An analysis of the factors involved in IOL decentration after phacoemulsification using CASIA 2 anterior segment optical coherence tomography.

PURPOSE: To evaluate the magnitude of IOL transversal shift (ITS) after phacoemulsification and to analyse the factors contributing to IOL decentration and ITS. METHODS: 94 consecutive patients who underwent cataract surgery and IOL implantation was enrolled. Each patient underwent anterior segment optical coherence tomography with CASIA 2 (Tomey, Nagoya, Japan) to assess crystalline lens decentration, thickness and diameter seven days preoperatively and at one and sixty days postoperatively. Univariate and multivariate linear regression analysis were performed to evaluate the determinants of ITS and final decentration. RESULTS: The preoperative crystalline lens diameter was associated with the ITS and with the IOL final decentration. A positive association between the final IOL decentration and the first post-surgical day decentration was found (p < 0.0001). CONCLUSION: Greater crystalline lens diameter was associated with greater decentration and with greater ITS. Day-one IOL decentration seems to be the main determinant of final IOL decentration.

Repeatability assessment of anterior segment measurements in myopic patients using an anterior segment OCT with placido corneal topography and agreement with a swept-source OCT.

BACKGROUND: The precision of anterior segment biometric measurements in eyes has become increasingly important in refractive surgery. The purpose of this study is to assess the repeatability of the automatic measurements provided by a new spectral-domain optical coherence tomograph (SD-OCT)/Placido topographer (MS-39, CSO) and its agreement with a swept-source OCT (SS-OCT) biometer (CASIA SS-1000, Tomey) in patients with myopia. METHODS: The right eye of 235 subjects was scanned 3 times with both devices. The evaluated parameters included central corneal radius of the steep meridian, central corneal radius of the flat meridian, mean central corneal radius, thinnest corneal thickness, central corneal thickness, anterior chamber depth, corneal volume and diameter. The intraobserver repeatability of the MS-39 measurements was calculated using intraclass correlation coefficient (ICC), within subject standard deviation, coefficient of repeatability, coefficient of variation and repeated-measures analysis of variance of the 3 repeated measurements. The agreement between the two devices was evaluated by 95% limits of agreement (LoA). RESULTS: The majority of the parameters acquired from MS-39 showed high repeatability. The repeatability of corneal diameter was slightly lower than the other measurements, although the ICC remained high. Agreement with the CASIA SS-1000 was good, indicated by the Bland-Altman plots with narrow 95% LoA values for all parameters assessed. CONCLUSIONS: The high repeatability of automatic measurements by the new device supports its clinical application in eyes with myopia, and the good agreement between the two devices indicates they could be used interchangeably for the parameters evaluated.

Evaluation of changes of anterior segment parameters in patients with pseudoexfoliation syndrome after cataract surgery using anterior segment optical coherence tomography.

The aim of the study was to compare the anterior segment parameters after cataract surgery in pseudoexfoliation syndrome (PEX) and control eyes. We conducted a prospective comparative study of 36 eyes (PEX group), 16 eyes (PEXG group) and 46 eyes (control group) of 98 patients after phacoemulsification with intraocular lens implantation. Before surgery, 1 week, 1 month and 3 months postoperatively, anterior chamber parameters were evaluated by swept source anterior segment optical coherence tomography (AS-OCT). Anterior chamber depth (ACD), angle opening distance (AOD500/750), trabecular-iris space area (TISA500/750), trabecular-iris angle (TIA500/750) and lens vault (LV) were assessed at each study visit. Preoperatively, ACD, AOD500/750 and TISA500/750 were significantly smaller, while LV was significantly greater in PEX and PEXG eyes than in controls. 3 months postoperatively all irido-corneal parameters and ACD were significantly greater in all study groups without intergroup differences. ACD and LV significantly increased in PEX group between 1 and 3 months after surgery while being stable in control group. Relative increases in ACD, AOD500, TISA750, TIA500/750 were significantly higher in PEX and PEXG groups than in controls. Our study finds that ACD and iridocorneal parameters in AS-OCT demonstrated significantly greater relative increases 3 months after phacoemulsification in PEX and PEXG groups than in control eyes. Significantly greater deepening of anterior chamber and opening of the irido-corneal angle may be a reason for different refractive outcomes and IOP control in patients with PEX and PEXG after routine cataract surgery.

Correlation of anterior segment optical coherence tomography and ultrasound biomicroscopy in congenital corneal opacity.

PURPOSE: To investigate the correlation between swept-source anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in congenital corneal opacity (CCO). METHODS: All children with unilateral or bilateral congenital corneal opacities who underwent examination under anesthesia (EUA) and anterior segment optical coherence tomography (AS-OCT) imaging from January 1, 2022, to December 31, 2022, were included. Main outcome measures were corneal and anterior segment evaluation and correlation of UBM and AS-OCT findings. RESULTS: A total of 22 eyes of 15 patients were imaged using both technologies. The age at first EUA ranged from 11 days to 4 years. Different phenotypes were classified based on the clinical examination, UBM, and AS-OCT findings. Fourteen eyes were diagnosed with Peters anomaly, congenital corneal staphyloma was observed in 4 eyes, 2 eyes had coloboma, 1 eye had peripheral sclerocornea, and 1 eye was diagnosed with congenital primary aphakia. AS-OCT and UBM findings were closely correlated in 18 of 22 eyes (82%) but AS-OCT failed to provide detailed information in 4 eyes (18%) where UBM revealed more details. CONCLUSIONS: Although AS-OCT offers valuable preliminary data for initial assessment and counseling, it may not consistently provide precise assessments in all cases. Therefore, UBM should be considered for definitive evaluation.

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.

Atypical presentation of bilateral iridoschisis with abnormal visibility of iris vessels: Role of anterior segment optical coherence tomography.

PURPOSE: To describe clinical and anterior segment optical coherence tomography (AS-OCT) findings in a patient with bilateral iridoschisis and unilateral angle closure glaucoma (ACG) associated with abnormal visibility of iris vessels. CASE PRESENTATION: A 67-year-old male patient with a history of red and painful left eye (LE) one year earlier, presented to our ophthalmology department for a routine examination.Ophthalmic examination of the right eye revealed narrow anterior chamber with sectorial iris atrophy associated to abnormal visibility of an iris vessel. Intraocular pressure (IOP) was 12 mmHg with normal optic disc appearance. LE anterior chamber was narrow with diffuse iris atrophy and abnormal vessels visibility. IOP was 28 mmHg with an important optic disc excavation. On gonioscopy, angle was narrow without neovessels nor synechiae. AS-OCT of both eyes revealed shallow angles, iris splitting with material release in the anterior chamber, while pigmented epithelium was preservedAnti-glaucoma eye drops were prescribed and peripheral laser iridotomy was performed in both eyes with decreased IOP at 14 mmHg in the LE. CONCLUSION: Iridoschisis is a rare ocular condition characterized by a separation between the anterior and posterior layers of iris stroma with several clinical presentations, and may be associated with abnormal visibility of iris vessels in some cases. The diagnosis of iridoschisis may be challenging and AS-OCT can be a very useful tool to confirm the diagnosis in atypical presentations and to detect associated angle closure.

Evaluation of the Effect of Scleral Buckling on Anterior Segment and Refractive Changes Using Anterior Segment Optical Coherence Tomography.

PURPOSE: To evaluate the changes of anterior segment and refractive parameters after scleral buckling (SB) surgery for uncomplicated rhegmatogenous retinal detachment (RRD) using anterior segment optical coherence tomography (AS-OCT). METHODS: Thirty-six RRD eyes were consecutively enrolled. Analysis concerned the central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), iris-trabecular contact (ITC), angel opening distance (AOD), angle recess area (ARA), trabecular-iris space area (TISA)，trabecular iris angle (TIA) and refractive parameters, including average keratometry (AvgK), cylindrical power (CYL), regular astigmatism, asymmetry and high order irregularity (HOI) at baseline and 1 day, 1 month, 2 months, 6 months and 12 months postoperatively. AS-OCT was performed at RRD diagnosis and day 1, week 1, month 1 and month 6 after SB to evaluate the scleral buckling. RESULTS: A statistically significant postoperative CCT increase, ACD and ACV decrease were observed at 1 day and 1 month postoperatively. ITC analysis showed that the angle of the entire circumference narrowed at 1 month postoperatively. There was a significant decrease in all the angle parameters (AOD500/750, ARA500/750, TISA500/750, and ARA500/750) at 1 day and 1 month after SB surgery. However, all of the above parameters returned to the preoperative level at 12 months. Refractive parameters including AvgK, regular astigmatism, CYL, asymmetry, and HOI of anterior corneal surface and total corneal increased on the 1 day and 1 month after SB surgery and persisted even after 12 months follow-up. However, there was no significant difference in refractive parameters of posterior corneal surface during follow-up. CONCLUSION: The changes in the structure of anterior segments after SB surgery were almost returned to the preoperative levels at 12 months postoperatively. However, SB surgery has a long-term effect on refractive parameters throughout a 12-month follow-up.

Anterior Segment Optical Coherence Tomography for Cases of High Intraocular Pressure Following XEN Implant for Glaucoma.

PRCIS: This study showed that the XEN patency should be verified by OCT imaging in cases of encapsulated blebs. Although fibrosis plays the principal role, humor aqueous flow reduction could affect the "spacer" effect that inhibits the fibroblast attachments. PURPOSE: To evaluate the application of the anterior segment optical coherence tomography (AS-OCT) imaging in studying the relationship between a low flow rate through the XEN63 and the development of a cystic bleb. METHODS: Retrospective case series of 3 eyes presenting a cystic bleb after an XEN63 implantation for uncontrolled intraocular pressure (IOP). Demographic and clinical data were obtained from medical records. The imaging findings, complications, and managements following the surgery were evaluated. RESULTS: Three patients, with an average age of 67.3 years, initially showed a patent stent lumen and a functional bleb after surgery. The IOP of all eyes increased on average at 28.3 days from the surgery, with a mean value of 39.66 mm Hg. The slit lamp examination showed a cystic bleb. The AS-OCT imaging confirmed the previous finding and revealed either a partial or total occlusion of the stent internal ostium. A Nd:YAG laser, in proximity to the ostium, was performed to resolve the obstruction. Although the AS-OCT imaging showed the device patency and the IOP immediately decreased, the latter became elevated again. Consequently, in all the cases, a further needling procedure was needed to achieve an adequate IOP reduction. Six months after the two-step procedure, the IOP averaged 13.33 mm Hg, the XEN63 lumens appeared cleared, and the blebs showed a functional morphology. No adverse events were observed. CONCLUSION: The development of a cystic bleb may result from an altered balance between the flow rate through the XEN63 and the fibrosis development in the postoperative healing process. A proper follow-up based on slit lamp biomicroscopy, IOP measurement, and AS-OCT imaging is advisable to estimate and manage a cystic bleb following XEN63 implantation.

Progressive Changes in the Anterior Segment and Their Impact on the Anterior Chamber Angle in Primary Angle Closure Disease.

PURPOSE: To investigate longitudinal changes in the anterior segment (AS) using serial optical coherence tomography (OCT) images and determine the impact of these changes on the anterior chamber angle (ACA) in eyes with primary angle closure disease (PACD) treated with laser peripheral iridotomy (LPI). DESIGN: Retrospective clinical cohort study. METHODS: This study included 103 patients with PACD who underwent LPI and were followed up by a mean 6.7 ± 1.7 AS-OCT examinations for a mean 6.5 ± 2.9 years. Temporal changes in AS-OCT parameters, including anterior chamber depth (ACD), angle opening distance (AOD750), angle recess area (ARA750), iris thickness (IT750), lens vault (LV), and pupil diameter (PD), were analyzed by multivariate linear mixed effects models (LMEMs). RESULTS: Multivariate LMEMs showed that decrease in AOD750 was not significant (-1.59 µm/y, P = .222); however, ARA750 decreased over time (-2.3 × 103 µm2/y, P = .033) and SSA showed marginal significance (-0.20°/y, P = .098), and LV increased significantly (11.6 µm/y, P < .001) after LPI. Mean LV change was negatively associated with AOD750, ARA750, and SSA, whereas PD was negatively associated with ARA750 (P < .001 each). PD decreased with aging (-13.7 µm/y, P = .036), accompanied by thinning of IT750 (-1.7 µm/y, P = .063). CONCLUSIONS: LV tends to increase with aging, which contributes to the shallowing of the anterior chamber and narrowing of ACA in PACD eyes treated with LPI. In the meantime, pupillary constriction and subsequent peripheral iris thinning associated with aging could possibly offset the effect of ACA narrowing.

Primary congenital glaucoma: An iridotrabeculodysgenesis?

PURPOSE: To analyze primary congenital glaucoma (PCG) anterior chamber and angle anomalies over 360° as possible biomarkers of severity and prognosis. METHODS: A cross-sectional observational study was conducted analyzing anterior segment anomalies of PCG patients over 4 years of age who underwent trabeculectomy combined with trabeculotomy and age-matched controls using anterior segment optical coherence tomography (ASOCT), CASIA-2. Anterior iridotrabecular adhesions or anterior iris insertion was identified and quantified from the scleral spur using the iridotrabecular contact (ITC) index parameter as a surrogate. RESULTS: There was a variable but significantly increased anterior iridotrabecular adhesion on ITC index, ITC area, corneal volume, anterior chamber volume, iris volume, anterior chamber depth, and small/absent trabecular meshwork in PCG eyes compared to control eyes. In PCG eyes, anterior iridotrabecular adhesion had a positive correlation with pre-operative central corneal thickness (CCT) (r = 0.53, P = 0.02), review iris thickness (r = 0.4, P = 0.04), and ITC area (r = 0.85, P < 0.001). Review iris thickness had a negative correlation with pre-operative vertical cup-disc ratio (r = -0.51, P = 0.008). Iris hypoplasia with fewer or absent folds, collarette, pupillary ruff, and pupillary ruff to collarette distance was significantly different from controls. CONCLUSION: ASOCT in PCG eyes has shown that they have variable anterior iridotrabecular tissue adhesions, anomalous tissue/membranes in the angle, and iris hypoplasia correlating with pre-operative cup-disc ratio. These features could be used as gonioscopic and clinical biomarkers to assess the severity and prognosis of the disease. The presence of abnormal iris morphology and iridotrabecular tissue anomalies in PCG suggests that it is more than just isolated trabeculodysgenesis and is probably best considered as part of the anterior segment dysgenesis spectrum.

[Ocular complications in intense pulsed light therapy (case study)]. / Glaznye oslozhneniya intensivnoi fototerapii (klinicheskoe nablyudenie).

A 24-year-old female patient with photophobia, discoria, redness and dryness in her right eye after intense pulsed light (IPL) therapy applied for posttraumatic subcutaneous hemorrhage received a comprehensive ophthalmic examination including optical coherence tomography (OCT) and OCT angiography of the anterior eye segment. Her best corrected visual acuity was 20/20 in both eyes. Medically induced mydriasis revealed discoria with paresis of pupil dilatator in the left eye (pupil size 4.2 mm and 6.6 mm in the right and left eye, respectively). Anterior segment OCT showed anterior chamber cytosis and increased iris vascularity. The patient was prescribed topical 1.0% tropicamide 2 times per day and 1.0% dexamethasone 4 times per day for two weeks. Examination performed after 3 months showed no restoration of pupil dilatator function in the left eye. The case demonstrates potential ocular complications of IPL therapy, which may include iris burn with iritis and persistent pupil dilatator dysfunction.

[Applications of anterior segment optical coherence tomography in corneal refractive surgery].

Anterior segment optical coherence tomography (AS-OCT) has the characteristics of non-contact, noninvasive, high sensitivity, and repeatability, and offers high-resolution in vivo imaging of the structures of the anterior eye segment. It can be used in the diagnosis and assistance of conditions related to the anterior eye segment. This review provides an update on the research and clinical applications of AS-OCT in corneal refractive surgery, including preoperative keratoconus screening, intraoperative real-time visualization of corneal structures, postoperative corneal evaluation, and management of postoperative complications. We also explore the potential application of AS-OCT in combination with corneal biomechanical detection for corneal refractive surgery.

The ocular anterior segment examination of perinatal newborns by wide-field digital imaging system: a cross-sectional study.

PURPOSE: The aim of this study was to evaluate and summarize the developmental rules of the ocular anterior segment of neonates by means of wild-field digital imaging system. METHODS: We used the wide-field digital imaging system to sequentially capture images of the neonates' eyes within 42 days after delivery, including the ocular surface, anterior segment, and fundus. At the same time, basic information at the time of birth and examination was collected. RESULTS: Among 248 newborns, 51.21% were male. Abnormalities of the anterior segment such as visualization of anterior chamber angle vessels (79.03%) and iris vessels (51.21%), iris process (42.34%), persistent pupillary membranes (19.35%), albinism, congenital cataracts, corneal leucoma, and subconjunctival hemorrhage were observed in this study. There were significant differences in the appearance of iris vessels among different sex, gestational age and birth weight, postmenstrual age and weight at the time of examination and iris color groups. The iris vessels were more visualized in males relative to females (OR = 6.313, 95% CI 2.529-15.759). The greater the postmenstrual age at the time of examination, the lower the visualization of iris vessels (OR = 0.377, 95% CI 0.247-0.575). In addition, although visualization of anterior chamber angle vessels differed within the birth gestation age and weight at examination groups, there was no significant correlation by regression analysis. CONCLUSIONS: The anterior segment of perinatal neonates can be visualized by the wide-field digital imaging system. The neonatal iris and anterior chamber angle are immature, and the visible vessels at the anterior chamber angle that vanish later than the surface of the iris are characteristic structures.

The use of the built-in macro mode of smartphone cameras for pediatric external and anterior segment digital photography.

We describe a novel method for clinical ophthalmic photography that uses the inherent macro-photography mode available in most recent smartphones, without additional attachments. This method facilitates acquisition of high-quality external and anterior segment clinical photography in children who may have difficulty remaining still enough for anterior segment photography at the slit lamp. We describe this technique and discuss its advantages and limitations.