Trabecular-ciliary Process Distance Research Articles

Direct observation and measurement of circumlental space and its relation to anterior chamber angle characteristics in iridotomized phakic eyes with primary angle closure disease

Primary angle closure disease (PACD) is a major cause of blindness worldwide. It has a high prevalence in East Asia, especially in China, which leads to a higher incidence of blindness than open-angle glaucoma. The aim of this study was to directly observe the circumlental space (CLS) in laser peripheral iridotomized eyes with PACD and to determine whether this structure plays a role in the pathogenesis of PACD. Fifty eyes of 50 patients with PACD, who had received laser peripheral iridotomy performed with neodymium:yttrium–aluminum-garnet were recruited from glaucoma clinics from March 2021 to May 2022, including 17 primary angle closure suspect (PACS), 16 primary angle closure (PAC) and 17 primary angle closure glaucoma (PACG). They were classified into two groups based on whether the ciliary process and the crystalline lens equator were in contact using slit-lamp photograph: the attached group and the unattached group. The demographic, clinical characteristics and anterior segment parameters measured from ultrasound biomicroscopy were compared between the attached group and the unattached group. Thirty-three eyes were assigned to the attached group and 17 eyes belonged to the unattached group. In the unattached group, the mean CLS was 0.10 ± 0.07 mm. No significant differences were identified between the different diagnosis groups in age, sex, best-corrected visual acuity, intraocular pressure, white-to-white, axial length, central corneal thickness, anterior chamber depth, flat keratometry, steep keratometry or iridotomy diameter (p > 0.05). The unattached group had shorter trabecular-ciliary process distance (p = 0.021) and larger ciliary process area (p = 0.001) compared with the attached group. Small CLS and its potential effect (partial ciliary block) might be considered as one of the mechanisms of PACD.

Anterior Segment Characteristics of Eyes with Anterior Chamber Depth Less than 2.8mm and Axial Length Greater than 25mm.

This study aimed to investigate anterior segment parameters of eyes, with anterior chamber depth (ACD) less than 2.8mm and axial length greater than 25.0mm. This cross-sectional study included 180 myopic eyes of 180 consecutive patients with axial length greater than 25.0mm. Patients were divided into low ACD (ACD < 2.8mm, n = 56) and normal ACD (ACD ≥ 2.8mm, n = 124) groups. Anterior segment parameters were measured using Scheimpflug imaging and ultrasound biomicroscopy. A general linear model was used to compare parameters between the two groups, after adjusting for age and spherical equivalent. Compared with the normal ACD group, the low ACD group had lower values for the following parameters: corneal diameter, trabecular-anterior iris surface angle, angle-opening distance at 500μm, anterior chamber volume, anterior chamber width, anterior vault, iris thickness at 500μm, ciliary sulcus-to-sulcus diameter, distance between cornea and sulcus, trabecular-ciliary process distance, maximum ciliary body thickness, ciliary process length, relative anterior vault, relative distance between cornea and sulcus, and relative lens position (general linear model, p < 0.05). In contrast, central corneal thickness, iris curvature, lens thickness, lens vault, and iris-ciliary angle were greater in the low ACD group (general linear model, p < 0.05). A smaller anterior segment, as well as a thicker and more anteriorly positioned lens, may correlate with shallow ACD in eyes with long axial length.

Long-term effects of mild cataract extraction versus laser peripheral iridotomy on anterior chamber morphology in primary angle-closure suspect eyes

AimTo compare lens extraction (LE) and laser peripheral iridotomy (LPI) on anterior segment morphology in primary angle-closure suspect (PACS) eyes.MethodsThis prospective clinical trial included 144 patients with PACS who underwent...

Anterior Segment Parameter Changes after Cataract Surgery in Open-Angle and Angle-Closure Eyes: A Prospective Study.

Background: To investigate the anterior segment parameters before and after cataract surgery in open-angle eyes and different subtypes of primary angle-closure glaucoma (PACG) eyes and to further explore the potential relationship between the anterior rotation of the ciliary process and crystalline lens. Methods: An observational, prospective study was performed on 66 patients who had cataract surgery including 22 chronic PACG patients, 22 acute PACG patients, and 22 open-angle cataract patients. Anterior segment parameters including the trabecular-ciliary process distance, ciliary process area, trabecular-ciliary angle (TCA), maximum ciliary body thickness (CBTmax), and so on, were measured using ultrasound biomicroscopy preoperatively and 3 months postoperatively. Results: After the surgery, there were significant increases in TCA (p < 0.001) and CBTmax (p < 0.05) in all three groups, while there was no significant change in the trabecular-ciliary process distance (p > 0.05) in all three groups. No significant difference in the changes of ciliary process area, TCA, and CBTmax (p > 0.05) pre- and postoperatively among the three groups were identified. Conclusions: Extractions of crystalline lenses played similar roles in terms of decreasing the anterior rotation of ciliary processes in open-angle eyes and angle-closure eyes. A natural anatomical abnormality may be a more important factor in the anterior rotation of ciliary processes in PACG patients.

Ultrasound biomicroscopic imaging demonstrate thinner ciliary body thickness in eyes with angle closure.

To compare the ciliary body thickness between eyes with primary angle closure (PAC) and primary angle-closure glaucoma (PACG) with the normal eyes, and to investigate the association between ciliary body thickness and ciliary processes situation. In this cross-sectional study, 57 patients with PAC/PACG were matched to 57 normal subjects after propensity score matching (PSM) adjusting for age and gender. All subjects underwent conventional ocular examinations and ultrasound biomicroscopy (UBM) examination, among which the patients with PAC/PACG performed the examinations one month after laser peripheral iridotomy (LPI). Quantitative parameters were measured, which included ciliary body thickness at the position of 1 mm posterior to the scleral spur (CBT1), trabecular-ciliary process distance (TCPD) and trabecular-ciliary process angle (TCA). Eyes with PAC/PACG presented significantly thinner CBT1, shorter TCPD and smaller TCA (P<0.001) than the normal eyes, both in comparison of the means of four quadrants and in comparisons of each quadrant. After removing images with peripheral anterior synechia (PAS), the same results were also found in comparisons between the two groups. Significant correlations were found between TCPD (R 2=0.537, P<0.001) and TCA (R 2=0.517, P<0.001) with CBT1. Eyes with PAC/PACG have thinner ciliary body thickness and more anteriorly situated ciliary processes. Thinner ciliary body thickness is associated with anterior situation of the ciliary processes.

The ocular biometry characteristics of young patients with primary angle-closure glaucoma

BackgroundAlthough primary angle-closure glaucoma (PACG) mainly occurs in elderly people, diagnosis of PACG in young patients is not uncommon. So far, there is no article specialized on the ocular anatomical characteristics in these patients.In this study, ocular anatomical characteristics in young PACG patients are analyzed.MethodsIn this retrospective, comparative study, patients diagnosed with PACG and received ultrasound biomicroscopy (UBM) examination in our department were included. Patients were divided into two groups: a young group composed of patients ≤ 45 years and an old group composed of patients > 45 years. A-scan ultrasonography and ultrasound biomicroscopy (UBM) were used to measure ocular biometric parameters of patients in the two groups including axial length (AL), lens thickness (LT), central anterior chamber depth (ACD), anterior chamber width (ACW), angle opening distance 500 (AOD500), anterior chamber angle 500 (ACA500), iris thickness 1000 μm from the iris root (IT1000), iris thickness 500 μm from the iris root (IT500), trabecular-ciliary process angle (TCPA), trabecular-ciliary process distance (TCPD), scleral– ciliary process angle (SCPA), lens vault (LV), and pupil diameter (PD). Plateau iris (PI) and basal iris insertion were determined from UBM images, and the prevalence of PI and basal iris insertion were compared between the two groups. The incidence of postoperative malignant glaucoma (MG) was also determined in both groups and ocular anatomical predictors for the development of MG were evaluated in young PACG patients.ResultsOne hundred fifteen patients were included into young group and 480 patients were included into old group. The young group had shorter TCPD, shorter AL, narrower TCPA, narrower SCPA thinner Lens compared to the old group. There were no significant differences in ACD, AOD 500, ACA500, LV, IT500, IT1000, PD or ACW between the two groups. The prevalence of PI was 22.6% in old group and 66.1% in young group (P < 0.001). More young PACG patients displayed basal iris insertion compared to old PACG patients (P < 0.001). 87 patients in the young group and 201 patients in the old group underwent trabeculectomy in our study. Among these patients, 21 young patients and 11 old patients developed MG after trabeculectomy (P < 0.001).ConclusionsShorter AL, more anteriorly positioned ciliary body, higher prevalence of PI may be responsible for the etiology of young PACG patients. Our results suggest that shorter AL, shorter TCPD and narrower TCPA may be predictors for development of MG in young PACG patients after trabeculectomy.

Ultrasound Biomicroscopy Observation of Suspicious Primary Angle Closure Combined with the Relaxation of Zonule.

Purpose To investigate the difference in anterior segment parameters between suspicious primary angle closure (PACS) patients and normal patients as assessed by ultrasound biomicroscopy (UBM). Methods From June 2019 to November 2020, 39 patients (50 eyes) with PACS in the Ophthalmology Department of Qingdao University Affiliated Hospital who underwent phacoemulsification and intraocular lens implantation were selected as the PACS group. 32 patients (50 eyes) who underwent phacoemulsification and intraocular lens implantation were selected as the normal group. In addition to routine preoperative examinations such as visual acuity, noncontact intraocular pressure, axis length (AL), and ocular B-ultrasound examination, UBM examinations were also performed, including measuring the central anterior chamber depth (ACD), the maximum transverse diameter of the ciliary process at both ends (STS), the vertical distance between the anterior apex of the lens and the maximum transverse diameter at both ends of the ciliary processes (h), and angle opening distance (AOD500), iris-zonule distance (IZD), trabecular-ciliary process distance (TCPD), trabecular-iris angle (TIA), iris thickness (IT), trabecular-ciliary process angle (TCPA), and anterior placement of the ciliary body (APCB) at four quadrants (superior, nasal, inferior, and temporal quadrants). Results Compared with the normal group, the PACS group showed statistically differences in AL, ACD, h, ACD/AL, h/STS, IZD, AOD500, TCPD, TIA, TCPA, and APCB (P < 0.05), and there were no significant differences in STS and IT between the two groups (P > 0.05). In the PACS group, there were significant differences in AL, ACD, h, ACD/AL, h/STS, IZD, TCPD, TCPA, and APCB between PACS patients with zonular relaxation and without zonular relaxation (P < 0.05), while there were no significant differences in STS, AOD500, TIA, and IT (P > 0.05). Conclusion UBM quantitatively enables to identify the anterior segment morphology, especially the zonules in patients of suspicious primary angle closure combined with the relaxation of zonule. Accurate measurement of UBM can be used to predict whether patients with PACS are combined with zonular relaxation, so as to provide a clinical imaging evidence for the diagnosis.

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

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). 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. 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. 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.

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%.

Comparative Study of the Effects of 1% Atropine on the Anterior Segment.

Purpose To investigate the influences of atropine on changes in anterior segment geometry, as measured by ultrasound biomicroscopy in children. Methods A prospective observational study was performed. Anterior segment parameters were obtained by UBM before and after the instillation of 1% atropine. Univariate linear regression was performed to identify the variables contributing to the changes in the trabecular meshwork-iris angle (TIA). Results The study included 21 boys and 37 girls with a mean age of 10.79 ± 2.53 years. Anterior chamber parameters including the central anterior chamber depth, TIA, angle opening distance at 500 μm from the scleral spur, iris thickness 750 μm and 1500 μm from the scleral spur, trabecular-ciliary angle (TCA), trabecular-ciliary process distance, sclera-iris angle (SIA), and sclera-ciliary process angle significantly increased after cycloplegia (P < 0.05). In contrast, the lens vault, iris cross-sectional area, and maximum ciliary muscle thickness significantly decreased after cycloplegia. Univariate analysis identified the change in TCA and the change in SIA and the TIA before mydriasis as determinants of the change in TIA. Conclusions Atropine causes statistically significant changes in various anterior segment parameters in children. The change in anterior chamber angle is associated with the change in TCA and the change in SIA and the TIA before mydriasis.

Ultrasound Biomicroscopic Evaluation of Anterior Segment Parameters and Surgical Area Following Trabeculectomy Surgery.

Objectives:This study used ultrasound biomicroscopy (UBM) imaging to evaluate the anterior segment structure and surgical area of patients with open angle glaucoma following a trabeculectomy procedure.Methods:Consecutive patients with primary open angle or pseudoexfoliative glaucoma who underwent a trabeculectomy were included. UBM was used to examine the anatomical parameters of anterior chamber depth, anterior chamber angle, angle opening distance at 500 µm (AOD500), trabecular ciliary process distance (TCPD), iris ciliary process distance, scleral ciliary process angle (SCPA), and ciliary process thickness, as well as the internal ostium opening, ostium-iris distance, and scleral flap dimensions. Bleb morphologies were evaluated qualitatively using the Yamamoto classification and quantitatively according to the presence of drainage from the medial, lateral, and posterior borders.Results:Twenty-five eyes of 23 patients (4 female, 19 male) were included in the study. The TCPD and SCPA measurements were significantly greater in the postoperative third month (1.04±0.12 mm vs 1.09±0.16 mm, p<0.05; 58.6±3.9° vs 60.8±3.8°, p<0.05, respectively). Cases with a longer ostium-iris distance had a significantly greater AOD500, TCPD, and SCPA (p<0.05). Bleb drainage and morphological classification were correlated (p=0.001).Conclusion:UBM is a sound and efficient method to investigate anterior segment variations and the surgical bleb following a trabeculectomy. TCPD and SCPA values increased after surgery.

Anterior Segment Features in Nanophthalmos With Secondary Chronic Angle Closure Glaucoma: An Ultrasound Biomicroscopy Study.

We compare anterior segment parameters and the risk of malignant glaucoma between nanophthalmos with secondary chronic angle closure glaucoma (NSCACG) and chronic primary angle-closure glaucoma (CPACG). This retrospective case-control study included 32 NSCACG (32 eyes) and 36 CPACG (36 eyes) patients. Anterior segment parameters, including anterior chamber depth (ACD) and width (ACW), pupil diameter (PD), lens vault (LV), ciliary process-ciliary process distance (CCD), angle opening distance500 (AOD500), trabecular-iris angle (TIA), trabecular-ciliary processes distance (TCPD), ciliary body max thickness (CBMT), iris convexity (IC), peripheral iris thickness (PIT), iris-zonule distance (IZD), trabecular ciliary process angle (TCPA), and anterior vault (AV), were measured by ultrasound biomicroscopy. A-scan ultrasonography measurements, including lens thickness (LT) and axial length (AL), also were reviewed. ACD, ACW, CCD, TCPD, and AL were smaller, whereas the LV, LT/AL, LV/LT, LV/ACD, LT/ACD, LV/AV, and AV/AL were larger in NSCACG compared to CPACG eyes (all Bonferroni-corrected P < 0.05). Eyes with NSCACG had a higher risk of malignant glaucoma postoperatively than eyes with CPACG (P = 0.018). Characterized by narrower anterior segment, forward movement of larger lens, more anteriorly rotated ciliary bodies, and smaller CCD, NSCACG eyes have a higher risk of malignant glaucoma than CPACG eyes.

Clinical analysis of anterior segment anatomic parameters of silicone oil tamponade eyes

Objective To analyse the anterior segment parameters of phakic eyes and aphakic eyes after silicone oil tamponade. Methods The data of 55 eyes of 55 cases with silicone oil tamponade and follow up≥3 months from Sep. 2017 to Dec. 2017 were collected and analyzed retrospectively. There were 35 phakic eyes and 20 aphakic eyes. The anterior segment parameters of all eyes were measured before and after surgery with ultrasound biomicroscopy. Results The angle opening distance (AOD500), trabecular-iris angle (θ1), trabecular ciliary process distance (TCPD) and iris-ciliary process distance (ICPD) of the phakic eyes after surgery were lower than those before surgery (P<0.05). The iris-lens contact distance (ILCD) and the angle between iris inner surface and anterior surface of lens (θ2) were increased after surgery compared with those before surgery (P<0.05). AOD500 and θ1 in aphakic eyes increased after surgery (P<0.05). ICPD in aphakic eyes decreased after surgery (P<0.05). Conclusion After silicone oil tamponade, the parameters related to the degree of opening of the ocular angle in phakic eyes are less than those before operation, while those of aphakic eyes increase. The pupillary block and iris distention in phakic eyes increase after silicone oil tamponade. The distance between iris and ciliary body of phakic eyes and aphakic eyes are shorter and the angle between sclera and ciliary body are smaller than those before surgery. Key words: Silicone oil tamponade; Anterior segment; Phakic eyes; Aphakic eyes

Assessment of the changes in anterior segment parameters by ultrasound biomicroscopy after laser peripheral iridotomy

Purpose The aim of this study was to evaluate the changes in anterior segment parameters by ultrasound biomicroscopy (UBM) after laser peripheral iridotomy (LPI) in eyes with narrow drainage angles. Patients and methods A prospective study was conducted on 20 eyes of 20 different patients with primary angle-closure glaucoma in need for LPI. Patients underwent a detailed ophthalmic examination including slit lamp examination, intraocular pressure measurement, and gonioscopy. UBM was performed before and 1 week after LPI. Quantitative parameters included angle-opening distance (AOD), iris thickness, trabecular-iris angle, trabecular-ciliary process distance, iris-lens contact distance (ILCD), and iridocorneal angle recess area (ICA). Results The mean age of the patients was 55±9.6 years (range: 40–80 years), and 12 patients were females. LPI was performed in the supero-temporal quadrant in 12 eyes and in the supero-nasal quadrant in eight eyes. On gonioscopy, none of the angle structures were seen on primary gaze in the four quadrants in two eyes, in three quadrants in eight eyes, and in two quadrants in 10 eyes. After LPI, ILCD increased significantly in 10 eyes (P Conclusion LPI significantly changed the morphology and parameters of anterior segment in eyes with narrow drainage angles, with obvious widening of the drainage angle. Unlike gonioscopy, these changes could be objectively highlighted and quantified accurately by UBM.

Subclassification of Primary Angle Closure Using Anterior Segment Optical Coherence Tomography and Ultrasound Biomicroscopic Parameters

To classify eyes with primary angle closure (PAC) in terms of the features visualized using anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM). Retrospective, observational study. A total of 73 eyes of 73 patients with PAC. Participants' eyes that had undergone laser peripheral iridotomy (LPI) were imaged using AS-OCT and UBM under the same lighting conditions. Anterior chamber depth, anterior chamber width, iris cross-sectional area, peripheral iris thickness, iris curvature, lens vault (LV), and angle opening distance 500 μm from the scleral spur (SS) were determined using the AS-OCT image; trabecular-ciliary process angle (TCA), trabecular-ciliary process distance (TCPD), and ciliary body (CB) thickness 1 mm posterior to the SS were estimated on the UBM image using ImageJ software (Wayne Rasband, National Institutes of Health, Rockville, MD). Iris insertion, iris angulation, iris convexity, presence of ciliary sulcus, irido-angle contact, and CB orientation assessed on the UBM image were included. Partitioning around the medoids algorithm was used for cluster analysis based on the parameters obtained using AS-OCT and UBM. Axial length and pupil diameter were incorporated into statistical models. Clinical and anatomic characteristics were compared between the clusters, as classified using the partitioning around medoids algorithm method. Cluster analysis revealed that 2-group clustering produced the best results. The 2 clusters, which were defined in terms of parameters obtained using AS-OCT and UBM, showed differences in iris curvature (0.16±0.08 vs. 0.11±0.04 mm), TCA (91.0°±13.4° vs. 63.7°±6.2°), TCPD (0.99±0.22 vs. 0.78±0.16 mm), CB orientation (neutral/anterior, 35/13 vs. 0/25), and iris insertion (basal/middle/apical, 37/9/2 vs. 12/11/2). Pre-LPI intraocular pressure (IOP) (18.8±5.4 vs. 16.2±4.5 mmHg; P= 0.037) and percentage of IOP reduction after LPI (22.3%±17.9% vs. 8.3%±19.5%; P < 0.003) showed a significant difference between the 2 clusters. The most distinct difference between the 2 subgroups in the cluster analysis was TCA, suggesting that the position of the CB is important in subclassifying PAC. By using UBM, clinicians may obtain more clues about the mechanisms of PAC; in turn, they may learn to predict the IOP-lowering effects of LPI.

Anterior Segment Morphology in Primary Angle Closure Glaucoma using Ultrasound Biomicroscopy.

AimTo evaluate the configuration of the anterior chamber angle quantitatively and study the morphological changes in the eye with ultrasound biomicroscopy (UBM) in primary angle closure glaucoma (PACG) patients after laser peripheral iridotomy (LPI).Materials and methodsA total of 185 eyes of 185 PACG patients post-LPI and 126 eyes of 126 normal subjects were included in this prospective study. All subjects underwent complete ophthalmic evaluation, A-scan biometry, and UBM. The anterior segment and angle parameters were measured quantitatively and compared in both groups using Student’s t-test.ResultsThe PACG patients had shorter axial length, shallower central anterior chamber depth anterior chamber depth (ACD), and anteriorly located lens when compared with normal subjects. Trabecular iris angle (TIA) was significantly narrow (5.73 ± 7.76°) in patients with PACG when compared with normal subjects (23.75 ± 9.38°). The angle opening distance at 500 pm from scleral spur (AOD 500), trabecular-ciliary process distance (TCPD), iris-ciliary process distance (ICPD), and iris-zonule distance (IZD) were significantly shorter in patients with PACG than in normal subjects (p < 0.0001). The iris lens angle (ILA), scleral-iris angle (SIA), and scleral-ciliary process angle (SCPA) were significantly narrower in patients with PACG than in normal subjects (p < 0.0001). The iris-lens contact distance (ILCD) was greater in PACG group than in normal (p = 0.001). Plateau iris was seen in 57/185 (30.8%) of the eyes. Anterior positioned ciliary processes were seen in 130/185 eyes (70.3%) of eyes.ConclusionIn PACG patients, persistent apposition angle closure is common even after LPI, which could be due to anterior rotation of ciliary body and plateau iris and overcrowding of anterior segment due to shorter axial length and relative anterior lens position.How to cite this article: Mansoori T, Balakrishna N. Anterior Segment Morphology in Primary Angle Closure Glaucoma using Ultrasound Biomicroscopy. J Curr Glaucoma Pract 2017;11(3):86-91.

Endoscopic Cycloplasty (ECPL) and Lens Extraction in the Treatment of Severe Plateau Iris Syndrome.

To describe the anatomic and clinical results of the treatment of severe plateau iris syndrome with lens extraction and endoscopic cycloplasty (ECPL). A secondary aim was to describe 4 novel ultrasound biomicroscopy (UBM) measurements for plateau iris syndrome. Prospective case series with UBM evaluation. Included were 12 eyes of 6 patients with plateau iris refractory to laser iridotomy and iridoplasty, miotic and other glaucoma medical treatment, with appositional angle closure in at least 3 quadrants. Treatment consisted of lens extraction and ECPL, an endoscopic diode laser treatment of the ciliary processes in the superior, nasal, and inferior quadrants. UBM measurements were taken in all quadrants before and after surgery. The untreated temporal quadrants were used as controls. Measurement parameters included: anterior chamber depth (ACD), angle opening distance (AOD 500), trabecular ciliary process distance (TCPD), iris ciliary process distance (ICPD), iris depth (ID), iridocorneal angle (ICA), and sulcus angle (SA). Four novel measurements included: ciliary process thickness (CPT), ciliary process width (CPW), ciliary process area (CPA), and iris ciliary process contact length (ICPCL). Visual acuity, intraocular pressure, glaucoma medications, and complications were also followed. The ACD, AOD 500, and ICA all increased significantly (P<0.001). ICPD, CPT, CPW, CPA, and ICPL all decreased significantly (P<0.01). Parameters remaining unchanged were: TCPD, ID, and SA. The untreated quadrants showed similar measurements to the preoperative measurements. There were no serious complications noted. Treating the ciliary processes with diode laser using an endoscopic approach (ECPL) and lens extraction, results in opening of the anterior chamber angle and shrinkage of the ciliary processes in the treated areas. This effect seems to be primarily a result of the laser treatment in combination rather than the lens extraction alone. This effectively reverses the anatomic cause and angle closure of plateau iris syndrome.

Plateau Iris in Primary Angle Closure Glaucoma

To determine prevalence and anterior segment morphology of plateau iris in patients with primary angle closure glaucoma (PACG) after laser peripheral iridotomy using ultrasound biomicroscopy (UBM). In this prospective study, 262 PACG patients and 144 normal controls underwent UBM examination. Plateau iris in a quadrant was defined by the presence of anteriorly directed ciliary process, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact in the same quadrant. At least 2 quadrants had to fulfill these UBM criteria. UBM analysis showed plateau iris in 83/262 (31.68%, 95% confidence interval: 26.7%-37.9%) PACG eyes, it was common in female individuals (61.44%), and patients were significantly younger than PACG patients (P=0.006). Plateau iris was found in superior quadrant in 19/83 (22.89%) eyes, inferior quadrant in 19/83 (22.89%) eyes, nasal quadrant in 21/83 (25.3%) eyes, and temporal quadrant in 24/83 (28.91%) eyes. In plateau iris patients, the central anterior chamber depth was shallower, the anterior chamber angle, the scleral-iris angle, and the sclera-ciliary process angle were significantly narrower, and the trabecular ciliary process distance and the iris ciliary process distance were significantly shorter in patients than in PACG subjects. Patients with plateau iris had significantly shallow central ACD when compared with those with pupillary block and normal eyes. After laser peripheral iridotomy, about a third of PACG eyes had plateau iris. This is clinically important because these patients can develop synechial angle closure and should be followed up closely.

Biometric parameters of vitrectomized eyes

To analyze changes in various biometric parameters after vitrectomy. A total of 50 patients (50 eyes) were followed up. All of them underwent vitrectomy for idiopathic epiretinal fibrosis and macular hole. In addition to the standard ophthalmic examination, we performed a combined ultrasound study and ultrasound biomicroscopy before and after the surgery (at 2-3 weeks and 6 months). Variation statistics was applied to assess the results using the SPSS Statistica 20 software. According to ultrasound biomicroscopy, the following parameters increased: anterior chamber depth, trabecular-ciliary process distance, posterior chamber maximal depth and volume, and fiber length within the zonule of Zinn. In the late postoperative period (6 months after the surgery), there was an increase in lens volume and anterior-posterior ocular axis by the average of 0.15±0.04 mm. Against this background, clinical refraction shifted toward myopia by the average of 0.68±0.05 diopters in the early postoperative period and 1.7±0.15 diopters at 6 months. With the help of modern ultrasound examinations we have identified biometric changes in the anterior segment of vitrectomized eyes. We have also established a myopic shift of clinical refraction, which is most likely to be due to the increase in axial eye length and lenticular changes.

PSS4 - Efficacy And Safety of Surgical Treatment Options for Primary Angle Closure Glaucoma: a Meta-Analysis of Randomised Controlled Trials

Worldwide, glaucoma is the second highest cause of blindness. Surgery is the treatment of choice when medications fail to control intraocular pressure (IOP). This systematic literature review and meta-analysis aimed to compare efficacy and safety of the common surgical options available for primary angle closure glaucoma (PACG). Studies with PACG patients who underwent trabeculectomy, phacotrabeculectomy or phacoemulsification were screened and included from electronic databases. The outcomes compared were IOP (24 months), postoperative angle opening distance (AOD), postoperative trabecular-ciliary process distance, postoperative anterior chamber depth (ACD), synechial angle closure all at 1 year, best corrected visual acuity (BCVA) at 1 year and 2 years, and intra- and post-operative complications of the surgery like worse logarithmic minimal angle resolution BCVA, progression of glaucomatous optic neuropathy, progression of glaucomatous visual field at 2 years. Critical appraisal of studies was carried out using Cochrane’s Risk of Bias tool. Meta-analysis of clinical trials was conducted using RevMan v5.1, through pooling of medically controlled and uncontrolled glaucoma patients where available. Of the 704 studies that were screened, five randomised clinical trials were included. Pooled analysis of two studies showed IOP at 24 months was better controlled by phacotrabeculectomy (mean difference 1.46 [95%CI 0.24,2.67]). Post-operative AOD and ACD results favoured phacoemulsification (mean difference 123.60 [95%CI 51.46,195.74] and 230.60 [95%CI 106.30,354.90] respectively). The post-operative complications showed risk ratio of 0.07 (95%CI 0.01,0.34) showing fewer complications in phacoemulsification patients. The remaining outcomes showed no significant results. Phacoemulsification had significantly lesser complications than trabeculectomy, with risk ratio of 0.08 (95%CI 0.01,0.60). The analyses of the observational and economic studies are being carried out, the results of which will be included in the poster. The results show that while phacotrabeculectomy has better IOP control than phacoemulsification, the latter has higher safety than both phacotrabeculectomy and trabeculectomy.