Current and emerging medical therapies for glaucoma

Abstract

Glaucoma is a multifactorial optic neuropathy in which there is a characteristic acquired loss of retinal ganglion cells, at levels beyond normal age-related baseline loss, and corresponding atrophy of the optic nerve. Although asymptomatic in its earlier stages, the disease is nevertheless one of the leading global causes of irreversible blindness. Although elevated intraocular pressure (IOP) is one of the most important risk factors and lowering of IOP is the only proven treatment so far, the definition of glaucoma has evolved from a disease caused by increased IOP to one characterised by an IOP-sensitive, progressive optic neuropathy. In recent years, safer and better tolerated topical medications have been developed to control IOP more effectively, thereby limiting the need for surgery. New research has also noted the importance of diurnal IOP variation as a critical risk factor for progression of glaucomatous optic neuropathy (GON) and subsequent visual field loss. Moreover, new discoveries have further elucidated the basic pathophysiological and genetic mechanisms underlying the elevated levels of IOP, as well as the cellular mechanisms of GON. As our understanding of these complex pathways continues to improve, development opportunities for new therapeutic modalities will be enhanced.

Acceptance, Attitudes, and Beliefs of Singaporean Chinese Toward an Ocular Implant for Glaucoma Drug Delivery

“…1 Reduction of intraocular pressure (IOP) remains the main modifiable risk factor for the disease and the majority of patients with glaucoma are managed initially by medical treatment, 2 consisting of topical eye drops. Proportional reduction of IOP by 20% to 50% can decrease the average rate of progressive visual field loss by half.…”

Effect of Elevated Intracellular cAMP Levels on Actomyosin Contraction in Bovine Trabecular Meshwork Cells

“…Since the advent of topical prostaglandin analogs, pharmacologic strategies to reduce IOP have gained prominence over surgical treatments. 3 In humans, Ͼ80% of the aqueous humor exits the anterior chamber by the trabecular meshwork (TM) route. 4 Therefore, the outflow facility across the TM forms the primary determinant of IOP.…”

Glaucoma: Present Challenges and Future Trends

“…PGAs have been shown to reduce IOP more than timolol, which is considered a gold standard [40,41,42]. In addition, they more effectively prevent IOP spikes and fluctuations over 24 h [43]. …”

“…AAs decrease aqueous production and increase uveoscleral outflow, and the newer more specific α 2 -agonists (brimonidine and apraclonidine) cause fewer systemic hypotensive side effects than earlier nonselective AAs. Brimonidine is used for long-term therapy, whereas apraclonidine is most useful for short-term adjunctive use [43]. The major drawback of topical AAs is their frequent involvement in local allergic reactions.…”