This study aimed to investigate the relationship between corneal decompensation following laser peripheral iridotomy (LPI) and iridocorneal endothelial contact. Retrospective observational case series. Specular microscopy images of LPI recipients with narrow angles were taken at the central cornea and the 8 midperipheral corneal regions at approximately 3mm from the center. Eleven eyes of 11 patients had a minimum of ≤ 1600cells/mm2 among 8 midperipheral corneal endothelial cell densities (ECDs). Radial scans of the angles in the 8 directions were taken with ultrasound biomicroscopy (UBM) in the supine and face-down positions. The minimum and maximum angle opening distance at 750μm from the scleral spur of the 8 directions were defined as the narrowest and widest angles, respectively. The ECD of the narrowest angle direction was compared with the ECD of the widest angle direction. When UBM was performed with the subject in the supine position, the iris and cornea at the narrowest angle were in contact in only 4 of 11 eyes, while in the face-down position, the iris and the cornea at the narrowest angle were in contact in 10 of the 11 eyes. In the face-down UBM, the midperipheral ECD of the narrowest angle direction was significantly smaller than the midperipheral ECD of the widest angle direction (P = 0.006). The ECD of the narrow angle direction can decrease after LPI. This suggests that corneal endothelial cell damage following LPI may be due to mechanical damage from iridocorneal endothelial contact.

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

BackgroundTo evaluate changes in anterior segment morphology on anterior segment optical coherence tomography (AS-OCT) following pars plana vitrectomy (PPV) without tamponade.MethodsPatients who underwent PPV without tamponade for epiretinal membrane were evaluated. Eligible patients underwent intraocular pressure (IOP) measurement and AS-OCT preoperatively as well as 1 month and 6 months post-operatively. Anterior chamber width (ACW), anterior chamber depth (ACD), trabecular iris angle (TIA), angle opening distance at 500 and 750 µm (AOD), and trabecular iris space area at 500 and 750 µm (TISA) at four quadrants were recorded and analyzed. Additionally, the mean values of TIA (MTIA), AOD (MAOD), and TISA (MTISA) for each eye (mean of four quadrants) were analyzed.Results23 patients completed the study. The mean age of participants was 56.4 ± 3.6 years of age and 13/23 (56%) were female. Mean IOP of patients was 18.1 ± 1.1, 18.3 ± 1.1, and 18.1 ± 1.2 preoperatively,1 month post-operatively, and 6 months post-operatively, respectively. (p = 0.83). No difference was detected post-operatively in measurements of ACW, ACD, MTIA, MAOD500, MAOD750, MTISA500, and MTISA750.ConclusionPars plana vitrectomy without tamponade was not associated with changes in anterior chamber morphology.

Posture-Related Changes of Intraocular Pressure in Patients With Acute Primary Angle Closure.

PurposeTo evaluate the posture-related change in intraocular pressure (IOP) of eyes with angle-closure disease and the associated factors.MethodsEyes were prospectively enrolled and divided into three groups: eyes with acute primary angle-closure (APAC), fellow eyes of acute primary angle-closure (FAPAC), and eyes with nonacute primary angle-closure disease (PACD). All of them had been treated with laser peripheral iridotomy. IOP was measured in the sitting, supine, and lateral decubitus positions (LDP) five minutes after posture change. Anterior chamber angle parameters and angle-closure mechanism were evaluated by anterior segment optical coherence tomography.ResultsForty-four eyes were enrolled into each group. APAC eyes showed more LDP-Sitting IOP increase than fellow eyes (5.7 ± 2.7 vs. 2.2 ± 1.4 mm Hg, P < 0.001) and nonacute PACD eyes (3.6 ± 2.0 mm Hg, P < 0.001). LDP-sitting IOP change was higher in eyes with exaggerated lens vault (having shallow anterior chamber and volcano-like iris-lens configuration) than in those without it (APAC: 6.3 ± 2.6 vs. 3.9 ± 2.1 mm Hg, P = 0.011). Linear regression revealed that LDP-sitting IOP change in the APAC group was negatively associated with angle opening distance (AOD), trabecular iris space area, scleral spur angle, and anterior chamber depth (ACD1000). With multivariable stepwise regression analysis, AOD750 remained statistically significant (beta-coefficient = −8.36, P = 0.014).ConclusionsAPAC eyes had significant posture-related IOP changes, associated with narrower angle structures and exaggerated lens vault.

Anatomic Changes and Predictors of Angle Widening after Laser Peripheral Iridotomy: The Zhongshan Angle Closure Prevention Trial

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 (AOD750); poor angle widening, defined as the lowest quintile of change in mean AOD750; 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 AOD750 (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 AOD750 (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.

Comparing the Effect of Lens Extraction With Endocycloplasty to Lens Extraction Alone in Eyes With Plateau Iris Configuration: Pilot Study.

Lens extraction with endocycloplasty (LE/ECPL) results in greater angle deepening than LE alone in plateau iris eyes. This study directly compares an LE/ECPL treatment group with a control group. Quantitatively determine the effect of LE/ECPL versus LE alone for eyes with plateau iris configuration/plateau iris syndrome (PIC/PIS) on angle parameters. Patients with PIC/PIS who underwent LE/ECPL or LE alone were reviewed. Eyes with ultrasound biomicroscopy-documented PIC that underwent anterior segment optical coherence tomography examination before and after treatment were included. Angle parameters, angle opening distance (AOD), trabecular-iris space area (TISA), and trabecular-iris circumference volume (TICV) were calculated. Angle parameters were compared between treatments using a 2-sample t test. P-values were adjusted by the false discovery rate method (P*). A paired t test was used to compare treated (nasal) and untreated (temporal) angles in LE/ECPL-treated eyes. Twenty-three eyes of 14 participants were included. Ten eyes (43%) eyes of 7 participants were treated with LE/ECPL, and 13 eyes (57%) of 7 participants were treated with LE alone. Angles were deepened in both groups (P<0.001). Changes in AOD, TISA, and TICV showed that the magnitude of deepening in treated (nasal) quadrants was greater in LE/ECPL eyes than in LE alone eyes (P<0.05). ECPL-treated angles deepened more than the untreated angles by AOD, TISA, and TICV (P<0.002). Our study suggests that LE/ECPL is more effective than LE alone in opening the anterior chamber angle and that ECPL deepens treated angles more than untreated angles. This study directly compares an LE/ECPL treatment group with a control group, LE alone, allowing for separation of the effect of ECPL from LE.

The effects of single-dose administration of two topical antiglaucoma medications, 0.005% latanoprost and 0.125% demecarium bromide, on intraocular pressure and iridocorneal angle parameters in nonglaucomatous companion rabbits

Glaucoma is a blinding, painful disease in mammals, including rabbits. This study aimed to determine effects on intraocular pressure (IOP) and iridocorneal angle (ICA) morphology of two antiglaucoma therapies, 0.005% latanoprost (latanoprost) and 0.125% demecarium bromide (demecarium) in companion rabbits. Twenty healthy rabbits of varying breeds and ages were used. All animals received a complete ophthalmic examination including rebound tonometry and gonioscopy, and ICA imaging using spectral domain optical coherence tomography (SD-OCT), high-resolution ultrasound, and Scheimpflug imaging (Pentacam® HR). Angle opening distance (AOD) and angle recess area (ARA) were measured. Demecarium was applied to one eye and latanoprost to the contralateral eye. Each eye was re-evaluated 1 hour later with tonometry, imaging, and gonioscopy. Pre- and post-treatment groups were compared with a Wilcoxon signed-ranked test for IOP, ARA, AOD, and gonioscopy score. Estimates of treatment effects were performed to identify clinically significant differences of demecarium and latanoprost on ICA parameters. Latanoprost caused a significant increase in gonioscopy score, ARA, and AOD when measured via SD-OCT whereas demecarium caused a significant decrease in gonioscopy score, ARA, and AOD when measured via SD-OCT and Pentacam® HR. Demecarium significantly increased IOP whereas latanoprost had no effect on IOP. Based on the increased ICA parameters in normal companion rabbits, latanoprost can be considered as a glaucoma medication in rabbits. Demecarium increased IOP and decreased ICA parameters; therefore, its use in rabbits is not recommended.

The anterior and posterior biometric characteristics in primary angle-closure disease: Data based on anterior segment optical coherence tomography and swept-source optical coherence tomography.

Purpose:Obtaining a better understanding of the pathogenesis of primary angle-closure disease (PACD) still requires studies that provide measurements of anterior and posterior biometric characteristics together and that assess the relationship between them.Methods:In total, 201 eyes were enrolled in this cross-sectional study: 50 normal controls, 49 primary angle-closure suspect (PACS), 38 primary angle closure (PAC), and 64 primary angle-closure glaucoma (PACG) eyes. The anterior and posterior structural features were measured by anterior segment optical coherence tomography and swept-source optical coherence tomography.Results:All PACD groups had smaller anterior chamber depth (ACD), anterior chamber area (ACA), anterior chamber volume (ACV), angle opening distance at 750 μm from the scleral spur (AOD750), trabecular–iris space area at 750 μm from the scleral spur (TISA750), and angle recess area (ARA), as well as a larger lens vault (LV), than controls (all P < 0.001). The PACS and PAC groups had thicker iris thickness at 750 μm from the scleral spur (IT750) than controls (P = 0.017 and P = 0.002, respectively). Choroidal thickness (CT) was not statistically different among normal, PACS, PAC, and PACG eyes. Univariate and multivariate linear regression analysis revealed a significant association between thinner IT750 and increased CT in PACD eyes (P = 0.031, univariate analysis; P = 0.008, multivariate analysis).Conclusion:Thinner iris thickness was associated with increased CT in PACD eyes; however, the underlying mechanism needs further investigation.