The anterior segment of the eye usually refers to the cornea, iris, and lens. Most of the anterior segment conditions can be diagnosed clinically with a slit lamp.
However, even without a slit lamp, many anterior segment signs can be picked up using a torch together with close observation alone. This is particularly important as many potentially blinding conditions are caused by systemic diseases and it is important to pick these signs up early.
Different parts of the retina are particularly sensitive to certain hues. The majority of nerve fibres of the anterior visual pathways (optic nerve, optic chiasm and optic tract) serve our central vision, which is particularly sensitive to red and green light. Hence, diseases of the optic nerve (optic neuropathies) will cause red-green colour desaturation. Technique…
When is it true optic disc edema? The optic nerve head consists of a bundle of densely packed axons from 1.2 million retinal ganglion cells and also encases the central retinal artery and vein. Thus, true optic disc swelling should have both mechanical and vascular signs present. The above photo (Figure 1) illustrates a typical…
Subtitles in English for this video can be displayed by clicking on (first button on the bottom right hand corner of the video). Direct ophthalmoscopy is a troublesome skill for medical students and practitioners, but when practiced frequently, this is a technique that can be very useful in clinical practice. It is advisable that each medical…
Subtitles in English for this video can be displayed by clicking on (first button on the bottom right hand corner of the video). The size of the pupillary aperture at any point in time is dependent on a balance between sympathetic tone, parasympathetic tone, the light reflex and the near reflex. The light reflex is an…
When is it optic atrophy? The optic nerve comprises of 1.2 million myelinated axons. Once damaged, the axons do not regenerate (behaves more like a white matter tract than a true peripheral nerve). Thus optic atrophy is the common morphological endpoint of any optic neuropathy. Clinically, the neuro-retinal rim of the optic disc (the area…
Dr Jennifer Shum Introduction Glaucoma is a neurodegenerative disease characterized by the progressive death of retinal ganglion cells (RGC) and their axons, leading to characteristic optic nerve structural damage and visual field deficits. It is the second leading cause of blindness in developed countries. Risk factors A high intraocular pressure (IOP) is the strongest risk…