Ischaemic optic neuropathy.

Ischaemic optic neuropathy is of two types: anterior (AION) and posterior (PION), the first involving the optic nerve head (ONH) and the second, the rest of the optic nerve. Pathogenetically AION and PION are very different diseases. AION represents an acute ischaemic disorder of the ONH supplied by the posterior ciliary artery (PCA), while PION has no specific location in the posterior part of the optic nerve and does not represent an ischaemic disorder of any definite artery. The most important step towards a logical understanding of the underlying causes, clinical features, pathogenesis and rational management of AION, is to understand the basic scientific issues involved; these are discussed in some detail. AION clinically is of two types: (1) that due to giant cell arteritis (arteritic AION: A-AION) and (2) non-arteritic AION (NA-AION). NA-AION, the more common of the two, is one of the most prevalent and visually crippling diseases in the middle-aged and elderly, and is potentially bilateral. NA-AION is a multifactorial disease, with many risk factors collectively contributing to its development. Although there is no known treatment for NA-AION, reduction of risk factors is important in decreasing chances of involvement of the second eye and of further episodes. Our studies have suggested that nocturnal arterial hypotension is an important risk factor for the development and progression of NA-AION. The role of nocturnal arterial hypotension in the pathogenesis of NA-AION and management of nocturnal hypotension is discussed. Potent antihypertensive drugs, when used aggressively and/or given at bedtime, are emerging as an important risk factor for nocturnal hypotension, and there is some evidence that NA-AION may be occurring as an iatrogenic disease in some individuals. A-AION, by contrast, is an ocular emergency and requires immediate treatment with systemic corticosteroids to prevent further visual loss. The clinical parameters which help to differentiate the two types of AION, and their respective management are discussed.

Scientific literature and gospel truth.

We live in an age of science, an age in which science impacts practically every phase of our life. In the field of medicine, our entire understanding of diseases and their management depends on scientific knowledge. To obtain that knowledge, we rely on the published scientific literature. Therefore, the sanctity of science must be fiercely guarded. In medicine, true science leads to valid treatment--and preservation of the life, health and (for ophthalmologists) eyesight of our patients. A corrupted science results in corrupted scientific knowledge which in turn, in medicine, leads to wrong treatment and harm to the patients.

Retinal vein occlusion.

In this review of the retinal vein occlusion (RVO), I have summarized recent advances on several controversial and clinically important topics: classification of RVO into six distinct clinical entities; pathogeneses and demographic characteristics of various types of RVO; differentiation of non-ischemic from ischemic central retinal vein occlusion (CRVO); differentiation of hemi-CRVO (HCRVO) from major branch RVO (BRVO); and the course, complications and management of various types of RVO.

Remembrances of things past.

The author relates an unlikely journey from his rural village in India, through medical school, a prestigious fellowship with Sir Stewart Duke-Elder, and a colourful career in the United Kingdom and the U.S.A., as a clinician and researcher, particularly in the area of vascular disease of the eye and optic nerve.