Outcomes of Zone 3 Open Globe Injuries by Wound Extent: Subcategorization of Zone 3 Injuries Segregates Visual and Anatomic Outcomes.

PURPOSE: Open globe injuries (OGIs) are categorized by zone, with zone 3 (Z3) comprising wounds > 5 mm beyond the limbus. Outcomes of Z3 OGIs are highly heterogeneous. Open globe injuries with far posterior Z3 (pZ3) wounds were hypothesized to have worse visual and anatomic outcomes. DESIGN: Single-center retrospective cohort study. PARTICIPANTS: A total of 258 eyes with Z3 OGIs. METHODS: A retrospective review of Z3 OGIs treated at a tertiary center over 12 years. Wounds ≥ 10 mm posterior to the limbus were defined as pZ3. Outcomes were compared between pZ3 and anterior Z3 (aZ3) eyes. MAIN OUTCOME MEASURES: Visual acuity on a logarithm of the minimum angle of resolution (logMAR) scale. Secondary outcomes included anatomic outcomes, development of retinal detachment and proliferative vitreoretinopathy, and the number of secondary surgeries. RESULTS: A total of 258 Z3 OGI eyes with > 30 days follow-up were assessed; 161 (62%) were pZ3. At 3-month follow-up, pZ3 OGIs were more likely to exhibit no light perception (pZ3: 38%; aZ3: 17%; P < 0.003), lack count fingers vision (pZ3: 72%; aZ3: 43%; P < 0.002), and fail to read a letter on the eye chart (pZ3: 83%; aZ3: 64%; P < 0.001). The visual acuity distribution at 3 months was significantly worse for pZ3 compared with aZ3 injuries (P < 0.004). Similar results were found at final follow-up. Multiple linear regression showed that pZ3 location was independently associated with worse visual acuity (ß = 0.29, 95% confidence interval [CI], 0.09-0.50, P < 0.006) in addition to presenting acuity, age, vitreous hemorrhage, uveal prolapse, and afferent pupillary defect. Far posterior wounds injuries were more likely to develop retinal detachments (pZ3: 87%; aZ3: 71%; P < 0.01) and proliferative vitreoretinopathy (pZ3 66%; aZ3 47%; P < 0.03). Patients with pZ3 OGIs were significantly more likely to reach poor anatomic outcome (phthisis, enucleation, need for keratoprosthesis) compared with patients with aZ3 OGI (pZ3: 56%; aZ3: 40%; P < 0.03). CONCLUSIONS: Posterior OGI extension independently portends worse visual and anatomic outcomes. The effect on visual outcome was durable and clinically relevant compared with established predictors of OGI outcomes. Application of these findings improves the prognostic precision and will guide future research efforts to optimize surgical decision-making in severe OGI cases. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Androgen-sensitive hypertension associated with soluble guanylate cyclase-α1 deficiency is mediated by 20-HETE.

Dysregulated nitric oxide (NO) signaling contributes to the pathogenesis of hypertension, a prevalent and often sex-specific risk factor for cardiovascular disease. We previously reported that mice deficient in the α1-subunit of the NO receptor soluble guanylate cyclase (sGCα1 (-/-) mice) display sex- and strain-specific hypertension: male but not female sGCα1 (-/-) mice are hypertensive on an 129S6 (S6) but not a C57BL6/J (B6) background. We aimed to uncover the genetic and molecular basis of the observed sex- and strain-specific blood pressure phenotype. Via linkage analysis, we identified a suggestive quantitative trait locus associated with elevated blood pressure in male sGCα1 (-/-)S6 mice. This locus encompasses Cyp4a12a, encoding the predominant murine synthase of the vasoconstrictor 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE). Renal expression of Cyp4a12a in mice was associated with genetic background, sex, and testosterone levels. In addition, 20-HETE levels were higher in renal preglomerular microvessels of male sGCα1 (-/-)S6 than of male sGCα1 (-/-)B6 mice. Furthermore, treating male sGCα1 (-/-)S6 mice with the 20-HETE antagonist 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE) lowered blood pressure. Finally, 20-HEDE rescued the genetic background- and testosterone-dependent impairment of acetylcholine-induced relaxation in renal interlobar arteries associated with sGCα1 deficiency. Elevated Cyp4a12a expression and 20-HETE levels render mice susceptible to hypertension and vascular dysfunction in a setting of sGCα1 deficiency. Our data identify Cyp4a12a as a candidate sex-specific blood pressure-modifying gene in the context of deficient NO-sGC signaling.

Deletion of the murine cytochrome P450 Cyp2j locus by fused BAC-mediated recombination identifies a role for Cyp2j in the pulmonary vascular response to hypoxia.

Epoxyeicosatrienoic acids (EETs) confer vasoactive and cardioprotective functions. Genetic analysis of the contributions of these short-lived mediators to pathophysiology has been confounded to date by the allelic expansion in rodents of the portion of the genome syntenic to human CYP2J2, a gene encoding one of the principle cytochrome P450 epoxygenases responsible for the formation of EETs in humans. Mice have eight potentially functional genes that could direct the synthesis of epoxygenases with properties similar to those of CYP2J2. As an initial step towards understanding the role of the murine Cyp2j locus, we have created mice bearing a 626-kb deletion spanning the entire region syntenic to CYP2J2, using a combination of homologous and site-directed recombination strategies. A mouse strain in which the locus deletion was complemented by transgenic delivery of BAC sequences encoding human CYP2J2 was also created. Systemic and pulmonary hemodynamic measurements did not differ in wild-type, null, and complemented mice at baseline. However, hypoxic pulmonary vasoconstriction (HPV) during left mainstem bronchus occlusion was impaired and associated with reduced systemic oxygenation in null mice, but not in null mice bearing the human transgene. Administration of an epoxygenase inhibitor to wild-type mice also impaired HPV. These findings demonstrate that Cyp2j gene products regulate the pulmonary vascular response to hypoxia.

Asymmetric Deep Stromal Keratopathy in a Patient With Multiple Myeloma.

PURPOSE: To report a case of asymmetric deep stromal keratopathy in a patient with multiple myeloma. METHODS: Case report and literature review. RESULTS: An 85-year-old woman was found to have progressive visually significant left-sided deep stromal opacity in the setting of monoclonal gammopathy. Hematologic workup resulted in a diagnosis of IgG kappa multiple myeloma. Histopathology was significant for semicrystalline deposits in the posterior stroma. The patient's visual acuity improved to 20/50 7 months after penetrating keratoplasty. A similar deep stromal lesion appeared in the right eye 2 years after initial presentation. CONCLUSIONS: We present an unusual case of paraproteinemic keratopathy with a uniquely asymmetric presentation that resulted in a diagnosis of multiple myeloma.

Weight loss, saline loading, and the natriuretic peptide system.

BACKGROUND: In epidemiologic studies, obesity has been associated with reduced natriuretic peptide (NP) concentrations. Reduced NP production could impair the ability of obese individuals to respond to salt loads, increasing the risk of hypertension and other disorders. We hypothesized that weight loss enhances NP production before and after salt loading. METHODS AND RESULTS: We enrolled 15 obese individuals (mean BMI 45±5.4 kg/m(2)) undergoing gastric bypass surgery. Before and 6 months after surgery, subjects were admitted to the clinical research center and administered a large-volume intravenous saline challenge. Echocardiography and serial blood sampling were performed. From the pre-operative visit to 6 months after surgery, subjects had a mean BMI decrease of 27%. At the 6-month visit, N-terminal pro-atrial NP (Nt-proANP) levels were 40% higher before, during, and after the saline infusion, compared with levels measured at the same time points during the pre-operative visit (P<0.001). The rise in Nt-pro-ANP induced by the saline infusion (≈50%) was similar both before and after surgery (saline, P<0.001; interaction, P=0.2). Similar results were obtained for BNP and Nt-proBNP; resting concentrations increased by 50% and 31%, respectively, after gastric bypass surgery. The increase in NP concentrations after surgery was accompanied by significant decreases in mean arterial pressure (P=0.004) and heart rate (P<0.001), and an increase in mitral annular diastolic velocity (P=0.02). CONCLUSION: In obese individuals, weight loss is associated with a substantial increase in the "setpoint" of circulating NP concentrations. Higher NP concentrations could contribute to an enhanced ability to handle salt loads after weight loss.

Soluble guanylate cyclase α1-deficient mice: a novel murine model for primary open angle glaucoma.

Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide. The molecular signaling involved in the pathogenesis of POAG remains unknown. Here, we report that mice lacking the α1 subunit of the nitric oxide receptor soluble guanylate cyclase represent a novel and translatable animal model of POAG, characterized by thinning of the retinal nerve fiber layer and loss of optic nerve axons in the context of an open iridocorneal angle. The optic neuropathy associated with soluble guanylate cyclase α1-deficiency was accompanied by modestly increased intraocular pressure and retinal vascular dysfunction. Moreover, data from a candidate gene association study suggests that a variant in the locus containing the genes encoding for the α1 and ß1 subunits of soluble guanylate cyclase is associated with POAG in patients presenting with initial paracentral vision loss, a disease subtype thought to be associated with vascular dysregulation. These findings provide new insights into the pathogenesis and genetics of POAG and suggest new therapeutic strategies for POAG.

Atrial natriuretic peptide is negatively regulated by microRNA-425.

Numerous common genetic variants have been linked to blood pressure, but no underlying mechanism has been elucidated. Population studies have revealed that the variant rs5068 (A/G) in the 3' untranslated region of NPPA, the gene encoding atrial natriuretic peptide (ANP), is associated with blood pressure. We selected individuals on the basis of rs5068 genotype (AG vs. AA) and fed them a low- or high-salt diet for 1 week, after which they were challenged with an intravenous saline infusion. On both diets, before and after saline administration, ANP levels were up to 50% higher in AG individuals than in AA individuals, a difference comparable to the changes induced by high-salt diet or saline infusion. In contrast, B-type natriuretic peptide levels did not differ by rs5068 genotype. We identified a microRNA, miR-425, that is expressed in human atria and ventricles and is predicted to bind the sequence spanning rs5068 for the A, but not the G, allele. miR-425 silenced NPPA mRNA in an allele-specific manner, with the G allele conferring resistance to miR-425. This study identifies miR-425 as a regulator of ANP production, raising the possibility that miR-425 antagonists could be used to treat disorders of salt overload, including hypertension and heart failure.

Genetic modifiers of hypertension in soluble guanylate cyclase α1-deficient mice.

Nitric oxide (NO) plays an essential role in regulating hypertension and blood flow by inducing relaxation of vascular smooth muscle. Male mice deficient in a NO receptor component, the α1 subunit of soluble guanylate cyclase (sGCα1), are prone to hypertension in some, but not all, mouse strains, suggesting that additional genetic factors contribute to the onset of hypertension. Using linkage analyses, we discovered a quantitative trait locus (QTL) on chromosome 1 that was linked to mean arterial pressure (MAP) in the context of sGCα1 deficiency. This region is syntenic with previously identified blood pressure-related QTLs in the human and rat genome and contains the genes coding for renin. Hypertension was associated with increased activity of the renin-angiotensin-aldosterone system (RAAS). Further, we found that RAAS inhibition normalized MAP and improved endothelium-dependent vasorelaxation in sGCα1-deficient mice. These data identify the RAAS as a blood pressure-modifying mechanism in a setting of impaired NO/cGMP signaling.