Examinations of the fundus of the eye using an ophthalmoscope or an indirect magnifying glass
What is ophthalmoscopy?
Ophthalmoscopy is a method of examining the fundus and anatomical structures of the retina. It can be performed directly, with a hand-held ophthalmoscope or indirectly using a frontal ophthalmoscope and a suitable magnifying glass or biomicroscope and magnifying glass.
With manual ophthalmoscopy, the view of the retina is limited. Indirect ophthalmoscopy enables a three-dimensional view and is better for examining the periphery of the retina, where retinal detachment often occurs, which is considered one of the most urgent conditions in ophthalmology. The view of the ocular background can be improved by dilating the pupils (mydriasis) using one to two drops of 1% tropicamide and/or 2.5% phenylephrine, which is repeated after 5 to 10 minutes if necessary.
Before expanding, the depth of the anterior chamber is assessed because if the anterior chamber is shallow, mydriasis can cause an attack of acute angle-closure glaucoma. This assessment is done during the biomicroscopic examination. Contraindications for pupil dilation are head injury, suspected rupture of the eyeball, narrow angle of the eye and the already mentioned angle-closure glaucoma.
What can be found out by ophthalmoscopy?
Ophthalmoscopy can reveal opacities of the lens or vitreous, the ratio of the central fovea to the disc of the optic nerve and changes in the area of the macula, blood vessels and the periphery of the retina. The central socket is the central recess of the optic disc and the optic disc is the entire area of the optic nerve. An increase in the ratio between the central socket and the disc of the optic nerve is one of the most important clinical signs of damage to the optic nerve and most often occurs in glaucoma.
Retinal changes include hemorrhages, which appear as small or large areas of blood pooling and drusen (small subretinal yellow-white spots that indicate dry, age-related areas of macular degeneration). Vascular changes include arteriovenous crossing, a sign of chronic hypertension in which the retinal veins are compressed by the retinal arteries where they cross; copper wire sign, a feature of arteriosclerosis in which the thickening of the arteriole wall increases the thickness of the light reflection; silver wire sign, a feature of hypertension in which thin fibrosed arteriolar walls reduce the thickness of light reflection and loss of venous pulsations, which is a sign of increased intracranial pressure in patients known to have previously existed.
If you have noticed changes in your vision, react promptly and book an appointment for an ophthalmological examination.