Search

Objective: To evaluate the pharmacologic activity and tolerability of JSM6427, a potent and first selective small-molecule inhibitor of integrin alpha5beta1, in monkey and rabbit models of choroidal neovascularization (CNV)., Methods: JSM6427 selectivity for alpha5beta1 was evaluated by in vitro binding assays while the ability of JSM6427 to inhibit CNV was investigated in a laser-induced monkey model and a growth factor-induced rabbit model. Intravitreal injections of JSM6427 (100, 300, or 1000 microg) or vehicle were administered immediately after the CNV induction procedure and at weekly intervals for 4 weeks. Fluorescein angiography was performed weekly. Ocular tolerability was evaluated ophthalmoscopically and histologically in both models; additional assessments in monkeys included electroretinography, biomicroscopy, pathological examination, and analysis of JSM6427 pharmacokinetics., Results: JSM6427 was highly selective for the alpha5beta1-fibronectin interaction. Weekly intravitreal injections of JSM6427 resulted in a statistically significant dose-dependent inhibition of CNV in laser-induced and growth factor-induced models without any ocular JSM6427-related adverse effects. JSM6427 was cleared through the systemic circulation with no evidence of systemic accumulation., Conclusions: Intravitreal JSM6427 provided dose-dependent inhibition of CNV in monkey and rabbit experimental models., Clinical Relevance: JSM6427 may provide a new approach for the treatment of ocular neovascular diseases such as age-related macular degeneration in humans.

Objectives: To assess the safety and efficacy of intravitreous pegaptanib sodium for the treatment of macular edema following central retinal vein occlusion (CRVO)., Design: This dose-ranging, double-masked, multicenter, phase 2 trial included subjects with CRVO for 6 months' or less duration randomly assigned (1:1:1) to receive pegaptanib sodium or sham injections every 6 weeks for 24 weeks (0.3 mg and 1 mg, n=33; sham, n=32)., Main Outcome Measure: Visual acuity at week 30., Results: In the primary analysis at week 30, 12 of 33 (36%) subjects treated with 0.3 mg of pegaptanib sodium and 13 of 33 (39%) treated with 1 mg gained 15 or more letters from baseline vs 9 of 32 (28%) sham-treated subjects (P= .48 for 0.3 mg and P= .35 for 1 mg of pegaptanib sodium vs sham). In secondary analyses, subjects treated with pegaptanib sodium were less likely to lose 15 or more letters (9% and 6%; 0.3-mg and 1-mg pegaptanib sodium groups, respectively) compared with sham-treated eyes (31%; P= .03 for 0.3 mg and P= .01 for 1 mg of pegaptanib sodium vs sham) and showed greater improvement in mean visual acuity (+7.1 and +9.9, respectively, vs -3.2 letters with sham; P= .09 for 0.3 mg and P= .02 for 1 mg of pegaptanib sodium vs sham). By week 1, the mean central retinal thickness decreased in the 0.3-mg and 1-mg pegaptanib sodium groups by 269 microm and 210 microm, respectively, vs 5 microm with sham (P< .001)., Conclusions: Based on this 30-week study, intravitreous pegaptanib sodium appears to provide visual and anatomical benefits in the treatment of macular edema following CRVO., Application to Clinical Practice: Benefits accrued with intravitreous pegaptanib sodium treatment of macular edema following CRVO suggest a role for vascular endothelial growth factor in the pathogenesis of this condition., Trial Registration: clinicaltrials.gov Identifier: NCT00088283.

Objective: To determine the ability of angiostatin and the angiostatin-producing low-metastatic (LM) clone of Lewis lung carcinoma (LLC) to inhibit and regress corneal neovascularization, as compared with the non-angiostatin-producing high-metastatic (HM) clone., Methods: Three groups of C57BL6/J mice underwent chemical and mechanical denudation of corneal and limbal epithelium. One group remained tumor free while the other 2 were implanted with LLC cells (either the HM or LM clones) subcutaneously the day before, 2 weeks after, or 4 weeks after denudation. Corneas were harvested 2 weeks after tumor implantation (at 2, 4, and 6 weeks after denudation for tumor-free mice). Neovascularization was quantified by CD31 immunostaining. In a second experiment, recombinant angiostatin was delivered continuously for 2 weeks via an osmotic pump in mice with established corneal neovascularization., Results: The mean percentages of neovascularized corneal area in mice 2 weeks after LM-LLC implantation were 4.6%, 3.7%, and 37.0%, at 2, 4, and 6 weeks after scraping, respectively. In contrast, in the mice implanted with HM-LLC, the corresponding values were 45.4% (P =.01), 90.1% (P =.03), and 80.3% (P =.005). For tumor-free mice, the corresponding values were 62.0% (P =.003), 68.9% (P =.03), and 59.3% (P =.06). Mice implanted with angiostatin pumps had a 37.7% neovascularized corneal area 2 weeks after implantation and 4 weeks after scraping while mice implanted with sham pumps had 60.5% (P =.007)., Conclusion: Angiostatin inhibits and regresses corneal neovascularization induced by mechanical and alkali corneal injury., Clinical Relevance: This appears to be the first evidence of biologically induced regression of corneal neovascularization, and the first direct demonstration of angiostatin-induced regression of neovascularization in any tissue.

Objective: To evaluate the safety and efficacy of intravitreal injections of an antigen-binding fragment of a recombinant humanized monoclonal antibody directed toward vascular endothelial growth factor (rhuFab VEGF) in a monkey model of choroidal neovascularization (CNV)., Methods: In phase 1 of the study, each animal received intravitreal injections, 500 microg per eye, of rhuFab VEGF in one eye (prevention eye), while the contralateral eye received rhuFab VEGF vehicle (control eye) at 2-week intervals. On day 21, laser photocoagulation was performed to induce CNV. In phase 2, the vehicle-treated eye was crossed over and both eyes received 500 microg of rhuFab VEGF beginning 21 days following laser-induced injury at days 42 and 56. The eyes were monitored by ophthalmic examinations, color photographs, and fluorescein angiography., Results: rhuFab VEGF did not cause any ocular hemorrhages. All eyes treated with rhuFab VEGF developed acute anterior chamber inflammation within 24 hours of the first injection that resolved within 1 week, and this inflammation was less severe with subsequent injections. The incidence of CNV, defined angiographically, was significantly lower in the prevention eyes than the control eyes (P<.001). Subsequent treatments were associated with less leakage in eyes with established CNV that were crossed over from the control eyes to the treatment eyes (P =.001)., Conclusions: Intravitreal rhuFab VEGF injections prevented formation of clinically significant CNV in cynomolgus monkeys and decreased leakage of already formed CNV with no significant toxic effects., Clinical Relevance: This study provides the nonclinical proof of principle for ongoing clinical studies of intravitreally injected rhuFab VEGF in patients with neovascular age-related macular degeneration.

Objectives: To search for novel mutations that cause corneal stromal dystrophies and to confirm or revise the clinical diagnosis of patients with these mutations., Patients: Through review of the records of the Cogan Eye Pathology Laboratory at the Massachusetts Eye and Ear Infirmary, Boston, and of clinical records, we ascertained 14 unrelated patients with the clinical or histopathologic diagnosis of granular (3 cases), Avellino (5 cases), lattice (5 cases), or Reis-Bücklers (1 case) corneal dystrophy., Methods: Clinical records and histopathologic findings of the index patients and their relatives were reviewed. Patients and selected relatives donated a blood sample from which leukocyte DNA was purified and assayed for mutations in the BIGH3 gene and, in 2 patients, the gelsolin gene, using the polymerase chain reaction and direct genomic sequencing., Results: All index patients with the diagnosis of granular dystrophy or Avellino dystrophy had the missense mutation Arg555Trp or Arg124His, respectively, previously reported in the BIGH3 gene. Of the 5 index patients with a prior diagnosis of lattice dystrophy, 2 had the originally reported lattice mutation (Arg124Cys) in the BIGH3 gene, 1 had a more recently reported missense mutation (His626Arg) in the same gene, 1 had the missense mutation Asp187Asn in the gelsolin gene, and 1 had no detected mutation in either gene. Affected members of the family with Reis-Bücklers dystrophy did not carry the previously reported mutations Arg555Gln or Arg124Leu but instead carried a novel missense mutation Gly623Asp in the BIGH3 gene., Conclusions: Molecular genetic analysis can improve the accuracy of diagnosis of patients with corneal dystrophies. Two patients with a prior diagnosis of lattice corneal dystrophy had their diagnosis changed to gelsolin-related amyloidosis (1 case) or secondary, nonhereditary localized amyloidosis (1 case). A novel mutation in the BIGH3 gene that causes Reis-Bücklers dystrophy was uncovered through this analysis, and another recently reported novel mutation was encountered. These findings serve to expand our knowledge of the spectrum of pathogenic mutations in BIGH3.

Objective: To determine if anti-vascular endothelial growth factor antibody and a range of dextrans with varying diffusion radii and molecular weights are permeable through experimental choroidal neovascularization (CNV)., Methods: Choroidal neovascularization was induced in 10 cynomolgus monkey retinas by means of argon laser injury. Digital fundus fluorescein angiograms were performed with fluorescein sodium, fluoresceinated IgG antibodies (anti-vascular endothelial growth factor and a control antibody), and fluoresceinated dextrans with molecular weights of 4, 20, 40, 70 and 150 kd. The 40- and 70-kd dextrans straddle the effective diffusion radius of IgG. For each reagent, early and late angiograms were performed in a standardized fashion, with follow-up images obtained to monitor residual fluorescence., Results: Perfusion of retinal vessels and choroidal vasculature was seen with all reagents. Fluorescein and 4- and 20-kd dextran leaked rapidly from the CNV within the first minute. Angiography with the use of 40-kd dextran and fluoresceinated antibody, either anti-vascular endothelial growth factor or control IgG, showed fluorescence within the CNV that increased during the first 1 to 5 hours, with mild leakage from the CNV. By 24 hours, fluorescence in the CNV was minimal, although in some cases persistent fluorescence in the surrounding tissue was evident up to 2 weeks. The 70-kd dextran showed fluorescence within the CNV and leakage in 1 of 3 eyes. The 150-kd dextran showed fluorescence within the CNV but did not demonstrate leakage., Conclusions: Fluoresceinated antibodies and dextran with smaller effective diffusion radii showed CNV perfusion and leakage. Dextrans with larger effective diffusion radii (70 kd and 150 kd) perfused into CNV but did not show leakage consistently., Clinical Relevance: Determining the permeablity of antibodies and molecules of similar size through CNV can help ascertain the feasibility of using intravenously administered antibodies against angiogenic growth factors as a future treatment for choroidal neovascularization.

Objectives: To determine whether systemic hyperoxia can reverse retinal hypoxia and decrease vascular endothelial growth factor (VEGF) gene expression in ischemic nonhuman primate retina., Methods: Six eyes of 3 cynomolgus monkeys were studied. Retinal ischemia was induced via laser vein occlusion and confirmed with fluorescein angiography. Animals were randomly assigned to treatment with either 21% or 100% inhaled oxygen. Arterial PO2 was monitored while systemic acid-base status was maintained. An oxygen microelectrode on a micromanipulator was used to measure preretinal oxygen concentrations in ischemic and nonischemic retina in situ. RNA was isolated from fresh whole retinas, and VEGF messenger RNA levels were quantified with Northern blotting., Results: The preretinal PO2 in ischemic retina was less than the PO2 in nonischemic retina in animals breathing 21% oxygen (intervascular zone PO2, 14.3+/-0.53 vs 21.8+/-0.55 mm Hg; P=.002). After 8 hours of systemic hyperoxia (arterial PO2, 512+/-18 mm Hg), the preretinal PO2 in ischemic retina increased to 166.2+/-15.6 mm Hg (21.8% oxygen) and retinal VEGF messenger RNA levels were reduced by an average of 55%., Conclusions: These data demonstrate that systemic hyperoxia can lower retinal VEGF gene expression and reoxygenate ischemic adult primate retina.

Objective: To determine whether the angiogenic peptide vascular endothelial growth factor (VEGF) is sufficient to produce iris neovascularization in a nonhuman primate (Macaca fascicularis)., Methods: Eight eyes of 4 animals were studied. The 165-amino acid isoform of human recombinant VEGF (VEGF165) was injected into the vitreous of 5 cynomolgus monkey eyes (doses ranging from 0.25-2.5 micrograms per injection). Equal amounts of inactivated human recombinant VEGF (2 eyes) or vehicle (1 eye) were injected into contralateral control eyes. Eyes were assessed by slitlamp biomicroscopy, tonometry, iris color photography, fluorescein angiography, histopathologic examination, and immunostaining with antibodies against proliferating cell nuclear antigen., Results: All 5 bioactive VEGF-injected eyes developed neovascularization with dilated and tortuous iris vessels that leaked fluorescein. None of the 3 control eyes exhibited any iris vascular changes. Inflammation was absent in both treatment groups. A dose response to VEGF was observed in the single animal that received 2.5 micrograms and 0.25 microgram in the right and left eyes, respectively. Iris vessel endothelial cells were positive for proliferating cell nuclear antigen in the bioactive VEGF-injected eyes only. Injections of 1.25 micrograms of VEGF every 3 days during a 30-day period produced advanced iris neovascularization, ectropion uvea, and neovascular glaucoma., Conclusions: Intravitreal injections of recombinant human VEGF165 in amounts comparable with those measured in eyes with active neovascularization are sufficient to produce noninflammatory iris neovascularization in a nonhuman primate. Prolonged exposure to VEGF165 can produce ectropion uveae and neovascular glaucoma.

Objective: To determine if the angiogenic peptide vascular endothelial growth factor (VEGF) is required for retinal ischemia-associated iris neovascularization in a nonhuman primate., Methods: Laser retinal vein occlusion was used to produce retinal ischemia in 16 eyes of eight animals (Macaca fascicularis). Eyes were randomized to treatment every other day with intravitreal injections of either a neutralizing anti-VEGF monoclonal antibody or a control monoclonal antibody of the same isotype. Serial iris fluorescein angiograms were assessed using a standardized grading system and masked readers. Retinal VEGF and placental growth factor expression were assessed by Northern blotting. The specificity of the antibodies was determined in capillary endothelial cell proliferation assays prior to intravitreal injection., Results: Zero of eight eyes receiving the neutralizing anti-VEGF antibodies developed iris neovascularization. Five of eight control antibody-treated eyes developed iris neovascularization. The difference was statistically significant (P = .03). Intravitreal antibody injection did not impair the ability of the ischemic retina to increase VEGF messenger RNA expression. The anti-VEGF antibodies specifically inhibited VEGF-driven capillary endothelial cell proliferation in vitro., Conclusion: These data demonstrate that VEGF is required for iris neovascularization in an adult nonhuman primate eye. The inhibition of VEGF is a new potential therapeutic strategy for the treatment of ocular neovascularization.

We report the histopathological findings of the anterior cornea from a patient with skin biopsy-proven epidermolysis bullosa simplex. As seen with light microscopy, the cornea had a fibrocellular pannus deep to a thickened epithelial basement membrane. Transmission electron microscopy of the anterior cornea demonstrated a nonhomogeneous basal epithelial layer with abnormal attachment complexes to an irregular, multilaminar basement membrane. The findings of transmission electron microscopy of the bulbar conjunctiva were normal.