Head-down Posture Induces PERG Alterations in Early Glaucoma

PURPOSE: To probe susceptibility of retinal ganglion cells (RGC) to physiological stressors associated with moderate head-down body tilt in patients with suspicion of glaucoma or early manifest glaucoma. METHODS: One hundred nine subjects with best corrected visual acuity ≥20/20 and no disease other than glaucoma (glaucoma suspects, GS= 79, early manifest glaucoma, EMG=14, normal controls, NC= 16) and comparable age range were tested. Non-contact IOP, pattern electroretinogram (PERG), and brachial blood pressure/heart rate measurements were performed in three consecutive (~8 minutes apart) conditions: seated (baseline), −10 deg whole body head-down (HDT), and seated again (recovery). PERG amplitude and latency, IOP, and systolic/diastolic blood pressures, heart rate, calculated mean central retinal artery pressure, ocular perfusion pressure, and systolic/diastolic perfusion pressures were evaluated. RESULTS: During HDT, IOP significantly (P<0.001) increased in all groups approximately to the same extent (~20%). PERG amplitude did not change in NC but decreased significantly (P<0.001) in patients (GS, −25%, EMG −23%). PERG phase become delayed in NC (− 1.6%, P=0.04) but more so in patients (GS, −2.7%, P<0.001; EMG, −6.0%, P<0.001). The proportion of patients with PERG alterations significantly (P<0.05) exceeding those occurring in age- and baseline-adjusted NC were, GS: amplitude 20%, phase 15%; EMG: amplitude 14%, phase 50%. All measures recovered baseline values after HDT. CONCLUSIONS: Moderate HDT induces temporary worsening of RGC function in a subpopulation of GS and EMG patients. This non-invasive protocol may help disclose abnormal susceptibility of RGCs in a subset of the patients at risk of glaucoma

Mechanisms and treatment of organ failure in sepsis.

Sepsis is a dysregulated immune response to an infection that leads to organ dysfunction. Knowledge of the pathophysiology of organ failure in sepsis is crucial for optimizing the management and treatment of patients and for the development of potential new therapies. In clinical practice, six major organ systems - the cardiovascular (including the microcirculation), respiratory, renal, neurological, haematological and hepatic systems - can be assessed and monitored, whereas others, such as the gut, are less accessible. Over the past 2 decades, considerable amounts of new data have helped improve our understanding of sepsis pathophysiology, including the regulation of inflammatory pathways and the role played by immune suppression during sepsis. The effects of impaired cellular function, including mitochondrial dysfunction and altered cell death mechanisms, on the development of organ dysfunction are also being unravelled. Insights have been gained into interactions between key organs (such as the kidneys and the gut) and organ-organ crosstalk during sepsis. The important role of the microcirculation in sepsis is increasingly apparent, and new techniques have been developed that make it possible to visualize the microcirculation at the bedside, although these techniques are only research tools at present.SCOPUS: re.jinfo:eu-repo/semantics/publishe