Therapeutic Approaches for Age-Related Macular Degeneration

Abstract

Damage to the retinal pigment epithelium, Bruch's membrane and/or tissues underlying macula is known to increase the risk of age-related macular degeneration (AMD). AMD is commonly categorized in two distinct types, namely, the nonexudative (dry form) and the exudative (wet form). Currently, there is no ideal treatment available for AMD. Recommended standard treatments are based on the use of vascular endothelial growth factor (VEGF), with the disadvantage of requiring repeated intravitreal injections which hinder patient's compliance to the therapy. In recent years, several synthetic and natural active compounds have been proposed as innovative therapeutic strategies against this disease. There is a growing interest in the development of formulations based on nanotechnology because of its important role in the management of posterior eye segment disorders, without the use of intravitreal injections, and furthermore, with the potential to prolong drug release and thus reduce adverse effects. In the same way, 3D bioprinting constitutes an alternative to regeneration therapies for the human retina to restore its functions. The application of 3D bioprinting may change the current and future perspectives of the treatment of patients with AMD, especially those who do not respond to conventional treatment. To monitor the progress of AMD treatment and disease, retinal images are used. In this work, we revised the recent challenges encountered in the treatment of different forms of AMD, innovative nanoformulations, 3D bioprinting, and techniques to monitor the progress.

Keywords: 3D bioprinting; age-related macular degeneration; drusen; nanocarriers; retinal pigment epithelium; vascular endothelial growth factor.

Figure 1

Appearance of macula in a healthy (left) and in a damaged (right) eye (reproduced from Fernandes et al. (2022) [2], CC BY license).

Figure 2

Schematic representation of the gene therapy options available in the literature showing their Modus operandi.

Figure 3

Stem cell therapy in AMD diagram [authors own drawing].

Figure 4

Schematic representation of common nanocarriers. (A) liposome; (B) Nanomicelle; (C) Dendrimer; (D) Nanoemulsion (oil-in-water type on the left-hand side; water-in-oil type on the right-hand side); (E) Nanoparticles (solid core surrounded by a surfactant layer). [authors own drawing].