Salvatore Grisanti

CCR3 is a target for age-related macular degeneration diagnosis and therapy.

Age-related macular degeneration (AMD), a leading cause of blindness worldwide, is as prevalent as cancer in industrialized nations. Most blindness in AMD results from invasion of the retina by choroidal neovascularisation (CNV). Here we show that the eosinophil/mast cell chemokine receptor CCR3 is specifically expressed in choroidal neovascular endothelial cells in humans with AMD, and that despite the expression of its ligands eotaxin-1, -2 and -3, neither eosinophils nor mast cells are present in human CNV. Genetic or pharmacological targeting of CCR3 or eotaxins inhibited injury-induced CNV in mice. CNV suppression by CCR3 blockade was due to direct inhibition of endothelial cell proliferation, and was uncoupled from inflammation because it occurred in mice lacking eosinophils or mast cells, and was independent of macrophage and neutrophil recruitment. CCR3 blockade was more effective at reducing CNV than vascular endothelial growth factor A (VEGF-A) neutralization, which is in clinical use at present, and, unlike VEGF-A blockade, is not toxic to the mouse retina. In vivo imaging with CCR3-targeting quantum dots located spontaneous CNV invisible to standard fluorescein angiography in mice before retinal invasion. CCR3 targeting might reduce vision loss due to AMD through early detection and therapeutic angioinhibition.

Safety, penetration and efficacy of topically applied bevacizumab: evaluation of eyedrops in corneal neovascularization after chemical burn

Purpose:  That vascular endothelial growth factor (VEGF) plays a major role in inflammatory angiogenesis has been well established. This pilot study was designed to evaluate experimental treatment with bevacizumab eyedrops in corneal neovascularization induced by alkali burn. The feasibility of topical administration, corneal cell viability and corneal penetration were investigated in an animal model.

Vitreous Levels of Bevacizumab and Vascular Endothelial Growth Factor-A in Patients with Choroidal Neovascularization

PURPOSE To investigate the vitreous levels of bevacizumab and vascular endothelial growth factor-A (VEGF-A) after intravitreal injection of the drug in patients with choroidal neovascularization (CNV). DESIGN Interventional case series. PARTICIPANTS Eleven eyes of 11 patients with submacular hemorrhage and CNV due to age-related macular degeneration (n = 10) or angioid streaks (n = 1). METHODS All patients were treatment naïve except for a single dose of intravitreal injection of bevacizumab (1.25 mg/50 muL dose) and subsequent vitrectomy after various intervals (1-101 days) because of active and progressive lesion. Intravitreal free bevacizumab and VEGF-A levels were measured using enzyme-linked immunosorbent assay and microsphere-based immunoassay, respectively. Vitreous VEGF-A isoforms were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting. MAIN OUTCOME MEASURES Intravitreal bevacizumab and VEGF-A levels were measured and pharmacokinetic parameters were calculated. RESULTS Pharmacokinetics of intravitreal bevacizumab followed a 2-compartment model with initial and terminal half-lives of 0.5 and 6.7 days, respectively. Bevacizumab could be detected in all cases, ranging from 2.63 ng/ml to 165 microg/ml. The peak concentration was observed on the second day after intravitreal bevacizumab injection. Vitreous free VEGF-A levels ranged from 0.2 to 33.9 pg/ml and showed a negative correlation with the bevacizumab concentration (P<0.001; r = -0.955) and a positive correlation with time (P<0.001; r = 0.964). However, the percentage expression of VEGF-A(165) exhibited a positive correlation with the bevacizumab concentration (P = 0.032, r = 0.645) and a negative correlation with time (P = 0.007, r = -0.755). A time-dependent increase was found for the percentage expression of VEGF-A(189) (P = 0.023, r = 0.673). Neither bevacizumab- nor time-related alterations were found for VEGF-A(121). CONCLUSIONS Based on pharmacokinetics, the interval of 6-7 weeks would be appropriate for efficacy, although clinical trials should guide dosing recommendations. Vitreous levels of free VEGF-A showed a negative correlation with the bevacizumab concentration, which confirmed the in vivo binding affinity of bevacizumab to VEGF-A. The analysis of the VEGF-A isoforms suggests differences of interaction between bevacizumab and individual VEGF-A isoforms.

Histologic basis of variations in retinal pigment epithelium autofluorescence in eyes with geographic atrophy.

PURPOSE Lipofuscin contained in the retinal pigment epithelium (RPE) is the main source of fundus autofluorescence (FAF), the target of an imaging method useful for estimating the progression of geographic atrophy (GA) in clinical trials. To establish a cellular basis for hyperfluorescent GA border zones, histologic autofluorescence (HAF) was measured at defined stages of RPE pathologic progression. DESIGN Experimental study. PARTICIPANTS AND CONTROLS Ten GA donor eyes (mean age ± standard deviation, 87.1 ± 4.0 years) and 3 age-matched control eyes (mean age ± standard deviation, 84.0 ± 7.2 years) without GA. METHODS The 10-micrometer-thick sections were divided into zones of RPE morphologic features according to an 8-point scale. Any HAF excited by 488 nm light was imaged by laser confocal microscopy. The HAF intensity summed along vertical lines perpendicular to Bruchs membrane at 0.2-μm intervals served as a surrogate for FAF. Intensity profiles in 151 zones were normalized to grade 0 at a standard reference location in each eye. Cross-sectional area, mean, and sum autofluorescence for individual RPE cells were measured (cellular autofluorescence [CAF]). MAIN OUTCOME MEASURES Statistically significant differences in intensity and localization of HAF and CAF at defined stages of RPE morphologic progression for GA and control eyes. RESULTS The RPE morphologic features were most abnormal (cell rounding, sloughing, and layering; grade 2) and HAF intensity profiles were highest and most variable immediately adjacent to atrophic areas. Peaks in HAF intensity frequently were associated with vertically superimposed cells. The HAF value that optimally separated reactive RPE was 0.66 standard deviations more than the mean for uninvolved RPE and was associated with a sensitivity of 75.8% and a specificity of 76.3%. When variable cell area was accounted for, neither mean nor sum CAF differed significantly among the RPE pathologic grades. CONCLUSIONS Areas with advanced RPE alterations are most likely to exhibit clinically recognizable patterns of elevated FAF around GA, but may not predict cells about to die, because of vertically superimposed cells and cellular fragments. These data do not support a role for lipofuscin-related cell death and call into question the rationale of treatments targeting lipofuscin.

Intravitreal Aflibercept for Macular Edema Secondary to Central Retinal Vein Occlusion: 18-Month Results of the Phase 3 GALILEO Study

PURPOSE To evaluate intravitreal aflibercept for treatment of macular edema secondary to central retinal vein occlusion (CRVO). DESIGN Randomized, double-masked, phase 3 study. METHODS A total of 177 patients with macular edema secondary to CRVO were randomized to receive 2 mg intravitreal aflibercept (n = 106) or sham (n = 71) every 4 weeks for 20 weeks. From weeks 24 to 48, patients were monitored every 4 weeks; the former group received intravitreal aflibercept as needed (PRN), and the sham group received sham. From weeks 52 to 76, patients were monitored every 8 weeks, and both groups received intravitreal aflibercept PRN. The primary endpoint (proportion of patients who gained ≥15 letters) was at week 24. This study reports exploratory outcomes at week 76. RESULTS The proportion of patients who gained ≥15 letters in the intravitreal aflibercept and sham groups was 60.2% vs 22.1% at week 24 (patients discontinued before week 24 were considered nonresponders; P < .0001), 60.2% vs 32.4% at week 52 (last observation carried forward, P < .001), and 57.3% vs 29.4% at week 76 (last observation carried forward; P < .001). Mean μm change from baseline central retinal thickness was -448.6 vs -169.3 at week 24 (P < .0001), -423.5 vs -219.3 at week 52 (P < .0001), and -389.4 vs -306.4 at week 76 (P = .1122). Over 76 weeks, the most common ocular serious adverse event in the intravitreal aflibercept group was macular edema (3.8%). CONCLUSIONS The visual and anatomic improvements seen after fixed, monthly dosing at week 24 were largely maintained when treatment intervals were extended. Patients with macular edema following CRVO benefited from early treatment with intravitreal aflibercept.

Effects of bevacizumab on retinal function in isolated vertebrate retina.

Background: Bevacizumab (Avastin) is a recombinant protein that targets vascular endothelial growth factor (VEGF). In vitro, bevacizumab inhibits VEGF induced cell proliferation and tissue factor production. Abnormal angiogenesis involving VEGF is a central event during the development of choroidal neovascularisation (CNV). The present study was designed to evaluate the short term toxic effects of bevacizumab on retinal function for a therapeutic intraocular application. Methods: Isolated bovine retinas were perfused with an oxygen pre-incubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal potential using silver/silver chloride electrodes. Bevacizumab was added in different concentrations to the nutrient solution for 45 minutes. Thereafter the retina was reperfused for 60 minutes with normal nutrient solution. The percentage of a-wave and b-wave reduction during the application of bevacizumab was calculated and compared to control recordings. Results: During the application of three different concentrations of bevacizumab (0.08 mg/ml, 0.25 mg/ml, 0.8 mg/ml) no significant reduction of the a-wave and b-wave amplitude was observed. During the washout, the ERG amplitudes were unchanged. Conclusion: The present study suggests that an intraocular application of 0.25 mg/ml bevacizumab for the treatment of CNV is reasonable. No significant short term effects of bevacizumab on retinal function were detected, but long term effects cannot be excluded.

Early postoperative safety and surgical outcomes after implantation of a suprachoroidal micro-stent for the treatment of open-angle glaucoma concomitant with cataract surgery

Purpose To evaluate the safety of a new suprachoroidal device, the Cypass micro‐stent, for the surgical treatment of open‐angle glaucoma (OAG) implanted in conjunction with cataract surgery. Setting Multicenter clinical study. Design Prospective interventional case series. Methods This is an interim report of an ongoing safety study. Patients with OAG glaucoma (Shaffer grade 3 and 4) who were also candidates for cataract surgery in the affected eye had standard phacoemulsification followed by micro‐stent implantation in the supraciliary space. Included were patients with uncontrolled (≥21 mm Hg, Cohort 1) or controlled (<21 mm Hg, Cohort 2) medicated intraocular pressure (IOP) at baseline. Glaucoma medications were discontinued at surgery and resumed at the discretion of each investigator. Measures included adverse events/complications and postoperative changes in IOP or medication. Results The mean baseline medicated IOP was 21.1 mm Hg ± 5.91 (SD); the mean number of IOP‐lowering medications was 2.1 ± 1.1 (N = 184). There were no major events such as retinal or choroidal detachment or endophthalmitis. The most common complications were transient early hypotony (13.8%) and transient IOP increase (10.5%). Uncontrolled patients (n = 57) had a 37% IOP reduction (P<.001), with more than a 50% reduction in glaucoma medications at 6 months (P<.001). Intraocular pressure–controlled patients (n = 41) had a 71.4% reduction in glaucoma medications (P<.001). Conclusion Initial clinical experience with the new micro‐stent showed a low rate of surgical complications with concomitant decreases in IOP and/or glaucoma medications. Financial Disclosure Drs. Hoeh, Ahmed, Swaantje Grisanti, Salvatore Grisanti, Grabner, Nguyen, Rau, and Yoo are clinical investigators for Transcend Medical; Dr. Ahmed is a consultant to Transcend Medical; Dr. Ianchulev is an employee of Transcend Medical.

Bevacizumab as adjuvant for neovascular glaucoma

Purpose:  We aimed to evaluate the longterm effects of intraocular bevacizumab (Avastin®) injections as adjuvant treatment in patients with neovascular glaucoma.

Photoreceptor avascular privilege is shielded by soluble VEGF receptor-1

Optimal phototransduction requires separation of the avascular photoreceptor layer from the adjacent vascularized inner retina and choroid. Breakdown of peri-photoreceptor vascular demarcation leads to retinal angiomatous proliferation or choroidal neovascularization, two variants of vascular invasion of the photoreceptor layer in age-related macular degeneration (AMD), the leading cause of irreversible blindness in industrialized nations. Here we show that sFLT-1, an endogenous inhibitor of vascular endothelial growth factor A (VEGF-A), is synthesized by photoreceptors and retinal pigment epithelium (RPE), and is decreased in human AMD. Suppression of sFLT-1 by antibodies, adeno-associated virus-mediated RNA interference, or Cre/lox-mediated gene ablation either in the photoreceptor layer or RPE frees VEGF-A and abolishes photoreceptor avascularity. These findings help explain the vascular zoning of the retina, which is critical for vision, and advance two transgenic murine models of AMD with spontaneous vascular invasion early in life. DOI: http://dx.doi.org/10.7554/eLife.00324.001

The retinal tolerance to bevacizumab in co‐application with a recombinant tissue plasminogen activator

Aim: To investigate the retinal toxicity of bevacizumab in co-application with a commercially available recombinant tissue plasminogen activator (rt-PA), and to facilitate a new therapeutic concept in the treatment of massive subretinal haemorrhage caused by neovascular age-related macular degeneration (AMD). Methods: Isolated bovine retinas were perfused with an oxygen-preincubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal potential using Ag/AgCl electrodes. Bevacizumab (0.25 mg/ml) and rt-PA (20 μg/ml) were added to the nutrient solution for 45 min. Thereafter, the retina was reperfused for 60 min with normal nutrient solution. Similarly, the effects of rt-PA (20 μg/ml, 60 μg/ml and 200 μg/ml) on the a- and b-wave amplitudes were investigated. The percentages of a- and b-wave reduction during application and at washout were calculated. Results: During application of bevacizumab (0.25 mg/ml) in co-application with 20 μg/ml (rt-PA), the ERG amplitudes remained stable. The concentrations of rt-PA alone (20 μg/ml and 60 μg/ml) did not induce significant reduction of the b-wave amplitude. In addition, 20 μg/ml rt-PA did not alter the a-wave amplitude. However, 60 μg/ml rt-PA caused a slight but significant reduction of the a-wave amplitude. A full recovery was detected for both concentrations during the washout. At the highest tested concentration of 200 μg/ml rt-PA, a significant reduction of the a- and b-wave amplitudes was provoked during the exposure. The reduction of ERG amplitudes remained irreversible during the washout. Conclusion: The present study suggests that a subretinal injection of 20 µg/ml rt-PA in co-application with bevacizumab (0.25 mg/ml) for the treatment of massive subretinal haemorrhage seems possible. This is a safety study. Therefore, we did not test the clinical effectiveness of this combined treatment.