This chapter combines the traditional anatomical approach to embryology with the rapidly advancing understanding of developmental biological processes involved in eye formation and maturation. Knowledge of the gene networks involved in ocular development provides a foundation for understanding the impact…
Introduction This chapter first presents a number of key considerations and issues relevant to understanding and applying evidence from epidemiological studies of childhood visual impairment (VI), severe visual impairment (SVI), or blindness ( Box 1.1 and Box 1.2 ) –…
Eyelid trauma Periocular haematoma A ‘black eye,’ consisting of a haematoma (focal collection of blood) and/or periocular ecchymosis (diffuse bruising) and oedema, is a very common result of blunt injury and is generally innocuous. It is important to exclude serious…
Cornea Vortex keratopathy (cornea verticillata) Signs: (a) fine greyish or golden-brown opacities in the inferior corneal epithelium, (b) progressing to a whorl-like pattern that originates from a point below the pupil and swirls outwards, sparing the limbus ( Fig. 20.1…
Optic nerve Table 19.1 Signs of optic nerve dysfunction Reduced VA Relative afferent pupillary defect Dyschromatopsia: impairment of colour vision, mainly red and green Diminished light brightness sensitivity Diminished contrast sensitivity Visual field defects, varying with the underlying pathology Table…
Amblyopia Definition: unilateral, or rarely bilateral, subnormal best corrected VA caused by form vision deprivation and/or abnormal binocular interaction, for which there is no identifiable pathology of the eye or visual pathway. Classification Strabismic: resulting from abnormal binocular interaction in…
Muscae volitantes Muscae volitantes are extremely common minute fly- or worm-like physiological opacities best seen by the patient against a pale background. They are thought to be predominantly composed of embryological remnants in the vitreous gel. You’re Reading a Preview…
Definitions Retinal detachment (RD): separation of the neurosensory retina (NSR) from the RPE, with the accumulation of subretinal fluid (SRF). Rhegmatogenous RD: occurs when a full-thickness defect in the NSR permits synchytic (liquefied) vitreous to gain access to the subretinal…
Generalized photoreceptor dystrophies Retinitis pigmentosa Genetics: Typical retinitis pigmentosa (RP) is a group of retinal dystrophies initially mainly affecting the rod photoreceptor cells and subsequently cones (rod–cone dystrophy). It can be sporadic or inherited as AD, AR, or X-L; many…
Age-related macular degeneration Introduction Definition: degeneration affecting the macula; characterized by drusen and RPE changes, and sometimes CNV. Classification: non-exudative (‘dry’)—most common, and exudative (‘wet’); the latter is associated with more rapid progression to advanced sight loss. Importance: most common…