Ophthalmoscopy (funduscopy) is one of the basic investigative techniques in ophthalmology and it is also important for other medical specialties, including internal medicine.
For a better understanding is necessary to anatomically define the aim of ophthalmoscopy. Ophthalmoscopy is important for examination of the interior part of the eye including the retina and its blood vessels. The sensory retina contains special light-sensitive cells that convert the light energy into nerve impulses that are transferred by local nerves to the brain. The nerves merge into an optical nerve, one for each eye.
The examination is performed using an ophthalmoscope. There are more types of this device and we distinguish direct and indirect ophthalmoscope. The direct ophthalmoscope is a device of a size of flashlight that attaches to the examined eye. The indirect ophthalmoscope includes a light source, which is usually attached to the examiner's head and special lens, which is placed in front of the examined eye. Before the examination, the physician applies special pupil-dilating agent in form of drops into the examined eye. This causes pupil dilation (mydriasis), which significantly improves the visibility.
Schema - cross section of the eye
The examination may be performed without any preparation with the exception of administering pupil-dilating agent into the eye (mentioned above). The dilated pupil temporary worsens the vision and the examined person should not drive motor vehicles for few hours after the eye examination.
The test may be performed in patients with visual problems (including double vision). In addition, ophthalmoscopy should be regularly performed in diabetics for early diagnosis of diabetic retinopathy and in people with chronic hypertension, which damages the retina and increases risk of gradual development of macular degeneration. In neurology, ophthalmoscopy is very important for quick exclusion of intracranial hypertension when in need to perform an acute spinal tap. The spinal tap must not be done in patient with intracranial hypertension as it may cause sudden death. The ophthalmoscopy can diagnose the intracranial hypertension by finding swelling of the visible part of the optic nerve.
The only disadvantage is the aforementioned temporary blurred vision after the examination, which makes impossible driving a motor vehicle.
Ophthalmoscopy is a non-invasive, painless and easily accessible examination, which can give us important information not only about the eye fundus (and its diseases), but also about other neurological disorders such as the intracranial hypertension.