Progressive retinal nerve fiber layer (RNFL) thinning as a biomarker to guide intraocular pressure (IOP) lowering treatment in ocular hypertensives (OHT)

INTERVENTION: Investigator will monitor the enrolled subjects and make the decision to see is treatment is needed. Treatment parameters would be at the clinical discretion of the treating opthalmologist, Study team will examine retinal nerve fiber layer(RNFL) thickness of paradigm I participants using optical coherence tomography (OCT).. Upon detection of progressive retinal nerve fiber layer(RNFL) thinning, paradigm I participants will start to receive drug(s) for IOP lowering treatment. In 4‐month follow up visits, participants need to receive visual acuity (VA) measurement, slit‐lamp biomicroscopy for anterior and posterior segments, vertical cup‐to‐disc ratio (VCDR) measurement, Goldmann applanation tonometry and perimetry and optical coherence tomography. Participants need to receive fundus examination and central corneal thickness (CCT) with ultrasound pachymetry yearly Period of intervention is 5‐year. Drugs: prostaglandin analogue, 1 drop once daily, topical brimonidine, 1 drop, 2‐3 times daily, topical carbonic anhydrase inhibitor, 1 drop, 2‐3 times daily, topical In paradigm I, study team will examine RNFL thickness of paradigm I participants using OCT.. Upon detection of progressive RNFL thinning, paradigm I participants will start to receive drug(s) for IOP lowering treatment. In 4‐month follow up visits, participants need to receive visual acuity (VA) measurement, slit‐lamp biomicroscopy for anterior and posterior segments, vertical cup‐to‐disc ratio (VCDR) measurement, Goldmann applanation tonometry and perimetry and optical coherence tomography. Participants need to receive fundus examination and central corneal thickness (CCT) with ultrasound pachymetry yearly In Paradigm II, study team will examine according to OHTS‐EPGS risk prediction model five risk factors including higher IOP, older age, thinner central corneal thickness, VCDR and greater Visual Field (VF) pattern standard deviation (PSD) to examine participants’ risk to glaucoma. Upon detection of a 5‐year glaucoma conversion risk >15% calculated, participants will start to receive drug(s) for IOP lowering treatment. Participants need to receive fundus examination and central corneal thickness (CCT) with ultrasound pachymetry yearly. All participants are taking all the listed drugs at the same dose in Paradigm I. And for those participants in Paradigm II, they are taking all the listed drugs at the same dose.Participants in Paradigm I and II will have different dosage. Frequency of follow up visit: every 4 months for 5 years CONDITION: Retinal Nerve Fiber Layer Thinning ocular hypertension PRIMARY OUTCOME: Primary outcome measures the proportion of patients requiring IOP‐lowering treatment in 5 years., Using Optical Coherence Tomography to assess if patients require IOP‐lowering treatment. The outcome can be assessed by review of study records, SECONDARY OUTCOME: the proportion of patients with Visual Field (VF) progression ; ; Using visual field to access. The outcome can be assessed by review of study records, the total treatment costs in 5 years ; ; Looking at how much drug cost patients need to pay off. We will review the drug cost INCLUSION CRITERIA: 1) age more than or equal to 18 years; 2) best corrected VA is greater than or equal to 20/40 4) gonioscopically open anterior chamber angles 5) 3 reliable VF results without VF defects, normal optic disc and RNFL configuration in clinical examination 6) no RNFL abnormalities(i.e. within the 95% normal ranges) in the OCT RNFL thickness deviation map 7) no prior history of surgical/laser procedure for IOP lowering and receiving no topical IOP‐lowering medication. 8) IOP measurements for eligibility assessment are obtained after washout of prestudy topical IOP 3) an average IOP is more than or equal to 24mmHg but less than 32mmHg in at least 1 eye an more than or equal to 21mmHg but less than 32mmHg in the fellow eye measured from 3 separate baseline visits within 4 weeks