Receptor tyrosine kinase inhibitors AG013764 and AG013711 reduce choroidal neovascularization in rat eye

Research progress of VEGFR small molecule inhibitors in ocular neovascular diseases

Angiogenesis is the biological process in which existing blood vessels generate new ones and it is essential for body growth and development, wound healing, and granulation tissue formation. Vascular endothelial growth factor receptor (VEGFR) is a crucial cell membrane receptor that binds to VEGF to regulate angiogenesis and maintenance. Dysregulation of VEGFR signaling can lead to several diseases, such as cancer and ocular neovascular disease, making it a crucial research area for disease treatment. Currently, anti-VEGF drugs commonly used in ophthalmology are mainly four macromolecular drugs, Bevacizumab, Ranibizumab, Conbercept and Aflibercept. Although these drugs are relatively effective in treating ocular neovascular diseases, their macromolecular properties, strong hydrophilicity, and poor blood-eye barrier penetration limit their efficacy. However, VEGFR small molecule inhibitors possess high cell permeability and selectivity, allowing them to traverse and bind to VEGF-A specifically. Consequently, they have a shorter duration of action on the target, and they offer significant therapeutic benefits to patients in the short term. Consequently, there is a need to develop small molecule inhibitors of VEGFR to target ocular neovascularization diseases. This review summarizes the recent developments in potential VEGFR small molecule inhibitors for the targeted treatment of ocular neovascularization diseases, with the aim of providing insights for future studies on VEGFR small molecule inhibitors.

An optimized procedure for direct access to 1H-indazole-3-carboxaldehyde derivatives by nitrosation of indoles

The nitrosation of indoles under slightly acidic conditions and reverse addition conditions leads to the preparation of the corresponding indazole-3-carboxaldehydes in high yields and greatly minimizes side reactions.

Horizons in therapy for corneal angiogenesis

Corneal neovascularization can lead to a devastating disease process that involves the breakdown of the limbal barrier and the formation of blood vessels in the cornea, leading to severe visual impairment. This review discusses the delicate balance between antiangiogenic and angiogenic factors that govern the antiangiogenic privilege of the cornea. Current treatment methods, clinical trials, and future prospects in the management of corneal neovascularization also are discussed.

Improved assessment of laser-induced choroidal neovascularization

The primary objective of this study was to develop and evaluate new methods of analyzing laser-induced choroidal neovascularization (CNV), in order to make recommendations for improving the reporting of experimental CNV in the literature. Six laser burns of sufficient power to rupture Bruch's membrane were concentrically placed in each eye of 18 adult Norway rats. Eyes received intravitreal injections of either triamcinolone acetonide, ketorolac, or balanced salt solution (BSS). Fluorescein angiography (FA) was performed 2 and 3 weeks after injection, followed by choroidal flat mount preparation. Vascular leakage on FAs and vascular budding on choroidal mounts were quantified by measuring either the cross-sectional area of each CNV lesion contained within the best-fitting polygon using Adobe Photoshop (Lasso Technique or Quick Selection Technique), or the area of bright pixels within a lesion using Image-Pro Plus. On choroidal mounts, the Lasso Technique and Image-Pro Plus detected a significant difference in lesion size between either ketorolac or triamcinolone when compared to BSS, while the Quick Selection Technique did not (Lasso Technique, 0.78 and 0.64; Image-Pro Plus, 0.77 and 0.65). On FA, the Lasso Technique and Quick Selection Technique detected a significant difference in lesion size between either ketorolac or triamcinolone when compared to BSS, while Image-Pro Plus did not (Lasso Tool, 0.81 and 0.54; Quick Selection Tool, 0.76 and 0.57). Choroidal mounts and FA are both valuable for imaging experimental CNV. Adobe Photoshop and Image-Pro Plus are both able to detect subtle differences in CNV lesion size, when images are not manipulated. The combination of choroidal mounts and FA provides a more comprehensive assessment of CNV anatomy and physiology.

Age-related macular degeneration: experimental and emerging treatments

Purpose:

This essay reviews the experimental treatments and new imaging modalities that are currently being explored by investigators to help treat patients with age-related macular degeneration (AMD).

Design:

Interpretative essay.

Methods:

Literature review and interpretation.

Results:

Experimental treatments to preserve vision in patients with exudative AMD include blocking vascular endothelial growth factor (VEGF), binding VEGF, and modulating the VEGF receptors. Investigators are also attempting to block signal transduction with receptor tyrosine kinase inhibitors. Experimental treatments for non-exudative AMD include agents that target inflammation, oxidative stress, and implement immune-modulation. The effectiveness of these newer pharmacologic agents has the potential to grow exponentially when used in combination with new and improved imaging modalities that can help identify disease earlier and follow treatment response more precisely.

Conclusion:

With a better understanding, at the genetic and molecular level, of AMD and the development of superior imaging modalities, investigators are able to offer treatment options that may offer unprecedented visual gains while reducing the need for repetitive treatments.

Vascular endothelial growth factors and their inhibitors in ocular neovascular disorders

The introduction of pharmacotherapy has been one of the most important advances in the management of retinal disorders. Age-related macular degeneration (AMD) was once considered as an irrepressible disease leading to permanent macular damage, however anti-vascular endothelial growth factor (anti-VEGF) agents are now believed to halt the progression of the condition and improve vision in a considerable proportion of patients. Anti-VEGF agents are among the most commonly used drugs in ophthalmology but questions and uncertainties still surround their indications, efficacy and complications. This paper reviews the role of VEGF under physiologic and pathologic conditions in the eye and available anti-VEGF agents in current ophthalmic practice.

Anti-vascular endothelial growth factor therapy for ocular neovascular disease

PURPOSE OF REVIEW

Recent research has shown that vascular endothelial growth factor (VEGF) is responsible for many ocular pathologies involving neovascularization. Over the past several years several new agents targeting VEGF have become commercially available for intraocular use. These agents have revolutionized the care of neovascular age related macular degeneration and have great potential for other blinding conditions such as diabetic retinopathy, retinopathy of prematurity, and neovascular glaucoma.

RECENT FINDINGS

The VEGF Inhibition Study in Ocular Neovascularization (VISION) trial first showed that an anti-VEGF agent (pegaptanib) was able to prevent vision loss in neovascular age related macular degeneration. The Minimally Classic/Occult Trial of Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular AMD (MARINA) and Anti-VEGF Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in AMD (ANCHOR) trials showed that ranibizumab prevented moderate vision loss in neovascular age related macular degeneration and for the first time that a substantial proportion of patients regained vision. Smaller case series have shown that bevacizumab can regress retinal, iris and disc neovascularization. Ongoing trials are investigating the utility of anti-VEGF therapy in retinopathy of prematurity, diabetic retinopathy, and neovascular glaucoma.

SUMMARY

Newer anti-VEGF therapies have shown unprecedented efficacy in treating age related macular degeneration with many patients experiencing improvement in vision. Ongoing trials will help guide their use in age related macular degeneration and expand their indications to many other blinding diseases.