Neuroretinitis as a Complication of Cat Scratch Disease.

In this case report, a patient with neuroretinitis from a Bartonella henselae infection is described, and insights into methods to distinguish this type of case from more common etiologies of optic nerve edema are presented. A 21-year-old female with a history of right monocular vision loss due to amblyopia presented to the emergency department (ED) with occipital headache, fever, dizziness, nasal congestion, and painless blurry vision in the left eye for one day. A lumbar puncture found a slightly high opening pressure but no evidence of meningitis. The patient was diagnosed with a viral illness and discharged with outpatient follow-up. The patient, however, had persistent central vision loss and recurring headaches and returned to the ED. Subsequent ultrasound of the patient's optic nerve revealed significant optic nerve swelling. A new working diagnosis of idiopathic intracranial hypertension was made, and the patient was started on oral acetazolamide. On the next day, she was seen by ophthalmology, and recent scratches from her cat were noted on her arm. She tested positive for B. henselae and was started on doxycycline and rifampin. Nearly two weeks after the initial presentation, a macular star pattern, indicative of neuroretinitis, was noted on the fundoscopic exam. The patient had recovered her vision by three months later. In ED cases with unilateral vision loss, early use of point-of-care ultrasound and infection with B. henselae should always be considered. Early serology testing may be warranted to allow for earlier treatment since classic signs of neuroretinitis may not be apparent at the onset.

Emerging biological therapies for the treatment of age-related macular degeneration.

INTRODUCTION: Age-related macular degeneration (AMD) is the leading cause of blindness in individuals over age 50 in developed countries. Current therapy for nonexudative AMD (neAMD) is aimed at modifying risk factors and vitamin supplementation to slow progression, while intravitreal anti-vascular endothelial factor (VEGF) injections are the mainstay for treatment of choroidal neovascularization in exudative AMD (eAMD). AREAS COVERED: Over the past decade, promising therapies have emerged that aim to improve the current standard of care for both diseases. Clinical trials for neAMD are investigating targets in the complement cascade, vitamin A metabolism, metformin, and tetracycline, whereas clinical trials for eAMD are aiming to decrease treatment burden through novel port delivery systems, increasing drug half-life, and targeting new sites of the VEGF cascade. Stem cell and gene therapy are also being evaluated for treatment of neAMD and eAMD. EXPERT OPINION: With an aging population, the need for effective, long term, low burden treatment options for AMD will be in increasingly high demand. Current investigations aim to address the shortcomings of current treatment options with breakthrough treatment approaches. Therapeutics in the pipeline hold promise for improving the treatment of AMD, and are on track for widespread use within the next decade.

Intraoperative Retinal Changes May Predict Surgical Outcomes After Epiretinal Membrane Peeling.

Purpose: To investigate whether intraoperative retinal changes during epiretinal membrane (ERM) peeling affect anatomic or functional outcomes after surgery. Methods: We measured retinal thickness using an intraoperative optical coherence tomography (iOCT) device in patients undergoing pars plana vitrectomy with membrane peeling for idiopathic ERM. Changes in intraoperative central macular thickness (iCMT) were compared with postoperative improvements in CMT and best-corrected visual acuity (VA). Results: Twenty-seven eyes from 27 patients (mean age 68 years) underwent iOCT-assisted ERM peeling surgery. Before surgery, mean VA was logMAR 0.50 ± 0.36 (Snellen 20/63), and mean baseline CMT was 489 ± 82 µm. Mean iCMT before peeling was 477 ± 87 µm, which correlated well with preoperative CMT (P < 0.001). Mean change in iCMT was -39.6 ± 37 µm (range -116 to +77 µm). After surgery, VA improved to logMAR 0.40 ± 0.38 (Snellen 20/50) at month 1 and logMAR 0.27 ± 0.23 (Snellen 20/37) at month 3, whereas CMT decreased to 397 ± 44 µm and 396 ± 51 µm at months 1 and 3. Eyes that underwent greater amount of iCMT change (absolute value of iCMT change) were associated with greater CMT reduction at month 1 (P < 0.001) and month 3 (P = 0.010), whereas those with greater intraoperative thinning (actual iCMT change) showed a trend toward better VA outcomes at months 1 (P = 0.054) and 3 (P = 0.036). Conclusions: Intraoperative changes in retinal thickness may predict anatomic and visual outcomes after idiopathic ERM peeling surgery. Translational Relevance: Our study suggests that intraoperative retinal tissue response to ERM peeling surgery measured by iOCT may be a prognostic indicator for restoration of retinal architecture and for visual acuity outcomes.

Case Series on Initial Responses to Intravitreal Brolucizumab in Patients with Recalcitrant Chronic Wet Age-Related Macular Degeneration.

PURPOSE: To report a case series of initial responses to intravitreal brolucizumab in patients already undergoing anti-VEGF therapy for wet age-related macular degeneration. CASE SERIES: Six eyes (6 patients) with a history of wet age-related macular degeneration presented with either decline in vision or no improvement while undergoing treatment with anti-VEGF therapy - aflibercept or bevacizumab. Patients were switched to intravitreal brolucizumab. Four weeks post-injection, there was no significant change in visual acuity. Optical coherence tomography scans were taken and improved IRF/SRF, central macular thickness and average pericentral thickness were observed in all 6 patients. No serious adverse reactions were observed, including signs of vasculitis or increase in anterior chamber cell count at the 4-week follow-up for all 6 patients. CONCLUSION: Intravitreal brolucizumab appears to be a safe and limitedly effective option for patients with recalcitrant CNV from wet AMD.

Action of a minimal contractile bactericidal nanomachine.

R-type bacteriocins are minimal contractile nanomachines that hold promise as precision antibiotics1-4. Each bactericidal complex uses a collar to bridge a hollow tube with a contractile sheath loaded in a metastable state by a baseplate scaffold1,2. Fine-tuning of such nucleic acid-free protein machines for precision medicine calls for an atomic description of the entire complex and contraction mechanism, which is not available from baseplate structures of the (DNA-containing) T4 bacteriophage5. Here we report the atomic model of the complete R2 pyocin in its pre-contraction and post-contraction states, each containing 384 subunits of 11 unique atomic models of 10 gene products. Comparison of these structures suggests the following sequence of events during pyocin contraction: tail fibres trigger lateral dissociation of baseplate triplexes; the dissociation then initiates a cascade of events leading to sheath contraction; and this contraction converts chemical energy into mechanical force to drive the iron-tipped tube across the bacterial cell surface, killing the bacterium.

A case of Legionnaire's endophthalmitis.

Purpose: To report a case of endophthalmitis associated with Legionella Pneumophila . Case Report: A 46-year-old, highly myopic male with a complex history of recurrent retinal detachments, macular hole, cataract surgery and an infected scleral buckle in the left eye, presented with pain, redness, hypopyon and vision loss in the left eye, 14 days following blunt head trauma. Empirical treatment for endophthalmitis with intravitreal injections of Vancomycin and Ceftazidime afforded minimal improvement. He developed recurrent hypopyon and underwent vitrectomy surgery with intravitreal antibiotic injections at the time of surgery and had improvement. Intraoperative culture was positive for Legionella Pneumophila. He had continued episodes of recurrent inflammation which were quelled by intravitreal moxifloxacin injections performed every 3-10 days. He developed a recurrent RD with proliferative vitreoretinopathy (PVR) and underwent vitrectomy with silicone oil. The retina was reattached but had no light perception vision in the affected eye. Conclusion: When endophthalmitis is contracted in a work-place setting, a culture for L. pneumophila should be considered. A combination of intravitreal moxifloxacin and oral azithromycin may be effective.

Building atomic models based on near atomic resolution cryoEM maps with existing tools.

The EMDataBank Validation Challenge was a challenging task for students newly introduced to the cryoEM and molecular modeling fields. However, the competition provided an effective space for student modelers to discover and explore the potentials of atomic modeling and refinement by practicing on published atomic structures. Here, by employing manual molecular modeling programs such as Coot, Phenix, and Chimera, we have regularized and improved three targets. The T20S proteasome and TRPV1 ion channel allowed us to broaden our understanding of these modeling techniques while the 70S ribosome served as a challenge to test the limits of our abilities. We were successful in our efforts to improve each of the models and provide here our cohesive methodology for de novo modeling with and without homology models, which may serve as a starting point for other undergraduates and researchers just entering the realm of cryoEM. Additionally, we provide some constructive criticism to facilitate the introduction of said undergraduates and researchers into cryoEM in the future.