Nanomedicine for glaucoma: sustained release latanoprost offers a new therapeutic option with substantial benefits over eyedrops.

Glaucoma is a chronic progressive optic neuropathy that is characterized by optic nerve changes and visual field loss. Elevated intraocular pressure (IOP) is the main modifiable risk factor. Chronic instillation of daily eyedrops to lower IOP is the primary treatment of choice, although it requires patient adherence and correct performance. We have developed a nanoliposome drug delivery system for the longer term delivery of latanoprost. In the present open-label, pilot study, the safety and efficacy of a single subconjunctival injection of liposomal latanoprost was evaluated in six subjects with a diagnosis of either ocular hypertension (OHT) or primary open-angle glaucoma (POAG). Subconjunctival injection of liposomal latanoprost was well tolerated by all six subjects. From a baseline IOP of 27.55 ± 3.25 mmHg, the mean IOP decreased within 1 h to 14.52 ± 3.31 mmHg (range 10-18 mmHg). This represented a mean decrease of 13.03 ± 2.88 mmHg (range 9-17 mmHg), or 47.43 ± 10.05 % (range 37-63 %). A clinically and statistically significant IOP reduction (≥20 % IOP reduction, P = 0.001 to 0.049) was observed through 3 months after injection. The nanomedicine reported here is the first nanocarrier formulation that has an extended duration of action in humans, beyond a couple of weeks. The findings in this study open up a new treatment modality, which will greatly enhance patient compliance and improve treatment outcomes. The current study provides the evidence and support for further clinical studies of liposomal latanoprost in the treatment of glaucoma.