Track topics on Twitter Track topics that are important to you
Laser-induced choroidal neovascularization (CNV) model in nonhuman primates has played a critical role in the development of new therapies for neovascular age-related macular degeneration. The widespread use of this model, however, has been limited by its high costs, mainly due to the lower efficiency of animal use. To address this problem, we optimized the CNV model by repeated photocoagulation in the same eye of each animal and preliminarily evaluated this model for assessment of an anti-vascular endothelial growth factor (VEGF) agent. Seven rhesus monkeys were included and divided into two groups, which were named the laser-only and laser-bevacizumab groups. Each animal underwent 3 retinal photocoagulation sessions in the same eye at 4-week intervals to induce CNV. The animals in the laser-bevacizumab group received treatment in both eyes during the first photocoagulation session. Three weeks after the first laser treatment, the animals in the laser-bevacizumab group were given an intravitreal injection of bevacizumab in the repeated photocoagulation eye, while no medicine was administered to the contralateral eye. To assess the severity and development of CNV produced by each laser treatment, fluorescein angiography (FA) was performed in all animals at multiple time points. The laser lesions produced in each photocoagulation session were analysed separately using grading and densitometric methods, and CNV severity was represented by the CNV incidence and the mean integrated fluorescence intensity (MIFI), respectively. Our results showed that in the animals in the laser-only group, the average CNV incidence rates were 62.5%, 42% and 50% at 2 weeks after each laser treatment, and the average MIFI values (x10) were 3.83 ± 2.36, 2.66 ± 1.42 and 2.52 ± 0.18, respectively. No significant differences were found among treatments. Meanwhile, the time course of CNV development in each animal was generally the same after each photocoagulation session. In the laser-bevacizumab group, however, the average CNV incidence rates of each laser treatment were 50%, 0 and 37.5%, respectively, and the average MIFI values were 3.79 ± 0.47, 1.09 ± 0.35 and 2.37 ± 1.35, respectively. The differences between treatments 1 and 2 were statistically significant. Meanwhile, the CNVs induced by laser treatment 1 were reduced after bevacizumab administration. The average CNV incidence decreased from 50% at week 3-4.2% at week 4, and the average MIFI decreased from 4.62 ± 1.15 to 1.76 ± 0.81, both of which were statistically significant. However, the CNVs of treatments 2 and 3 did not show any significant changes over time. Additionally, the CNVs induced in both eyes of these animals during the first laser treatment showed no significant differences. Our study demonstrated that repeated retinal photocoagulation in the monkey eye produces relatively consistent CNVs, which can be used to assess the efficacies of anti-angiogenic agents more efficiently.
This article was published in the following journal.
Name: Experimental eye research
To investigate the role of Wnt/β-catenin signaling pathway in the restoration of induced pluripotent stem cell-derived retinal pigment epithelium (hiPSC-RPE) after laser photocoagulation. After diffe...
Subthreshold micropulse laser treatment has been intensively used for selected retinal diseases in the last decade; however, the exact mechanism of the action of lasers in the subthreshold micropulse ...
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among the elderly in developed countries. Subthreshold retinal laser therapy is a new technique that targets druse...
To investigate retinal and choroidal microvascular changes and structural choroidal involvement in retinal vein occlusion (RVO).
We investigated the outer retinal, RPE, and choroidal changes and the development of choroidal neovascularization (CNV) in fellow eyes of patients with unilateral polypoidal choroidal vasculopathy or ...
Our aim is to compare patient comfort when using the 532 nanometer (green) wavelength laser to the 577 nanometer (yellow) wavelength laser during pan retinal photocoagulation to treat pati...
To evaluate laser treatment of choroidal neovascularization (CNV) through randomized, controlled clinical trials. The Macular Photocoagulation Study (MPS) consisted of three sets of random...
Imaging of retinal morphological changes with time secondary to laser treatment as assessed with high definition optical coherence tomography (OCT). Furthermore changes in retinal function...
A randomized study to assess the safety and efficacy of single-session pan-retinal photocoagulation (PRP) using Pattern Scan Laser (PASCAL) in proliferative diabetic retinopathy (PDR) - 1,...
The object of the study is to compare treatment of iris/angle neovascularization with panretinal photocoagulation (laser) to treatment with panretinal photocoagulation and an anti-angiogen...
The coagulation of tissue by an intense beam of light, including laser (LASER COAGULATION). In the eye it is used in the treatment of retinal detachments, retinal holes, aneurysms, hemorrhages, and malignant and benign neoplasms. (Dictionary of Visual Science, 3d ed)
A technique utilizing a laser coupled to a catheter which is used in the dilatation of occluded blood vessels. This includes laser thermal angioplasty where the laser energy heats up a metal tip, and direct laser angioplasty where the laser energy directly ablates the occlusion. One form of the latter approach uses an EXCIMER LASER which creates microscopically precise cuts without thermal injury. When laser angioplasty is performed in combination with balloon angioplasty it is called laser-assisted balloon angioplasty (ANGIOPLASTY, BALLOON, LASER-ASSISTED).
A form of RETINAL DEGENERATION in which abnormal CHOROIDAL NEOVASCULARIZATION occurs under the RETINA and MACULA LUTEA, causing bleeding and leaking of fluid. This leads to bulging and or lifting of the macula and the distortion or destruction of central vision.
Techniques using laser energy in combination with a balloon catheter to perform angioplasty. These procedures can take several forms including: 1, laser fiber delivering the energy while the inflated balloon centers the fiber and occludes the blood flow; 2, balloon angioplasty immediately following laser angioplasty; or 3, laser energy transmitted through angioplasty balloons that contain an internal fiber.
Treatment using irradiation with LASER light of low power intensity so that the effects are not due to heat, as in LASER THERAPY. These non-thermal effects are thought to be mediated by a photochemical reaction that alters CELL MEMBRANE PERMEABILITY, leading to increased mRNA synthesis and CELL PROLIFERATION. Low-level laser therapy has been used for a wide variety of conditions, but most frequently for wound healing and pain control.
Ophthalmology is the branch of medicine that is devoted to the study and treatment of eye diseases. As well as mild visual defects correctable by lenses, ophthalmology is concerned with glaucoma, uveitis and other serious conditions affecting the eye, ...