Retinal Examination

Light entering the eye passes through the lens and falls on the retina. The retina is the innermost layer of the eyeball and is made up of neurons which convert the incoming light signals into neural impulses which travel to the brain. Examination of the retina provides the doctor with a lot of information about the health of the eye. The retina is a direct way of assessing the pressure inside the cranium also. Examination of the retina is called a retinal exam, fundoscopy or an ophthalmoscopy. This procedure can be used to diagnose acute and chronic conditions.

Procedure of Retinal examination

Retinal examination is a non invasive procedure that can be done directly or indirectly. Your provider looks directly at the retina through the lens of your eye. Sometimes eye drops re used to make sure that the pupil remains dilated during the examination.

• Direct ophthalmoscopy: an ophthalmoscope is used for this procedure. It is an instrument that consists of a handle, a light source and a viewing window. Your eye doctor will place this instrument in front of your eye and switch on the light. You will be asked to look at a point on the other side of the room. The lights of the room will be dimmed for better visualisation. The instrument will be slowly brought closer to the eye while the doctor looks through the viewing window. Eye drops are generally not required for this procedure.
• Indirect examination: before the procedure eye drops will be put onto your eyes to ensure that the pupil remains dilated. You may be asked to either sit or lie down. After the effect of the eye drop set in your eye doctor will then examine your eye through a condensing lens and light source mounted on the doctor’s forehead. This method allows for three-dimensional visualisation of structures in the eye in greater detail.

Indications for Retinal examination

Ophthalmoscopy is indicated when:

• An increase in intra cranial pressure is suspected
• There is a suspicion of occluded retinal vessel or retinal detachment
• A patient has a chronic disease like
• Diabetes
• Hypertension
• Atherosclerosis
• Glaucoma is suspected
• Macular degeneration is suspected.

Patients with AIDS are at an increased risk of retinal diseases, they are advised to undergo regular retinal examination.

Recovery from Retinal examination

Retinal examination is a simple procedure. You will be allowed to go home after the procedure. The results of the fundoscopy will be discussed with you by your provider on the next visit. Your vision may feel blurry for sometime if eye drops were used. This generally resolves on its own. Contact your doctor if it doesn’t resolve in a day.

Sources

• Liu, Y., Wu, F., Lu, L., Lin, D., & Zhang, K. (2015). Examination of the Retina. New England Journal of Medicine, 373(8), e9. doi:10.1056/nejmvcm1308125
• https://stanfordmedicine25.stanford.edu/the25/fundoscopic.html