When we go to the ophthalmologist, one of the tests that is usually performed is a fundus examination. This test, called ophthalmoscopy, allows the specialist to perform a review of the inner and posterior middle area of our eye. The specialist can observe various parts of our eye to assess its state of health.
This examination allows us to obtain a lot of information about diseases of the eyeball and other systemic diseases. These affect the back of the eye and the retina resulting in loss of vision and even blindness.
What is the difference between direct and indirect ophthalmoscopy?
In the case of direct ophthalmoscopy, the most common test, a light is applied using an instrument called an ophthalmoscope, followed by a set of lenses of different diopters to focus on the retina and macula; a flat, one-dimensional image of the internal structures of the eye is obtained, including the entire retina and optic nerve.
Indirect ophthalmoscopy allows three-dimensional vision of the retina by projecting light and using a lens. This test can help identify diseases such as macular degeneration or diabetic retinopathy.
In both cases, the ophthalmologist dilates the patient’s pupils before performing the fundus examination.
Once the pupil is dilated, how long does it take for the effect to wear off?
A mydriatic is used to dilate the pupils and is applied to the patient’s eye. The effect is fast, in about 10 minutes they are usually dilated. Depending on the strength of the mydriatic applied, the pupil may take between a couple of hours and up to a week to recover its normal diameter.
During the recovery period, our eyes will not focus well and light will bother us a lot, so we should not perform activities such as driving and other activities that involve focusing our eyes such as reading.
However, in patients over 50 years of age, it is very common to perform a fundus examination at least once a year to identify any serious retinal pathology.