Based on the results of population-based epidemiological surveys including Framinghan, Beaver Dam, Baltimore, Rotterdam, Barbados, and Egna-Neumarkt surveys, it is estimated that 3-6 million people in the United States have IOP >21 mm Hg without detectable glaucomatous retinal optic nerve morphology or visual functional impairment (with current screening tools). Of these, 4 to 10% have high IOP in people over 40 years of age. Approximately 0.5-1% of patients with hypertension develop glaucoma each year after a 5-10 year course of disease. With continued improvements in fundus and visual field examination techniques, this risk has been found to be less than 1% per year. The prevalence of hypertension is 10 to 15 times higher than the prevalence of POAG with (visual field damage as a criterion). Previously, risk factors for conversion of hypertension to glaucoma included IOP, age, gender, race, family history of glaucoma, cardiovascular system disease, endocrine system disease, abnormal atrial aqueous dynamics, structural abnormalities of the optic nerve, and other abnormal ocular manifestations such as refractive error, pigment spreading syndrome, and exfoliation syndrome; however, none of the risk factors alone could be used as a prognosis for hypertension However, no single risk factor can be used as an indicator of the prognosis of hypertension. The High Ocular Pressure Treatment Study (OHTS) by Kass et al. aimed to investigate whether treatment to control IOP was effective in reducing the incidence of glaucoma and to investigate the risk factors for conversion of hypertension to POAG. thickness was one of the risk factors for the development of glaucoma, and central corneal thickness became a stronger negative correlate in determining the prognosis of hypertension. According to OHTS, hypertension can be divided into the following categories: 1. Patients with moderately thick corneas and moderately elevated intraocular pressure (IOP), which may be corrected for IOP by corneal thickness values, may find that their actual IOP values are in the normal range and have a very low chance of developing glaucoma; 2. Patients who may have potential glaucomatous optic nerve damage, but whose visual field and fundus examination are normal, may develop glaucoma within 5 years. 3. patients with thin corneas and high IOP values have a higher chance of developing glaucoma. Medeiros et al. found that the central corneal thickness of patients with hypertension who developed glaucomatous visual impairment was significantly lower than that of patients without glaucomatous visual impairment, and they concluded that the central corneal thickness should be considered when evaluating the prognosis of patients with hypertension. Because of the positive correlation between central corneal thickness and IOP, central corneal thickness can be used as a negative predictor of the development of glaucoma. For patients with a central corneal thickness between 565 and 585 um, the chance of developing glaucoma within 5 years was 13%. Similarly, for patients with a cup-to-disc ratio greater than 0.3, if the central corneal thickness was less than 556 um, the chance of developing glaucoma within 5 years was 24%, while for patients with a central corneal thickness of 565-585 um, the chance of developing glaucoma within 5 years was 16%. These studies show that central corneal thickness is a negative predictor of POAG and one of the most important risk factors in determining the prognosis of hypertensive eye disease. The European Glaucoma Prevention Study (EGPS) group also reported that central corneal thickness is an important predictor of POAG development, in addition to age, cup-to-disc ratio and visual field sensitivity. Studies have shown that the likelihood of visual field damage increases rapidly when IOP > 21 mmHg, and is most pronounced at IOPs above 26 mmHg Patients with hypertension at 28 mmHg are 15 times more likely to have visual field damage than those with IOPs of 22 mmHg. Wax et al. concluded that the effect of IOP is continuous and that 24-hour IOP fluctuations versus multi-day IOP fluctuations are an important risk factor in determining the prognosis of hypertension. The range of IOP fluctuations in a normal person is 3-6 mmHg a day, and our scholars usually consider IOP fluctuations greater than 8 mmHg to be pathologic. In addition, studies have demonstrated that most patients with glaucoma have irregular 24-hour IOP fluctuations or inconsistent daily IOP fluctuation profiles. A recent review concluded that prognostic factors for the development of hypertension into POAG include older age, thin central cornea, large cup-to-disc ratio, large pattern standard deviation (PSD) on Humphrey visual field examination, and family history of glaucoma; while factors for progression of POAG are older age, high basal IOP, thin central corneal thinning, magnitude of IOP fluctuations, and possibly diabetes mellitus. Therefore, these individuals with hypertension should be monitored more closely than the general population for early detection of glaucomatous damage. Regarding the prevalence of POAG in patients with hypertension, OHTS reported that Kass et al [65] found a 9.5% prevalence of POAG with a decreasing trend in IOP of approximately 4.0% ± 11.6% at a mean follow-up of 5 years for hypertension; Higginbotham et al found a 16.1 % prevalence of POAG at a mean follow-up of 6.5 years for African Americans (a high-risk race) with hypertension. Higginbotham et al. found a 16.1% incidence of POAG in African Americans (a high-risk population) with a mean follow-up of 6.5 years; Kass et al [78] reported a 22% incidence of POAG with a mean follow-up of 13 years (7.5 years untreated and 5.5 years medically treated) for hypertension.