Purpose: To determine the prevalence and risk factors of exposure keratopathy (EK) across different intensive care units (ICU) at Columbia University Medical Center, including the Pediatric ICU (PICU), Medical ICU (MICU), and Neurologic ICU (NICU). Methods: In this prospective cohort study, 65 patients were examined daily during their admission in the PICU (27 patients), MICU (15 patients), and NICU (23 patients). Data on eyelid position, conjunctival and corneal changes, Bell's and blink reflexes, medications, Glasgow Coma Scale rating, and ventilation type were collected. Results: Overall EK percentages were as follows: PICU 19%, MICU 60%, and NICU 48%. The prevalence of EK was lowest in the PICU (P = 0.013). Factors associated with EK were lagophthalmos (P < 0.001), an absent Bell's reflex (P = 0.003), an absent blink reflex (P < 0.001), conjunctival injection (P < 0.001), a low Glasgow Coma Scale score (P < 0.001), intubation (P < 0.001), surgery before examination (P < 0.001), dialysis (P = 0.002), and administration of opioid (P < 0.001), sedative (P < 0.001), and neuromuscular blocking medications (P = 0.006). Conclusions: This is the first study to examine the rates and risk factors of EK across different ICU settings. The prevalence of EK was lowest in the PICU, which may partly be explained by the increased number of PICU patients receiving noninvasive ventilation and the absence of conjunctival chemosis.

It is widely believed that if a high number of genes are found for any tRNA in a rapidly replicating bacteria, then the cytoplasmic levels of that tRNA will be high and an open reading frame containing a higher frequency of the complementary codon will be translated faster. This idea is based on correlations between the number of tRNA genes, tRNA concentration and the frequency of codon usage observed in a limited number of strains as well as from the fact that artificially changing the number of tRNA genes alters translation efficiency and consequently the amount of properly folded protein synthesized. tRNA gene number may greatly vary in a genome due to duplications, deletions and lateral transfer which in turn would alter the levels and functionality of many proteins. Such changes are potentially deleterious for fitness and as a result it is expected that changes in tRNA gene numbers should be accompanied by a modification of the frequency of codon usage. In contrast to this model, when comparing the number of tRNA genes and the frequency of codon usage of several Salmonella enterica and Escherichia coli strains we found that changes in the number of tRNA genes are not correlated to changes in codon usage. Furthermore, these changes are not correlated with a change in the efficiency of codon translation. These results suggest that once a genome gains or loses tRNA genes, it responds by modulating the concentrations of tRNAs rather than modifying its frequency of codon usage.

Obstructive sleep apnea and TED have each been independently associated with elevated serologic and tissue inflammatory mediators. The systemic inflammation associated with OSA has been implicated in the pathogenesis of disease states aggravated by untreated OSA. Effective treatment of OSA decreases the levels of circulating inflammatory mediators. Currently, smoking is the only known modifiable risk factor in TED. There is evidence to implicate the pathologic elevation of inflammatory cytokines in the mechanism of smoking on TED. This preliminary investigation reveals a significantly greater prevalence of OSA risk factors among patients with TED-CON, suggesting that this may be another modifiable risk factor associated with TED. Based on screening with the STOP-Bang questionnaire, there is a higher percentage of patients at high risk of OSA with TED with CON than with TED without CON.

We report two cases of peripheral ulcerative keratitis (PUK) imaged with anterior segment optical coherence tomography (AS-OCT). The first patient had prolonged nonsteroidal anti-inflammatory drug use, while the second had inflammatory arthritis by laboratory findings without any systemic findings as well as possible concurrent tuberculosis. In both patients, AS-OCT demonstrated corneal thinning at the onset of the disease with improvement six months after initiation of intensive medical therapy. Our cases highlight the need for a multidisciplinary approach and careful monitoring in PUK cases, especially with objective measures such as corneal thickness assessed with AS-OCT.