Referable Macular Hemorrhage-A Clinically Meaningful Screening Target in Newborn Infants. Position Statement of the Association of Pediatric Retina Surgeons.

Universal newborn eye screening facilitates early diagnosis of ocular abnormalities and mitigates vision loss. "Referral warranted" eye disease is present at birth in about 5.5% of term infants, with "macular hemorrhage impinging on the fovea" representing about 50% of referral warranted disease. The Association of Pediatric Retina Surgeons held a symposium on February 9, 2021 that culminated in a position statement on "referable macular hemorrhage" (RMH) in newborn infants. RMH is meaningful in that in can cause amblyopia through deprivation, can be readily captured with wide-angle photography in a safe and efficient manner, and may lead to early intervention with mitigation of vision loss. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:3-6.].

TREK-1 channels regulate pressure sensitivity and calcium signaling in trabecular meshwork cells.

Mechanotransduction by the trabecular meshwork (TM) is an essential component of intraocular pressure regulation in the vertebrate eye. This process is compromised in glaucoma but is poorly understood. In this study, we identify transient receptor potential vanilloid isoform 4 (TRPV4) and TWIK-related potassium channel-1 (TREK-1) as key molecular determinants of TM membrane potential, pressure sensitivity, calcium homeostasis, and transcellular permeability. We show that resting membrane potential in human TM cells is unaffected by "classical" inhibitors of voltage-activated, calcium-activated, and inwardly rectifying potassium channels but is depolarized by blockers of tandem-pore K+ channels. Using gene profiling, we reveal the presence of TREK-1, TASK-1, TWIK-2, and THIK transcripts in TM cells. Pressure stimuli, arachidonic acid, and TREK-1 activators hyperpolarize these cells, effects that are antagonized by quinine, amlodipine, spadin, and short-hairpin RNA-mediated knockdown of TREK-1 but not TASK-1. Activation and inhibition of TREK-1 modulates [Ca2+]TM and lowers the impedance of cell monolayers. Together, these results suggest that tensile homeostasis in the TM may be regulated by balanced, pressure-dependent activation of TRPV4 and TREK-1 mechanotransducers.

Patient question-asking about glaucoma and glaucoma medications during videotaped medical visits.

We applied the ecologic model of communication in medical consultations to examine how patient, physician, and situational/contextual factors are associated with whether patients ask one or more questions about glaucoma and glaucoma medications during visits to ophthalmologists. Patients with glaucoma who were newly prescribed or already on glaucoma medications were recruited at six ophthalmology clinics. Patients' visits with their doctors were video-recorded and patients were interviewed after visits. Generalized estimating equations were used to analyze the data. Two hundred and seventy-nine patients participated. Patients asked one or more questions about glaucoma during 59% of visits and about glaucoma medications during 48% of visits. Patients who were newly prescribed glaucoma medications were significantly more likely to ask one or more questions about glaucoma and glaucoma medications. Whether providers asked patients if they had questions was not significantly associated with patient question-asking. Patients were significantly more likely to ask older providers questions about glaucoma medications and female providers questions about glaucoma. Eye care providers should encourage glaucoma patients to ask questions during their medical visits.

Orientation of endothelial cell division is regulated by VEGF signaling during blood vessel formation.

New blood vessel formation requires the coordination of endothelial cell division and the morphogenetic movements of vessel expansion, but it is not known how this integration occurs. Here, we show that endothelial cells regulate division orientation during the earliest stages of blood vessel formation, in response to morphogenetic cues. In embryonic stem (ES) cell-derived vessels that do not experience flow, the plane of endothelial cytokinesis was oriented perpendicular to the vessel long axis. We also demonstrated regulated cleavage orientation in vivo, in flow-exposed forming retinal vessels. Daughter nuclei moved away from the cleavage plane after division, suggesting that regulation of endothelial division orientation effectively extends vessel length in these developing vascular beds. A gain-of-function mutation in VEGF signaling increased randomization of endothelial division orientation, and this effect was rescued by a transgene, indicating that regulation of division orientation is a novel mechanism whereby VEGF signaling affects vessel morphogenesis. Thus, our findings show that endothelial cell division and morphogenesis are integrated in developing vessels by flow-independent mechanisms that involve VEGF signaling, and this cross talk is likely to be critical to proper vessel morphogenesis.