Increased Incidence of Pseudotumor Cerebri Syndrome Among Users of Tetracycline Antibiotics.

BACKGROUND: To determine whether the use of a tetracycline-class antibiotic is associated with an increased risk of developing pseudotumor cerebri syndrome (PTCS). METHODS: We identified patients in the University of Utah Health system who were prescribed a tetracycline-class antibiotic and determined what percentage of those individuals were subsequently diagnosed with PTCS secondary to tetracycline use. We compared this calculation to the number of patients with PTCS unrelated to tetracycline use. RESULTS: Between 2007 and 2014, a total of 960 patients in the University system between the ages of 12 and 50 were prescribed a tetracycline antibiotic. Among those, 45 were diagnosed with tetracycline-induced PTCS. We estimate the incidence of tetracycline-induced PTCS to be 63.9 per 100,000 person-years. By comparison, the incidence of idiopathic intracranial hypertension (IIH) is estimated to be less than one per 100,000 person-years (Calculated Risk Ratio = 178). CONCLUSIONS: Although a causative link between tetracycline use and pseudotumor cerebri has yet to be firmly established, our study suggests that the incidence of pseudotumor cerebri among tetracycline users is significantly higher than the incidence of IIH in the general population.

Refractive Outcomes Using Intraoperative Aberrometry for Highly Myopic, Highly Hyperopic, and Post-refractive Eyes.

PURPOSE: To evaluate whether intraoperative aberrometry improves the accuracy of refractive outcomes after cataract surgery in highly myopic, highly hyperopic, and post-refractive eyes. METHODS: This single-center, retrospective review compared the spherical equivalent of postoperative refraction to that predicted by the Barrett Universal II formula versus Optiwave Refractive Analysis (ORA) (Alcon Laboratories, Inc) for highly myopic and hyperopic eyes and to the Barrett True K formula versus ORA for post-refractive eyes. The number and magnitude of lens changes were analyzed and used to determine in how many cases refractive surprises were affected by ORA, with additional subanalysis of outcomes based on average keratometry values. RESULTS: ORA led to a change in the lens power implanted in 48% (96 of 198) of eyes, and prevented hyperopic surprise in 27% (15 of 55) and excess myopia in 46% (19 of 41). Steeper keratometry values correlated with more frequent changes on ORA-recommended implanted intraocular lens (P = .0031). ORA led to a similar percentage of eyes falling within ±0.50, ±0.75, and ±1.00 diopters compared to the Barrett Universal II and Barrett True K formulas. In post-refractive eyes, ORA led to a similar mean absolute error when compared to the Barrett True K formula (P = .62). For highly myopic eyes with an axial length of greater than 27 mm, ORA demonstrated a trend toward lower mean absolute error when compared to the Barrett Universal II formula (P = .076). CONCLUSIONS: ORA demonstrated similar refractive results to the Barrett True K formula in post-refractive eyes and to the Barrett Universal II formula in highly myopic and hyper-opic eyes and may provide additional benefit for eyes with steeper corneas or an axial length of greater than 27 mm. [J Refract Surg. 2021;37(9):609-615.].

The reduction of serum soluble Flt-1 in patients with neovascular age-related macular degeneration.

PURPOSE: To evaluate serum soluble Flt-1 (sFlt-1) in age-related macular degeneration (AMD) patients. DESIGN: Case-control study. METHODS: Study involved 56 non-AMD participants, 53 early AMD patients, and 97 neovascular AMD patients from Belfast in Northern Ireland. Serum samples were collected from each patient. Serum sFlt-1 was measured by human sVEGFR1/sFlt-1 ELISA kit. The results were analyzed by Excel and SPSS. RESULTS: Serum sFlt-1 concentration of non-AMD, early AMD, and neovascular AMD were 90.8 ± 2.9 pg/mL (± standard error of the mean), 88.2 ± 2.6 pg/mL, and 79.9 ± 2.2 pg/mL. sFlt-1 from neovascular AMD patients was significantly decreased compared to non-AMD and early AMD patients (ANOVA, P < .01). For each 10-point increase in sFlt-1, the odds for having neovascular AMD compared with non-AMD and neovascular AMD decrease by 27.8%, odds ratio (OR) = 0.722 (95% confidence interval [CI]: 0.588-0.888, P = .002) and 27.0%, OR = 0.730 (95% CI: 0.594-0.898, P = .003), respectively. In patients over 73 years of age, serum sFlt-1 <80 pg/mL was associated with a >6-fold higher risk of neovascular AMD. CONCLUSIONS: Reduced serum sFlt-1 differentiates those patients with neovascular AMD from both early AMD and non-AMD participants. In those aged over 73, serum sFlt <80 pg/mL seems to indicate a particularly high risk of neovascular AMD. Our results indicate serum sFlt-1 could be a biomarker for development of neovascular AMD.

AAV2 delivery of Flt23k intraceptors inhibits murine choroidal neovascularization.

Long-term inhibition of extracellular vascular endothelial growth factor (VEGF) in the treatment of age-related macular degeneration (AMD) may induce retinal neuronal toxicity and risk other side effects. We developed a novel strategy which inhibits retinal pigment epithelium (RPE)-derived VEGF, sparing other highly sensitive retinal tissues. Flt23k, an intraceptor inhibitor of VEGF, was able to inhibit VEGF in vitro. Adeno-associated virus type 2 (AAV2)-mediated expression of Flt23k was maintained for up to 6 months postsubretinal injection in mice. Flt23k was able to effectively inhibit laser-induced murine choroidal neovascularization (CNV). VEGF levels in the RPE/choroid complex decreased significantly in AAV2.Flt23k treated eyes. Neither retinal structure detected by Heidelberg Spectralis nor function measured by electroretinography (ERG) was adversely affected by treatment with AAV2.Flt23k. Hence AAV2.Flt23k can effectively maintain long-term expression and inhibit laser-induced CNV in mice through downregulation of VEGF while maintaining a sound retinal safety profile. These findings suggest a promising novel approach for the treatment of CNV.

Mutations in 2 distinct genetic pathways result in cerebral cavernous malformations in mice.

Cerebral cavernous malformations (CCMs) are a common type of vascular malformation in the brain that are a major cause of hemorrhagic stroke. This condition has been independently linked to 3 separate genes: Krev1 interaction trapped (KRIT1), Cerebral cavernous malformation 2 (CCM2), and Programmed cell death 10 (PDCD10). Despite the commonality in disease pathology caused by mutations in these 3 genes, we found that the loss of Pdcd10 results in significantly different developmental, cell biological, and signaling phenotypes from those seen in the absence of Ccm2 and Krit1. PDCD10 bound to germinal center kinase III (GCKIII) family members, a subset of serine-threonine kinases, and facilitated lumen formation by endothelial cells both in vivo and in vitro. These findings suggest that CCM may be a common tissue manifestation of distinct mechanistic pathways. Nevertheless, loss of heterozygosity (LOH) for either Pdcd10 or Ccm2 resulted in CCMs in mice. The murine phenotype induced by loss of either protein reproduced all of the key clinical features observed in human patients with CCM, as determined by direct comparison with genotype-specific human surgical specimens. These results suggest that CCM may be more effectively treated by directing therapies based on the underlying genetic mutation rather than treating the condition as a single clinical entity.

Targeting Robo4-dependent Slit signaling to survive the cytokine storm in sepsis and influenza.

The innate immune system provides a first line of defense against invading pathogens by releasing multiple inflammatory cytokines, such as interleukin-1beta and tumor necrosis factor-alpha, which directly combat the infectious agent and recruit additional immune responses. This exuberant cytokine release paradoxically injures the host by triggering leakage from capillaries, tissue edema, organ failure, and shock. Current medical therapies target individual pathogens with antimicrobial agents or directly either blunt or boost the host's immune system. We explored a third approach: activating with the soluble ligand Slit an endothelium-specific, Robo4-dependent signaling pathway that strengthens the vascular barrier, diminishing deleterious aspects of the host's response to the pathogen-induced cytokine storm. This approach reduced vascular permeability in the lung and other organs and increased survival in animal models of bacterial endotoxin exposure, polymicrobial sepsis, and H5N1 influenza. Thus, enhancing the resilience of the host vascular system to the host's innate immune response may provide a therapeutic strategy for treating multiple infectious agents.