Color Doppler Imaging Analysis of Ocular Blood Flow Velocities in Normal Tension Glaucoma Patients: A Meta-Analysis

Table 4

Quality-related data of the included studies.

Study	Inclusive criteria of NTG patients	Eye selection (NTG/control)	Type of treatment (topical)
[29]	Untreated IOP <21 mmHg; Characteristic optic disc damage; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Beta blockers, 37; Prostaglandin analogs, 35; Carbonic anhydrase inhibitors, 31; Alpha-adrenergic agents, 7
[43]	Untreated IOP <21 mmHg; Characteristic optic disc damage; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Beta blockers, 28; Prostaglandin analogs, 36; Carbonic anhydrase inhibitors, 20; Alpha-adrenergic agents, 6
[44]	Untreated IOP <21 mmHg; Characteristic optic disc damage; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Beta blockers, 26; Prostaglandin analogs, 28; Carbonic anhydrase inhibitors, 24; Alpha agonists, 6
[45]	Untreated IOP <21 mmHg; Characteristic optic disc damage; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Current topical IOP-lowering drugs; (medicine not available)
[46]	Untreated IOP <21 mmHg; Nerve fiber layer visual defects in each eye; Bilateral symmetric glaucomatous-type optic; disk cupping; Glaucomatous visual field loss	Random/random	NA (35% with a first-time diagnosis of NTG)
[47]	Untreated IOP <22 mmHg; Characteristic optic disc change; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Without any topical medication, 17 Using topical glaucoma medications with a wash-out period of 1 month, 17
[48]	Untreated IOP <22 mmHg; Typical glaucomatous disc damage; Glaucomatous visual field loss	Eye with worse field; loss/random	Without any topical medication, 14 Using topical glaucoma medications with a wash-out period of 1 month, 11
[49]	Untreated IOP <18 mmHg; Glaucomatous-type cupping of the optic disk; Glaucomatous visual field loss	NA	NA
[50]	Untreated IOP <20 mmHg; Glaucomatous optic nerve abnormality; Glaucomatous visual field loss	NA	NA
[51]	Simple open angle glaucoma and normal pressure; Glaucomatous appearance of optic disc; Perimetric alterations (MD > 2dB, CPSD > 4dB)	NA	NA
[52]^①	Untreated IOP <21 mmHg; Progressive glaucomatous optic nerve damage; (bilateral NTG)	Random/random	Using topical glaucoma medications with a wash-out period of 1 month
[53]	Untreated IOP <21 mmHg; Abnormal thinning of the neuroretinal rim with glaucomatous cupping of the optic nerve head (cup-to-disc ratio 0.6); Glaucomatous visual field loss	Right eye preferential/right eye preferential	Using topical glaucoma medications with a wash-out period of 6 weeks
[54]	Untreated IOP <22 mmHg; Functional defect of visual field (stage 1L according to Glaucoma Staging System 2)	Random eye in diseased; eyes/random	Without any topical medication
[55]	Untreated IOP <22 mmHg; Bilateral glaucomatous optic disc cupping; Glaucomatous visual field loss	Right eye/right eye	NA
[56]	Untreated IOP <21 mmHg; Glaucomatous excavation of the optic disc; Glaucomatous visual field loss	Random/random	NA
[57]	Untreated IOP <21 mmHg; A progressive optic neuropathy characterized by optic nerve head excavation; Glaucomatous visual field loss	Random/random	Current topical IOP-lowering drugs; (medicine not available)
[58]	Untreated IOP <21 mmHg; Glaucomatous optic nerve head cupping; Glaucomatous visual field loss	Random/random	Without any topical medication
[30]	Untreated IOP <21 mmHg; Glaucomatous optic nerve head cupping; Glaucomatous visual field loss	Random eye in diseased; eyes/random	Without any topical medication or using topical glaucoma medications with a wash-out period of 3 weeks
[59]^②	Untreated IOP <21 mmHg; Glaucomatous optic nerve abnormality; Glaucomatous visual field loss; (bilateral NTG and NTG with one eye)	Right eye/right eye	Beta blockers, 8
[60]	Untreated IOP <21 mmHg; Characteristic disc; Glaucomatous visual field loss	Right eye/right eye	Current topical IOP-lowering drugs, 12; (medicine not available); Without any topical medication, 27; NA 3
[61]	Untreated IOP <21 mmHg; Characteristic optic disc damage; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Current topical IOP-lowering drugs; (medicine not available)
[62]	Untreated IOP <21 mmHg; Characteristic optic disc change; Glaucomatous visual field loss	Eye with greater glaucomatous; damage/random	Current topical IOP-lowering drugs; (medicine not available)
[28]	Untreated IOP <21 mmHg; Glaucomatous optic nerve appearance; Glaucomatous visual field loss	Random eye in diseased; eyes/random	Without any topical medication

NA = not available.
^①In that study, all NTG patients selected were with bilateral NTG. That study aimed to investigate the effects of nipradilol on retrobulbar hemodynamic. NTG patients and normal controls were given nipradilol in one random eye and placebo in the other. This meta-analysis only used the data of the eye which would be instilled with nipradilol before the NTG patients and normal controls were given nipradilol.
^②That study provided outcome measurements data of both eyes, but this meta-analysis only chose the data of right eye according to the eye selection method of several of the other included studies. The NTG patients in that study were composed of 22 patients with bilateral normal tension glaucoma and 2 patients with normal tension glaucoma who had only one eye (one had only right eye and one had only left eye).