Scleral buckling surgery for rhegmatogenous retinal detachment with subretinal proliferation

PurposeTo evaluate the outcome of scleral buckling surgery in patients with rhegmatogenous retinal detachment (RRD) with subretinal proliferation.MethodsIn this retrospective study, a chart review of all patients with RRD associated with subretinal proliferation who were primarily treated with scleral buckling procedure, from April 2007 to April 2014, was undertaken. Main outcome measures were anatomical retinal reattachment and visual acuity.ResultsForty-four eyes of 43 patients including 24 males and 19 females with a mean age of 26.5±13.1 years were evaluated. Immediately after the surgery, retina was reattached in all eyes. However, five eyes (11.3) needed additional surgery for retinal redetachment. Single surgery anatomical success rate was 88.7. Four eyes (9.1), needed pars plana vitrectomy for the treatment of redetachment associated with proliferative vitreoretinopathy and scleral buckle revision surgery was successfully performed in the other eye. Best corrected visual acuity improved from 1.5±0.9 logMAR before surgery to 1.1±0.7 logMAR after surgery (P2 lines was found in 23 eyes (52.2) and worsening of best corrected visual acuity of >2 lines was observed in 2 eyes (4.5).ConclusionsScleral buckling surgery is highly successful in eyes with RRD associated with subretinal proliferation. © 2015 Macmillan Publishers Limited All rights reserved

Activation of Kv7 channels as a novel mechanism for NO/cGMP‐induced pulmonary vasodilation

[Background and Purpose]: The NO/cGMP pathway represents a major physiological signalling controlling tone in pulmonary arteries (PA), and drugs activating this pathway are used to treat pulmonary arterial hypertension. Kv channels expressed in PA smooth muscle cells (PASMCs) are key determinants of vascular tone. We aimed to analyse the contribution of Kv1.5 and Kv7 channels in the electrophysiological and vasodilating effects evoked by NO donors and the GC stimulator riociguat in PA.[Experimental Approach]: Kv currents were recorded in isolated rat PASMCs using the patch‐clamp technique. Vascular reactivity was assessed in a wire myograph.[Key Results]: The NO donors diethylamine NONOate diethylammonium (DEA‐NO) and sodium nitroprusside hyperpolarized the membrane potential and induced a bimodal effect on Kv currents (augmenting the current between −40 and −10 mV and decreasing it at more depolarized potentials). The hyperpolarization and the enhancement of the current were suppressed by Kv7 channel inhibitors and by the GC inhibitor ODQ but preserved when Kv1.5 channels were inhibited. Additionally, DEA‐NO enhanced Kv7.5 currents in COS7 cells expressing the KCNQ5 gene. Riociguat increased Kv currents at all potentials ≥−40 mV and induced membrane hyperpolarization. Both effects were prevented by Kv7 inhibition. Likewise, PA relaxation induced by NO donors and riociguat was attenuated by Kv7 inhibitors.[Conclusions and Implications]: NO donors and riociguat enhance Kv7 currents, leading to PASMC hyperpolarization. This mechanism contributes to NO/cGMP‐induced PA vasodilation. Our study identifies Kv7 channels as a novel mechanism of action of vasodilator drugs used in the treatment of pulmonary arterial hypertension.This work was funded by Ministerio de Economía y Competitividad grants (SAF2016‐77222R to F.P.‐V. and A.C. and SAF2016‐75021‐R to C.V. and T.G.), the Cardiovascular Medical Research and Education Fund (A.C.), Fundación Contra la Hipertensión Pulmonar‐EMPATHY, Comunidad de Madrid (B2017/BMD‐3727 to A.C. and L.M.), and Instituto de Salud Carlos III (PI15/01100 to L.M. and CB/11/00222 to C.V.) with funds from the European Union (Fondo Europeo de Desarrollo Regional FEDER). G.M.‐P., M.C., and S.E.‐R. are supported by CIBERES, Universidad Complutense and FPU grants.Peer reviewe