What is Glaucoma?

Glaucoma is a chronic, progressive condition in which optic nerve damage occurs, typically due to pressure within the eye. Over time, the nerve damage can lead to vision loss. The risk for blindness in people with this condition depends on the degree of intraocular pressure, severity of disease, age of onset, and other determinants of susceptibility, such as family history of glaucoma.1 Glaucoma affects about 2% of US adults over age 40.2

In healthy eyes, a clear fluid normally flows continuously in and out of the anterior chamber, nourishing nearby tissues. This fluid exits the chamber at the “open angle” where the cornea and iris meet and then flows through a spongy meshwork, draining away from the eye.3

In open-angle glaucoma—the most common form—this drainage angle between the iris and cornea is wide open. However, fluid passes too slowly through the meshwork drain and builds up, increasing the pressure inside the eye and on the optic nerve.3 There is no identifying pathology for this “clogging” that occurs, and it is often silent and painless.1,3

Closed-angle glaucoma also involves intraocular pressure from fluid buildup in the eye, but this is caused by an anatomic narrowing of the drainage angle. This can suddenly close completely, causing a fast and steep increase in intraocular pressure that can pose a significant risk for vision loss.1,3



Intraocular Pressure Reduction

Lowering intraocular pressure (IOP) is the only intervention proven to prevent vision loss glaucoma. Treatment typically starts with medications, such as drops, that reduce intraocular pressure.

The most common glaucoma drops today (prostaglandin analogs, or PGAs) activate the prostaglandin FP receptor.4 This receptor is 1 of 9 prostanoid receptors that have been identified: FP, EP1-4, DP1, DP2, IP, and TP.5 FP activation leads to an increase in intracellular calcium ions and primarily lowers IOP through the uveoscleral outflow pathway.5 However, not all patients respond:
・~25% have inadequate responses to PGAs4
・~40% require adjunctive therapy4


Santen is also committed to preserving vision by pursuing the development of Sepetaprost, an eye drop that treats glaucoma with a novel mechanism of action.


    1. International Council on Ophthalmology. ICO Guidelines for Glaucoma Eye Care: 2016. Available at: www.icoph.org/downloads/ICOGlaucomaGuidelines.pdf. Accessed on January 28, 2019.
    2. American Academy of Ophthalmology. Preferred Practice Pattern® Guidelines. Primary Open-Angle Glaucoma. San Francisco, CA: American Academy of Ophthalmology; 2015.
    3. National Institutes of Health. National Eye Institute. Facts about glaucoma. Available at: https://nei.nih.gov/health/glaucoma/glaucoma_facts. Accessed on January 28, 2019.
    4. Aihara M, et al. Intraocular pressure‑lowering effect of omidenepag isopropyl in latanoprost non‑/low‑responder patients with primary open‑angle glaucoma or ocular hypertension: the FUJI study. Jpn J Ophthalmol. 2020;64:398-406.
    5. Aihara M. Prostanoid receptor agonists for glaucoma treatment. Jpn J Ophthalmol. 2021;65(5):581-590.