Eye diseases. Technique for examining the eye in transmitted light and ophthalmoscopy (the most important)

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Eye diseases. Technique for examining the eye in transmitted light and ophthalmoscopy (the most important)

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10. Technique of examining the eye in transmitted light and ophthalmoscopy

The deep media of the eye (lens and vitreous body) are examined in transmitted light using an ophthalmoscope. The light source (a frosted electric lamp with a power of 60100-2030 W) is placed to the left and behind the patient, the doctor sits opposite. Using an ophthalmic mirror placed in front of the researcher's right eye, a beam of light is directed into the pupil of the examined eye from a distance of XNUMX cm. The researcher examines the pupil through the opening of the ophthalmoscope. In cases where the refractive media of the eye are transparent, the reflex from the fundus of the eye is uniformly red. Various obstacles in the path of the light beam, i.e., clouding of the media, delay some of the rays reflected from the fundus of the eye. Against the background of the red pupil, these opacities are visible as dark spots of various shapes and sizes. Changes in the cornea can be easily excluded during examination using lateral illumination.

If there is a significant change in the vitreous body due to inflammation of the vascular tract or hemorrhage, the fundus reflex becomes dim or absent.

The fundus of the eye is examined using the ophthalmoscopy method, which is one of the most important methods for studying the organ of vision, allowing one to judge the condition of the retina, its vessels, choroid and optic nerve. The most widely used ophthalmoscopy method is the reverse. The study is carried out in a darkened room. An ophthalmoscopic mirror is placed in front of the right eye of the researcher sitting at a distance of 4050 cm from the subject. The light source is positioned behind and to the left of the patient, as in a transmitted light examination. After obtaining a uniform glow of the pupil, the researcher places a magnifying glass (usually 13,0 diopters) 78 cm in front of the patient’s eye, resting his finger on his forehead. A true reverse image of the fundus, magnified approximately 5 times, is seen hanging in the air at a distance of about 7 cm in front of the magnifying glass. To examine a larger area of the fundus, if there are no contraindications, the patient’s pupil is first dilated with a 1% solution of homatropine or a 0,25% solution of scopolamine.

Examination of the fundus begins with the most visible part of the optic nerve head. Against the red background of the fundus, the optic disc appears as a yellowish-pink, slightly oval formation with clear boundaries. The color, contours and tissue of the optic nerve head change due to inflammatory and congestive phenomena, optic nerve atrophy, damage to the choroid and many general diseases, in particular blood vessels, etc. Pay attention to the condition of the retinal vessels emerging from the middle of the optic nerve head, their caliber, color, width of the reflex strip located along the lumen of larger arteries and eyelids.

A thorough study of changes in the fundus of the eye is carried out using direct ophthalmoscopy.

Author: Shilnikov L.V.

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