Glaucoma
Conditions
Interventions
Normal tension glaucoma (NTG) group:N/A
Primary open-angle glaucoma (POAG) group:N/A
Control group:N/A
Sponsors
Department of Ophthalmology and Visual Sciences (DOVS), Chinese University of Hong Kong
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Diagnostic criteria of NTG: (1) Six median untreated intraocular pressure (IOP) readings consistently less than 21 mmHg, with no more than 1 reading equal to 23 or 24 mmHg and no single measurement more than 24 mmHg. At least 2 readings were obtained at a different time of the day from the rest; (2) Drainage angle of Shaffer grade II or above on dark room gonioscopy; (3) Glaucomatous optic disc cupping and loss of neuroretinal rim; (4) Fulfils the minimal criteria for glaucomatous visual field defect (see below); (5) Glaucoma eyes with ‘Moderate’ and ‘Advanced’ visual field defects according to the Glaucoma grading scale of Hodapp-Parrish-Anderson 21 i.e. mean deviation (MD) in Humphrey automated perimetry of -6.00 to -20.00 dB; (6) Participants of "Identification of anatomical vascular risk factors for normal tension glaucoma (NTG) and NTG progression" study as normal tension glaucoma (NTG) participants or normal control participants. Diagnostic criteria of POAG: (1) Documented maximum IOP (IOPmax) of >=30mmHg with or without IOP-lowering medication, but excluding elevated IOP associated with episodes of acute primary angle closure attack; (2) Drainage angle of any Shaffer grading on gonioscopy; (3) Glaucomatous optic disc cupping and loss of neuroretinal rim; (4) Fulfils the minimal criteria for glaucomatous visual field defect (see below); (5) Glaucoma eyes with ‘Moderate’ and ‘Advanced’ visual field defects according to the Glaucoma grading scale of Hodapp-Parrish-Anderson (Table 2), i.e. mean deviation (MD) in Humphrey automated perimetry of -6.00 to -20.00 dB. Control subjects: Age-matched healthy controls are recruited from our clinic at Hong Kong Eye Hospital. They have an anterior chamber angle of Shaffer grade II or above, untreated IOP of below 21 mmHg, and no family or personal history of glaucoma or other ocular diseases (except visually insignificant senile cataract or myopia / hyperopia of less than 3D), and no systemic diseases that may increase the risk of developing glaucoma, such as uveitis, diseases requiring the use of steroid, having ocular hypertension and / or suspicious optic nerve head morphology.
Exclusion criteria
Exclusion criteria: (1) Secondary causes for ocular hypertension or glaucomatous optic neuropathy (e.g., previous ocular trauma, steroids use, uveitis, etc.); (2) Patients with diseases precluding accurate measurement of IOP, visual acuity, OCT / OCT-A imaging, and performance of VF tests; (3) Patients who had previous ocular surgery (except uncomplicated cataract surgery); (4) Patients with systemic vascular disorders as ischemic disturbance is a significant risk factor to POAG and NTG; (5) Patients who have taken systemic antibiotics in the last 6 months; (6) Unable to give informed consent. Patients with diabetes mellitus, or who are unable to provide informed consent, will not be invited to participate in this study.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Gut microbiome composition; | — |
Countries
China
Contacts
Public ContactProf Clement Tham
Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong
Outcome results
None listed