Preseptal (periorbital) cellulitis, subperiosteal abscess and orbital cellulitis are conditions which are still frequently seen in ENT, Ophthalmic and Paediatric practice. They are parts of the spectrum of the disease processes seen in the acutely inflamed orbit. The clinician should try and establish which of the three conditions the patient has, as both subperiosteal abscess and orbital cellulitis are more serious conditions than preseptal cellulitis.

There is still much confusion in the literature over the terms ‘periorbital cellulitis’ and ‘orbital cellulitis', and the terms are often used interchangeably. This makes an analysis of the literature with regard to the features of the conditions difficult. The introduction of the term ‘the acute orbit’ might possibly lead to less confusion ifitisusedto cover all inflammatory processes in the orbit. Descriptions, definitions and classifications of orbital inflammations have been given by many authors in the literature. There are many causes of the acute orbit, but sinusitis remains the commonest cause.