Ophthalmoscopy

the Ophthalmoscope
The Ophthalmoscope simple (mirror).

Ophthalmoscopy - examination of the fundus of the eye with an eye mirrors - Ophthalmoscope. When ophthalmoscopy simple (mirror) Ophthalmoscope (Fig) necessary light source, which is usually placed to the left of the analyzed.
In electric Ophthalmoscope there is a lighting system, additional light source is not required. The research is conducted in a dark room. Distinguish ophthalmoscopy in forward and reverse. When ophthalmoscopy direct eye consider directly through a medium with an index investigated eyes, holding a mirror close to your eye; you can see a live image of the eye. When ophthalmoscopy reverse manner use, except Ophthalmoscope, a magnifying glass, usually +13 diopters. Mirror kept at a distance of approximately 50 cm and a magnifier to 7 and from the research eyes. However, magnifier and eye investigating get back the image of the eye. When ophthalmoscopy in the opposite form of the fundus of the eye seen increased 5 times in a direct - 16 times. So ophthalmoscopy in reverse as used for General examination of the fundus, ophthalmoscopy in a direct way " for inspection of its separate parts. Sometimes before ophthalmoscopy patient extend the pupil, in burying kongungualny bag 1% solution gomatropina or 2-3% solution of ephedrine (as instructed by the doctor). Cm. also the fundus of the Eye.

Ophthalmoscopy (from the Greek. ophthalmos - eye and skopeo - examine, investigate) is a method of examination of the fundus with the help of special devices - ofthalmoskopiu.
There are simple (mirror) ophthalmoscopy, the use of which is possible only if there is an external source of light and electric ophtalmoscopy secured own lighting system. Both types of devices can be equipped with movable disks or tapes with a set of corrective lenses (refractive ophthalmoscopy). There are also manual (portable) and stationary (large) ophthalmoscopy (Fig. 1).
Modern electric ophthalmoscopy, as a rule, are streletskii, i.e. allow ophthalmoscopy in conditions of maximum eliminate light reflexes from the optical surfaces of the device and from the surface of the cornea. The basis basrefleks Acting on the principle of separation of a beam of light illuminating the fundus of the eye, from a beam of light reflected from the research of the fundus and falling on the eye of the observer.
There is Acting in direct and return the form. When Acting in a direct way the eye is visible at a higher increase than in the study of reverse manner, but in the latter case, more Ophthalmoscope field of view.
So, on average, when ophthalmoscopy in direct view of the fundus of the eye seen increased 16 times, and in the study of reverse manner with a magnifying glass in 13,0 D - 4 times. When Acting in a reverse manner, the degree of increase depends on the optical power magnifier (less refractive power, the greater the increase), as well as from the refraction of the investigated eyes. Acting in the opposite view is fundus examination, in a direct way " for a more thorough study of its separate parts.
Ophthalmoscopy in its direct form, you can directly see the fundus in advanced pupil investigational eye, optical system which at this time is like a magnifying glass. The study was conducted in a darkened room usually manual electric Ophthalmoscope. The doctor is coming with the Ophthalmoscope to investigated the eye and sends it the beam of light from a distance of 0.5-2 cm (Fig. 2). However, to obtain a clear picture of the fundus of the eye, in addition to that, the relaxation of accommodation of the eye doctor and studied eyes and definite relationship between the refraction. This ratio shall be such as to ensure the connection of rays emerging from the study of the eye, the retina of the eye of the observer. Modern devices for Acting in a direct way have a disk or tape with glasses of various forces. By rotating a disk or tape in the course rays during the study empirically impose such glass at which the eye is clearly visible.
Ophthalmoscopy in the opposite view is produced in a darkened room simple mirror Ophthalmoscope. On the left, and a few posterior to the patient placed a light source - Matt electric lamp 60-100 watts. The doctor sits down at a distance of 40-50 cm from the patient, takes a right hand Ophthalmoscope, in the left - biconvex Lupu (usually 13,0 D) and sends mirror reflected beam to the pupil investigated eyes. After receiving uniform glow pupil investigating puts a magnifying glass in front of the eye of the patient, his finger to his forehead, and slowly pushes Lupu from the eye at a distance of 7-8 cm (Fig. 3). The opening mirrors, center magnifier and the pupil investigated eyes must be on one line. Accomoder now to the frontal plane, located in 5-8 cm from the magnifying glass between her and her eye investigating sees as though hanging in the air valid return and enlarged image of the eye.
A valuable addition to the usual Ophthalmoscope research is Acting in different rays of the spectrum. Spectral Acting allows to reveal these details fundus of the eye in norm and pathology, which under normal O. unnoticed. This is because depending on the spectral composition of the light used to study the fundus of the eye, various structural education it is allocated with greater or lesser clarity. So, when Acting in beskrajnim light particularly well visible region of the yellow spot of the retina; retinoscopy in the yellow-green light lets you clearly identify vessels and figure retinal nerve fiber, etc. A. M. Vodovozov designed the original instrument - ofthalmogerpesa, which you can explore the fundus of the eye in red, yellow, yellow-green, blue, purple, and beskrajnim light.
Ophthalmoscopy direct use for refractometric the difference in the level of the eye. Rotating disk refractive electric Ophthalmoscope, an observer while Acting in the course introduces ray lens, in which an image of the ocular fundus is most clear. If in the study area of the fundus there are roughnesses, when installing the optical they will be seen as unclear, blurry areas. To clearly see these irregularities, it is necessary to introduce in the course of the rays of the Ophthalmoscope other lens. The algebraic difference between the optical power of the lens - the last and the original will show the difference in refraction investigated irregularities and the fundus of the eye. The difference in the level can be calculated in the linear dimension, knowing that the change of refraction 1.0 D is deepening or vastanie this area by about 0.4 mm
The principle ophthalmoscopy is the basis and some other methods of research of the eye (the measurement of the elements of the fundus, the localization of pathological focus in the fundus, the study of the visual fixation and others).
Successful attempts were made to get the image of the fundus of the eye on the TV screen with the help of electronic devices [Ridley (F. Ridley), B. A. Rozenberg].

Fig. 1. Great Streletsky Ophthalmoscope.
Fig. 2. The position of the patient and doctor when ophthalmoscopy in a direct way.
Fig. 3. The position of the patient and doctor when ophthalmoscopy reverse manner.