The ophthalmoscopy, also called ocular funduscopy or funduscopy, is a special examination of the eye that allows the examining doctor to take a look at the fundus in order to make a medical assessment. The fundus includes the retina, the choroid, the point where the optic nerve exits the eye, as well as all the blood vessels in the back of the eye. All these parts of the eye are normally not visible to the person opposite from the outside.
In principle, one could say that the back of the eye is made visible by means of special mirrors and illumination techniques. The eye itself does not necessarily have to be “changed” for this. The background of the eye is then illuminated in such a way that the ophthalmologist can assess the different structures such as the retina, the choroid, the nervus oprticus in its exit, the yellow spot and the surrounding supplying blood vessels and recognize possible pathological changes and processes.
In order to be able to see through the entire eye to the back of the eye, it is of course necessary that the eye, including its vitreous body, cornea and lens, is free of any clouding, deposits or other material that could obstruct vision. If the ophthalmologist wants to examine the fundus of the eye, there are basically two different examination techniques available. The “indirect opthalmoscopy” and the “direct opthalmoscopy”.
In indirect ophthalmoscopy, the ophthalmologist shines a small lamp into the eye to be examined from a distance of about 60 centimeters. In most cases, the doctor uses a so-called head ophthalmoscope for this purpose. This is a device with an integrated lamp that the doctor can attach to the head, leaving both hands free for the examination and yet allowing the position of the light source to be varied at the same time.
In order to enlarge the fundus of the eye, the doctor holds a converging lens with one hand in front of the patient’s eye, at a distance of about 5 centimeters from it. The light beam now comes out of the head lamp and falls through the convergent lens into the patient’s eye and onto the fundus of the eye. At the same time, the converging lens enlarges the view of the fundus for the ophthalmologist at a magnification of about 4.5 times. If it is necessary for a patient to have a very good overview of the fundus as well as a view of the details, the two examination techniques can be easily combined to offer the patient the best possible examination of the fundus.