J. Hillenkamp

Selective retina therapy for acute central serous chorioretinopathy

Aims To evaluate selective retina therapy (SRT) as a treatment of acute central serous chorioretinopathy. Methods 30 eyes of 30 patients with central serous chorioretinopathy of at least a 3u2005months duration were recruited. 14 eyes were randomised to an SRT group (Q-switched neodymium-doped yttrium lithium fluoride (Nd:YLF) laser, wavelength 527u2005nm, t=1.7u2005μs, energy 100–370u2005μJ, spot diameter 200u2005μm, pulse repetition rate 100u2005Hz,) and 16 eyes to a control group. After 3u2005months of follow-up, patients in the control group with persistence of subretinal fluid (SRF) were allocated to a cross-over group, treated with SRT and followed up for further 3u2005months. The main outcome measures were change of best-corrected Early Treatment Diabetic Retinopathy Study visual acuity (BCVA) and SRF. Results At 3u2005months of follow-up, the mean (SD) improvement of BCVA was significantly greater after SRT than in the control group: 12.7 (7.2) versus 6.3 (8.9) letters (p=0.04). SRF had decreased significantly more after SRT as compared with that the control group: 203 (136)u2005μm versus 41 (150)u2005μm (p=0.005). In eight eyes allocated to the cross-over group, the mean BCVA had increased during 3u2005months of follow up before SRT by 1.4 (5.2) letters and continued to increase during 3u2005months following SRT by 7.4 (6.3) letters, while SRF increased by 39.5 (160.2)u2005μm before SRT and decreased by 151.5 (204.9)u2005μm after SRT. In six of the eight eyes, SRF had completely resolved 3u2005months after SRT. Conclusions SRT appears to expedite functional recovery and the re-absorption of SRF as compared with that in untreated controls. A larger prospective, randomised phase 3 confirmative patient study is warranted. Trial registration number NCT00987077

Vectorial release of matrix metalloproteinases (MMPs) from porcine RPE-choroid explants following selective retina therapy (SRT): towards slowing the macular ageing process.

The purpose of this study was to investigate release of matrix metalloproteinases (MMP) 2 and 9 during retinal pigment epithelium (RPE) wound healing after Selective Retina Therapy (SRT) with laser energy levels below and above the threshold of RPE cell death. Following exposure to SRT using a prototype pulsed Nd:YLF laser with energies of 80-180 mJ/cm(2) fresh porcine RPE-monolayers with Bruchs membrane and choroid were cultured in modified Ussing chambers which separate the apical (RPE-facing) and basal (choroid facing) sides of the RPE monolayer. Threshold energy for RPE cell death and wound healing were determined with calcein-AM viability test. Inactive and active forms of MMP 2 and 9 were quantified within tissue samples and in the culture medium of the apical and basal compartments of the Ussing chamber using gelatine zymography. Laser energies of 160-180 mJ/cm(2) resulted in cell death within 1 h while 120-140 mJ/cm(2) resulted in delayed death of exposed RPE cells. All cells survived 80 and 100 mJ/cm(2). Laser spots healed within 6 days after SRT accompanied by a transient vectorial increase of MMPs. SRT with 180 mJ/cm(2) increased active MMP 2 by 1.9 (p < 0.05) and 1.6 (p < 0.05) fold in tissue and basal compartments, respectively, without alterations in the apical compartment. Pro-MMP 2 levels were also significantly increased in all compartments (p < 0.05). Release of MMP 9 was not altered. Laser energy below the threshold of RPE cell death did not alter the release of MMP 2 or 9. The findings suggest that the release of active MMP 2 on the basal side of the RPE during wound healing following SRT may address age-related pathological changes of Bruchs membrane with a potential to slow degenerative macular ageing processes before irreversible functional loss has occurred.

Compatibility of recombinant tissue plasminogen activator (rtPA) and aflibercept or ranibizumab coapplied for neovascular age-related macular degeneration with submacular haemorrhage

Background/aims Subretinal coapplication of recombinant tissue plasminogen activator (rtPA) and vascular endothelial growth factor (VEGF)-antagonists is a new treatment option for age-related macular degeneration complicated by submacular haemorrhage. Here, we investigate the compatibility of rtPA and aflibercept or ranibizumab in vitro because intraoperatively, rtPA or rtPA-induced plasmin may cleave aflibercept or ranibizumab. Methods Aflibercept and ranibizumab, respectively, were incubated with rtPA or plasmin, separated in gel electrophoresis and stained with Coomassie or silver. The antiangiogenic activity of the VEGF-antagonists was quantified by VEGF-ELISA after incubation with the supernatant of primary porcine retinal pigment epithelium cell cultures. Results In electrophoresis, ranibizumab displayed no additional fragments when it was coapplied with rtPA or plasmin. Its VEGF-inhibiting efficacy remained unchanged in coapplication with rtPA with or without blood, or plasmin. rtPA did not cleave or functionally compromise aflibercept. When aflibercept was coapplied with plasmin, electrophoresis displayed additional bands in Coomassie (30u2005kDa, 27u2005kDa, 19u2005kDa, 15u2005kDa) and silver staining (31u2005kDa, 26u2005kDa, 21u2005kDa, 19u2005kDa, 15u2005kDa). While at a clinical dosage (800u2005µg/mL) VEGF was inhibited by aflibercept when coapplied with plasmin, at borderline concentrations (400u2005ng/mL) VEGF-binding ability of aflibercept was abolished. Conclusions Ranibizumab is not cleaved or functionally compromised by rtPA or plasmin. Aflibercept is cleaved and its VEGF-binding ability is reduced when coapplied with plasmin. In clinical practice, rtPA and ranibizumab can be coapplied as a treatment for neovascular age-related macular degeneration with submacular haemorrhage while the antiangiogenic activity of aflibercept may be compromised when coapplied with rtPA in the presence of plasmin.

Vision loss under silicone oil tamponade

PurposeWe aimed to investigate frequency, time course and pathophysiology of vision loss in eyes with macula-on rhegmatogenous retinal detachment operated with vitrectomy and silicone oil tamponade.Patients and methodsFifteen eyes of 15 patients who had been operated with 5,000 centistoke silicone oil between 2006 and 2014 were included in a retrospective case series. Examinations included logMAR best corrected visual acuity (BCVA), visual field testing (VF), spectral domain optical coherence tomography (OCT), electrophysiology, and fluorescein angiography.ResultsVision loss was seen in eight (53xa0%) eyes of 15 patients with symptomatic central scotoma, which was confirmed by VF (5/6). Preoperative median BCVA of these patients was 0.15 (0.5 to 0), prior to oil removal 0.7 (1.0 to 0.5), and 6xa0weeks post oil removal 1.0 (1.5 to 0.2). BCVA recovered in five patients to a median of 0.15 (0.5 to 0.1), and it remained 1.0 in three (20xa0%) out of 15 eyes. OCT revealed significant thinning of the foveal and parafoveal combined nerve fiber, ganglion cell and inner plexiform layers in affected eyes (mean 58.3xa0μm +/−13, horizontal scan through fovea, 500xa0μm radius) compared to their healthy fellow eyes (mean 84.5xa0μm +/−12.3; pu2009<u20090.01, nu2009=u20096 patients, 12 eyes) and compared to eyes with no vision loss under silicone oil.ConclusionsWe find persisting vision loss in three out of 15 patients treated for macula-on rhegmatogenous retinal detachment with silicone oil tamponade. Thinning of inner retinal layers possibly evoked by silicone oil tamponade might be a pathophysiological explanation for vision loss in these patients.

Hyperthermia-induced upregulation of vascular endothelial growth factor in retinal pigment epithelial cells is regulated by mitogen-activated protein kinases

PurposeLocalized application of hyperthermia is a potential treatment for retinal diseases. Vascular endothelial growth factor (VEGF) derived from the retinal pigment epithelium (RPE) is implicated in a variety of retinal pathologies. As it has been recently shown that hyperthermia may induce VEGF in the RPE, the aim of this study was to investigate hyperthermia-induced VEGF secretion and the pathways of hyperthermal VEGF upregulation in the RPE.Material and methodsThe human RPE cell line (Arpe-19) was exposed to 40°, 42°, 45° and 50xa0°C for one, five and 15xa0min. Cell viability was evaluated using a trypan blue exclusion assay, VEGF secretion was evaluated by an enzyme-linked immunosorbent assay ELISA) and VEGF expression was investigated using a Western blot. Involvement of mitogen-activated protein kinase (MAPK) pathways (ERK1/2, JNK, p38) and transient receptor potential vanilloid (TRPV) channels on VEGF induction was investigated using commercially available inhibitors (U0126, SB203580, SP600125, ruthenium red). Expression and phosphorylation of MAPKs was investigated using a Western blot.ResultsHyperthermia induces time- and temperature-dependent cell death in human RPE cells. VEGF expression and secretion is induced by hyperthermia in a time- and temperature-dependent manner mediated by p38 and to a lesser degree by JNK. TRPV channels seem to play a minor role in regulation of hyperthermia-induced VEGF secretion.ConclusionsHyperthermia induces temperature-dependent secretion of VEGF in the RPE, which is mediated by p38 and, to a lesser extent, JNK. This may lead to undesired effects from hyperthermal treatment of retinal diseases.

The role of pigment epithelial detachment in AMD with submacular hemorrhage treated with vitrectomy and subretinal co-application of rtPA and anti-VEGF

PurposeTo assess the incidence of pigment epithelial detachment (PED) in age-related macular degeneration (AMD) with submacular hemorrhage (SMH) and its response to treatment with pars plana vitrectomy (ppV), subretinal co-application of recombinant tissue plasminogen activator (rtPA) and anti-VEGF, and an intravitreal gas tamponade.MethodsConsecutive interventional case series of 132 eyes of 129 patients with neovascular AMD with SMH. All eyes underwent ppV with subretinal co-application of rtPA and bevacizumab followed by a gas tamponade. Postoperatively, two additional intravitreal anti-VEGF injections were applied monthly, followed by intravitreal anti-VEGF injections applied PRN thereafter. PEDs and SMHs were evaluated with SD-OCT pre- and postoperatively.ResultsPreoperatively, 88 of 132 (67%) eyes were examined by OCT, and in 81 of these eyes the RPE could be visualised. A PED was found in 74 (91%) eyes, and no PED was found in five (6%) eyes. Median height of preoperative PED was 503xa0μm (range 150–1242, nu2009=u200965) and reduced to 344 (nu2009=u200962) and 306xa0μm (nu2009=u200927) after 3 and 12xa0months respectively. Two eyes showed a pre-existing rip of the RPE. Postoperatively, a rip was documented in 12 of 128 (9%) eyes. Median height of SMH was 762xa0μm (range 217–1840), median diameter was 4.3 (1.5-15) disc diameter. A complete displacement of the SMH from the fovea was achieved in 112 of 129 (87%) eyes. Overall, median best-corrected logMAR visual acuity (BCVA) improved significantly from preoperative 1.6 (0.5–2.0, nu2009=u2009132) to 1.0 (0.2–2.0) 3 (nu2009=u2009132) and 12xa0months (nu2009=u200974) postoperatively. Excluding eyes with pre-existing macular scars (nu2009=u200922), BCVA 3xa0months postoperatively was 0.8. Height of PED or SMH did not correlate with postoperatively BCVA, while size of SMH showed a mild correlation (rhou2009=u20090.25, pu2009=u20090.005).ConclusionPpV with subretinal co-application of rtPA and bevacizumab and an intravitreal gas tamponade effectively displaces SMH and improves BCVA. Preoperatively, PED is found in the majority of eyes. Height of PED or SMH did not correlate with postoperatively BCVA. Tears of the RPE occur as frequently as in exudative AMD without SMH.