Anterior Chamber Angle Research Articles

Manifestations of persistent pupillary membrane.

To study the clinical and structural manifestations of persistent pupillary membranes (PPM) using light and electron microscopy. This descriptive case series study included 32 children (38 eyes) with different clinical PPM types. The cases were collected between 2005 and 2023. The age of the patients ranged from 7months to 13years, with a mean age of 3 ± 2.6years. All children underwent standard ophthalmological examinations, including biomicroscopy, keratometry, gonioscopy, ophthalmoscopy, tonometry, visometry, ultrasonic biometry, scanning, and photo and video recording. Surgical removal of PPM was performed in 15 children (17 eyes), and the removed PPMs were histologically and electron microscopically studied. The PPMs were of different sizes, configurations, and volumes. The vast majority, 25 children (29 eyes, 76.3%), had type II PPM with iridolenticular attachment (Duke-Elder classification, 1964). Six children (8 eyes, 21.1%) had type I PPMs with iris-to-iris attachment. In one case (one eye, 2.67%), a combination of type I and type II PPM was observed. In the eyes with PPM, microphthalmia and microcornea were observed in 34.2% and 23.7% of cases, respectively. PPM affected the size and configuration of the pupil in 44.76% of cases and the anterior chamber angle structure in 26.3% of cases. The lens remained transparent in 84.2% of the cases. Congenital cataracts were observed in 15.89%. Visual acuity in the eyes with PPM varied from light perception to 0.4 logMAR. In 50.0% of cases, significant visual loss occurred in type II PPM. Histomorphological and electron microscopic studies showed that PPM was the remnant of the tunica vasculosa lentis, had a mesodermal origin, and did not penetrate the anterior lens capsule. For the first time, the clinical features of PPM were analyzed in a significantly large number of cases, and the analysis showed that PPMs with iridolenticular attachment were dominant. They were of different sizes and configurations and had a dense fit to the lens, causing significant visual loss and thus requiring surgical removal. In almost half of the cases, PPM caused pupil narrowing, decentration, and deformation, whereas the crystalline lens remained transparent in most cases (84.2%).

Anterior chamber morphological and refractive outcomes following phacoemulsification in pseudoexfoliative eyes: A case-control study.

To compare changes in angle morphology, anterior chamber depth (ACD) and refractive prediction error (PE) after phacoemulsification between pseudoexfoliative (PEX) and non-PEX eyes. Prospective case-control study of eyes submitted to cataract surgery. Biometric data and angle parameters - Anterior Chamber Angle (ACA), Angle Opening Distance (AOD), Scleral Spur Angles (SSA) and Trabecular Iris Space Area (TISA) - were measured preoperatively and 1-month postoperatively through swept-source anterior segment optical coherence tomography. Postoperative refractive prediction error (PE) was calculated using an optimized A-constant and the Kane formula. Sixty eyes (30 PEX and 30 non-PEX) of 60 patients were included. Preoperative angle analysis revealed a lower ACA, AOD, SSA and TISA in PEX group (p < 0.05), without biometric differences (p > 0.05). A tendency for a higher magnitude of morphometric angle changes in PEX eyes was observed, with a superior increase of SSA at 500 µm (0°) and TISA at 750 µm (0°) (p = 0.030 and p = 0.041, respectively). The anterior chamber deepened in both groups (p = 0.01), with arithmetic and percentile change being higher in PEX group (p = 0.017 and p = 0.047, respectively). A significant PE hyperopic shift was observed (p = 0.035) only in PEX group. Pseudoexfoliative eyes with cataract have narrower angles, revealing a tendency for higher angle opening after surgery, along with an increased ACD deepening compared to non-PEX eyes, which may be explained by PEX-associated zonular laxity. Moreover, a significant hyperopic shift was observed in PEX eyes, a relevant fact to take into consideration when selecting intraocular lens power.

Analysis of the correlations between changes in posterior segment and anterior chamber segment after implantable collamer lens implantation in highly myopic patients

PurposeTo evaluate the impact of Implantable Collamer Lens (ICL) implantation on anterior chamber angle parameters and posterior segment structures in highly myopic eyes and explore potential correlations between these changes. The study aimed to assess alterations in superficial and deep vessel density (SVD, DVD), foveal avascular zone (FAZ) area, and retinal nerve fiber layer (RNFL) thickness to clarify the safety profile of ICL implantation.MethodsProspective observational study, included 36 highly myopic eyes undergoing ICL implantation in surgery group and 23 non-surgical control eyes in non-surgery group. Anterior chamber parameters were assessed using AS-OCT, and posterior segment changes, including SVD, DVD, FAZ, and RNFL, were evaluated using OCT and OCTA preoperatively and at intervals up to 3 months postoperatively. Statistical analyses included paired t-tests, Wilcoxon tests, and Spearman correlation.ResultsICL implantation significantly improved uncorrected distance visual acuity (UDVA) (p < 0.01). Anterior chamber depth (ACD) and angle parameters, such as AOD and TISA, decreased initially but stabilized by 3 months. SVD and DVD showed early postoperative fluctuations, returning to baseline by 3 months, while the FAZ area and subfoveal choroidal thickness remained stable. Significant correlations were identified between anterior segment narrowing and posterior vascular changes, particularly in the pericentral region.ConclusionsICL implantation effectively and safely corrects high myopia, with stable anterior and posterior structural changes by 3 months. Transient vascular density fluctuations correlated with anterior chamber angle alterations, highlighting the need for long-term studies to further understand these dynamics and ensure retinal safety postoperatively.Trial registrationThe study was approved by the ethics committee of Aier Eye Hospital, Jinan University (No. GZAIER2023IRB25; China Clinical Trial Record No. MR-44-24-009241).

The Change of Ciliary Muscle-Trabecular Meshwork-Schlemm Canal Complex after Phacoemulsification using Swept-Source-Optical Coherence Tomography

Introduction: Cataract surgery has been reported to have a reducing effect on intraocular pressure (IOP) in glaucomatous and non-glaucomatous eyes. This effect seems to be more noticeable in eyes with narrow angles (NAs) than in eyes with open angles (OAs). Decrease in IOP may be a result of the increase in anterior chamber angle and Schlemm canal (SC) after cataract surgery. The purpose of this paper was to evaluate the relationship between Schlemm canal-cross-sectional area (SC-CSA) changes and trabecular meshwork, ciliary muscle changes after cataract surgery and the difference in non-glaucomatous eyes with NAs and OAs. Methods: IOP, SC-CSA, Schlemm canal diameter (SCD), trabecular meshwork width (TMW) and thickness (TMT), trabecular-iris angle at 500 µm from the scleral spur (TIA500), and the distance between the inner apex of the ciliary muscle and scleral spur (IA-SS) were measured by swept-source-optical coherence tomography preoperatively and 1-week post-surgery. Patients were divided into NA and OA groups according to the degree of TIA500, and SC-CSA-related parameters were compared. Results: Seventy-five patients (89 eyes) were included. IOP significantly decreased, SC-CSA, SCD, TMW, TMT, and TIA500 significantly increased post-surgery (p < 0.001). Changes in nasal SC-CSA were associated with TMW (p = 0.003) and TIA500 (p < 0.001) changes; changes in temporal SC-CSA were associated with TMW (p = 0.001) and TMT (p < 0.001) changes. SC-CSA expansion was correlated with changes in TMW (β3.726 ± 1.085, p = 0.001 nasally; β3.405 ± 0.945, p = 0.001 temporally), TMT (β5.224 ± 2.033, p = 0.012 nasally; β11.853 ± 3.059, p < 0.001 temporally), and TIA500 (β40.330 ± 15.100, p = 0.009 nasally; β35.453 ± 17.527, p = 0.047 temporally). There was no association between SC-CSA expansion and IA-SS changes. SC-CSA expansion was greater in the NAs than in the OAs group (p < 0.001). Conclusion: Cataract surgery results in IOP reduction and SC-CSA expansion. Increased SC-CSA correlates with increases in TMW, TMT, and TIA500. SC-CSA increased more in NAs than in OAs group post-surgery, which may explain the greater decrease in IOP in eyes with NAs.

Topographic factors associated with anterior chamber angle narrowing in patients with keratoconus.

To identify topographic determinants of the anterior chamber angle (ACA) in patients with keratoconus (KCN). Four hundred and ten eyes of 294 patients with KCN were recruited for this study. First, complete ocular examinations were performed for all patients, including visual acuity measurement, refraction, and slit-lamp biomicroscopy. Then, all participants underwent corneal imaging by the Oculus Pentacam HR. The mean age of the participants was 32.40±8.52y (15-60y) and 69.5% of them were male. The mean ACA was 38.47°±5.75° (range: 14.40° to 56.50°) in the whole sample, 38.24°±6.00° in males, and 38.98°±5.11° in females (P=0.447). The mean ACA was significantly different among different groups of cone morphology, as patients with nipple cones showed the lowest mean ACA. Moreover, there were statistically significant differences in the mean ACA among different groups of cone locations, with patients having central cones exhibiting the lowest mean ACA (P<0.001). Anterior and posterior Q values were significantly, directly correlated with ACA (anterior Q: r=0.122, P=0.014, posterior Q: r=0.192, P<0.001). This study provides critical insights into the risk factors for ACA narrowing in KCN patients, which is essential for planning intraocular surgeries. Patients with nipple and central cones exhibited the most significant ACA narrowing. Additionally, more negative Q-values are associated with increased ACA narrowing, highlighting the need for targeted diagnostic and therapeutic strategies.

SOME FEATURES OF LINEAR AND ANGULAR PARAMETERS OF THE EYE’S ANTERIOR SEGMENT IN PATIENTS WITH OCULAR HYPERTENSION AND GLAUCOMA

Purpose – detection of some features of the relationship between anterior segment structures in eyes with ocular hypertension and primary glaucoma using ultrasound biomicroscopy (UBM). Material and methods A total of 60 patients (60 eyes) aged 27-60 years (46.6±11.4) with ophthalmic hypertension (n=7) and primary glaucoma (n=53) (0-2 stages in accordance with Mills glaucoma classification) were examined. They were divided into 3 groups in accordance with the axial length (AL): 16 short (&lt;23.0mm), 23 medium (23.0-24.5mm) and 11 long eyes (&gt;24.5mm). Main linear (mm) and angular (°) parameters of the eye’s anterior segment were measured using UBM (Ellex Eye Cubed, 40 MHz, Ellex Inc., Australia). Results The anterior chamber depth in short eyes was measured as 2.11±0.05, in medium – 2.47±0.04, in long – 3.02±0.06, posterior chamber depth: 0.58 ± 0.04, 0.65 ± 0.03, 0.69 ± 0.05. Iris thickness in root zone was 0.34±0.02, 0.34±0.01, 0.33±0.03. Ciliary body thickness at 1 mm from scleral spur: 0.47±0.03, 0.55±0.04, 0.62±0.05, at 2 mm: 0.28±0.03, 0.33±0.02, 0.38±0.03 respectively. “Trabecula-iris” distances at 250 µm from the scleral spur was: 0.09±0.03, 0.12±0.03, 0.21±0.04, at 500 µm: 0.14±0.02, 0.18±0.03, 0.27±0.03. “Trabecula-ciliary processes” was 0.65±0.05, 0.87±0.04, 1.07±0.06, length of Zinn zonules – 0.33±0.05, 0.52±0.04, 0.71±0.06 respectively. Anterior chamber angle (at 12´) was 16.34±5.65, 22.49±3.85, 27.04±3.23, “sclera-iris” angle: 15.80±2.34, 19.56±1.12, 24.97±1.59, “sclera-ciliary processes” angle – 38.21±2.44, 48.69±2.97, 51.22±3.66. Almost all patients had a predominantly flat iris profile, in short eyes it was more convex and anterior positioned, in long eyes – a straight iris profile combined with predominant posterior position, but in several cases – a concave profile. Conclusion Anterior chamber depth in combination with different AL is the most important factor in spatial arrangement of the eye's anterior segment structure. In eyes with a short AL a shallow posterior chamber depth, adjoining the iris to trabecula and partial coverage of posterior chamber by ciliary processes were observed. There were some difficulties in visualizing Zinn zonules due to coverage by ciliary processes and their adjoining to the root zone of iris in medium and long eyes. A flat iris profile was found in all 3 groups of glaucoma patients, but in eyes with medium and high AL it was more convex. Key words: ultrasound biomicroscopy, glaucoma, ocular hypertension, biometry

Topographic determinants of anterior chamber angle narrowing in patients with keratoconus

Purpose: To identify topographic determinants of the anterior chamber angle in a sample of patients with keratoconus.Methods: Two hundred patients who visited a tertiary eye hospital and were diagnosed with keratoconus, were recruited for this study. First, complete ocular examinations were performed for all patients, including measurement of uncorrected distance visual acuity, objective and subjective refraction, and slit‐lamp biomicroscopy. Then, all study participants underwent corneal imaging by the Pentacam rotating Scheimpflug imaging system. The keratoconus was diagnosed based on distorted keratometric mires, scissoring of retinoscopic reflex, abnormal corneal topography (inferior‐superior asymmetry, focal or inferior steepening, or a bow‐tie pattern with skewed radial axes &gt; 21°) consistent with keratoconus as well as the presence of at least one keratoconus biomicroscopic sign.Results: The mean age of study participants was 32.40± 8.52 years (15‐60 years) and 69.5% of them were male. No statistically significant difference was found in the anterior chamber angle between males and females (p‐value = 0.447). There was a statistically significant inverse correlation between anterior chamber angle and age (r = ‐0.262, p‐value &lt; 0.001). The mean anterior chamber angle was significantly different among different groups of cone morphology; patients with nipple cone had the lowest mean anterior chamber angle (p‐value = 0.001). Moreover, there was a statistically significant difference in the mean anterior chamber angle among different groups of cone location; the lowest mean anterior chamber angle belonged to patients with central cones (p &lt; 0.001). Anterior and posterior Q‐values were significantly directly correlated with anterior chamber angle (anterior Q: r = 0.122, p‐value = 0.014, posterior Q: r = 0.192, p‐value &lt; 0.001).Conclusions: Keratoconus patients with nipple and central cones and more negative Q‐values were more prone to anterior chamber angle narrowing. It is recommended that the risk of angle closure be taken into account in this group of patients for diagnostic and treatment procedures.

Dry eye disease and morphological changes in the anterior chamber in people with cystic fibrosis.

Cystic fibrosis (CF) is caused by variants in a gene that encodes a protein essential for water and ion transport in the epithelial cells of exocrine organs. Given the possible relationship of this protein and conjunctival and corneal epithelium, the aim of this study was to evaluate ophthalmologic alterations in people with CF. Forty-five people with CF underwent pulmonary evaluation including inflammatory score (IS). These people along with 98 sex-matched controls underwent ophthalmologic evaluation including dry eye disease (DED) testing, corneal topography using Pentacam™ and macular and peripapillary retinal nerve fiber layer (pRNFL) thickness with optical coherence tomography (OCT). The CF group presented a higher percentage of pathologic tear break-up time (T-BUT) (55.6 % vs 25 %, p = 0.001) and Schirmer's test 1 (40 % versus 19.4 %, p = 0.009) than the control group. In the CF group, an inverse correlation was observed between T-BUT and IS (r=- 0.373, p = 0.012), as well as T-BUT and peripheral eosinophilia (r=-0.338; p = 0.023). People with CF presented lower values of central corneal thickness (p = 0.009), thinnest point (p = 0.006), anterior chamber volume (p = 0.034), and anterior chamber angle (p = 0.011) than the control group and lower pRNLF thickness in the superior temporal sector (p = 0.002). Our findings indicate a higher prevalence of dry eye disease (DED) among people with CF compared to controls. The severity of the condition increases with higher systemic inflammation. Additionally, CF may affect the anterior segment of the eye, leading to a reduction in the nerve fiber layer and early signs of glaucoma.

Therapeutic keratoplasty in fungal keratitis

Background: Therapeutic keratoplasty (TPK) is done for microbial keratitis not responding to medical management as well as for lesions adjacent to the limbus which can later progress and involve the limbus/sclera. The surgery aims to eradicate the infection and restore the globe in perforated corneal ulcers. The anatomical and functional outcome of the surgery depends on various factors like a causative organism, the timing of surgery, the size of the lesion, the graft size, inflammation, surgical maneuvers, etc., Recurrence of fungal keratitis has been seen in 5–14% of patients who undergo TPK, possibly due to recurrence in the recipient bed, anterior chamber, or posterior segment. Purpose: In this video, we describe the surgical technique of TPK in patients with refractory fungal keratitis. The video elucidates the various intraoperative surgical measures to improve the outcome and decrease the risk of recurrence of infection after the surgery. The tips and tricks of the same have been described in five key headings for easy understanding and to aid beginners as well to perform the surgery with ease. Synopsis: A 54-year-old male presented with a decrease in vision in the right eye for 15 days. He had a history of trauma with sugarcane leaf before the onset of symptoms. Full thickness corneal infiltrate with limbus threatening lesion in the superonasal quadrant and collagenolysis was seen. Corneal scraping revealed septate fungal hyphae which later had Aspergillus flavus growth on Sabouraud dextrose agar. After initial medical management for fungal keratitis as the lesion was limbus threatening and was refractory to medical management, therapeutic keratoplasty was planned. The video describes the surgical planning and tips and tricks for the surgery. Highlights: The video described the surgery in five broad headings. The first is the trephine size which should include the entire infiltrate and should be at least 1 mm more than the infiltrate size in its largest axis. This reduces the risk of recurrence by taking care of the microscopic spread which can be missed on slit lamp examination. Second is the partial thickness trephination which is done after stabilizing the globe. Third is ensuring that no ledge is left behind as it can become a source of recurrence of infection later. Next, two peripheral iridectomies as made with Vanna’s scissors. Lastly, anterior chamber angles should be formed at the end of the surgery to decrease the risk of secondary glaucoma and increase the chances of graft survival. This video highlights all these factors to increase the overall outcomes of therapeutic keratoplasty done in a patient with fungal keratitis. Video link: https://youtu.be/OpLBwhwFvRo

Brillouin assessment of the crystalline lens in patients with high myopia after long‐term implantable collamer lens V4c implantation

AbstractPurposeTo evaluate the long‐term effects of implantable collamer lens (ICL) V4c on the biomechanical and morphological properties of crystalline lenses in Chinese adults with high myopia using Brillouin microscopy (BM).MethodsIn this case–control study, 102 highly myopic eyes from 102 patients (18–48 years, preoperative spherical equivalent (SE): −6.00–−21.00 D) were categorised into ICL and control groups, matched by age, axial length (AL), lens thickness (LT) and preoperative SE. The biomechanical and morphological properties of the lenses were measured by BM. Ocular and anterior segment parameters, including AL, anterior chamber depth, volume, angle and LT, were assessed using Pentacam and IOL Master 700.ResultsNo significant differences were observed in Brillouin morphological parameters between the ICL and control groups, including the width of top plateau (WTP), width of bottom plateau (WBP), bottom‐top (B‐T), slope of anterior cortex (SAC), and slope of posterior cortex (SPC) (all p &gt; 0.05). A slight decrease in biomechanical metrics (height of plateau, Height) was observed in the ICL group, compared with the control group (p = 0.012). Linear regression analysis revealed age‐related changes in morphological metrics among all participants, including WTP (p = 0.0001), WBP (p = 0.0001), and SPC (p &lt; 0.0001), while B‐T and SAC were age‐independent (both p &gt; 0.05). No age‐related changes in Height were observed (p &gt; 0.05).ConclusionsICL V4c did not significantly alter lens morphology as assessed using BM. A slight decrease in lenticular biomechanics was observed after ICL implantation.

Frequency Analysis of Ocular Hypertension after Microinvasive Ultrasonic and Traditional Guillotine Vitrectomy 25G

Purpose. To compare the frequency of ocular hypertension in patients in the early postoperative period after microinvasive ultrasonic and 25G pneumatic guillotine vitrectomy.Patients and methods. The article presents the results of studying intraocular pressure (IOP) and the frequency of postoperative ophthalmohypertension in patients in the early postoperative period after microinvasive ultrasound and pneumatic guillotine 25G vitrectomy. We analyzed the data of 256 patients (256 eyes) — 158 women, 98 men who underwent vitreoretinal surgery for the pathology of the vitreomacular interface, retinal detachment, diabetic proliferative retinopathy, hemophthalmia at the Optimed, Ufa with a follow-up for 1 month. For tamponade, physiological saline, gas-air mixture, silicone oil, sterile air were used, depending on the nature and severity of vitreoretinal pathology. The mean age was 59.2 ± 12.5 years. In the main group, patients were operated with microinvasive ultrasonic vitrectomy 25G (n = 136), in the control group — using pneumatic guillotine vitrectomy 25G (n = 120). Non-contact tonometry (Nidek Tonoref 3, Japan) was performed with a correction according to measurements of the central thickness of the cornea on a reflective microscope with pachymetry function (Tomey, ЕМ-3000, Japan) before surgery and on days 1, 7, and 30 after vitrectomy. Exclusion criteria from the study were: the presence of symptomatic ophthalmohypertension, glaucoma, traumatic injury to the angle of the anterior chamber, immature and mature cataracts, lens luxation. IOP indicators in both groups at different times of the early postoperative period (days 1, 7, 30) did not differ statistically significantly.Results. The frequency of ocular hypertension on day 7 in the main group was 20.6 %, in the control group — 20 %, and on day 30 — 11 % and 10 %, respectively (the difference between the groups was not statistically significant, p &gt; 0.05). The highest IOP values were observed with silicone oil tamponade.Conclusion. The first analysis of the frequency of ocular hypertension in patients after microinvasive ultrasonic vitrectomy 25G did not reveal statistically significant differences with pneumatic guillotine vitrectomy for various types of tamponade.

Surgical Treatment of Complicated Cataract in Patients with High-Grade Ametropia (Literature Review)

Carrying out phacoemulsification in eyes with concomitant pathology — extreme ametropia requires an individual approach due to the characteristics of the anteroposterior size of the eyeball and the presence of concomitant pathology. Difficulties arise at the stages of calculating the anterior-posterior axis of the eye, preoperative diagnosis, calculating the optical power of the intraocular lens, phacoemulsification and postoperative management. In the preoperative management of patients with hypermetropia, attention should be paid to the anterior eye segment, the angle of the anterior chamber of the eye, intraocular pressure; patients with high myopia require a detailed examination of the fundus. Difficulties in the intraoperative period in patients with short eye length are associated with the shallow depth of the anterior chamber, lack of space for manipulation; patients with long eyes require additional anesthesia to relieve pain when filling the eyeball with irrigation fluid. In the postoperative period, hyperopic patients need monitoring of intraocular pressure, myopic patients need fundus ophthalmoscopy with optical coherence tomography. To identify treatment tactics for cataract surgery in patients with high degrees of ametropia according to modern literature data. To perform the review, a search of literature sources was analyzed in the PubMed database using the keywords “cataract”, “high hyperopia”, “high myopia” and data from publications on the topic of the article for the period up to 2023 inclusive. The literature analysis has shown that recently more and more attention has been paid to the problem of high-grade ametropia. This is due to the widespread, progressive disease course, early cataracts development and other complications that significantly reduce vision.

Incidence of acute angle closure in patients with primary angle closure without prophylactic iridotomy during pharmacological mydriasis for cataract surgery.

The objective was to study the incidence of acute primary angle closure (acute PAC) during pharmacologic mydriasis before cataract surgery and changes in anterior chamber angle parameters in patients with primary angle closure diseases (PACD) with and without prophylaxis laser peripheral iridotomy (LPI). This was a prospective, comparative study of cataract patients with PACD with and without prophylaxis LPI presented at the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand during June 2022 to December 2023. The incidence of acute PAC during pharmacologic mydriasis prior to cataract surgery was recorded. Changes in anterior chamber depth (ACD) and anterior chamber angle parameters measured with anterior segment optical coherence tomography before and after cataract surgery were compared between groups using Student t test. There were 195 eyes of 116 patients with a mean age of 70 years enrolled in the study. Eighty patients were women and 36 were men. There were 99 eyes without prophylaxis LPI and 96 eyes with LPI. There was significantly more angle-closure glaucoma in the non-LPI group than in the LPI group. Preoperatively, all anterior chamber angle parameters were significantly greater in the LPI group than in the non-LPI group (P < .001 all parameters), except ACD (P = .83) and anterior chamber width (ACW) (P = .30). All participants underwent uneventful cataract surgery. Postoperatively, all parameters of the anterior chamber angle and ACD increased significantly in both groups. When comparing between groups, all postoperative anterior chamber angle parameters were not significantly different between the groups, but ACD was significantly greater (P = .036) and ACW was lower in the LPI group (P = .008). There was no incidence of acute PAC occurring during pharmacological mydriasis before cataract surgery in both groups. There was no incidence of acute PAC in patients with and without prophylaxis LPI during pharmacological mydriasis in the preoperative preparation for cataract surgery. Eyes without LPI showed significantly lower preoperative anterior chamber angle parameters compared to eyes with previous LPI, but not significantly different postoperatively. The benefits of prophylactic LPI for PACD scheduled for cataract surgery must be further investigated.

Primary angle-closed diseases recognition through artificial intelligence-based anterior segment-optical coherence tomography imaging.

In this study, artificial intelligence (AI) was used to deeply learn the classification of the anterior segment-Optical Coherence Tomography (AS-OCT) images. This AI systems automatically analyzed the angular structure of the AS-OCT images and automatically classified anterior chamber angle. It would improve the efficiency of AS-OCT image analysis. The subjects were from the glaucoma disease screening and prevention project for elderly people in Shanghai community. Each scan contained 72 cross-sectional AS-OCT frames. We developed a deep learning-based AS-OCT image automatic anterior chamber angle analysis software. Classifier performance was evaluated against glaucoma experts' grading of AS-OCT images as standard. Outcome evaluation included accuracy (ACC) and area under the receiver operator curve (AUC). 94895 AS-OCT images were collected from 687 participants, in which 69,243 images were annotated as open, 16,433 images were annotated as closed, and 9219 images were annotated as non-gradable. The class-balanced train data were formed from randomly extracting the same number of open angle images as the closed angle images, which contained 22,393 images (11127 open, 11256 closed). The best-performing classifier was developed by applying transfer learning to the ResNet-50 architecture. against experts' grading, this classifier achieved an AUC of 0.9635. Deep learning classifiers effectively detect angle closure based on automated analysis of AS-OCT images. This system could be used to automate clinical evaluations of the anterior chamber angle and improve efficiency of interpreting AS-OCT images. The results demonstrated the potential of the deep learning system for rapid recognition of high-risk populations of PACD.

Anterior Segment Pharmacological Accommodative Changes and Its Impact on the Circumferential Anterior Chamber Angle after ICL V4c Implantation: Angle following ICL implantation.

To investigate the pharmacological accommodative changes of the anterior segment and its impact on the circumferential anterior chamber angle (ACA) after implantable collamer lens (ICL) implantation using swept-source optical coherence tomography (SS-OCT). Eye and ENT Hospital, Fudan University, Shanghai, CHINA. Prospective randomized contralateral eye study. Eight men and 24 women (mean age, 28.2 ± 5.8 years; range, 19-42 years); 64 eyes were included at 3 months after ICL implantation. One eye per patient was randomly assigned to undergo tropicamide instillation (mydriasis group), and the contralateral eye underwent pilocarpine instillation (miosis group). SS-OCT examinations were performed before and after instillation to measure angle parameters. Trabecular-iris angle 500 (TIA500), angle opening distance 500 (AOD500), trabecular-iris space area (TISA500), angle opening distance circumference area 500 (AODA500), trabecular-iris circumference volume 500 (TICV500), and central vault (ICL to crystalline lens [ICL-L]) were evaluated. Relative to baseline levels, TIA500, AOD500, and TISA500 values all increased significantly in both groups (all P < 0.01). AODA500 and TICV500 values increased by 19.7% and 12.1%, respectively, in the mydriasis group (all P < 0.001), and these values similarly increased by 23.4% and 27.7%, respectively, in the miosis group (all P < 0.001). After instillation, the ICL-L decrease in the miosis group was significantly larger than that in the mydriasis group (P = 0.004). Mean AOD500, TISA500, and TICV500 in the miosis group were significantly larger than those in the mydriasis group (all P ≤ 0.036), especially at 8 and 10 o'clock (all P ≤ 0.014). Correlation analyses indicated that the increase in anterior chamber angle parameters was positively correlated with the change in ICL-L for both groups. Pilocarpine induced a more significant increase in ACA than tropicamide, because of different mechanism of anterior segment changes. We recommend circumferential meridian scan to assess angle status.

Swept-source optical coherence tomography assessment of Schlemm's canal after phacoemulsification with goniosynechialysis in Chinese patients with primary angle-closure glaucoma.

Primary angle-closure glaucoma (PACG) is a leading cause of irreversible blindness worldwide. However, the features of the morphology of Schlemm's canal (SC) in PACG eyes after phacoemulsification with goniosynechialysis (phaco-GSL) surgery are still unknown. This study aimed to evaluate changes in the SC in Chinese patients with PACG after phaco-GSL using swept-source optical coherence tomography (SS-OCT). In this prospective, cross-sectional study, 70 patients with PACG [of whom 35 had acute primary angle-closure glaucoma (APACG) and 35 had chronic primary angle-closure glaucoma (CPACG)] who were scheduled to undergo phaco-GSL surgery were recruited from the Eye, Ear, Nose, and Throat Hospital of Fudan University from December 2021 to December 2022. The anterior chamber angle (ACA), Schlemm's canal diameter (SCD), and Schlemm's canal area (SCA) were measured by SS-OCT at the baseline, and 1 month, 3 months and 6 months after surgery. A multivariate linear regression analysis was conducted to examine the predictors of change in the mean SCA and SCD. Postoperative intraocular pressures (IOPs) were significantly reduced in both the APACG and CPACG patients (both P<0.01). The ACA, SCD, and SCA increased significantly after surgery, and this increase was maintained to the end of the follow-up period in both the APACG group (SCD: 104.62±8.70 vs. 176.54±16.97 μm; SCA: 2,904.89±706.88 vs. 5,315.58±1,078.29 μm2; all P<0.01) and CPACG group (SCD: 105.89±16.71 vs. 168.78±17.64 μm; SCA: 2,775.99±559.28 vs. 5,055.54±803.38 μm2; all P<0.01). However, there was no significant difference in the increase between the APACG and CPACG groups (P>0.05). The multiple linear regression analysis showed that the IOP change was associated with the SCD change (β =0.281, P=0.040) and SCA change (β =0.295, P=0.039). SC expansion was observed after phaco-GSL surgery in patients with PACG (both APACG and CPACG). A correlation between SC expansion and the IOP decrease was also observed. Our findings suggest that SC provides valuable information that could be used to assess the efficacy of phaco-GSL.

Factors Influencing Corneal Endothelial Cell Density after Descemet Stripping Automated Endothelial Keratoplasty

Purpose: To identify determinants of corneal endothelial cell density at 12 months after Descemet stripping automated endothelial keratoplasty (DSAEK).Methods: This study included patients with bullous keratopathy who underwent DSAEK with internationally sourced donor corneas from March 2021 to March 2022. We assessed various preoperative factors in recipients (age, cause of bullous keratopathy, intraocular pressure, visual acuity, anterior chamber volume, depth and angle, pupil size, white-to-white corneal diameter, and preoperative corneal endothelial cell density) and donors (age, death to preservation time, preservation to transplantation time, death to transplantation time, corneal endothelial cell density, trephine size, and precut tissue thickness). We analyzed factors influencing corneal endothelial cell density up to 12 months after keratoplasty.Results: This study involved 53 patients, with an average recipient age of 65.9 ± 14.6 years prior to surgery. Donor corneas had an average endothelial cell density of 2,871.6 ± 271.6 cells/mm&lt;sup&gt;2&lt;/sup&gt;. At 6 and 12 months postoperatively, endothelial cell densities had decreased by 36.9% and 47.2%, respectively, compared with preoperative levels. Multivariate linear regression analysis indicated that endothelial cell densities at 3 and 12 months postoperatively were linked to recipient age and anterior chamber depth.Conclusions: Corneal endothelial cell density after DSAEK typically stabilized after initial decline; higher densities were found in older recipients and individuals with shallower anterior chambers.

DYNAMICS OF CHANGES IN THE ANATOMICAL PARAMETERS OF THE ANTERIOR CHAMBER OF THE EYE WITH VARIOUS TYPES OF APHAKIA CORRECTION IN PATIENTS WITH SILICONE TAMPONADE OF THE VITREAL CAVITY

Rationale: In case of combined pathology, in particular aphakia and regmatogenic retinal detachment, an important point is the leveling of changes in the iridocrustal apparatus. When analyzing the morphoanatomic parameters of the angle and depth of the anterior chamber using optical coherence tomography, distinctive features were revealed in patients with various methods of correcting the defect of the iridohrustal barrier.Objective: of the study was to evaluate anatomical changes in the angle and depth of the anterior chamber in patients with various types of intraocular correction of the defect of the capsule-binding apparatus under conditions of tamponade of the vitreal cavity with silicone oil.Methods: Studies were conducted on 74 eyes of patients aged 56 to 75 years with various methods of correction of aphakia and silicone tamponade of the vitreal cavity.Results: There was a significant decrease in the anterior chamber angle in various sectors in patients with aphakia, in contrast to patients with anterior chamber and transclerally fixed intraocular lenses. A similar trend is observed in patients with anterocameral intraocular lenses, relative to the group of patients with artifacia. A decrease in the depth of the anterior chamber was revealed in patients with anterior chamber lenses relative to patients with transcleral fixation and articulation was revealed in the upper sector. In the temporal sector, there is a decrease in this indicator in patients with aphakia relative to patients with artifakia.Conclusion: In the conditions of silicone tamponade of the vitreal cavity, the technique of transcleral fixation of intraocular lenses provides the most physiological indicators of the anterior chamber angle comparable to single-format indicators of patients with artifacia.

Surface vs. skeleton: the relationship between surface topographic and radiographic measurements of shoulder symmetry in patients with scoliosis.

This study evaluates the relationship between existing radiographic measurements of shoulder asymmetry with novel surface topographic (ST) measurements, hypothesizing that these relationships will be weak. Data were gathered from a prospectively collected registry of patients who underwent ST scanning at a single tertiary care institution. Inclusion criteria were diagnosis of juvenile or adolescent idiopathic scoliosis, age 11-21, same-day ST and EOS radiographic evaluation. Twelve radiographic variables that evaluate shoulder height were measured, as well as curve magnitudes and vertebral axial rotation. ST data were collected using the 3dMDbody scanning system. Three ST measurements of shoulder symmetry were evaluated: ST-based AC angle (the angle between a line made between the surface of the AC joints and a line parallel to the ground), Shoulder Normal Asymmetry angle (the angle between the mirrored normals to the planes defined by the jugular notch, vertebral prominence, and AC joint), and Shoulder Volume Asymmetry Index (difference in volumes between the right and left shoulder). Univariate, followed by a stepwise multivariate linear regression was performed to evaluate the correlations of the radiographic measurements to the ST-based measurements. Correlation categories: weak (x < 0.4), moderate (0.4 ≤ x < 0.6), strong (0.6 ≤ x < 0.8), and very strong (x ≥ 0.8). 141 patients with idiopathic scoliosis were evaluated (65.2% female, mean age 15.1years, mean BMI 20.5kg/m2, with mean maximum curve 44.7 degrees). ST-based AC angle had moderate-to-strong correlations with several radiographic measurements, while ST-based Shoulder Normal Asymmetry angle and Shoulder Volume Asymmetry Index had weak or no correlation with individual radiographic measures. Multivariate models created using a combination of radiographic variables demonstrated a strongly positive correlation between radiographic variables and ST-based AC angle (R = 0.678) and moderately positive correlations with ST-based Shoulder Normal Asymmetry Angle (R = 0.488), and ST-based Shoulder Volume Asymmetry Index (R = 0.514). Radiographic measurements may be acceptable stand-ins for two-dimensional ST measurements such as AC angle, but not for more complex shoulder measurements based on three dimensions. This study demonstrates the inadequacy with which radiographic assessments evaluate shoulder height asymmetry and highlights the use of ST measurements.

Assessment of clinical efficacy and safety of ICL implantation in patients with relatively shallow anterior chamber depth in early and midterm postoperative time

To investigate the clinical effect and safety of Implantable Collamer Lens (ICL) implantation in myopic patients with relatively shallow anterior chamber depth (ACD). Retrospective analysis, comparative, non-interventional case series. Patients with myopia who underwent ICL implantation were included in the study and were categorized into two groups: one with a relatively shallow ACD (2.60mm≤ACD ＜ 2.80mm) and the other with a normal ACD (ACD ≥2.80mm). Each group comprised 51 eyes and were reviewed for at least 6 months. To evaluate preoperative and postoperative visual acuity, intraocular pressure (IOP), central vault, ACD, endothelial cell density (ECD) and anterior chamber angle parameters [ trabecular iris angle (TIA), angle opening distance at 500μm and 750μm (AOD500, AOD750), trabecular iris space area at 500μm and 750μm (TISA500, TISA750) ]. Analyze the trend of postoperative data changes of 1 week, 1 month, 3 months, and at least 6 months. Patients in relatively shallow ACD with vault <100μm or >1000μm were performed detailed follow-up. The postoperative uncorrected distance visual acuity (UDVA) and best corrected visual acuity (BCVA) surpassed the preoperative BCVA in two groups. The group differences of effectiveness index (EI) was p=0.409 and of safety index (SI) was p=0.563. The EI were 1.07 and 1.09, SI were1.10 and 1.21. Postoperative vision and refractive error were effectively corrected. The preoperative and postoperative IOP and ECD values of the two groups were within the normal range, and the preoperative and postoperative differences and the group differences of IOP and ECD were p=0.649, p=0.501, p=0.222, p=0.276. The ACD in two groups were reduced by approximately 25% and 26%, the nasal and temporal TIA were reduced to 45% and 50% approximately. The nasal and temporal AOD500, AOD750, TISA500, and TISA750 in the relatively shallow ACD group were reduced 40% approximately and in the normal ACD group were reduced to 30% approximately. All the preoperative and postoperative differences and the group differences of anterior segment parameters were statistically significant (all p<0.01), with more significant anterior segment changes in normal ACD group.The postoperative data in two groups showed that when the follow-up time was prolonged, the central vault was decreasing, and the postoperative ACD was increasing, the postoperative TIA increased slowly in relatively shallow ACD group and decreased slowly in normal ACD group, temporal TIA were greater than nasal TIA, with no significant variation. There were four eyes in the relatively shallow ACD group in the remarkable abnormal postoperative central vault. Three eyes had second operation: one eye had an ICL alignment, and two eyes had ICL replacement. Patients with relatively shallow ACD who underwent ICL implantation had fine postoperative clinical efficacy and safety.