Progressive Changes in the Neuroretinal Rim and Retinal Nerve Fiber Layer in Glaucoma: Impact of Baseline Values and Floor Effects.

PURPOSE: To determine whether more severe baseline damage impedes measurement of minimum rim width (MRW) and peripapillary retinal nerve fiber layer thickness (RNFLT) change in glaucoma patients because of a floor effect. DESIGN: Prospective, longitudinal cohort study in a hospital-based setting. PARTICIPANTS: The study included patients with open-angle glaucoma and healthy control subjects. Participants had at least 5 years of follow-up with OCT every 6 months. METHODS: Baseline global and sectorial MRW and RNFLT values were classified as within normal limits, borderline, or outside normal limits based on reference normative values. Regression analysis was used to determine the magnitude and significance of MRW and RNFLT change. Additionally, the follow-up period for each participant was divided into 2 equal halves (first and second periods) to determine whether there was attenuation of MRW and RNFLT change with follow-up time. MAIN OUTCOME MEASURES: Rates of global and sectoral MRW and RNFLT changes (slopes). RESULTS: A total of 97 patients with glaucoma (median age, 70.3 years) and 42 healthy subjects (median age, 64.8 years) were followed for a median of 6.9 years and 7.0 years, respectively. The median mean deviation of the visual field in glaucoma patients was -4.30 decibels (dB) (interquartile range, -7.81 to -2.06 dB; range, -20.68 to 1.37 dB). Statistically significant changes in global and sectoral MRW and RNFLT were detected across all baseline classifications; however, there was a tendency for less change with increasing baseline damage. In glaucoma patients, RNFLT slopes, but not MRW slopes, were significantly more positive (less change) in the second period compared with the first. There were also no differences in MRW or RNFLT slopes in the first and second periods in healthy subjects. CONCLUSIONS: Significant MRW and RNFLT changes were detected at all levels of baseline damage. However, an attenuation in the rate of RNFLT change compared with MRW indicates an earlier floor effect in RNFLT measurements globally and in equivalent sectors. Because the axonal component of these measurements should be equivalent, our results suggest important differences in tissue remodeling at the level of the optic nerve head and peripapillary retina. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Comparison of the ClearSight™ finger cuff monitor versus invasive arterial blood pressure measurement in elective cardiac surgery patients: a prospective observational study.

PURPOSE: To determine the acceptability of the ClearSight™ system (Edwards Lifesciences Corp., Irvine, CA, USA) for continuous blood pressure monitoring during elective cardiac surgery compared with arterial catheterization. METHODS: We enrolled 30 patients undergoing elective cardiac surgery in a prospective observational study. Blood pressure measurements were recorded every 10 sec intraoperatively. We determined agreement based on the Association for the Advancement of Medical Instrumentation (AAMI) recommendations. Statistical analysis included fixed bias (difference of measurements between methods), percentage error (accuracy between ClearSight measurement and expected measurement from arterial line), and interchangeability (ability to substitute ClearSight monitor without effecting overall outcome of analysis). We used a paired samples t test to compare the time required for placing each monitor. RESULTS: We found fixed bias in the differences between the ClearSight monitor and invasive arterial blood pressure measurement in systolic blood pressure (SBP; mean difference, 8.7; P < 0.001) and diastolic blood pressure (DBP; mean difference, -2.2; P < 0.001), but not in mean arterial pressure (MAP; mean difference, -0.5; P < 0.001). Bland-Altman plots showed that the means of the limits of agreement were greater than 5 mm Hg for SBP, DBP, and MAP. The percentage errors for SBP, DBP, and MAP were lower than the cutoff we calculated from the invasive arterial blood pressure measurements. Average interchangeability rates were 38% for SBP, 50% for DBP, and 50% for MAP. Placement of the ClearSight finger cuff was significantly faster compared with arterial catheterization (mean [standard deviation], 1.7 [0.6] min vs 5.6 [4.1] min; P < 0.001). CONCLUSIONS: In this prospective observational study, we did not find the ClearSight system to be an acceptable substitute for invasive arterial blood pressure measurement in elective cardiac surgery patients according to AAMI guidelines. Nevertheless, based on statistical standards, there is evidence to suggest otherwise. STUDY REGISTRATION: ClinicalTrials.gov ( NCT05825937 ); first submitted 11 April 2023.

RéSUMé: OBJECTIF: Notre objectif était de déterminer l'acceptabilité du système ClearSight™ (Edwards Lifesciences Corp., Irvine, CA, USA) pour la surveillance continue de la tension artérielle pendant une chirurgie cardiaque non urgente par rapport au cathétérisme artériel. MéTHODE: Nous avons recruté 30 patient·es bénéficiant d'une chirurgie cardiaque non urgente pour une étude observationnelle prospective. Les mesures de la tension artérielle ont été enregistrées toutes les 10 sec en période peropératoire. Nous avons déterminé l'accord sur la base des recommandations de l'Association for the Advancement of Medical Instrumentation (AAMI). L'analyse statistique comprenait le biais fixe (différence de mesures entre les méthodes), le pourcentage d'erreur (précision entre la mesure ClearSight et la mesure attendue à partir de la ligne artérielle), et l'interchangeabilité (capacité de remplacer la mesure invasive par le moniteur ClearSight sans affecter le résultat global de l'analyse). Nous avons utilisé des échantillons t appariés pour comparer le temps nécessaire à la mise en place de chaque moniteur. RéSULTATS: Nous avons constaté un biais fixe dans les différences entre le moniteur ClearSight et la mesure invasive de la tension artérielle dans la tension artérielle systolique (TAS; différence moyenne, 8,7; P < 0,001) et la tension artérielle diastolique (TAD; différence moyenne, −2,2; P < 0,001), mais pas dans la tension artérielle moyenne (TAM; différence moyenne, −0,5; P < 0,001). Les graphiques de Bland-Altman ont montré que les moyennes des limites d'accord étaient supérieures à 5 mm Hg pour la TAS, la TAD et la TAM. Les pourcentages d'erreurs pour la TAS, la TAD et la TAM étaient inférieurs au seuil que nous avons calculé à partir des mesures invasives de la tension artérielle. Les taux d'interchangeabilité moyens étaient de 38 % pour la TAS, de 50 % pour la TAD et de 50 % pour la TAM. La mise en place du moniteur digital ClearSight a été significativement plus rapide que celle du cathétérisme artériel (moyenne [écart type], 1,7 [0,6] min vs 5,6 [4,1] min; P < 0,001). CONCLUSION: Dans cette étude observationnelle prospective, nous n'avons pas trouvé que le système ClearSight était un substitut acceptable à la mesure invasive de la tension artérielle chez les patient·es de chirurgie cardiaque non urgente, selon les directives de l'AAMI. Néanmoins, sur la base des normes statistiques, il existe des données probantes suggérant le contraire. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov ( NCT05825937 ); première soumission le 11 avril 2023.

Transconjunctival XEN45 implantation for secondary open-angle glaucoma management in a pediatric patient with WAGR syndrome.

Purpose: To report a case of XEN45 gel stent implantation in a pediatric patient with WAGR syndrome as a successful surgical intervention in the management of multifactorial secondary open-angle glaucoma. Observations: A 6-year-old female with a history of WAGR syndrome, bilateral congenital aniridia, pseudophakia OD and glaucoma OD, was referred for a XEN45 gel stent OD. IOP was persistently elevated at 24 mm Hg despite two glaucoma medications. Implantation of the XEN45 gel stent was performed using a transconjunctival ab externo approach. There were no significant intra-or-postoperative adverse events associated with the stent. The patient achieved good IOP-lowering control without glaucoma medications across the 18-month follow-up period. Conclusions: A XEN45 stent through a transconjunctival ab externo approach may be an effective surgical intervention in pediatric patients with secondary open-angle glaucoma associated with aniridia and aphakia.

Effects of 3D Stratification of Retinal Ganglion Cells in Sholl Analysis.

BACKGROUND: Sholl analysis is used to quantify the dendritic complexity of neurons. Differences between two-dimensional (2D) and three-dimensional (3D) Sholl analysis can exist in neurons with extensive axial stratification of dendrites, however, in retinal ganglion cells (RGCs), only 2D analysis is typically reported despite varying degrees of stratification within the retinal inner plexiform layer. We determined the impact of this stratification by comparing 2D and 3D analysis of the same RGCs. NEW METHOD: Twelve retinas of mice expressing yellow fluorescent protein in RGCs under the control of the Thy1 promotor were whole-mounted. The entire dendritic arbor of 120 RGCs was traced, after which 2D and 3D Sholl analysis was performed. Two parameters describing dendritic complexity; area under the curve (AUC) and peak number of intersections (PNI) were then derived and analyzed. RESULTS AND COMPARISON WITH EXISTING METHODS: The AUC and PNI were significantly higher with 3D analysis compared to 2D analysis with medians of 2805 and 2508 units, and 31 and 27, respectively (P < 0.01). Both 2D and 3D AUC increased with arbor thickness. The discrepancy in AUC between the two methods depended on mean AUC (with every 1 unit increase in mean AUC resulting in a discrepancy of 0.1 unit), but not arbor thickness. CONCLUSION: In RGCs imaged in vitro, there is a difference in AUC and PNI derived with 2D and 3D Sholl analysis. Where possible, 3D Sholl analysis of RGCs should be performed for more accurate quantitative analysis of dendritic structure.