Comparison of Outcomes From Delayed-Onset Bleb-Related Endophthalmitis Treated With Pars Plana Vitrectomy Versus Vitreous Biopsy.

PRCIS: Bleb-related endophthalmitis (BRE) is a serious complication of glaucoma filtration surgery. The current study reports similar visual and intraocular pressure (IOP) outcomes in eyes treated with pars plana vitrectomy (PPV) compared with vitreous biopsy and injection of intravitreal antibiotics (TI). PURPOSE: The purpose of this study was to investigate the isolated organisms, visual acuity (VA), and IOP outcomes associated with delayed-onset BRE in eyes treated with PPV versus TI. PATIENTS AND METHODS: A retrospective chart review was conducted at the Bascom Palmer Eye Institute (Miami, Florida) and the University of Florida (Gainesville, FL) identifying patients treated for BRE with at least 1 month of follow-up from the inception of an electronic health record (2014 and 2011, respectively) through 2021. All patients had undergone bleb-forming glaucoma surgery at least 1 month before endophthalmitis diagnosis. RESULTS: Thirty-nine eyes from 39 patients (33 from Bascom Palmer, 6 from University of Florida) were included. Trabeculectomy was performed in 34 of 39 eyes (87.2%). Streptococcus species (9 eyes, 23.1%) and Staphylococcus species (8 eyes, 20.5%) were the most common isolated organisms and were similar in both treatment groups ( P =0.49). Baseline VA was worse in the PPV group (logarithm of the minimum angle of resolution: 2.51 vs. 2.16, P =0.04), but VA at last follow-up was similar ( P =0.48) in both groups. After recovery from BRE, the average IOP in the PPV group was 15.1 mm Hg on 0.9 IOP-lowering medications compared with 12.6 mm Hg on 1.2 medications in the TI group (IOP: P =0.56; medications: P =0.80). Additional glaucoma surgery was performed in 44.4% of the PPV eyes and 16.7% of the TI eyes ( P =0.09). CONCLUSION: In eyes with delayed-onset BRE, isolated organisms, visual outcomes, and IOP control were similar after initial PPV compared with TI.

Heart Failure Induced by Perinatal Ablation of Cardiac Myosin Light Chain Kinase.

Background: Germline knockout mice are invaluable in understanding the function of the targeted genes. Sometimes, however, unexpected phenotypes are encountered, due in part to the activation of compensatory mechanisms. Germline ablation of cardiac myosin light chain kinase (cMLCK) causes mild cardiac dysfunction with cardiomyocyte hypertrophy, whereas ablation in adult hearts results in acute heart failure with cardiomyocyte atrophy. We hypothesized that compensation after ablation of cMLCK is dependent on developmental staging and perinatal-onset of cMLCK ablation will result in more evident heart failure than germline ablation, but less profound when compared to adult-onset ablation. Methods and Results: The floxed-Mylk3 gene was ablated at the beginning of the perinatal stage using a single intra-peritoneal tamoxifen injection of 50 mg/kg into pregnant mice on the 19th day of gestation, this being the final day of gestation. The level of cMLCK protein level could no longer be detected 3 days after the injection, with these mice hereafter denoted as the perinatal Mylk3-KO. At postnatal day 19, shortly before weaning age, these mice showed reduced cardiac contractility with a fractional shortening 22.8 ± 1.0% (n = 7) as opposed to 31.4 ± 1.0% (n = 11) in controls. The ratio of the heart weight relative to body weight was significantly increased at 6.68 ± 0.28 mg/g (n = 12) relative to the two control groups, 5.90 ± 0.16 (flox/flox, n = 11) and 5.81 ± 0.33 (wild/wild/Cre, n = 5), accompanied by reduced body weight. Furthermore, their cardiomyocytes were elongated without thickening, with a long-axis of 101.8 ± 2.4 µm (n = 320) as opposed to 87.1 ± 1.6 µm (n = 360) in the controls. Conclusion: Perinatal ablation of cMLCK produces an increase of heart weight/body weight ratio, a reduction of contractility, and an increase in the expression of fetal genes. The perinatal Mylk3-KO cardiomyocytes were elongated in the absence of thickening, differing from the compensatory hypertrophy shown in the germline knockout, and the cardomyocyte thinning shown in adult-inducible knockout.