Enhanced morphological assessment based on interocular asymmetry analysis for keratoconus detection.

PURPOSE: To clarify the interocular asymmetry of corneal morphological descriptors and evaluate its discriminant ability of keratoconus (KC). METHODS: This retrospective study recruited 344 normal participants and 290 KC patients, randomized to training and validation datasets. Interocular correlation and agreement were evaluated on 44 corneal morphological descriptors derived from Schiempflug tomography. Logistic regression models were constructed using binocular data and of which diagnostic performance was evaluated using the area under receiver operating characteristics curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI). RESULTS: Interocular agreement of corneal descriptors is better in the normal than in KC except for dimensions of cornea and anterior chamber. The interocular asymmetry increases along with the severity of KC. Interocular asymmetry in maximum anterior keratometry, mean anterior keratometry and higher-order aberrations of anterior surface show high AUC above 0.950. Binocular logistic regression index reaches an AUC of 0.963 with high specificity (95.2%) and brings gain to monocular parameters in distinguishing the normal eyes from KC (NRI = 0.080 (0.042 ~ 0.118), P < 0.001) and IDI = 0.071 (0.049 ~ 0.092), P < 0.001). Interocular asymmetry benefits even more in subclinical keratoconus (SKC) detection reflected by NRI (0.4784 (0.2703-0.6865), P < 0.001) and IDI (0.2680 (0.1495-0.3866), P < 0.001) measures. CONCLUSION: Interocular asymmetry is a well-characterized feature of KC and related to the severity. It is feasible to apply the interocular asymmetry in diagnosis of KC and SKC as a replenishment of monocular parameters and in progression tracking.

Assessment of the iridocorneal angle pigmentation and structures after the implantation of EVO+ Visian Implantable Collamer Lens.

PURPOSE: To evaluate the effect of EVO+ Visian Implantable Collamer Lens (ICL) implantation on the iridocorneal angle pigmentation and structures. METHODS: Myopic refractive surgery candidates who underwent posterior chamber EVO+ ICL implantation were evaluated preoperatively and 3 and 6 months postoperatively. High-resolution images of the iridocorneal angle (nasal, superior, temporal and inferior quadrants) were acquired during gonioscopy. A masked observer, blinded to study visits and patients' information, evaluated the angle width, apparent iris root insertion, iris configuration, and trabecular meshwork pigmentation according to the Spaeth scale in two different occasions. The intra-rater reliability was estimated using the weighted Gwet's Agreement Coefficient (AC2). Differences between visits were analyzed using the Cochran Q test or the Friedman test. RESULTS: Twenty-one patients (13 females and 8 males) aging 31.3 ± 6.3 years old were recruited. The intra-rater reliability of gonioscopy assessment was excellent for every parameter assessed (AC2 ≥ 0.97). No significant differences were found among the study visits for any quadrant in the angle width (p ≥ 0.74), apparent iris root insertion (p ≥ 0.22), iris configuration (p ≥ 0.21) and trabecular meshwork pigmentation (p ≥ 0.24). Mean pigmentation of trabecular meshwork for the four quadrants did not vary either among visits (p = 0.25). CONCLUSIONS: The EVO+ ICL implantation after uneventful procedures appears not to clinically affect the iridocorneal angle pigmentation and/or structures during a short-medium follow-up using gonioscopy assessment. The intra-rater reliability of glaucoma specialists assessing iridocorneal angle structures using gonioscopy images is very high.

Deep Learning-Based Model for Automatic Assessment of Anterior Angle Chamber in Ultrasound Biomicroscopy.

OBJECTIVE: The goal of the work described here was to develop and assess a deep learning-based model that could automatically segment anterior chamber angle (ACA) tissues; classify iris curvature (I-Curv), iris root insertion (IRI), and angle closure (AC); automatically locate scleral spur; and measure ACA parameters in ultrasound biomicroscopy (UBM) images. METHODS: A total of 11,006 UBM images were obtained from 1538 patients with primary angle-closure glaucoma who were admitted to the Eye Center of Renmin Hospital of Wuhan University (Wuhan, China) to develop an imaging database. The UNet++ network was used to segment ACA tissues automatically. In addition, two support vector machine (SVM) algorithms were developed to classify I-Curv and AC, and a logistic regression (LR) algorithm was developed to classify IRI. Meanwhile, an algorithm was developed to automatically locate the scleral spur and measure ACA parameters. An external data set of 1,658 images from Huangshi Aier Eye Hospital was used to evaluate the performance of the model under different conditions. An additional 439 images were collected to compare the performance of the model with experts. RESULTS: The model achieved accuracies of 95.2%, 88.9% and 85.6% in classification of AC, I-Curv and IRI, respectively. Compared with ophthalmologists, the model achieved an accuracy of 0.765 in classifying AC, I-Curv and IRI, indicating that its high accuracy was as high as that of the ophthalmologists (p > 0.05). The average relative errors (AREs) of ACA parameters were smaller than 15% in the internal data sets. Intraclass correlation coefficients (ICCs) of all the angle-related parameters were greater than 0.911. ICC values of all iris thickness parameters were greater than 0.884. The accurate measurement of ACA parameters partly depended on accurate localization of the scleral spur (p < 0.001). CONCLUSION: The model could effectively and accurately evaluate the ACA automatically based on fully automated analysis of UBM images, and it can potentially be a promising tool to assist ophthalmologists. The present study suggested that the deep learning model can be extensively applied to the evaluation of ACA and AC-related biometric risk factors, and it may broaden the application of UBM imaging in the clinical research of primary angle-closure glaucoma.

Quantitative and qualitative assessment of anterior segment optical coherence tomography capture of disease state in childhood anterior uveitis.

BACKGROUND/AIMS: Anterior segment optical coherence tomography (AS-OCT) assessment of anterior chamber inflammation is an emerging tool. We describe the performance of AS-OCT in a paediatric population. METHODS: A mixed-methods prospective study, using routine clinical assessment as reference standard, and AS-OCT, with Tomey CASIA2 or Heidelberg Spectralis HS1, as index test, with data collected on patient perceptions of imaging. Repeatability, diagnostic indices, responsiveness to clinical change and clinical correlations of imaging-based metrics (image cell count, size, density and brightness) were assessed, with construction of receiver operated characteristic curves. Exploratory thematic analysis of responses from families was undertaken. RESULTS: A total of 90 children (180 eyes) underwent imaging. Bland Altman limits of agreement for CASIA2 repeatability ranged from +17 cells (95% CI 13.6 to 21.1) to -19 cells (95% CI -15.6 to -23.2) and HS1 from +1 (95% CI 0.9 to 1.2) to -1.0 (-1.2 to -0.8) cells. CASIA2 imaging had higher sensitivity of 0.92 (95% CI 0.78 to 0.97) vs HS1 imaging 0.17 (95% CI 0.07 to 0.34), with positive correlation between clinical grade and CASIA2 cell count (coefficient 12.8, p=0.02, 95% CI 2.2 to 23.4). Change in clinical grade at follow-up examinations correlated with change in image based 'cell' count (r2=0.79, p<0.001). Patients reported a potential positive impact of seeing their disease activity. CONCLUSION: Our findings suggest that OCT-based imaging holds the promise of deeper understanding of disease, improved patient experience and more granular monitoring of activity with resultant improved outcomes, but further work is needed to refine acquisition and analysis protocols.

Early Assessment of Circumferential Anterior Segment Structures Following Implantable Collamer Lens V4c Implantation Via SS-OCT.

Purpose: To explore early changes in circumferential anterior segment structures following Implantable Collamer Lens (ICL) V4c implantation via swept-source optical coherence tomography (SS-OCT). Methods: In 103 eyes of 56 myopic patients undergoing ICL V4c surgery, anterior segments were measured via SS-OCT to compute local anterior chamber angle (ACA) parameters on the nasal-temporal (0°-180°), superior-inferior (90°-270°), and superior nasal-inferior temporal (80°-260°) meridians, including angle-opening distance at 500 µm (AOD500), trabecular-iris space area at 500 µm (TISA500), trabecular-iris angle at 500 µm (TIA500), and circumferential ACA parameters, including AOD area at 500 µm (AODA500), trabecular-iris circumference volume at 500 µm (TICV500), and the index and area of iris-trabecular contact (ITC). ACA parameters were compared preoperatively and at 1 week, 1 month, and 3 months postoperatively and compared among quadrants. Mixed-effects model was used to evaluate the parameters correlated with the post-ITC parameters. Results: The mean AOD500, TISA500, TIA500, AODA500, and TICV500 were decreased by 65.4% to 71%, 64.1% to 69.3%, 53.8% to 61.5%, 69.9%, and 69.2%, respectively, at 1 week postoperatively. The ITC index and area values rose from 1.436% ± 4.427% and 0.070 ± 0.254 mm2 to 12.343% ± 13.216% and 0.903 ± 1.304 mm2 (all P < 0.05). No further decreases in ACA parameters were observed beyond 1 week postoperatively (all P > 0.05). Significant differences were observed among quadrants, with the narrowest in the superior-nasal quadrant, followed by the superior quadrant. The 3-month vault was significantly correlated with the ITC index and area at 3 months postoperatively. Conclusions: Anterior segment structures were significantly shallow at 1 week with no further decreases thereafter. In light of anatomical variability, we recommend circumferential meridian scan to assess angle status, with special attention to the superior-nasal and superior quadrants. Translational Relevance: We investigated the early changes in circumferential anterior segment structures following ICL V4c implantation, thus providing a better perspective for understanding anterior segment structural characteristics after ICL V4c surgery.

Translation model for CW chord to angle Alpha derived from a Monte-Carlo simulation based on raytracing.

BACKGROUND: The Chang-Waring chord is provided by many ophthalmic instruments, but proper interpretation of this chord for use in centring refractive procedures at the cornea is not fully understood. The purpose of this study is to develop a strategy for translating the Chang-Waring chord (position of pupil centre relative to the Purkinje reflex PI) into angle Alpha using raytracing techniques. METHODS: The retrospective analysis was based on a large dataset of 8959 measurements of 8959 eyes from 1 clinical centre, using the Casia2 anterior segment tomographer. An optical model based on: corneal front and back surface radius Ra and Rp, asphericities Qa and Qp, corneal thickness CCT, anterior chamber depth ACD, and pupil centre position (X-Y position: PupX and PupY), was defined for each measurement. Using raytracing rays with an incident angle IX and IY the CW chord (CWX and CWY) was calculated. Using these data, a multivariable linear model was built up in terms of a Monte-Carlo simulation for a simple translation of incident ray angle to CW chord. RESULTS: Raytracing allows for calculation of the CW chord CWX/CWY from biometric measures and the incident ray angle IX/IY. In our dataset mean values of CWX = 0.32±0.30 mm and CWY = -0.10±0.26 mm were derived for a mean incident ray angle (angle Alpha) of IX = -5.02±1.77° and IY = 0.01±1.47°. The raytracing results could be modelled with a linear multivariable model, and the effect sizes for the prediction model for CWX are identified as Ra, Qa, Rp, CCT, ACD, PupX, PupY, IX, and for CWY they are Ra, Rp, PupY, and IY. CONCLUSION: Today the CW chord can be directly measured with any biometer, topographer or tomographer. If biometric measures of Ra, Qa, Rp, CCT, ACD, PupX, PupY are available in addition to the CW chord components CWX and CWY, a prediction of angle Alpha is possible using a simple matrix operation.

Assessment of Anterior Uveitis Through Anterior-Segment Optical Coherence Tomography and Artificial Intelligence-Based Image Analyses.

Purpose: The purpose of this study was to develop an automated artificial intelligence (AI) based method to quantify inflammation in the anterior chamber (AC) using anterior-segment optical coherence tomography (AS-OCT) and to explore the correlation between AI assisted AS-OCT based inflammation analyses and clinical grading of anterior uveitis by Standardization of Uveitis Nomenclature (SUN). Methods: A prospective double blinded study of AS-OCT images of 32 eyes of 19 patients acquired by Tomey CASIA-II. OCT images were analyzed with proprietary AI-based software. Anatomic boundaries of the AC were segmented automatically by the AI software and Spearman's rank correlation between parameters related to AC cellular inflammation were calculated. Results: No significant (p = 0.6602) differences were found between the analyzed AC areas between samples of the different SUN grading, suggesting accurate and unbiased border detection/AC segmentation. Segmented AC areas were processed by the AI software and particles within the borders of AC were automatically counted by the software. Statistical analysis found significant (p < 0.001) correlation between clinical SUN grading and AI software detected particle count (Spearman ρ = 0.7077) and particle density (Spearman ρ = 0.7035). Significant (p < 0.001) correlation (Pearson's r = 0.9948) between manually and AI detected particles was found. No significant (p = 0.8080) difference was found between the sizes of the AI detected particles for all studies. Conclusions: AI-based image analysis of AS-OCT slides show significant and independent correlation with clinical SUN assessment. Translational Relevance: Automated AI-based AS-OCT image analysis suggests a noninvasive and quantitative assessment of AC inflammation with clear potential application in early detection and management of anterior uveitis.

Anterior chamber changes assessment by Scheimpflug analysis after intravitreal dexamethasone implantation.

PURPOSE: To evaluate structural changes in the anterior chamber and intraocular pressure (IOP) changes following intravitreal dexamethasone implantation. METHODS: Forty-two eyes of 42 patients that received intravitreal dexamethasone implant for the management of macular edema secondary to diabetic retinopathy or branch retinal vein occlusion (BRVO) were included in the study. IOP was measured by Goldmann applanation tonometry. Anterior chamber depth (ACD) and iridocorneal angle (ICA) was measured by a Scheimflug camera (Sirius, CSO, Italy) the day before the injection of the dexamethasone implant and on postoperative day 1, first week, and first month. RESULTS: Mean IOP was 15.14 ± 2.77 mmHg before the procedure and, 15.67 ± 3.70 mmHg, 15.86 ± 3.11 mmHg, 16.21 ± 2.75 mmHg on day 1, first week, and first month following intravitreal dexamethasone implantation, respectively. Mean ICA and ACD were significantly higher in pseudophakic eyes compared to phakic eyes. However, there was no statistically significant change in ICA before and after the procedure (on postoperative day 1, first week, and first month) among both phakic and pseudophakic patients (p = 0.783). Similarly, ACD remained unchanged after the procedure (on postoperative day 1, first week, and first month) compared to the initial measurement (p = 0.802). CONCLUSION: This study confirmed that there was an increase in IOP. However, these changes were not accompanied with a change in ACD or ICA.

Angle-supported intraocular lens versus scleral-sutured posterior chamber intraocular lens in post-cataract surgery aphakic patients: two-year follow-up cost-effectiveness analysis.

PURPOSE: To compare visual, anatomical and economical outcomes of patients with secondary anterior chamber intraocular lens (AC-IOL) implantation and secondary scleral fixated intraocular lens (SF-IOL) implantation. METHODS: In this retrospective observational study, 38 aphakic patients after complicated phacoemulsification divided in two groups, AC-IOL group (17 patients receiving AC-IOL implantation) and SF-IOL group (21 patients receiving SF-IOL implantation). Corrected distance visual acuity (CDVA), patient reported visual outcome (VF-14) and endothelial cell density (ECD) were measured at baseline and two-year follow-up. Complication rate was registered. The global cost of each procedure and the incremental cost-effectiveness ratio (ICER) were calculated. RESULTS: No statistically significant difference was found in CDVA (logMAR 0.24 ± 0.17 vs. 0.32 ± 0.26, p = 0.27), VF-14 (68 ± 18 vs. 61 ± 20, p = 0.24), ECD (1456.48 ± 525.15 vs. 1341.71 ± 374.33, p = 0.48) and overall complication rate (p = 0.79) postoperatively between the SF-IOL group and the AC-IOL group. The ECD loss rate was significantly higher in the AC-IOL group (15.5% vs. 3.5%, p = 0.004). The average global cost of the two procedures was higher in the SF-IOL group (p < 0.005) and ICER showed an additional payment of 693 € for each patient in SF-IOL group against a saving of 186 endothelial cells 2 years postoperatively. CONCLUSION: AC IOL and SF-IOL implantation showed similar outcomes in terms of visual function and safety profile. Higher ECD loss was found in AC-IOL group. The global cost of implantation was significantly lower for AC-IOL, but the ICER seems to justify the SF-IOL implantation in patients with low ECD.

A Deep Learning System for Automatic Assessment of Anterior Chamber Angle in Ultrasound Biomicroscopy Images.

Purpose: To develop and assess a deep learning system that automatically detects angle closure and quantitatively measures angle parameters from ultrasound biomicroscopy (UBM) images using a deep learning algorithm. Methods: A total of 3788 UBM images (2146 open angle and 1642 angle closure) from 1483 patients were collected. We developed a convolutional neural network (CNN) based on the InceptionV3 network for automatic classification of angle closure and open angle. For nonclosed images, we developed a CNN based on the EfficienttNetB3 network for the automatic localization of the scleral spur and the angle recess; then, the Unet network was used to segment the anterior chamber angle (ACA) tissue automatically. Based on the results of the latter two processes, we developed an algorithm to automatically measure the trabecular-iris angle (TIA500 and TIA750), angle-opening distance (AOD500 and AOD750), and angle recess area (ARA500 and ARA750) for quantitative evaluation of angle width. Results: Using manual labeling as the reference standard, the ACA classification network's accuracy reached 98.18%, and the sensitivity and specificity for angle closure reached 98.74% and 97.44%, respectively. The deep learning system realized the automatic measurement of the angle parameters, and the mean of differences was generally small between automatic measurement and manual measurement. The coefficients of variation of TIA500, TIA750, AOD500, AOD750, ARA500, and ARA750 measured by the deep learning system were 5.77%, 4.67%, 10.76%, 7.71%, 16.77%, and 12.70%, respectively. The within-subject standard deviations of TIA500, TIA750, AOD500, AOD750, ARA500, and ARA750 were 5.77 degrees, 4.56 degrees, 155.92 µm, 147.51 µm, 0.10 mm2, and 0.12 mm2, respectively. The intraclass correlation coefficients of all the angle parameters were greater than 0.935. Conclusions: The deep learning system can effectively and accurately evaluate the ACA automatically based on fully automated analysis of a UBM image. Translational Relevance: The present work suggests that the deep learning system described here could automatically detect angle closure and quantitatively measure angle parameters from UBM images and enhancing the intelligent diagnosis and management of primary angle-closure glaucoma.

Iridocorneal angle assessment in children with spontaneously regressed retinopathy of prematurity.

PURPOSE: To assess anterior segment anatomic parameters in school-aged children with spontaneously regressed retinopathy of prematurity (sr-ROP) and in children born preterm without ROP history (preT). METHODS: sr-ROP and preT children were compared with healthy, born at term children (control group). Biometric characteristics were measured with the IOLMaster. Iridocorneal angle structure was evaluated using Visante AS-OCT, and angle opening distance, trabecular iris space area and scleral spur angle were calculated. Best-corrected visual acuity (BCVA) was measured with the ETDRS chart. RESULTS: We examined 22 eyes of 11 children with sr-ROP, 26 eyes of 13 preT children and 24 eyes of 12 healthy controls, with a median age of 8 years. sr-ROP children exhibited worse mean BCVA and reduced AL compared to controls (p = 0.001 and p = 0.007, respectively). A narrower iridocorneal angle was found in sr-ROP compared to the preT and the control groups. Preterm children were found to have similar anterior chamber angle metrics compared to the full-term control group. CONCLUSION: In this study, school-aged children with a history of sr-ROP had narrower angles compared to preterm- and term-born children. AS-OCT demonstrated structural differences of the iridocorneal angle in sr-ROP, possibly reflecting a mild developmental arrest of the anterior segment.

Assessment of precision of astigmatism measurements taken by a sweptsource optical coherence tomography biometer - IOLMaster 700.

Purpose: : To assess the repeatability of ocular measurements, particularly astigmatism, taken using the latest version of an swept-source optical coherence tomography (SS-OCT) device, IOLMaster 700. Methods: This prospective observational study done in a private eye care centre. Study included 213 eyes of 152 patients diagnosed with cataract. Axial length (AL), Anterior corneal astigmatism (ΔK), Total corneal astigmatism (ΔTK), Aqueous depth (AD), Lens thickness (LT), Iris barycentre distance (IBD) and White to white distance (WTW) were analysed; three measurements were taken for each patient in the same sitting by the same examiner in an undilated state using the SS-OCT device. Repeatability was analysed using intraclass coefficient (ICC) and coefficient of variation (CV) measures, and astigmatism values were transformed into vector components (J0/J45) and categorised based on magnitude. Results: Astigmatism vector components (J0/J45) showed poor repeatability (ICC < 0.5 and CV > 0), while iris coordinates (IBD) and astigmatism magnitude had good correlation (ICC > 0.9) but more variations between the readings which was least for magnitude ≥ 1.5D; however, rest of the parameters demonstrated excellent repeatability (ICC > 0.9 with P value < 0.05). Conclusion: IOLMaster 700 demonstrated good reliability for the parameters measured, although, for astigmatism and iris barycentre distance, more number of readings and cross reference with other devices may be required to get clinically accurate results.

Optical Coherence Tomography and ImageJ Software for objective assessment of optical density of anterior chamber iris cyst.

Aim: To report the optical characteristics of the fluid in an anterior chamber iris cyst. Method: A 26-year-old male presented with blurring of vision in his right eye for two months, without any other associated ocular complaints. His visual acuity was 6/ 9 on Snellen's chart. On slit lamp examination, a small translucent pigmented cyst was noted inferiorly in the anterior chamber, struck on to the cornea at 6 o'clock periphery, without any feeder vessel. Anterior segment optical coherence tomography (OCT) revealed a cystic lesion with hyperreflective walls and hypo reflective lumen attached to the cornea, compressing the endothelium. Results: The optical density (OD) of the cyst fluid was determined using ImageJ, an open code Java-based image processing software. The OD of cyst fluid was found comparable to the anterior chamber fluid. Conclusion: Ultrasound biomicroscopy (UBM) and OCT are useful tools for the diagnosis of cystic lesions of the anterior segment. The innovative use of an OCT image and the ImageJ software to determine the optical density of the iris cyst may aid in the diagnosis and follow-up of such cases.

Iridocorneal Angle Assessment After Laser Iridotomy With Swept-source Optical Coherence Tomography.

AIM: To investigate the reliability of anterior chamber angle (ACA) measurements in narrow angles and assess the effect of laser peripheral iridotomy (LPI) on these measurements using novel swept-source optical coherence tomography (SS-OCT) technology. MATERIALS AND METHODS: In this prospective observational study, patients with gonioscopically narrow angles were enrolled and scheduled for prophylactic LPI. Twelve ACA sections were obtained in each eye using SS-OCT (ANTERION, Heidelberg Engineering, Germany) before and after Nd:YAG LPI. A built-in algorithm calculated ACA measurements after manual identification of the scleral spur and ACA recess. Eight ACA parameters were evaluated: ACA (ACA 500, ACA 750); scleral spur angle (SSA 500, SSA 750); angle opening distance (AOD 500, AOD 750); and trabecular iris space area (TISA 500, TISA 750). The effect of LPI was assessed for each parameter, both nasally and temporally. RESULTS: Ten patients (18 eyes) were enrolled (mean age, 61.8±13.6 y; 60.0% female individuals). On average, the ACA was wider nasally than temporally (P=0.004). LPI significantly widened the ACA (range, 26.7-29.4%; P<0.05). ACA 500 increased by 29.4% (P<0.001), ACA 750 by 29.2% (P=0.002), SSA 500 by 27.3% (P=0.003), SSA 750 by 28.1% (P=0.001), AOD 500 by 28.6% (P=0.009), AOD 750 by 28.6% (P=0.003), TISA 500 by 27.3% (P=0.004), and TISA 750 by 26.7% (P=0.200). CONCLUSIONS: SS-OCT ANTERION imaging can be used to reliably measure ACA before and after LPI. ACA, AOD, SSA, and TISA are all valid ACA measurement methods.

Assessment of anterior segment measurements using a high-resolution imaging device.

PURPOSE: To assess the repeatability of several anterior segment parameters obtained with swept-source optical coherence tomography (SS-OCT). METHODS: We measured 5-times consequently several parameters in 69 eyes using the ANTERION SS-OCT. White-to-white (WTW), angle-to-angle (ATA), spur-to-spur (STS), and lens vault distances were measured in the horizontal- and vertical-meridian. Anterior-chamber-angle (ACA), scleral-spur-angle (SSA), angle-opening-distance (AOD), and trabecular-iris-space-area (TISA) were measured at 500 and 750 µm for the superior-, nasal-,inferior-, and temporal-quadrants. Intrasubject standard deviation (Sw),coefficient of variation (CoV), coefficient of repeatability (CoR), and intraclass-correlation-coefficient (ICC) were calculated for each parameter. Bland-Altman analysis was done. RESULTS: We have not found statistically significant differences between repeated measurements (p > 0.05). Repeatability was good for the different parameters evaluated. Sw values in distances and areas were low and ranged from 0.01 to 0.07. CoR values showed a similar pattern being larger for those metrics measuring angles. The same happened with CoV values, being very small for WTW,ATA, and STS distances (0.16-0.57%). ICC values for all parameters analyzed were > 0.97. Bland-Altman plots evidenced the narrow limits of agreement for all parameters. CONCLUSIONS: The ANTERION SS-OCT demonstrated high repeatability measuring different distances, angles, and areas of the anterior segment of the eye.

Automated Gonioscopy Assessment of XEN45 Gel Stent Angle Location After Isolated XEN or Combined Phaco-XEN Procedures: Clinical Implications.

PRéCIS:: Angle location of the XEN implant both in isolated and in combined procedures did not appear to influence long-term outcomes. However, more posterior stent placements seem to be associated with increased early postoperative complications. PURPOSE: The purpose of this study was to assess success and safety outcomes of different levels of insertion of the XEN45 gel stent in the angle in standalone and combined procedures. METHODS: This was a cross-sectional study of patients in whom XEN had been implanted without intraoperative gonioscopy. Automated gonioscopy was used for postoperative analysis of the XEN location, classified as anterior or posterior relative to the scleral spur. Absolute success was defined as ≥20% intraocular pressure decrease from baseline and ranging from 6 to 21 mm Hg without medication and qualified success if medicated. The need for additional drainage surgery was considered failure, but needling was allowed. Clinical data were retrieved from patient files. RESULTS: Gonioscopy-assisted XEN location was performed on 42 eyes of 33 patients (14 isolated and 28 combined procedures) on average 18±9 months after surgery. Absolute (32% vs. 35%; P>0.99) and qualified (44% vs. 65%; P=0.22) success was similar in both anterior and posterior placements, respectively. Kaplan-Meier survival analysis yielded similar median survival times for both groups. The distribution of XEN insertion level in the angle was similar in standalone and combined procedures (P=0.75). Although overall safety outcome measures did not differ significantly, the proportion of intraoperative and early postoperative complications was higher in posterior XEN placements (P=0.03). CONCLUSIONS: Different locations of XEN45 did not seem to significantly impact late success and safety outcomes, although stents inserted more posteriorly may be associated with a higher rate of early complications. Combined implantation of XEN with phacoemulsification does not seem to influence stent location in the iridocorneal angle in a setting without intraoperative gonioscopy.

Pupil expansion device use and operative outcomes with topical dilation vs intracameral epinephrine in resident-performed cataract surgery.

PURPOSE: To compare the use of topical dilation drops vs topical drops with the addition of intracameral epinephrine in resident-performed cataract surgery and the effects on pupil expansion device (PED) use, surgical costs, and surgical times. SETTING: Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, USA. DESIGN: Retrospective chart review. METHODS: Resident-performed primary cataract surgical cases using topical dilation drops only or drops with the addition of intracameral epinephrine were analyzed for PED use, surgical time, and costs in all patients and in patients with a history of tamsulosin use. RESULTS: In the topical group, PEDs were used in 31.1% of cases compared with 13.5% of cases in the intracameral group (P < .0001). History of tamsulosin use was noted in about one third of cases in both groups. For patients with a history of tamsulosin use, PED use decreased from 52.7% in the topical cases to 17.9% in the intracameral group (P < .0001). Surgical times were on average 7.1 minutes slower with PED use than without PED use. There was a medication savings of $50.44 USD per case in the intracameral group compared with the topical group. Factoring in the $100 to $130 USD per PED used, total surgical costs were $19 267 USD less in the intracameral group over 6 months. CONCLUSIONS: Intracameral epinephrine with lidocaine decreases the need for PED use during cataract surgery, lowers intraoperative costs, and improves efficiency compared with topical dilation drops alone.

Preoperative Risk Assessment for Progression to Descemet Membrane Endothelial Keratoplasty Following Cataract Surgery in Fuchs Endothelial Corneal Dystrophy.

PURPOSE: To identify preoperative corneal tomographic features that predict progression to endothelial keratoplasty (EK) following cataract surgery in Fuchs endothelial corneal dystrophy (FECD) and establish a regression model to identify high-risk patients. DESIGN: Prospective, observational cohort study. METHODS: Setting: Hospital Universitario Ramón y Cajal, Madrid, Spain. STUDY POPULATION: Sixty-eight patients (84 eyes) with FECD who underwent phacoemulsification. INTERVENTION: We assessed preoperative best-corrected visual acuity; ultrasound central corneal thickness; pachymetric, anterior chamber depth, and corneal backscatter variables using Scheimpflug imaging; and endothelial cell density. MAIN OUTCOME MEASURES: Progression to EK. RESULTS: A total of 33 eyes (39.3%) needed EK after phacoemulsification to rehabilitate vision. On multivariate analysis, anterior layer (AL) corneal backscatter between 0 and 2 mm from the apex and relative increase in central corneal thickness from the "relative pachymetry display" by the Pentacam were significant predictors of the risk of progression to EK. Using these 2 variables, a risk score (RISC score) was derived from the regression model (area under the curve = 0.973; best cutoff point with a specificity of 95% representing a sensitivity of 96%). Excluding corneal backscatter data from the multivariate regression model, corneal thickness at the pupil center by the Pentacam and relative increase in central corneal thickness were significant predictors and provided a modified risk score (RIPT score) with similar performance. CONCLUSION: Both scores demonstrated accuracy in predicting progression to EK using easily accessible preoperative data. This approach, which can be readily implemented by surgeons, allows for individualized risk assessment.