Retinal fundoscopy

Retinal fundoscopy

Retinal fundoscopy is a test that allows a doctor to see inside the back of the eye (called the Retina) and other structures using a magnifying instrument (ophthalmoscope) and a light source. Retinal fundoscopy is done to examine the retina and detect cataract as well as other eye diseases like Glaucoma.

Diagnosis

Normal – The retina, blood vessels and the optic disc appear normal.

Abnormal findings include:

• Features of glaucoma (increased pressure) in the optic nerve.

• Diabetic retinopathy (damage to the retina due to high sugars) or hypertensive retinopathy (damage to the retina due to high blood pressure) – (mild, moderate, severe).

• Vascular occlusions (blockage of blood vessel, usually by a clot).

• Infection and inflammation on retina or vitreous (clear gel that fills the space between the lens and the retina).

• Evidence of cataract.

• Retinal tear or detachment.

• Macular degeneration (loss of vision in the centre of the visual field).

Reliability

Retinal fundoscopy is considered to be 90-95 per cent accurate and can detect the early signs of many serious diseases.

Performing the test

The patient is asked to sit comfortably or may lie in supine (face upwards) position to minimise head movements. The patient is then asked to fixate on a target directly ahead or above the face at a distance. The best view of the fundus is obtained through a dilated pupil and this is especially true in older patients.

Note: Patient co-operation plays a vital role when performing the test. It is important to minimise your movement while the bright light shines into your eye as failing in doing so will cause considerable discomfort. Also, your doctor will allow you to rest for 10-15 seconds during the prolonged examination.

Word of advice

Examination of the ocular fundus (interior of the eye) is an important component of clinical evaluation in every individual. This is true for patients with a strong family history of ocular diseases. Also, patients with Diabetes, increased intracranial pressure, ischemic cardiac problem and glaucoma should be tested frequently before complications worsen.

Since bright light is used in retinal fundoscopy to dilate the pupil, the effect lasts for three to four hours. Hence, the patient should be informed in advance so that somebody can accompany them on their way back home. Driving on your own should be avoided.

Also, before going for the test, it is best to inform your doctor about

• Allergic reactions to medications

• Whether you have persisting eye problems e.g. glaucoma

• Your case history or whether you have a strong family history of glaucoma

Disadvantages

The only drawback is that you may develop an allergic reaction to the eye drops. Although such reactions are rare they may cause:

• dry mouth

• flushing (the patient's skin may become red and hot)

• narrow-angle glaucoma (acute attacks of eye pain due to rise in intraocular pressure)

• dizziness

• nausea and vomiting

Advantages

• Non-invasive procedure

• Affordable

• Detects the initial stages of a disease and give a true picture of the systemic condition and functions.

Dr Anand Palimkar is Consultant Ophthalmologist at Chellaram Diabetes Clinic, Pune.