Effect of Nailfold Application of Latanoprostene Bunod on Nailfold Capillary Blood Flow

In this study, the study team investigates the effect of topically-applied latanoprostene bunod (LTB) on the blood flow at the nailfold of the 4th finger in patients with primary open angle glaucoma. LTB is a new anti-glaucoma eye drop which received FDA clearance in early November 2017. It has two components: the prostaglandin analog (PGA) which decreases intraocular pressure (IOP) by enhancing the drainage of the aqueous (the fluid in the front part of the eye) from the eye, and the nitric oxide (NO) moiety which naturally dilates arteries in the body. The capillaries at the nailfold are comparable to those of the optic nerve head, which makes them a reasonable surrogate for evaluation of the effect of LTB on the blood flow. Therefore, this study may provide indirect evidence for the beneficial effect of LTB on blood flow to optic nerve which can potentially save the optic nerve from glaucomatous damage. Primary open angle glaucoma is a progressive condition and is the most common cause of irreversible blindness worldwide. Primary open angle glaucoma (POAG) is a subset of the glaucomas defined by an open, normal appearing anterior chamber angle and raised intraocular pressure (IOP), with no other underlying disease.

In addition to LTB, the study team will use latanoprost (L), an-FDA approved PGA anti-glaucoma eye drop and normal saline (NS: the physiologic solution composed of 0.9% salt and water), as controls to make sure the effects of LPB on nail fold capillary blood flow is not due to its PGA (as L is) or due to the placebo effect (as NS is).

This study may also serve as background information for the development of new anti-glaucoma medications which can be injected into the eye to facilitate blood flow to the optic nerve.