Plateau Iris Research Articles

Loss values of style transfer from UBM to AS-OCT images for plateau iris classification

Ultrasound biomicroscopy (UBM) is the standard for diagnosing plateau iris, but its limited accessibility in routine clinical settings presents challenges. While anterior segment optical coherence tomography (AS-OCT) is more convenient, its effectiveness in detecting plateau iris is limited. Previous research has demonstrated that combining UBM and AS-OCT image pairs through neural style transfer has improved classification accuracy. However, obtaining paired images is impractical in everyday practice. In this study, we propose a novel semi-supervised approach that eliminates the need for paired images. A generative model learns to distinguish plateau and non-plateau features from UBM images. AS-OCT images are input into the generator, which attempts to transform them into corresponding UBM images. The model’s performance is measured by loss values, representing the difficulty of transforming AS-OCT images, which are then used to predict plateau iris. The classification baseline, which applies AS-OCT solely without the style-transfer of UBM information, obtained 52.72% sensitivity, 60.82% specificity, and 57.89% accuracy for external validation; in contrast, the classification with neural style transfer of the image pairs respectively obtained 94.54%, 100.00%, and 98.03%, whereas the semi-supervised approach using loss values classification obtained 93.10%, 93.13%, and 93.12%, respectively. This semi-supervised transfer learning model presents a novel technique for detecting plateau iris with AS-OCT.

Potential utility of anterior segment optical coherence tomography and biometry in differentiating plateau iris configuration from pupillary block

ABSTRACT Clinical relevance Angle closure glaucoma is one of the most common blinding diseases encountered mainly in older age groups, although it may also occur at a younger age. Identifying the underlying cause of angle closure helps in designing specific treatment strategies essential for effective disease management. Background Primary angle closure disease, caused due to pupillary block (PB) and plateau iris configuration (PIC), necessitates different management strategies. This study assessed the potential utility of anterior segment optical coherence tomography (ASOCT) and optical biometry in distinguishing PIC from PB in primary angle closure disease of the young (PACDy). Methods Patients aged 20–40 years with PACDy and age-matched healthy controls were recruited. Ophthalmic examinations included gonioscopy, ultrasound biomicroscopy, ASOCT, and biometry. Anterior chamber depth, lens thickness, axial length, central corneal thickness, lens position, relative lens position, vitreous cavity length, lens vault, relative lens vault and angle opening distance, trabecular iris space area, and trabecular iris angle were measured. Receiver operating characteristics curve analysis evaluated the discriminative ability of these parameters. Results Of the 280 eyes, 128 were normal and 152 had PACDy. Of 128 PACDy, 88 had PIC, and 64 had PB. Both PIC and PB had significantly smaller ASOCT and biometric parameters than normal eyes. However, PIC had intermediate biometric values that fell between normal eyes and PB. All the aforementioned parameters, except central corneal thickness, showed excellent discriminating ability of PIC and PB from normal eyes; however, no single parameter can strongly differentiate PB from PIC. Axial length and relative lens vault had the highest, although weak, power for discriminating PB from PIC. Conclusion ASOCT and biometry effectively distinguish PIC and PB from normal eyes, but no single parameter reliably differentiates PIC from PB. Comprehensive gonioscopy and ultrasound biomicroscopy may be necessary for accurate diagnosis in PACDy.

Intraocular pressure and gonioscopic findings in primary angle-closure disease in India-a big data study.

To describe the gonioscopic profile and intraocular pressure (IOP) in primary angle-closure (PAC) disease in patients presenting to a tertiary eye care network in India. A cross-sectional hospital-based study that included 31 484 new patients presenting between 2011 and 2021. Patients with a clinical diagnosis of PAC/suspect/glaucoma were included. The data was collected from an electronic medical record system. PAC glaucoma (PACG) (47.55%) was the most common diagnosis followed by PAC (39.49%) and PAC suspect (PACS; 12.96%). Female preponderance (54.6%) was noted with higher mean age at presentation among males (P<0.0001). PACS and PAC showed the highest prevalence in 6th decade but PACG was higher at 7th decade. The probability of angle opening was 95.93%, 90.32% and 63.36% in PACS, PAC and PACG eyes respectively post peripheral iridotomy (PI). Plateau iris syndrome (PIS) was noted in 252 eyes and all showed post dilated rise of IOP. A post dilated IOP rise was also noted with 8.86%, 33.95% and 57.19% eyes with PACS, PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum. The superior quadrant is the narrowest angle and difficult to open with indentation and post PI. The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise. The post dilated IOP rise in angle closure eyes warrants a careful dilatation, especially with PIS.

Gap Analysis of Glaucoma Examination Concept Representations within Standard Systemized Nomenclature of Medicine – Clinical Terms

PurposeStandardization of eye care data is important for clinical interoperability and research . We aimed to address gaps in the representations of glaucoma examination concepts within Systemized Nomenclature of Medicine – Clinical Terms (SNOMED-CT), the preferred terminology of the American Academy of Ophthalmology. DesignStudy of data elements. MethodsStructured eye exam data fields from two electronic health records (EHR) systems (Epic Systems and Medisoft) were compared against existing SNOMED-CT codes for concepts representing glaucoma examination findings3. Glaucoma specialists from multiple institutions were surveyed to identify high-priority gaps in representation, which were discussed among the SNOMED International Eye Care Clinical Reference Group. Proposals for new codes to address the gaps were formulated and submitted for inclusion in SNOMED-CT. Main Outcome MeasuresGaps in SNOMED-CT glaucoma examination concept representations ResultsWe identified several gaps in SNOMED-CT regarding glaucoma examination concepts. A survey of glaucoma specialists identified high-priority data elements within the categories of tonometry and gonioscopy. For tonometry, there was consensus that we need to define new codes related to maximum intraocular pressure (IOP) and target IOP, and to delineate all methods of measuring IOP. These new codes were proposed and successfully added to SNOMED-CT for future use. Regarding gonioscopy, the current terminology did not include the ability to denote the gonioscopic grading system used (e.g., Shaffer or Spaeth), degree of angle pigmentation, iris configuration (except for plateau iris), and iris approach. There was also no ability to specify eye laterality or angle quadrant for gonioscopic findings. We proposed a framework for representing gonioscopic findings as observable entities in SNOMED-CT. DiscussionThere are existing gaps in the standardized representation of findings related to tonometry and gonioscopy within SNOMED-CT. These are important areas for evaluating clinical outcomes and enabling secondary use of EHR data for glaucoma research. This international, multi-institutional collaborative process enabled identification of gaps, prioritization, and development of data standards to address these gaps. ConclusionAddressing these gaps and augmenting SNOMED-CT coverage of glaucoma examination findings could enhance clinical documentation and future research efforts related to glaucoma.

Clinical and genetic features in autosomal recessive bestrophinopathy in Chinese cohort

PurposeTo provide a genotype and phenotype characterization of the BEST1 mutation in Chinese patients with autosomal recessive bestrophinopathy (ARB) through multimodal imaging and next-generation sequencing (NGS).MethodsSeventeen patients from 17 unrelated families of Chinese origin with ARB were included in a retrospective cohort study. Phenotypic characteristics, including anterior segment features, were assessed by multimodal imaging. Multigene panel testing, involving 586 ophthalmic disease-associated genes, and Sanger sequencing were performed to identify disease-causing variants.ResultsAmong 17 ARB patients, the mean follow-up was 15.65 months and average onset age was 30.53 years (range: 9–68). Best corrected visual acuity ranged from light perception to 0.8. EOG recordings showed a typically decreased Arden ratio in 12 patients, and a normal or slightly decreased Arden ratio in two patients. Anterior features included shallow anterior chambers (16/17), ciliary pronation (16/17), iris bombe (13/17), iridoschisis (2/17), iris plateau (1/17), narrow angles (16/17) and reduced axial lengths (16/17). Sixteen patients had multiple bilateral small, round, yellow vitelliform deposits distributed throughout the posterior pole, surrounding the optic disc. Initial diagnoses included angle-closure glaucoma (four patients), Best disease (three patients), and central serous chorioretinopathy secondary to choroidal neovascularization (CNV) (one patient), with the remainder diagnosed with ARB. Fourteen patients underwent preventive laser peripheral iridotomy, four of whom also received combined trabeculectomy and iridotomy in both eyes for uncontrolled intraocular pressure. One patient received intravitreal conbercept for CNV. Overall, 15 distinct disease-causing variants of BEST1 were identified, with 14 (82.35%) patients having missense mutations. Common mutations included p. Arg255-256 and p. Ala195Val (both 23.68%), with the most frequent sites in exons 7 and 5.ConclusionsThis study provides a comprehensive characterization of anterior segment and genetic features in ARB, with a wide array of morphological abnormalities. Findings are relevant for refining clinical practices and genetic counseling and advancing pathogenesis research.

Anterior Chamber Angle and Intraocular Pressure Control After Phacoemulsification in Primary Angle Closure With Different Mechanisms.

Different mechanisms of angle closure represented distinct aspects of intraocular pressure (IOP) control after phacoemulsification. Classification of angle closure mechanisms is necessary for postoperative IOP management and glaucoma progression in primary angle closure eyes. To investigate the relationship between the anterior chamber angle (ACA) characteristics, measured by swept-source anterior segment optical coherence tomography (SS AS-OCT), and intraocular pressure (IOP) control after phacoemulsification in eyes with primary angle closure disease (PACD) with different angle closure mechanisms. PACD eyes were classified into 3 groups according to angle closure mechanisms using preoperative SS AS-OCT images; pupillary block (PB), plateau iris configuration (PIC), exaggerated lens vault (ELV). This retrospective, clinical cohort study included eighty-five eyes of 85 PACD patients: 34 with PB, 23 with PIC, and 28 with ELV. ACA parameters were measured preoperatively and 1 month postoperatively using SS AS-OCT. IOP measurements were performed preoperatively and during 6 months postoperatively. Postoperative IOP reduction and fluctuation were calculated, and their correlations with SS AS-OCT parameters were analyzed. PIC group showed the lowest postoperative IOP reduction compared with the other groups ( P =0.023). Preoperative ACA measurements were significantly associated with postoperative IOP reduction in ELV and PB groups, while postoperative measurements were in PIC group. Preoperative and postoperative change of iridotrabecular contact (ITC) index and area were correlated with postoperative IOP reduction in PB and ELV groups but not in PIC group. Postoperative ITC index ( P =0.031) and area ( P =0.003) showed significant correlations with postoperative IOP fluctuation only in PIC group. SS AS-OCT parameters including ITC index and area showed different associations with postoperative IOP control, which should be considered in determination of lens extraction and treatment of PACD eyes.

Zonulopathy and Its Relation to Primary Angle Closure Disease: A Review.

This paper aims to discuss the anatomical features of zonule fibers that center the lens in the eye and summarizes the relationship between zonulopathy and PACD. The increasing lens vault (LV) and lens thickness (LT) is a recognized mechanism for primary angle closure glaucoma (PACG). Zonulopathy, causing the abnormal lens position, is an important factor in this mechanism. Several anatomically distinct sets of zonular fibers are present in primate eyes, including ciliary zonules, vitreous zonules, and attachments between the posterior insertion zone of the vitreous zonules and the posterior lens equator (PVZ INS-LE strands). Zonulopathy, as a clinical diagnosis, exhibits zonular laxity and loss, long anterior lens zonules (LAZ). Slit lamp, gonioscopy, ultrasound biomicroscopy (UBM), anterior segment optical coherence tomography (AS-OCT) aid in the diagnosis of zonulopathy. The proportion of underdiagnosed zonulopathy among primary angle closure disease (PACD) patients before operation is high. According to the intraoperative signs, zonulopathy could be determined better. There is a high prevalence of zonulopathy among PACD patients compared with the general population. Because of the different insertion zone in lens capsules, different zonular fibers play different parts in lens position and shape. Zonular laxity and loss cause the lens to be thicker and move anteriorly, forming narrow-angle and high intraocular pressure, and then the higher intraocular pressure damages zonule fibers further and causes angle closure. Loss of vitreous zonules may make the ciliary body rotate anterior excessively and pull iris forward, leading to iridotrabecular contact. LAZ eyes tend to be hyperopic and have short axial length, increased LT and anterior lens position, plateau iris configuration, and characteristics that are consistent with elevated risk for angle closure. Zonulopathy may be a risk for PACD. A clear knowledge of zonulopathy and its relation to PACD would be helpful to the diagnosis and treatment.

Plateau iris syndrome: Epidemiology, diagnosis, and treatment: A narrative review.

Plateau iris syndrome (PIS) was first coined in 1958 to describe the iris configuration of a patient, 2 years later; the concept of plateau iris was published. In 1992, the anatomic aspects of plateau iris were studied using ultrasound biomicroscopy (UBM) determining it as a form of primary angle-closure glaucoma caused by a large or anteriorly positioned ciliary body that leads to mechanical obstruction of the trabecular meshwork, this condition is most often found in young patients. We aim to review the current literature and knowledge on the diagnosis and treatment options of PIS; the search was conducted in PubMed, LILACS, and BIREME internet search sites using keywords and snowball search strategy of articles published until 2022, focusing on PIS history, epidemiology, clinical diagnosis, UBM feature, and treatment.

The Diagnostic Value of Ultrasound Biomicroscopy in Anterior Segment Diseases.

The purpose of this study was to analyze the use of ultrasound biomicroscopy (UBM) in the diagnosis and follow-up anterior segment diseases. The records of patients who presented to our clinic for UBM between January 1, 2004, and December 31, 2018 were reviewed retrospectively. Demographic characteristics, indications for UBM imaging and findings of the patients were recorded. Also, the change in clinical indications over the years were analyzed. The study included 1.256 eyes of 917 patients, of whom 723 (57.6%) were female and 533 (42.4%) were male. The mean age was 48.7±14.8 years (range: 12-85 years). Indications for UBM imaging were to evaluate glaucoma pathogenesis and surgical outcomes (n=764, 60.8%), iris and ciliary body masses (n=263, 20.9%), congenital anomalies of the crystalline lens and complications of cataract surgery (n=86, 6.8%), the etiology of hypotony (n=57, 4.5%), corneal diseases (n=46, 3.7%), anterior segment findings after trauma (n=22, 1.8%), conjunctival pathologies (n=11, 0.9%), and scleral pathologies (n=7, 0.6%). In patients with glaucoma, the most common reason for requesting UBM according to years was to investigate the plateau iris configuration. UBM is an important imaging method used in the determination of the pathophysiology of anterior segment diseases, clinical evaluation, planning of surgical treatment and analyzing the outcomes.

Changes in Anterior Segment Parameters After Laser Peripheral Iridotomy in Caucasian Eyes With Different Primary Angle Closure Mechanisms.

Subgrouping of angle closure mechanisms based on the swept-source optical coherence tomography images may help to identify the predominant underlying anatomic mechanism, evaluate personal treatment, and improve the better outcomes. The purpose of this study was to evaluate changes in anterior segment parameters in Caucasian eyes with different angle closure mechanisms before and after laser peripheral iridotomy (LPI). Sixty-six subjects underwent swept-source optical coherence tomography (CASIA, Tomey Corporation) angle imaging in the dark before and 7 days after LPI. On the basis of the baseline swept-source optical coherence tomography images, the eyes were categorized into 4 angle closure mechanisms, namely pupillary block (PB), plateau iris configuration (PIC), thick peripheral iris (TPI), and large lens vault (LLV). Sixteen out of 128 cross-sectional images (11.25 degrees apart) per volume scan were selected for analysis. We used a generalized estimating equation to compare quantitative parameters among angle closure mechanisms and between before and after LPI after adjusting the intereye correlation. The mean age of subjects was 67.7±9.2 years, with the majority being female (82.2%). One hundred twenty-nine eyes (67 primary angle closure suspects, 34 primary angle closure, and 28 primary angle closure glaucoma) were categorized into PB (n=71, 55%), PIC (n=40, 31%), TPI (n=14, 10.9%), and LLV (n=4, 3.1%). Anterior chamber depth was the shallowest in the LLV, followed by TPI, PB, and PIC group at baseline. Widening of the angle and reduction of the iris curvature (IC) due to LPI were observed in all groups (all P <0.01). When compared to the PB group, the LPI-induced angle widening in the TPI group was significantly less even though the iris curvature reduction in the TPI group was greater (all P <0.05). In patients with angle closure, anterior segment morphology and LPI-induced angle widening were different among the various angle closure mechanisms.

Qualitative ultrasound biomicroscopy in glaucoma.

UBM is a high-resolution ultrasound technique which allows non-invasive, in vivo imaging of the anterior segment and iridocorneal angle. This video is compilation of short video clips and images which gives description on identification of angle closure due to pupillary block, peripheral anterior synechiae, iris bombe, plateau iris, supra ciliary effusion, and malignant glaucoma. It also shows video demonstrating partially and fully patent iridotomy and features of trabeculectomy bleb. Synopsis: This video summarizes importance of UBM application in angle closure glaucoma to understand its pathophysiology by showing the relationship between the peripheral iris, trabecular meshwork and ciliary processes. UBM provides two-dimensional, grayscale images of the angle structures and allows identification of non-pupillary block mechanism in angle closure glaucoma, which can be recorded for qualitative and quantitative analyses. https://youtu.be/prsmGnR8jYc.

MVGL-Net: A generalizable multi-view convolutional network for anterior segment OCT

ObjectiveCorrect diagnosis of primary angle-closure disease (PACD) and classification of plateau iris configuration (PIC) existence is essential for appropriate glaucoma treatment. A fast non-contact method that can automatically detect PACD and PIC would be valuable for improving treatment decisions and reducing the misdiagnosis rate. MethodsIn this work, we propose an automated method to analyze anterior segment optical coherence tomography (AS-OCT) images and test it on two tasks using two multi-institution datasets containing more than 12,000 image slices from more than 400 eyes. Our method, called multi-view glaucoma network (MVGL-Net), leverages the multi-view nature of AS-OCT images for PACD diagnosis and, more importantly, can detect PIC with minimal transfer learning. ResultsThe MVGL-Net achieves comparable prediction results to other published models when used for PACD diagnosis. In the PIC diagnosis task, MVGL-Net significantly outperforms the existing models on PACD and achieves performance comparable to manual measurements on the AS-OCT images reported in the literature with an AUC of 0.71. ConclusionsThe experimental results demonstrate that the MVGL-Net model is a fast, generalizable approach that, when compared with existing models, achieves comparable results for angle-closure detection and improved results for PIC diagnosis, a more challenging medical imaging task.

Imaging Plateau Iris Using Ultrasound Biomicroscopy

Imaging Plateau Iris Using Ultrasound Biomicroscopy

ICL Explant Due to Ocular Hypertension, Reduced Endothelial Cell Count and Anterior Sub Capsular Cataract Due to Patient Selection Error

Implantable Collamer Lenses (ICL) are phakic lenses that are implanted in the posterior chamber of the eye for the correction of myopia, hyperopia, and astigmatism in those patients who cannot undergo corneal refractive surgery, the main feature of the latest models. Of ICL is a hole in the optical center of the lens, which facilitates the natural flow of aqueous humor. Among the contraindications for ICL implantation are: Corneal pathologies, cataracts, glaucoma, retinal pathologies such as degenerations or detachments, diabetic retinopathy, patients allergic to collagen, pseudo-exfoliative syndrome, pigment dispersion syndrome, pupillary abnormalities, endothelial count less than 2000 mm2, uveitis, under 20 years of age or with unstable refraction. We present the case of a 24-year-old female patient who came to the clinic for refractive surgery due to high myopia, an ICL -18.00 D implant was proposed in the left eye. In the preoperative examinations: the UBM presented an iris plateau with multiple angle-closing cysts. In the optic nerve OCT she presents a moderate and severe decrease in nerve fibers and the visual field with PHG: outside normal limits, MD: -12.84 dB. After the postoperative period, the patient presented with ocular hypertension that was controlled with antihypertensive, he achieved IOP control a month after the operation, but after a few months postoperatively he presented a low endothelial cell count and an anterior sub capsular cataract, for which it was decided to explant the ICL. Finally, cataract surgery was performed and a monofocal IOL was implanted.

Plateau Iris: A Review.

To review the concept of plateau iris and summarize the recent evidence on its diagnosis and management. This is a narrative review on the plateau iris. A literature review was conducted in PubMed, Google Scholar, and Scopus databases using keywords: angle-closure glaucoma, glaucoma, nonpupillary block glaucoma, plateau iris, and plateau iris management. This review defined the current knowledge about plateau iris. First of all, the anatomy and epidemiology were discussed. Then, we outlined the available evidence on the diagnosis of plateau iris and its differential diagnosis. Conclusively, the treatment options were mentioned. Plateau iris is a condition in which nonpupillary block mechanisms are responsible for intraocular pressure elevation and angle closure attack when a patent peripheral iridotomy has removed the relative pupillary block. An anteriorly positioned ciliary body causes mechanical obstruction of trabecular meshwork in these patients. It is usually seen in younger patients with angle closure and is diagnosed by gonioscopic examination and imaging modalities such as Ultrasound biomicroscopy. Despite the known mechanism of plateau iris, there is no consensus over treatment. Low-dose pilocarpine and Argon laser peripheral iridoplasty are nonsurgical treatments for these patients, but their effects are short-term. Cataract extraction with/without endocyclophotocoagulation (ECP), endocycloplasty, excisional goniotomy, and transscleral cyclophotocoagulation are alternative treatments. Patients should be examined periodically for further progression or recurrence of plateau iris. In cases of glaucoma unresponsive to conventional medical treatments, surgical treatments such as trabeculectomy and drainage devices should be considered.

Ultrasound Biomicroscopy and Anterior Segment Optical Coherence Tomography in the Diagnosis of Plateau Iris and Pupillary Block

Ultrasound Biomicroscopy and Anterior Segment Optical Coherence Tomography in the Diagnosis of Plateau Iris and Pupillary Block

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.

Diagnostic performance of anterior segment optical coherence tomography in detecting plateau iris

ObjectiveTo evaluate the diagnostic performance of manual grading of anterior segment optical coherence tomography (AS-OCT) in detection of plateau iris configuration (PIC) based on the presence of standardised ultrasound biomicroscopy...

Prevalence of Plateau Iris in Primary Angle Closure Glaucoma: An Egyptian Hospital Based Ultrasound Biomicroscopy Study.

PurposeTo determine the distribution and the anatomical characteristics of plateau iris (PI) in primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM).MethodsFifty UBM images of PACG cases were studied over one year by retrospective analysis. The data from UBM images including angle opening distance at 500 and 750 μm (AOD500 and AOD750), trabecular-iris angle (TIA), angle recess area at 750 μm (ARA750), maximum ciliary body thickness (CBTmax), anterior placement of ciliary processes (APCP), central anterior chamber depth (CACD), axial lens thickness (ALT), and ciliary sulcus status were analyzed and compared between the PI and non-PI cases.ResultsEighteen cases had PI (36%). The mean AOD500, AOD750, and TIA were significantly smaller in PI than in non-PI eyes (P = 0.01; P = 0.046; and P = 0.026). Values of the ARA750 and CBTmax were not significantly different between the two groups (P = 0.208 and P = 0.368). CACD was deeper in the PI group (P = 0.011). ALT was higher in the non-PI group (P = 0.001). The mean APCP of the PI group was more than those of the non-PI group (P < 0.001). The number of cases with obliterated ciliary sulcus in more than two quadrants was significantly more in the PI group (P < 0.001).ConclusionAround one-third of PACG eyes were found to have PI on UBM imaging. The number of obliterated ciliary sulcus and APCP were important UBM parameters that help in PI diagnosis.

Glaucoma Progression After Lens Extraction in Primary Angle-closure Glaucoma According to Angle-closure Mechanism.

Long-term prognosis of primary angle-closure was assessed after lens extraction (LE) according to different mechanisms of angle closure (AC). Patients with pupillary block (PB) had a higher probability of glaucomatous progression than patients with plateau iris configuration (PIC). The aim was to investigate and compare the clinical characteristics and long-term prognosis of primary angle-closure disease (PACD) after LE according to different mechanisms of AC. In this retrospective observational cohort study, 118 eyes with PACD that underwent LE (mean follow-up; 6.0±3.5 y after surgery) were included. PACD eyes were categorized into three subgroups according to their dominant AC mechanisms, determined by anterior segment optic coherent tomography obtained before LE; PB, PIC, and exaggerated lens vault (ELV). Postoperative glaucomatous progression was determined according to functional (visual field) or structural (optic disc photographs or optic coherent tomography measured retinal nerve fiber layer thickness) criteria. Univariate and multivariate logistic regression analysis was performed to determine the risk factors associated with glaucomatous progression. Fifty-two, 51, and 15 eyes with PB, PIC, and ELV, respectively, were included. All eyes showed significant intraocular pressure reduction, with a greater reduction in the ELV group than in the PB group after LE (27.0% vs. 12.5%, P=0.018). Lower baseline retinal nerve fiber layer thickness [odds ratio (OR): 0.966, P=0.004] and thinner central corneal thickness (OR: 0.985, P=0.021), and the PB group (OR: 2.891, P=0.022, reference to PIC group) were significantly associated with glaucomatous progression after LE. In eyes with PACD, glaucoma progression was observed following LE despite reduced intraocular pressure. The probability of progression was highest in eyes with pupil block as a mechanism of AC. Close monitoring of glaucoma in these patients is suggested.