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

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

Consequences of Clot Formation and Hyphema Post-Internal Trabeculotomy for Glaucoma.

PRCIS: Clot formation and hyphema following internal trabeculotomy represent distinct clinical entities. The eyes with clot formation exhibited a more pronounced postsurgical intraocular pressure spike, longer residual intracameral bleeding, and a higher risk of reoperation. PURPOSE: The aim of this study was to investigate the consequences of clot formation and hyphema in the anterior chamber after internal trabeculotomy. MATERIALS AND METHODS: In this retrospective interventional comparative study, we investigated the surgical outcomes of internal trabeculotomy in 142 eyes of 142 patients at Sensho-kai Eye Institute. RESULTS: Concurrent clot formation and L≥2 hyphema (height of hyphema ≥1 mm) was observed in 22 eyes. In these cases, the postsurgical IOP was 29.3 mm Hg at 1 week, significantly higher than the 16.1 mm Hg in eyes that had L≥2 hyphema but without clot formation ( P =0.0002). However, the 1-week postsurgical IOP in L≥2 hyphema and clot (-) eyes, which measured 16.1 mm Hg was not significantly greater than that in L<2 hyphema and clot (-) eyes, which measured 18.7 mm Hg ( P =0.162). Thus, clot formation was identified as a significant factor contributing to high postsurgical IOP at 1 week. The resolution time for anterior chamber bleeding in eyes with concurrent clot formation and L≥2 hyphema was 12.3 days, longer than the 5.8 days observed in L≥2 hyphema eyes without clot formation ( P =0.016). Among the 22 eyes with concurrent L≥2 hyphema and clot formation, 8 required anterior chamber washout. Three of the 10 eyes that underwent washout necessitated additional trabeculectomy, a rate significantly higher than that in nonwashout eyes ( P <0.001). CONCLUSIONS: After internal trabeculotomy, the sequelae of concurrent clot formation and L≥2 hyphema in the anterior chamber were more severe than those of simple hyphema without clots. Clot formation negatively affected postoperative IOP.

Ocular Biometric Components in Hyperopic Children and a Machine Learning-Based Model to Predict Axial Length.

Purpose: The purpose of this study was to investigate the development of optical biometric components in children with hyperopia, and apply a machine-learning model to predict axial length. Methods: Children with hyperopia (+1 diopters [D] to +10 D) in 3 age groups: 3 to 5 years (n = 74), 6 to 8 years (n = 102), and 9 to 11 years (n = 36) were included. Axial length, anterior chamber depth, lens thickness, central corneal thickness, and corneal power were measured; all participants had cycloplegic refraction within 6 months. Spherical equivalent (SEQ) was calculated. A mixed-effects model was used to compare sex and age groups and adjust for interocular correlation. A classification and regression tree (CART) analysis was used to predict axial length and compared with the linear regression. Results: Mean SEQ for all 3 age groups were similar but the 9 to 11 year old group had 0.49 D less hyperopia than the 3 to 5 year old group (P < 0.001). With the exception of corneal thickness, all other ocular components had a significant sex difference (P < 0.05). The 3 to 5 year group had significantly shorter axial length and anterior chamber depth and higher corneal power than older groups (P < 0.001). Using SEQ, age, and sex, axial length can be predicted with a CART model, resulting in lower mean absolute error of 0.60 than the linear regression model (0.76). Conclusions: Despite similar values of refractive errors, ocular biometric parameters changed with age in hyperopic children, whereby axial length growth is offset by reductions in corneal power. Translational Relevance: We provide references for optical components in children with hyperopia, and a machine-learning model for convenient axial length estimation based on SEQ, age, and sex.

Changes in ocular biometrics following cycloplegic refraction in strabismic and amblyopic children.

This study was aimed to analyze ocular biometric changes following cycloplegia in pediatric patients with strabismus and amblyopia. Cycloplegia is routinely used to measure refractive error accurately by paralyzing accommodation. However, effects on axial length (AL), anterior chamber depth (ACD), keratometry (Km), and white-to-white distance (WTW) are not well studied in this population. This retrospective study examined 797 patients (1566 eyes) undergoing cycloplegic refraction at a Samsung Kangbuk hospital pediatric ophthalmology clinic from 2010 to 2023. Ocular biometry was measured before and after instilling 1% cyclopentolate and 0.5% phenylephrine/0.5% tropicamide. Patients were categorized by strabismus diagnosis, age, refractive error and amblyopia status. Differences in AL, ACD, Km, WTW, and refractive error pre- and post-cycloplegia were analyzed using paired t tests. ACD (3.44 ±â€…0.33 vs 3.58 ±â€…0.29 mm, P < .05) and WTW (12.09 ±â€…0.42 vs 12.30 ±â€…0.60 mm, P < .05) increased significantly after cycloplegia in all groups except other strabismus subgroup (Cs) in both parameters and youngest subgroup (G1) in ACD. Refractive error demonstrated a hyperopic shift from -0.48 ±â€…3.00 D to -0.06 ±â€…3.32 D (P < .05) in overall and a myopic shift from -6.97 ±â€…4.27 to -8.10 ±â€…2.26 in high myopia (HM). Also, AL and Km did not change significantly. In conclusion, cycloplegia impacts ocular biometrics in children with strabismus and amblyopia, significantly increasing ACD and WTW. Refractive error shifts hyperopically in esotropia subgroup (ET) and myopically in high myopia subgroup (HM), eldest subgroup (G3) relating more to anterior segment changes than AL/Km. Understanding cycloplegic effects on biometry is important for optimizing refractive correction in these patients.

Refraction and ocular biometric parameters in 3-to 6-year-old preschool children : a large-scale population-based study in Chengdu, China.

PURPOSE: To understand the ocular biometric parameters characteristics and refractive errors in 3-to 6-year-old preschool children in Chengdu, China, and to investigate the prevalence of refractive errors. METHOD: A school-based cross-sectional study was conducted in Chengdu from 2020 to2022 with a total of 666 kindergartens. All children were measured by non-cycloplegic autorefraction and uncorrected visual acuity (UCVA) and ocular biometric parameters. Finally, univariate linear regression models were used to analyze the relationship between ocular biometric parameters and refraction. RESULTS: A total of 108,578 preschool children aged 3-6 underwent examinations, revealing a myopia prevalence of 6.1%. The mean axial length (AL), keratometry (K), corneal radius (CR), axial length/corneal radius (AL/CR) Ratio, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were 22.35 ± 0.69 mm, 43.35 ± 1.58 D, 7.80 ± 0.28 mm, 2.87 ± 0.08, 533.31 ± 32.51 µm, 2.70 ± 0.28 mm, 3.91 ± 0.27 mm, and 15.20 ± 0.68 mm, respectively. With increasing age, AL, CR, AL/CR ratio, CCT, ACD, LT, and VCD also increased. Regardless of age, males consistently exhibited longer AL, flatter corneal curvature, shallower ACD, thicker CCT, thinner LT, and longer VCD compared to females. AL, K, CR, LT, and VCD all showed significant linear relationships with SE (all P < 0.001) in univariate linear regression analysis after adjusting for gender and age. CONCLUSION: The prevalence of myopia among preschool children aged 3-6 in Chengdu is relatively low. Ocular biometric parameters affecting refractive errors include AL, K, CR, LT, and VCD. The preschool period serves as a critical phase for myopia prevention and control.

Evaluation of eye and serum findings in different waters in rabbits by drowning and submersion modeling.

Background/aim: This study investigated serum, vitreous, and anterior chamber fluid electrolyte changes, corneal thickness (CT), corneal volume (CV), anterior chamber volume (ACV), and anterior chamber depth (ACD) as an auxiliary diagnostic method in the identification of drowning in fresh or salt water. Materials and methods: The study used 35 healthy, adult, male, white New Zealand rabbits, seperated into five groups (control, saltwater drowning (SWD), saltwater immersion (SWI), freshwater drowning (FWD), freshwater immersion (FWI)). CT, CV, ACV, and ACD measurements were made with Pentacam topography at 0, 2, and 4 h in all groups. Magnesium (mg), sodium (Na), and chlorine (Cl) were measured in the blood at 0 and 2 h, and in blood, vitreous fluid, and humor aqueous at 4 h. Results: It was determined that CT, CV, ACV, and ACD are not of great value in drowning diagnosis and are affected by the fresh or salt water rather than drowning. Vitreous Na, Cl, and Mg levels are ineffective in determining drowning after one h. Anterior chamber fluid may provide valuable information in the differentiation freshwater - saltwater drownings at the 4th h in corpses retrieved from water. Conclusion: Anterior chamber fluid Na and Cl levels, especially in corpses removed from salt water, can be an easily used test that can help diagnose drowning.

Long-term results of anterior chamber iris claw intraocular lens implantation in children with ectopia lentis in Marfan syndrome.

PURPOSE: To report the long-term clinical and endothelial cell count (ECC) results of lensectomy with primary anterior chamber iris claw lens implantation in the eyes of patients ≤18-year-old with ectopia lentis due to Marfan syndrome. METHODS: The medical records of Marfan patients operated on at a single institution from September 2007 to August 2020, with minimum follow-up of 2 years, were reviewed retrospectively. The following data were analyzed: sex, age at surgery, indication for surgery, the position of the lens in relation to the undilated and dilated pupil, corneal endothelial cell counts (ECC), peri- and postoperative complications, pre- and postoperative best-corrected visual acuity. RESULTS: A total of forty-two eyes of 23 patients (12 girls and 11 boys) were included. At least two or more postoperative ECCs were collected from 33 eyes (17 patients). Median age at IOL implantation was 6.1 years (range, 1.8-18). Median overall follow-up time was 6.2 years (range, 2-13.5). Median ECC follow-up time was 6.2 years (range, 2-10). Mean best-corrected visual acuity was 0.71 ± 0.38 logMAR before surgery and 0.02 ± 0.25 logMAR at final follow-up. The mean annual ECC decline was 0.71% ± 2.24. Total cell loss from first to last postoperative measurement was 150 cells ± 394 cells/mm2 (4.81%). Pre- and first postoperative data were available for 17 eyes of 10 patients, with a mean cell loss before and directly after surgery of 269 ± 268 cells (7.94%). Surgery related complications were iris bombé due to blockage of peripheral iridectomy in 3 eyes and claw dislocation due to direct impact trauma in 3 eyes. CONCLUSIONS: In our large, pediatric study cohort, anterior chamber iris claw IOL implantation resulted in an excellent visual outcome and normal endothelial cell loss compared with normative data. Safety measures are recommended to avoid traumatic dislocation of IOLs.

Associations between corneal curvature and other anterior segment biometrics in young myopic adults.

To investigate the associations between corneal curvature (CC) and other anterior segment biometrics in young myopic adults. In this retrospective multi-center study, 7893 young myopic adults were included. CC and other anterior segment biometrics were measured by Scheimpflug imaging (Pentacam). CC was defined as SimK at central 3 mm area, and other anterior segment biometrics included white-to-white corneal diameter (WTW), central corneal thickness (CCT), corneal volume (CV) at 3 mm, 5 mm, and 7 mm area, anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), anterior corneal eccentricity (ACE) and asphericity (ACAP), posterior corneal eccentricity (PCE) and asphericity (PCAP), anterior chamber depth (ACD), and anterior chamber volume (ACV). Univariate regression analyses were used to assess the associations between CC and other anterior segment biometrics, and multivariate regression analyses were further performed to adjusted for age, gender and spherical equivalent. CC was higher in patients of female gender and higher myopia (all P < 0.05). Eyes in higher CC quartiles had lower WTW, thinner CCT, lower CV at 3 mm and 5 mm, lower ACD, and lower ACV (all P < 0.001), but had larger ACA, larger PCA, less PCE and less PCAP (all P < 0.001), compared to eyes in lower CC quartiles. The trends of CV at 7 mm, ACE and ACAP were inconsistent in different CC quartiles. After adjusting for age, gender and spherical equivalent with multivariate linear regression, CC was positively correlated to CV at 7 mm (ßs = 0.069), ACA (ßs = 0.194), PCA (ßs = 0.187), ACE (ßs = 0.072), PCAP (ßs = 0.087), and ACD (ßs = 0.027) (all P < 0.05), but was negatively correlated to WTW (ßs = - 0.432), CCT (ßs = - 0.087), CV-3 mm (ßs = - 0.066), ACAP (ßs = - 0.043), PCE (ßs = - 0.062), and ACV (ßs = - 0.188) (all P < 0.05). CC was associated with most of the other anterior segment biometrics in young myopic adults. These associations are important for better understanding of the interactions between different anterior segment structures in young myopic patients, and are also useful for the exploration of the pathogenesis of myopia.

Iris atrophy following intracameral dexamethasone injection: a report of two pediatric cases.

We report 2 pediatric cases of iris atrophy that developed roughly 1 month after intracameral injection of dexamethasone suspension 9% following unilateral goniotomy and cataract extraction.

Estimation of angle parameters by ASOCT and biometric parameters by optical biometer in eyes with occludable angles and open angles.

PURPOSE: To compare anterior chamber angle (ACA) parameters measured by Anterior Segment Optical Coherence Tomography (ASOCT) and biometric parameters measured by Swept-Source (SS) OCT-based biometry among patients with suspected occludable angles and open angles. METHODS: An analytical, cross-sectional study was performed on subjects attending our ophthalmology outpatient department with suspected occludable angles (van Herick grades 0, 1, and 2) in group 1, and with open angles (van Herick grades 3 and 4) in group 2. Each subject underwent a complete ophthalmic examination to exclude any intraocular pathology like cataract. We recruited 128 eyes of 64 subjects, 34 in group 1 and 30 in group 2. Each eye was henceforth subjected to ASOCT (Spectralis, Heidelberg Engineering, Heidelberg) and SS-OCT-based optical biometry (IOL Master 700, Carl Zeiss Meditec AG). Anatomical parameters were recorded and compared between the two groups. RESULTS: The main outcome measures of the study included nine ASOCT parameters (central corneal thickness [CCT], lens vault, AOD750, ACA, TISA750 [nasal and temporal], and ACW) and five optical biometric parameters (CCT, ACD, WTW, LT, and axial length). We found a significant difference (p < 0.05) among all the anatomical parameters between the two groups, except CCT which was not significantly different (p = 0.297). CONCLUSIONS: ASOCT and SSOCT biometry overcome the challenges of gonioscopy and allow screening for angle closure disease in otherwise normal subjects. ASOCT may serve as an alternative to gonioscopy as it clearly separates occludable angles from open angles in a non-invasive and objective manner.

Correlation Between Anterior Chamber Angle Status and Limbal Stem Cell Deficiency in Primary Angle-Closure Glaucoma.

PURPOSE: To investigate the correlation between the opening and closing states of anterior chamber angle (ACA) and the density of limbal epithelial basal cells (LEBCs) in subjects with primary angle-closure glaucoma (PACG). DESIGN: Cross-sectional observational study. METHODS: A total of 54 eyes of 29 patients diagnosed with PACG were included in the study. Fifty-four eyes from normal subjects were included as control. Automatic evaluation system for ultrasound biomicroscopy images of anterior chamber angle was used to assist ophthalmologists in identifying the opening or closing state of ACA, and the in vivo confocal microscopy (IVCM) was used to evaluate the density of LEBCs in different directions. RESULTS: (1) The average density of LEBCs in the superior, inferior, nasal, and temporal limbus of the eyes in the PACG group was lower than that in the control group, and this pattern did not align with the density distribution observed in the control group. (2) In the early, moderate and advanced PACG, the density of LEBCs corresponding to the closed angle was lower than that in the control group (P < .05). Compared with the density of LEBCs corresponding to the closed angle and the open angle, the closed angle of PACG in the early, moderate and advanced stages was less than that in the open angle (P < .05 in the early and moderate stages; advanced stage P > .05). (3) The basal cell density was processed by dimensionless analysis. In the data calculated by averaging and minimizing, both closed angle dimensionless values were smaller than the open angle (P < .05). (4) Comparative analysis was conducted among the normal, open-angle, and closed-angle conditions in the superior, inferior, nasal, and temporal limbus. In the early stage of PACG, significant differences were observed in 4 limbal regions (P < .05), while in the moderate PACG stage, this difference was noted in 3 limbal regions (P < .05). In advanced PACG, 2 limbal regions exhibited significant differences (P < .05). These findings suggest that during the early PACG stage, angle closure is the predominant influencing factor on LEBCs density, while in the advanced stage, the decrease in density is attributed to a combination of angle closure and the natural progression of the disease. CONCLUSIONS: There is a significant correlation between anterior chamber angle status and LEBCs. Advanced PACG and angle closure should be highly suspected of the occurrence of limbal stem cell deficiency (LSCD).

Aqueous misdirection syndrome: clinical outcomes and risk factors for treatment failure.

PURPOSE: To evaluate the outcomes of postoperative aqueous misdirection and factors predicting failure of interventions. METHODS: This retrospective study included 49 eyes from 47 patients with aqueous misdirection following glaucoma or cataract surgery. Resolution of aqueous misdirection (AM) was deepening of the central anterior chamber (AC) and intraocular pressure (IOP) ≤ 21 mmHg. The Cox proportional hazards regression model was used to evaluate risk factors for failure of various treatments. RESULTS: 10/49 eyes (20%) resolved with conservative management, and 39/49 eyes (80%) needed multiple intervention, of which 95% (37/39) eyes achieved resolution of aqueous misdirection. Pseudophakia predicted the need for multiple interventions with a hazard ratio of 2.391 (1.158-4.935), p = 0.02). Among the risk factors assessed for resolution of AM, longer axial length (HR: 0.61 (0.414-0.891), p < 0.01) and eyes with prior glaucoma surgery predicted resolution (HR: 0.142 (0.027-0.741), p < 0.01) and delayed presentation predicted failure (HR: 1.002 (1.0002-1.0031), p < 0.02). CONCLUSION: Pseudophakic eyes were more refractory and predicted the need for multiple interventions. Eyes with prior glaucoma surgery and those with longer axial length had achieved resolution faster, and delayed presentation was a risk factor for failure to resolve.

Predictability comparison of sizing parameters for postoperative vault after implantable Collamer lens implantation.

PURPOSE: This study aims to assess the accuracy of three parameters (white-to-white distance [WTW], angle-to-angle [ATA], and sulcus-to-sulcus [STS]) in predicting postoperative vault and to formulate an optimized predictive model. METHODS: In this retrospective study, a cohort of 465 patients (comprising 769 eyes) who underwent the implantation of the V4c implantable Collamer lens with a central port (ICL) for myopia correction was examined. Least absolute shrinkage and selection operator (LASSO) regression and classification models were used to predict postoperative vault. The influences of WTW, ATA, and STS on predicting the postoperative vault and ICL size were analyzed and compared. RESULTS: The dataset was randomly divided into training (80%) and test (20%) sets, with no significant differences observed between them. The screened variables included only seven variables which conferred the largest signal in the model, namely, lens thickness (LT, estimated coefficients for logistic least absolute shrinkage of -0.20), STS (-0.04), size (0.08), flat K (-0.006), anterior chamber depth (0.15), spherical error (-0.006), and cylindrical error (-0.0008). The optimal prediction model depended on STS (R2=0.419, RMSE=0.139), whereas the least effective prediction model relied on WTW (R2=0.395, RMSE=0.142). In the classified prediction models of the vault, classification prediction of the vault based on STS exhibited superior accuracy compared to ATA or WTW. CONCLUSIONS: This study compared the capabilities of WTW, ATA, and STS in predicting postoperative vault, demonstrating that STS exhibits a stronger correlation than the other two parameters.

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.

Double trouble in DMEK surgery: Learning experience and review of the literature.

PURPOSE: To report a challenging Descemet Membrane Endothelial Keratoplasty (DMEK) case, complicated by intraoperative aqueous misdirection and spontaneous anterior chamber fibrin reaction. METHODS: A 70-year-old female affected by corneal edema due to Fuchs endothelial dystrophy underwent a triple procedure (cataract extraction - IOL implantation - DMEK surgery) in her left eye. This report illustrates the management of the intraoperative complications of aqueous misdirection syndrome and anterior chamber fibrin reaction. RESULTS: Despite the optimal management of the posterior pressure and the thorough removal of the fibrinous reaction during the case, the DMEK graft was not completely unfolded and centred at the end of the surgical procedure. Nonetheless, the patient showed good long-term anatomical and functional recovery: at the last follow-up (2 years after surgery), central corneal thickness was 526 µm with a best corrected visual acuity of 20/25 and an endothelial cell density of 1112 cell/mm2. CONCLUSION: Early recognition and prompt management of intraoperative aqueous misdirection syndrome and anterior chamber fibrin reaction during DMEK surgery is essential to ensure good functional and anatomical outcomes.

Quantitative analysis of dynamic iris changes in primary angle-closure disease with long axial lengths: the Handan Eye Study.

OBJECTIVE: To investigate dynamic iris changes in patients with primary angle-closure disease (PACD) with long axial length (AL) compared to those with short and medium AL. METHODS: This observational cross-sectional study enrolled participants aged 35 years or older from the Handan Eye Study follow-up examination who were diagnosed with PACD and underwent Visante anterior segment optical coherence tomography (ASOCT) imaging under light and dark conditions. The right eye of each participant was included in the analysis. AL was categorized as short (<22.0 mm), medium (≥22.0 to ≤23.5 mm), or long (>23.5 mm). Anterior segment parameters, including iris dynamic changes, were compared among the three groups with different ALs. RESULTS: Data from 448 patients with PACD were analyzed. We found that 10.9% of included eyes had a long AL with a flatter cornea; larger central anterior chamber depth, angle opening distance, anterior chamber width, anterior chamber area, and volume; and smaller lens thickness and lens vault (LV) (P < 0.05) than those with short AL. No significant difference existed between the three groups in iris thickness, iris cross-sectional area (IA), iris curvature, or pupil diameter (PD) change between light and dark (P > 0.05). The significant associated factors for IA changes were area recess area (ARA) in the dark, LV in the dark, and PD change from light to dark (P < 0.05). CONCLUSIONS: Dynamic and static iris parameters were consistent across patients with PACD with short, medium, or long AL and may contribute to the pathogenesis of angle closure in atypical PACD.