Issue 1 - 2020

Author: M. Bruce Shields, M.D.
Marvin L. Sears Professor Emeritus, Department of Ophthalmology and Visual Science, Yale University School of Medicine, USA

Core Concepts

• The definition of glaucoma has evolved since ancient times to the present understanding of a group of characteristic optic neuropathies.
• Manifest glaucoma has the two basic stages of optic nerve damage and progressive loss of visual field.
• The glaucomatous process includes three pre-manifest stages (initial event, early ocular tissue alteration and pre-neuropathy event) and the two manifest stages. 
• All glaucomas have the five stages of the glaucomatous process, which is important to recognize in order to know how closely to follow each patient and when and how to treat.
• Since all forms of glaucoma share the five stages of the glaucomatous process, it may be that primary and secondary divisions should be reconsidered in future classifications of the glaucomas.

Author: Karin R. Pillunat, MD, PhD; Lutz E. Pillunat, MD, PhD
Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, Germany

Core Concepts

• Chronic systemic diseases, such as arterial hypertension (aHTN), vascular dysregulation, cardiac arrhythmia and dyslipidemia may be modifiable risk factors for primary open-angle glaucoma (POAG).
• Despite conflicting findings, most of the population-based glaucoma studies do describe an association between aHTN and POAG.
• Arterial HTN is a common comorbidity in patients with POAG.
• Sleep-time systemic hypotension is associated with progression of the disease and needs to be sought and avoided.
• Blood pressure fluctuations and intraocular pressure (IOP) fluctuations cause fluctuations in ocular perfusion pressures, which in turn cause blood flow instability and oxidative stress at the optic nerve head (ONH) compounded by the deficient autoregulation capacity associated with POAG.
• Primary vascular dysregulation (PVD) is often associated with low blood pressure and vasospastic symptoms. Most of the symptoms result from an impaired autoregulation of blood supply. The condition is associated with a higher risk of normal pressure glaucoma (NPG).
• Atrial fibrillation (AF) has been shown to increase the risk of developing NPG.
• Hypercholesterolemia might be associated with POAG. Long-term statin use seems to be associated with a reduced incidence of POAG.

Author: Paul R. Healey BMedSc, MBBS(Hons) MMed, PhD, FRANZCO Clinical Associate Professor, Sydney University
Glaucoma Service, Westmead & Sydney Eye Hospitals

Core Concepts

• Glaucoma and Diabetes have a complex relationship:
• Primary open angle glaucoma is more common in people with diabetes.
• Elevated glucose levels are partially neuroprotective for ischaemic and glaucomatous ganglion cells.
• Diabetic vascular disease may cause ocular ischemia, and even secondary angle closure through neovascularisation of the iridocorneal angle.
• Intravitreal injections for diabetic retinopathy or maculopathy can cause acute (usually transient) and chronic (often sustained) elevations in intraocular pressure (IOP) which can place glaucomatous stress on the optic nerve.
• Long acting intravitreal steroids such as off-label triamcinolone as well as fluocinolone or dexamethasone implants can increase IOP through the steroid response.

Author: Denis Wakefield MD, DSc, FRACP, FRCPA
Professor of Medicine, University of NSW and Director Sutherland Centre of Immunology, Sydney, Australia.

Core Concepts

• Glaucoma may be associated with common systemic diseases
• Spondyloarthritis in adults and  JIA (Juvenile Idiopathic Arthritis) in children are associated with inflammatory eye disease and glaucoma.
• Acute and chronic ocular infections are associated with glaucoma.
• Sleep apnoea is associated with hypertension and raised IOP.
• Drugs, particularly corticosteroids, may precipitate glaucoma.