![]() ![]() Note any opacity that seems to interfere. Direct the light to the pupil and look for an orange-red glow. Position the ophthalmoscope about 15° lateral to the patient's line of vision.As you peer through the aperture, keep both eyes opened, press the ophthalmoscope firmly against your bony orbit, and hold the handle at a slight angle away from the patient's face.Position yourself about a foot from the patient at eye level, and ask the patient to stare at a spot on the wall just over your shoulder.This avoids bumping noses with the patient. To examine the patient's right eye, hold the ophthalmoscope in your right hand and look through the aperture with your right eye to exam the patient's left eye, hold the ophthalmoscope in your left hand and look through the aperture with your left eye.Keep your index finger on the lens disc during the exam, so the diopters can be adjusted as necessary to focus in on the retinal structures.Turn the lens disc until the largest white circle of light can be seen, and the diopter indicator reads 0, meaning the ophthalmoscope lens is neither converging nor dispersing the light.After darkening the room, turn on the ophthalmoscope and shine the light on your hand or on the wall.Unless the patient's refractive errors make it difficult to focus on the retina, it is usually best to remove your own eyeglasses for the exam.Be familiar with these features before attempting to examine the patient. Since mydriatic eye drops are typically not used in general practice, the view of the fundus is limited to only a section of the posterior retina. A photograph showing an ophthalmoscopic view on the normal retina. A diagram showing a sagittal view of the human eye with the structures labeled.įigure 2: Normal retina. A blind spot approximately 15° temporal to the line of gaze results from a lack of photoreceptor cells at the optic disc.įigure 1. Just lateral and slightly inferior is the fovea, a darkened circular area that demarcates the point of central vision. The disc usually contains a central whitish physiologic cup where the vessels enter it normally occupies less than half the diameter of the entire disc. The first landmark observed during the funduscopic exam is the optic disc, which is where the optic nerve and retinal vessels enter the back of the eye ( Figure 2). Light is refracted as it passes sequentially through the cornea, the lens, and the vitreous body. The spherical eyeball collects and focuses light on the neurosensory cells of the retina. The ophthalmoscope is primarily used to examine the fundus, or the inner wall of the posterior eye, which consists of the choroid, retina, fovea, macula, optic disc, and retinal vessels ( Figure 1). The simplest ophthalmoscopes consist of an aperture to look through, a diopter indicator, and a disc for selecting lenses. Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA ![]()
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