Table 10. Distribution of related keywords in the articles during 2009-2018.

Ranking	2009-2018	2009-2013	2014-2018
1	Glaucoma	Glaucoma	Glaucoma
2	Intraocular pressure	Intraocular pressure	Intraocular pressure
3	Optical coherence tomography	Optical coherence tomography	Optical coherence tomography
4	Retinal ganglion cells	Trabeculectomy	Retinal ganglion cells
5	Trabeculectomy	Retinal ganglion cells	Trabeculectomy
6	Vision	Vision	Primary open-angle glaucoma
7	Primary open-angle glaucoma	Primary open-angle glaucoma	Vision
8	Retinal nerve fiber layer	Ocular hypertension	Retinal nerve fiber layer
9	Retina	Cataract	Retina
10	Ocular hypertension	Retina	Open-angle glaucoma
11	Open-angle glaucoma	Retinal nerve fiber layer	Optic nerve head
12	Cataract	Open-angle glaucoma	Trabecular meshwork
13	Neuroprotection	Angle-closure glaucoma	Ocular hypertension
14	Optic nerve head	Neuroprotection	Cataract
15	Trabecular meshwork	Central corneal thickness	Neuroprotection
16	Optic nerve	Prostaglandin analogs	Optic nerve
17	Angle-closure glaucoma	Optic nerve	Primary angle-closure glaucoma
18	Pseudoexfoliation glaucoma	Pseudoexfoliation glaucoma	Normal tension glaucoma
19	Normal tension glaucoma	Normal tension glaucoma	Spectral-domain optical coherence tomography
20	Primary angle-closure glaucoma	Optic nerve head	Pseudoexfoliation glaucoma