Progression from Ocular Hypertension into Glaucoma

Ocular hypertension (OHT) is characterized by raised intraocular pressure (IOP) >21 mmHg without any visual field (functional) or optic nerve (structural) defect featuring glaucoma. Raised IOP is a major risk factor of glaucoma and a proportion of eyes with OHT progresses into primary open angle glaucoma. Glaucoma is a debilitating disease with potential for blindness if left untreated and associated reduction in the quality of life of the affected individual. It is challenging for the clinicians to decide whether an OHT will progress into glaucoma or not based on the risk factor model of the Ocular hypertension treatment study. Moreover, the question whether only IOP or a myriad of factors like central corneal thickness, baseline IOP, visual field, family history of glaucoma, ocular biomechanics are all important in determining the progression is yet to be answered. The rate of progression is also important and needs analysis for further discussion. Summarizing the landmark studies on ocular hypertension and glaucoma to date are imperative in this regard. This chapter presents the overview of OHT and its possible etiology and pathophysiology, risk factors, clinical tests evaluating OHT eyes and elaborates on the progression of OHT to glaucoma over time in relation to the treatment.