Primary open-angle glaucoma of normal pressure (literature review)

The review is devoted to normal-tension glaucoma (NTG) – pathogenesis, risk factors, clinical features, diagnosis and treatment. The key mechanisms in the pathogenesis of NTG are: disturbance of the transmembrane pressure gradient between intraocular pressure (IOP) and intracranial pressure, decreased perfusion pressure, vascular dysregulation, genetic mutations, immune response and metabolic disorders. Risk factors include arterial hypotension, racial predisposition (mainly Asian populations), thin cornea, obstructive sleep apnea syndrome and low systolic pressure. Clinical features of NTG: predominance in women, rounded excavation of the optic disc with sloping edges, decreased perfusion pressure and less pronounced daily fluctuations in IOP (on average, 3.2 mm Hg). Diagnosis requires a comprehensive approach using optical coherence tomography, perimetry, assessment of asymmetry parameters (IOP, corneal thickness) and analysis of systemic factors (heart rate variability, hemodynamics). Treatment is aimed at achieving “tolerant IOP” (below the average statistical norm) using prostaglandin analogues, carbonic anhydrase inhibitors, laser trabeculoplasty and microinvasive surgery. Despite progress, unresolved issues remain, including the causal relationship between decreased blood flow and neurodegeneration, as well as the role of immune and metabolic disorders. Key words: primary open-angle glaucoma, normal-tension glaucoma, clinical features, development risk factors, diagnosis