Anterior chamber and angle characteristics in Chinese children (6-11 years old) with different refractive status using swept-source optical coherence tomography.

BACKGROUND: The anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT). METHODS: In a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 µm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D). RESULTS: Out of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6-11 years) were included. The mean SER and AL were - 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson's correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL. CONCLUSION: In primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.

Anterior Segment Changes in Patients With Glaucoma Following Cataract Surgery.

This prospective observational study investigates the impact of cataract surgery on anterior segment parameters in nonglaucomatous and primary open-angle glaucoma (POAG) eyes, utilizing anterior segment optical coherence tomography (AS-OCT). The study involved 42 Caucasian patients, divided into a control group and a POAG group. Comprehensive ophthalmic examinations were performed along with AS-OCT imaging and biometry preoperatively, as well as on one day, one week, and one month following cataract surgery. The results showed significant post-operative changes in anterior chamber depth (ACD) and angle width in both groups, suggesting that cataract surgery may influence the structural parameters associated with glaucoma risk and management. Specifically, a marked increase in ACD and improvement in angle-opening distances were observed, highlighting the potential of cataract extraction to alter intraocular fluid dynamics favorably. Despite these changes, the study noted an initial spike in increased intraocular pressure (IOP) in POAG patients immediately post-operative, which stabilized during follow-up. For the control group, IOP showed gradually reducing IOP values in the follow-up visits. The findings underscore the role of advanced imaging technologies in understanding glaucoma's pathophysiology and the potential benefits of cataract surgery in glaucoma patients. The study advocates for further research with a larger, more diverse patient population and extended follow-up to explore the long-term implications of cataract surgery on glaucoma dynamics, emphasizing the importance of personalized management and treatment strategies particularly for glaucoma patients.

Anterior segment parameters on optical coherence tomography in healthy South Asian children.

PURPOSE: High resolution spectral domain optical coherence tomography (SD-OCT) was used to assess the anterior segment structure parameters in healthy South Asian children. METHODS: 108 eyes of 54 healthy children ≤ 16 years were recruited after a thorough eye exam. The anterior segment analysis was be done by Optopol Revo 80 high resolution SD-OCT. Central corneal thickness (CCT), Angle opening distance (AOD), Anterior chamber (AC) angle, Trabecular iris space area (TISA), Trabecular iris angle (TIA), iris thickness at 2 mm, internal AC diameter and lens vault were evaluated. RESULTS: Mean age was 11.38 years. Mean IOP was 13.63 mmHg, mean axial length, 22.82 mm, mean spherical equivalent, -0.14 D, mean CCT, 532.6 µm and mean CDR was 0.31. The mean internal AC diameter was 11609.15 µm. The nasal and temporal AC angles was 53.54° and 50.37°, respectively [P = .033]. The nasal and temporal AOD500 were 0.9 mm and 0.85 mm, respectively [P = .629]. The nasal and temporal AOD750 were 1.21 mm and 1.06 mm, respectively [P = .583]. The nasal TIA was 41.75°; the temporal TIA; 40.24° [P = .325]. The nasal TISA500 was 0.33 mm2; the temporal TISA500, 0.31 mm2 [P = .012]. The nasal TISA750 was 0. 59 mm2; the temporal TISA750, 0.56 mm2 [P = .746]. The nasal iris thickness at 2 mm was 483.54 µm; the temporal iris thickness, 505.8 µm [P = .273]. The mean lens vault was -519.58 µm. CONCLUSIONS: Our study data depicts the normal anterior segment parameters in healthy Pakistani children.

Predictors of angle widening after laser iridotomy in Chinese patients with primary angle-closure suspect using ultrasound biomicroscopy.

AIM: To assess the predictive value of baseline parameters of ultrasound biomicroscopy (UBM) for angle widening after prophylactic laser peripheral iridotomy (LPI) in patients with primary angle-closure suspect (PACS). METHODS: Angle-opening distance (AOD), trabecular iris angle (TIA), iris thickness, trabecular-ciliary process angle, and trabecular-ciliary process distance were measured using UBM performed before and two weeks after LPI. Iris convexity (IC), iris insertion, angulation, and ciliary body (CB) size and position were graded. Uni- and multivariate regression analyses were used to determine factors predicting the change in AOD (ΔAOD500, calculated as an angle width change before and after LPI) in all quadrants and in subgroup quadrants based on IC. RESULTS: In 94 eyes of 94 patients with PACS, LPI led to angle widening with increases in AOD500 and TIA (P<0.01). Multivariable regression analysis showed that IC (P<0.001), CB position (P=0.007) and iris insertion (P=0.049) were significantly predictive for ΔAOD500. All quadrants were categorized into extreme IC (27.8%), moderate IC (62.3%), and absent IC (9.9%) subgroups. The AOD500 increased by 220% and no other predictive factor was found in the extreme IC quadrants. The AOD500 increased by 55%, and baseline iris angulation was predictive for smaller changes in ΔAOD500 in the moderate IC quadrants. CONCLUSION: In PACS patients, quadrants with greater iris bowing predict substantial angle widening after LPI. Quadrants with a flatter iris, anteriorly positioned CB, and basal iris insertion are associated with less angle widening after LPI. Quadrants with iris angulation as well as a flatter iris configuration predict a smaller angle change after LPI.

Distribution of anterior chamber angle measurements in South African young adults: an optical coherence tomography study.

PURPOSE: Assessment of anterior chamber angle (ACA) variables is important to screen, diagnose and monitor ocular anomalies. Even though data on ACA variables, such as angle-opening distance taken at 500 µm (AOD500) and trabecular-iris angle (TIA), are available in the literature, limited information is available about these variables in African sub-populations. The purpose of this study is to describe the distribution of ACA measurements (AOD500 and TIA) in a South African young adult population. METHODS: In this cross-sectional study, 700 young adults were recruited from a university student population using two-stage random sampling. The Optovue iVue 100 optical coherence tomographer was used to measure the ACA variables. The distribution of the AOD500 and TIA measurements was analysed using descriptive and inferential statistics. Data from only the right eyes were analysed because the ACA measurements in the two eyes showed high levels of interocular symmetry. RESULTS: The measurements for the nasal and temporal ACAs were asymmetrically distributed (p < 0.001). The median AOD500 measurements in the nasal and temporal angles were 539 µm and 542 µm, respectively. The median TIA measurements were similar (~ 36°) in the two horizontal angles. The temporal ACA measurements were slightly higher than the nasal ACA measurements. Females had higher median ACA measurements than males (p ≥ 0.029). CONCLUSION: The ACA measurements in South African young adults resemble non-Gaussian curves. The ACA measurements are different from that reported in other sub-populations worldwide and most participants had ACA measurements associated with non-occludable ACAs.

Comparison of iridocorneal angle parameters measured by spectral domain optical coherence tomography and ultrasound biomicroscopy in dogs.

OBJECTIVE: To compare the measurements of iridocorneal angle parameters between spectral domain optical coherence tomography (SD-OCT) and ultrasound biomicroscopy (UBM) in dogs. ANIMALS STUDIED AND PROCEDURES: A total of 47 eyes of dogs were scanned at the temporal limbus using SD-OCT and UBM. Iridocorneal angle (ICA) and angle opening distance (AOD) were measured from the obtained images accordingly. The intra-observer and inter-observer reproducibility were evaluated using the intraclass correlation coefficient. To evaluate intra-observer reproducibility, measurements of the first and second grading from the first examiner were compared. To evaluate inter-observer reproducibility, measurements between the two examiners were compared. Agreement between ICA and AOD for SD-OCT and UBM was evaluated using Bland-Altman plots. RESULTS: In the first grading, the mean ICA and AOD for SD-OCT were 31.4 ± 6.4° and 641.4 ± 270.8 µm, respectively. The mean ICA and AOD for UBM were 32.0 ± 4.8° and 700.4 ± 238.8 µm, respectively. For ICA and AOD measurements, intra-observer reproducibility was excellent for both devices, whereas inter-observer reproducibility was excellent for SD-OCT and good for UBM. The mean difference in ICA between SD-OCT and UBM was 0.6° with a limit of agreement (LoA) span of 18.9°. The mean difference in AOD between SD-OCT and UBM was 58.9 µm with a LoA span of 804.4 µm. CONCLUSIONS: Spectral domain optical coherence tomography is an effective non-contact imaging modality for the evaluation of canine iridocorneal angle parameters in a clinical setting. Reproducibility of measurements obtained is comparable or superior to UBM, but values obtained by SD-OCT and UBM for AOD are not interchangeable between devices.

Predictive Equation for Angle Opening Distance at 750 µm After Laser Peripheral Iridotomy in Primary Angle Closure Suspects.

Aim: The aim of this study was to investigate the changes in anterior segment parameters as assessed by ultrasound biomicroscopy (UBM) after laser peripheral iridotomy (LPI) and to propose a prediction equation for the width of the angle after LPI. Design: This was a prospective study. Participants: The participants included 100 subjects with primary angle closure suspect (PACS). Methods: Anterior segment UBM parameters were measured, whereas AOD750 was chosen to indicate the width of the angle associated with gonioscopic angle closure, as found in a prior study. Main Outcome Measures: Angle parameters, iris parameters, anterior chamber parameters and ciliary body parameters. Results: All angle parameters increased after LPI, including the mean angle opening distance at 750 µm (AOD750), mean angle opening distance at 500 µm from the scleral spur (AOD500), mean angle opening distance at 750 µm from the scleral spur (AOD750), and mean angle recess area at 750 µm from the scleral spur (ARA750). Among iris parameters and ciliary body parameters, the iris thickness at 2,000 µm (IT2000), iris curvature (IC), and trabecular-ciliary process distance (ICPD) were reduced after LPI. The final equation consisted of four parameters: anterior chamber depth (ACD), iris thickness at 750 µm from the scleral spur (IT750), AOD750, and lens vault (LV). This equation explained 42.7% of the variability in the angle opening indicator AOD750 after LPI, whereas in the plateau iris configuration subgroup, the accuracy of the prediction equation reached the highest a maximum of 68.6%. Conclusions: There was an increase in angle opening and iris flattening after LPI. An equation involving four angle parameters was constructed, this equation which could explained 42.7% of the variability in the angle opening indicator AOD750 after LPI whereas in the plateau iris configuration subgroup, the accuracy of the prediction equation reached a maximum of 68.6%.

Evaluation of anterior chamber parameters with spectral-domain optical coherence tomography.

PURPOSE: To evaluate several anterior chamber parameters in healthy young adults using spectral-domain optical coherence tomography and to describe the repeatability and reproducibility of this method. STUDY DESIGN: Prospective clinical study. METHODS: Fifty-two eyes of 52 healthy volunteers were enrolled. Manual measurements of the anterior chamber angle (ACA500 and ACA750), angle opening distance (AOD500 and AOD750), angle-to-angle distance (ATA), anterior chamber width (ACW), and lens vault (LV) were obtained. RESULTS: The mean nasal ACA500 was 44.87 ± 12.92°; ACA750, 43.94 ± 10.41°; AOD500, 672.54 ± 270.19 µm; AOD750, 881.87 ± 290.55 µm. The mean temporal ACA500 was 41.46 ± 11.20°; ACA750, 41.27 ± 11.31°; AOD500, 603.15 ± 232.28 µm; AOD750, 823.46 ± 308.76 µm. The differences between the corresponding nasal and temporal parameters were statistically significant. The ACW was 11.97 ± 0.42 mm, the ATA was 12.10 ± 0.43 mm, and the LV was 3.71 ± 232.93 µm. The ACA was highly associated with the LV. The intraclass correlation coefficients ranged from 0.984 to 0.999 for the intraobserver repeatability and from 0.966 to 0.998 for the interobserver reproducibility. CONCLUSIONS: This study assessed anterior chamber parameters in healthy young adults using spectral-domain optical coherence tomography. This technique reveals the spatial relationships of the ocular structures, provides high-resolution images, and results in high degrees of intraobserver and interobserver repeatabilities.

Investigation of the variability of anterior chamber scan protocol with Cirrus high definition optical coherence tomography.

IMPORTANCE: The evaluation of anterior chamber scan of Cirrus optical coherence tomography for routine clinical use. BACKGROUND: To assess the variability of anterior chamber angle measurements. DESIGN: This was a cross-sectional study. PARTICIPANTS: Forty subjects aged 40-80 years were included. METHODS: One randomly selected eye from 40 subjects was imaged with Cirrus optical coherence tomography (Carl Zeiss Meditec, Dublin, CA) by two different operators (expert vs. non-expert) with a 15-min interval for inter-observer and intra-observer variability of image acquisition. For image grading, the angle opening distance (AOD750) and the trabecular iris space area (TISA750) of nasal and temporal quadrants were measured with a customized algorithm (ImageJ, NIH, Bethesda, MD) by two different graders in a masked and random fashion. Bland Altman analysis and intraclass correlation coefficient (ICC) were calculated. MAIN OUTCOME MEASURES: ICC and limit of agreements (LOA). RESULTS: There were 15 (37.5%) eyes with closed angles. For inter-observer variability, the mean difference (95% LOA) of AOD750 for image acquisition and grading were -0.0039 mm (-0.0486, 0.0408) and 0.0011 mm (-0.0228, 0.025), respectively. The mean difference (95% LOA) of AOD750 for intra-observer variability for image acquisition and grading were 0.0013 mm (-0.0362, 0.0389) and -0.0013 mm (-0.0482, 0.0457), respectively. The ICCs were all ≥0.9. There was no significant difference in measurement variability between open and closed angles (P > 0.05). CONCLUSIONS AND RELEVANCE: Anterior chamber scan had low inter-observer and intra-observer variability in quantitative evaluation that was not affected by the angle status or the experience of an operator.

Changes in the intraocular pressure and anterior chamber angle in patients with chronic renal failure before and after hemodialysis / 实用医学杂志

Objective To investigate changes in the intraocular pressure(IOP) and anterior chamber angle in patients with chronic renal failure before and after hemodialysis. Methods Fifty?eight patients(116 eyes) with chronic renal failure were measured with Goldmann applanation tonometer and anterior segment optical coherence tomograph. The patients were divided into three groups based on gonioscopy results:the narrow angle group(22 eyes),the Iris neovascular group(3 eyes)and the open angle group(91 eyes). IOP was measured by Goldmann applanation tonometer in patients in the three groups before and after hemodialysis. Anterior chamber angle opening distance (AOD) was detected by anterior segment optical coherence tomograph before and after hemodialysis. The blood urea nitrogen,creatinine,albumin were also determined before and after hemodialysis. All changes in the parameters were analyzed with a paired t test. Results The IOP in narrow angle eyes and in neovascular eyes increased significantly after hemodialysis ,while the IOP in open angle eyes showed no significant changes. The AOD decreased significantly after hemodialysis. The blood urea nitrogen and creatinine decreased significantly in 58 patients,while albumin increased after hemodialysis. Conclusion The IOP in narrow angle eyes and in neovascular eyes increased after hemodialysis ,correlating with the resistance increase of aqueous outflow pathway and the change of plasma osmotic pressure. As a result ,it is recommended that the condition of eye of patients with chronic renal failure should be checked ,and patients should receive appropriate controlling measure or treatment before hemodialysis.

Changes in Japanese eyes after laser peripheral iridotomy: an anterior segment optical coherence tomography study.

BACKGROUND: The aim was to investigate the changes in anterior segment parameters, as assessed by anterior segment optical coherence tomography in Japanese subjects after laser peripheral iridotomy (LPI). DESIGN: This was a prospective observational study. PARTICIPANTS: The participants include 72 subjects with angle closure including primary angle closure suspect (PACS), primary angle closure (PAC), and primary angle closure glaucoma (PACG). METHODS: Anterior segment optical coherence tomography parameters was measured by customized software. Complete data of 51 subjects were available for final analysis. MAIN OUTCOME MEASURES: These were the following parameters: angle opening distance, trabecular-iris space area, anterior chamber depth, width, area and volume (iris thickness, curvature, and area, and lens vault (LV). RESULTS: A total of 25 PACS, 17 PAC and 9 PACG were included. Mean age was 74.7 ± 6.7 years, and majority were women (80.4%). Following LPI, there was a significant increase in mean gonioscopic angle width (1.16 vs. 1.93, P < 0.001) and a corresponding increase in angle opening distance, trabecular-iris space area, and angle recess area (all P < 0.001). The anterior chamber area (P < 0.001), anterior chamber volume (P < 0.001) and anterior chamber depth (P = 0.003) increased significantly; and iris curvature (P < 0.001) was significantly reduced. There were no significant changes in anterior chamber width, LV, iris thickness and area. Age-adjusted and gender-adjusted analysis for predictors of percentage change in angle opening distance 750 showed significant association with greater baseline LV (ß = 0.32, P = 0.03). No significant differences were noted in the mean percentage change in parameters between the PACS and PAC-PACG. CONCLUSIONS: An increase in anterior chamber dimensions, angle widening and iris flattening; with a constant LV, iris thickness and iris area after LPI was demonstrated in Japanese eyes with angle closure.

Clinical efficacy of micro incision phacoemulsification and intraocular lens implantation in patients with shallow anterior chamber and cataract / 国际眼科杂志(Guoji Yanke Zazhi)

? AIM: To investigate the efficacy and safety of phacoemulsification combined with intraocular lens implantation in the treatment of shallow anterior chamber with cataract.?METHODS: Retrospective case series. From February 2014 to July 2015 in our hospital,65 eyes in 65 patients with cataract were enrolled and divided into mild and high risk of shallow anterior chamber group. Best-corrected visual acuity ( BCVA ) , intraocular pressure ( IOP ) , central anterior chamber dept ( CACD ) , angle opening distance ( AOD ) , complications pre- and post treatment, were observed and analyzed as outcome measures.?RESULTS: In this study, the mild shallow anterior chamber group included 34 eyes; postoperative BCVA were improved in 29 eyes, with 4 eyes remaining stable and decreased in 1 eye; BCVA was improved in 16 eyes, with 10 eyes remaining stable and decreased in 5 eyes in high risk of shallow anterior chamber group postoperatively. BCVA had a better prognosis in the mild shallow anterior chamber group than another group ( t=-2. 956, P<0. 05). Meanwhile, IOP decreased by 5. 71± 2. 07mmHg and CACD increased by 1. 37 ± 0. 38mm in the mild shallow anterior chamber group, by 9. 77±4. 04mmHg and 1. 67±0. 43mm respectively in high risk group, and the difference has statistical significance ( t=-5. 02,-3. 04; P<0. 05). The mean preoperative nasal AOD500 was 200. 57± 33. 74μm, and they were 346. 62 ± 101. 37μm and 410. 75 ± 137. 48μm and 398. 69 ± 122. 28μm respectively at postoperative 1d, 1 and 3mo, and all nAOD500 comparing with preoperative were increased obviously, and the difference has statistical significance (F=203. 75, P<0. 01). And AOD500 at temporal, superior and inferior presented similar trends. Complications were corneal edema ( 5 eyes ) , transient intraocular hypertension ( 2 eyes ) , posterior capsular opacification ( 4 eyes ) , and posterior capsular rupture (1 eye).?CONCLUSION:Micro incision cataract surgery is useful, effective and safe in patients with cataract and shallow anterior chamber which can stabilize or improve BCVA, reduce IOP, deepen CACD and open the anterior chamber angle.

Association between baseline angle width and induced angle opening following prophylactic laser peripheral iridotomy.

PURPOSE: To evaluate the association between baseline angle width and laser peripheral iridotomy (LPI)-induced opening of the anterior chamber angle. METHODS: Anterior segment optical coherence tomography images captured before and after LPI were analyzed to determine the angle opening distance at 250 µm (AOD250), 500 µm (AOD500), and 750 µm (AOD750) from the scleral spur; trabecular-iris space area at 500 µm (TISA500) and 750 µm (TISA750) from the scleral spur; angle recess area at 750 µm (ARA750) from the scleral spur; and trabecular-iris angle (TIA). Differences in preoperative and postoperative measurements for the anterior chamber angle width parameters were compared by paired Student's t-tests. Univariate and linear mixed-effects regression models were used to examine the association between baseline and LPI-induced opening of anterior chamber angle width parameters. RESULTS: Eighty-four eyes of 52 primary angle closure suspects were included in the analysis. AOD250, AOD500, AOD750, TISA500, TISA750, ARA750, and TIA significantly increased following LPI by paired Student's t-tests (all P < 0.0001). Lower baseline measurements were significantly associated with greater postoperative opening in all anterior chamber angle width parameters in both univariate and linear mixed-effects regression analyses (all P < 0.05). CONCLUSIONS: Our results showed significant opening of the anterior chamber angle width after LPI and demonstrated an inverse association between baseline and LPI-induced opening of the anterior chamber angle width, such that eyes with a more crowded anterior chamber angle undergoing LPI had a greater magnitude of increase in anterior chamber angle width after the procedure.

Effects of Transient Prone Position on Vault and Anterior Chamber Angle in ICL Implanted Patients

PURPOSE: To evaluate the effects of transient prone position on vault and anterior chamber angle parameters in ICL implanted patients. METHODS: 40 eyes of 20 ICL implanted patients with at least 1 month of follow-up were included in the present study. The central ICL vault and anterior chamber parameters including angle opening distance at 500 (AOD500) were measured with the Visante anterior segment optical coherence tomography (OCT) (Carl Zeiss, Dublin, CA) in both the sitting and prone positions by tilting the OCT 90 degrees in the vertical axis and having the patient fixate downwards towards the floor. RESULTS: The mean central vault was 0.55 +/- 0.21 mm (SD) and 0.59 +/- 0.21 mm (SD) in the sitting and prone positions, respectively (p < 0.0001). The nasal and temporal AOD500 were 0.26 +/- 0.11 mm and 0.28 +/- 0.08 mm, respectively in the sitting position, which decreased to 0.24 +/- 0.10 mm and 0.26 +/- 0.08 mm in the prone position, however, both were not statistically significant (p = 0.08, p = 0.09). AOD500 was inversely correlated with vault (r = -0.47; p = 0.0024). There were no significant correlations between increase of vault and anterior chamber depth or white to white nor ICL vault. CONCLUSIONS: Transient prone positioning of ICL implanted patients can induce a significant increase in ICL vault.

Clinical Significance of Ultrasound Biomicroscopy in Early Stage of Traumatic Hyphema

PURPOSE: To evaluate the clinical significance of angle-opening distance 500 (AOD500) using ultrasound biomicroscopy (UBM) in the early stage of traumatic hyphema. METHODS: The participants of this study were 46 hospitalized traumatic hyphema patients. We measured the quantity of initial blood clotting using a slit-lamp and the range of angle recession, AOD500 using UBM and then reviewed the relationship between the two. RESULTS: The difference of AOD500 in the traumatic and the non-traumatic eye measured by UBM at admission increased significantly in the wider recessed angle group (p=0.008), but did not increase at a statistically significantly level in the larger initial blood clot grade group (> or =Grade 2). CONCLUSIONS: These results suggest that the measurement of the angle-opening distance of both eyes using UBM will aid in evaluating the range of angle recession in patients in the early stage of traumatic hyphema.

Changes of Anterior Chamber Depth and Angle After Cataract Surgery Measured by Anterior Segment OCT

PURPOSE: To report the change of anterior chamber parameters according to cataract severity after cataract surgery and to determine its relationship to the severity of cataract by using anterior segment optical coherence tomography. METHODS: We measured the anterior chamber parameters in 19 eyes of 14 patients before, 1 week after, and 1 month after cataract surgery by slit lamp-adapted optical coherence tomography (SL-OCT). The measured parameters were as follows : the anterior chamber depth (ACD), the angle-opening distance 250 micrometer from the scleral spur (AOD250), the angle-opening distance 500 micrometer from the scleral spur (AOD500), and the trabecular-iris angle (TIA). We analyzed the relationship between the severity of cataract and the change of the anterior chamber parameters. RESULTS: The ACD, AOD250, AOD500, and TIA increased significantly at postoperative 1 week (P=0.000, 0.002, 0.005, 0.022) and 1 month (P=0.000, 0.004, 0.001, 0.002). The preoperative parameters were negatively correlated with the differences between the postoperative 1 week and preoperative parameters (gamma=-0.834, -0.591, -0.421, -0.826) and between postoperative 1 month and preoperative parameters (gamma=-0.659, -0.700, -0.770, -0.821). The change of parameters at postoperative 1 week (by N P=0.959, 0.916, 0.824, 1.000, by C P=0.454, 0.665, 0.578, 0.578) and 1 month (by N P=0.858, 0.973, 0.959, 0.959, by C P=0.999, 0.207, 0.950, 0.981) were not significantly different according to the severity of cataract (N, C). CONCLUSIONS: Our results showed that cataract surgery significantly deepened the anterior chamber and widened its angle. The shallower and narrower the preoperative anterior chamber depth and angle were, respectively, the greater the postoperative changes of anterior chamber depth and angle were.

Ultrasound biomicroscopic dimensions of the anterior chamber in angle-closure glaucoma patients

In order to evaluate the morphologic types of appositional angle-closure glaucoma, biometric measurements were made in angle-closure glaucoma patients using Ultrasound biomicroscopy (UBM). Twenty-six patients with primary angle-closure glaucoma and 21 cataract patients with as a control group were examined. The angle-closure glaucomatous eyes were classified as type B in which the angle closure started at the bottom of the angle and type S in which the angle closure occurred in the vicinity of Schwalbe's line. The trabecular-ciliary process distance (TCPD, type B; 873.20+/-86.77 microm, type S; 832.52+/-82.96 microm, control; 1233.50+/-73.01 microm, p = 0.000) and the angle opening distance (AOD500, type B; 89.75+/-63.27 microm, type S; 88.85+/-72.95 microm, control; 304.40+/-104.30 microm, p = 0.000) were significantly shorter in patients with angle closure vice control group. No significant difference were noted in the three groups of patients in regards to iris thickness or ciliary process-iris angle. In this study, we have demonstrated that there are two types of appositional angle-closure and have shown the forward rotation of the ciliary process without changes of the ciliary process-iris angle in cases of angle-closure glaucoma.