Differences in the temporal expression of regulatory growth factors during choroidal neovascular development.

Although the roles of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and hepatocyte growth factor (HGF) in pathologic neovascularization have been well characterized in certain tissues, their particular functions and expression patterns in choroidal neovascularization (CNV) have not been clearly established. After localized laser trauma to Bruch's membrane to induce CNV development, the temporal changes in mRNA and protein expression of these 3 cytokines were documented and compared histologically to areas of immunofluorescence, the proliferation of endothelial cells, neovascular development, and temporal changes in vascular permeability. Changes in mRNA and protein levels of bFGF and HGF occurred quickly and reached peak expression within hours.

Comparing pegaptanib and triamcinolone efficacy in the rat choroidal neovascularization model.

Objective: To evaluate the prophylactic effect of intravitreal pegaptanib sodium on choroidal neovascularization membrane (CNVM) development and compare its performance with that of triamcinolone acetonide.

Methods: In drug-treated and control groups, CNVMs were induced by laser trauma. Immediately after undergoing the laser procedure, animals received intravitreal injections of pegaptanib sodium, 8 or 17 mug; triamcinolone acetonide, 200 mug; or a vehicle solution.

Oral administration of lumiracoxib reduces choroidal neovascular membrane development in the rat laser-trauma model.

Purpose: To determine whether lumiracoxib, a highly selective cyclooxygenase-2 (COX-2) inhibitor that exhibits anti-inflammatory and antiangiogenic properties, can inhibit experimental choroidal neovascular membrane (CNVM) development induced by focal laser trauma in a well-characterized Brown Norway rat CNVM model.

Methods: Over a 35-day period, 24 rats received daily oral gavage dosages of 20 mg/kg lumiracoxib in a 0.5% (w/v) suspension of sodium carboxymethylcellulose (CMC), while a control group received the 0.

Characterization of a transgenic mouse line lacking photoreceptor development within the ventral retina.

A unique transgenic mouse line was generated by incorporating a minigene that contained a cone-specific human cone transducin alpha-subunit (GNAT2) promoter, an attenuated diphtheria toxin A (DTA) gene, and an enhancer element from human interphotoreceptor retinoid-binding protein (IRBP) gene. This transgenic mouse line is designated h-GNAT2pro-DTA. During postnatal retinal development, both transgenic and non-transgenic retinas showed similar morphology and thickness at P1.

Anastomotic vessels remain viable after photodynamic therapy in primate models of choroidal neovascularization.

Purpose: Anastomotic vessels in exudative age-related macular degeneration (AMD) represent a serious clinical feature that reportedly does not respond well to either photocoagulation or photodynamic therapy (PDT). Anastomoses also occur in various animal models of choroidal neovascularization (CNV). In the present study, anastomotic vessels and their patency were evaluated in two primate CNV laser-trauma models after PDT, by using two novel photosensitizers.

Future pharmacological treatment options for nonexudative and exudative age-related macular degeneration.

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in the industrialised world. Within the past decade, researchers have introduced many promising prevention and treatment options in an attempt to minimise the central vision loss imparted from AMD. Based on large-scale, randomised, prospective, placebo-controlled trials, a specially formulated combination of the antioxidants vitamin C, vitamin E, beta-carotene, copper and zinc is the only proven means of AMD prophylaxis.

Current and future treatment options for nonexudative and exudative age-related macular degeneration.

Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the industrialised world. Although relatively simple to diagnose through direct visualisation augmented with rapid sequence fluorescein angiography, treatment has presented a far greater challenge because the true aetiology of AMD is largely unknown. Within the past decade, researchers have introduced many new, potentially promising treatment and prevention options in an attempt to minimise the damage imparted from AMD.

Evaluation of photopoint photosensitizer mv6401, indium chloride methyl pyropheophorbide, as a photodynamic therapy agent in primate choriocapillaris and laser-induced choroidal neovascularization.

Purpose: To assess the potential of a new photosensitizer, indium chloride methyl pyropheophorbide (PhotoPoint MV6401), for ocular photodynamic therapy (PDT) in normal choriocapillaris vessels and experimentally induced choroidal neovascularization in New-World monkeys (Saimiri sciureus).

Methods: PhotoPoint MV6401 (Miravant Pharmaceuticals, Inc., Santa Barbara, CA) was activated at 664 nm using a DD3-0665 (Miravant Systems, Inc.

Corticosteroids in posterior segment disease: an update on new delivery systems and new indications.

Purpose Of Review: Corticosteroids are traditionally used for inflammatory disorders because of their ability to diminish neutrophil transmigration, limit access to sites of inflammation, and decrease cytokine production. More recently, however, investigators have focused on the angiostatic and antipermeability properties of corticosteroids for posterior segment diseases such as age-related macular degeneration (AMD), diabetic retinopathy, and macular edema. Both new angiostatic and traditional corticosteroids are currently undergoing evaluation as new delivery techniques such as intravitreal injection and intraocular sustained-release devices facilitate high local angiostatic and antipermeability concentrations while minimizing extraocular toxicity.

The squirrel monkey: characterization of a new-world primate model of experimental choroidal neovascularization and comparison with the macaque.

Purpose: To evaluate and characterize the New-World squirrel monkey as a primate model for experimental choroidal neovascularization (CNV) studies and to compare it with the current Old-World macaque monkey model.

Methods: Fibrovascular tissues (FVT) were elicited in 12 maculae of seven squirrel monkeys by laser photocoagulation using optimized laser parameters (532 nm, 0.05 second, 75 micro m, 650 mW).

Squalamine lactate reduces choroidal neovascularization in a laser-injury model in the rat.

Purpose: To determine if systemically administered squalamine lactate, a novel aminosterol with antineoplastic and antiangiogenic activity, inhibits the development of experimental choroidal neovascularization membranes (CNVMs) induced by laser trauma in a rat model.

Methods: Twenty anesthetized male Brown-Norway rats received a series of 8 krypton red laser lesions per eye (647 nm, 0.05 second, 50 microm, 150 mW).

An update on photodynamic therapy in age-related macular degeneration.

Age-related macular degeneration (AMD) is the leading cause of irreversible loss of central vision in people aged > 50 years in the western world. Until recently, the only proven treatment to reduce the risk of vision loss from its more severe neovascular form was laser photocoagulation, but this treatment was suitable for only 15% of cases. Photodynamic therapy (PDT) with verteporfin was recently proposed to be effective in reducing the risk of visual loss for an estimated 20 - 30% of neovascular AMD patients.