Ento Key

Neuroimaging Computed tomography Physics Computed tomography (CT) uses X-ray beams to obtain tissue density values from which detailed cross-sectional images are formed by a computer. Tissue density is represented by…

Introduction Anatomy and physiology General The cornea is a complex structure which, as well as having a protective role, is responsible for about three-quarters of the optical power of the…

Retinal Circulation Arterial system • The central retinal artery , an end artery, enters the optic nerve approximately 1 cm behind the globe. It is composed of three anatomical layers: ○…

Classification The Standardization of Uveitis Nomenclature (SUN) Working Group guidance on uveitis terminology, endorsed by the International Uveitis Study Group (IUSG), categorizes uveitis anatomically ( Fig. 11.1 ): • Anterior…

Benign Epibulbar Tumours Conjunctival naevus Introduction A conjunctival naevus is the most common melanocytic conjunctival tumour; the overall risk of malignant transformation is less than 1%. Treatment by excision is…

Introduction Anatomical landmarks The macula ( Fig. 14.1A ) is a round area at the posterior pole, lying inside the temporal vascular arcades. It measures between 5 and 6 mm in…

Introduction Anatomy of the peripheral retina Pars plana The ciliary body starts 1 mm from the limbus and extends posteriorly for about 6 mm. The anterior 2 mm consist of the pars plicata,…

Introduction General The hereditary fundus dystrophies are a group of disorders that commonly exert their major effect on the retinal pigment epithelium (RPE)–photoreceptor complex and the choriocapillaris to cause a…

Introduction Aqueous production Aqueous humour is produced from plasma by the ciliary epithelium of the ciliary body pars plicata, using a combination of active and passive secretion. A high-protein filtrate…

Eyelid Trauma Periocular haematoma A ‘black eye’, consisting of a haematoma (focal collection of blood) and/or periocular ecchymosis (diffuse bruising) and oedema ( Fig. 21.1A ) is the most common…