Diplopia | Double Vision

Diplopia (Double Vision): Types, Causes, Diagnosis and Treatment

What is Diplopia?

Double Vision or Diplopia is a common and troublesome subjective complaint. Diplopia is derived from Greek words ‘diplous’ meaning double and ‘ops’ meaning eye.

The patient’s ability to walk, read and perform day-to-day activities is suddenly hampered. It leads to formation of two images of the same object instead of one at the retina. Recent squint is the most common cause of diplopia.

There are two types of diplopia- ‘binocular diplopia’ or double vision when both the eyes are open and ‘uniocular diplopia’, when one eye is closed. Obviously the causes of each type vary.

Some of the important causes of diplopia are diabetes, multiple sclerosis, raised blood pressure, brain tumors, migraine, aneurysms, strokes, myasthenia gravis, and thyroid eye diseases. The most common cause of diplopia is cataract.

Diplopia is accompanied by symptoms like headache, droopy eyelids, nausea, pain around eyes and squint.

Urgent medical attention is required in case of sudden onset of diplopia as it could be an indication of a potentially grave condition. The diagnosis is made by hematological tests and imaging like MRI or CT scans.

Identifying and curing the cause can eliminate diplopia. The condition can be improved upon by surgery, medications and application of special glasses.

What are the Types of Diplopia?

There are two types of diplopia- ‘binocular diplopia’ or double vision when both the eyes are open and ‘uniocular diplopia’, when one eye is closed. Obviously the causes of each type vary.

 The plausible causes of diplopia can be:

Binocular Diplopia

In this condition an individual with both open eyes sees double image of a single object. It is primarily due to wrong alignment of two eyes, called as ‘squint’. Only sudden onset of ‘squint’ is responsible for diplopia. The underlying pathology is the paralysis of the muscles of the eye or higher nerve palsies.

Uniocular Diplopia

The condition is a less common one and here the image of a single object is formed by one eye closed. The structural defects of the optical system of the eye are chiefly responsible for this type of diplopia. Cataract is the most common cause of uniocular diplopia.

What are the Causes of Diplopia?

Some of the important causes of diplopia are diabetes, multiple sclerosis, raised blood pressure, brain tumors, migraine, aneurysms, strokes, myasthenia gravis, and thyroid eye diseases.

The most common cause of diplopia is cataract. The causes of diplopia can be classified into two categories depending on whether they cause binocular or uniocular diplopia. 

Binocular Diplopia

The misalignment of the eye muscles is responsible for this type of diplopia. The eye muscles regulate the movement of the eye and any disease or paralysis affecting the muscles directly affects the eye.  

Brain Diseases

There are few diseases of the brain, which are responsible for diplopia. They are as:

  • Strokes
  • Aneurysms
  • Tumors of the brain
  • Raises pressure of the brain due to trauma, hemorrhage or any infection
  • Migraine or headaches

Instant medical attention should be seeked in cases of diplopia resulting due to above-mentioned causes.

Muscles Disease

Myasthenia Gravis:

Myasthenia gravis is an autoimmune disease and is characterized by blockage of the muscle stimulation at the nerve head. Diplopia is the common symptoms and sometimes-droopy eyelids may be present.

Thyroid Eye Disease:

It commonly leads to diplopia and weakens the muscles of the eyes. 

Nerve Disease

Ailments like diabetes, multiple sclerosis and Guillian Barre syndrome can cause paralysis of the eye muscles as they affect the nerves supplying the muscles of the eye. So they are an important cause of diplopia and squint. 

How to Diagnose Diplopia?

Urgent medical attention is required in case of sudden onset of diplopia as it could be an indication of a potentially grave condition. The diagnosis is made by hematological tests and imaging like magnetic resonance imaging (MRI) or computed tomography (CT) scans.

Treatment for Diplopia

Identifying and curing the cause can eliminate diplopia. The condition can be improved upon by surgery, medications and application of special glasses. Diagnosing the cause and subsequent elimination constitutes the treatment of diplopia. 

Surgery for Diplopia

Surgery can be done in case of a weak eye muscle or trapped eye muscle in any fractured bone due to injury.

Medications:

  • They are very useful in Myasthenia gravis.
  • In thyroid eye disease surgery and/ or medical therapy can be opted for.
  • In diabetes, blood sugar should be controlled. 

By wearing special glasses or an eye patch can reduce the effects of diplopia, if it cannot be reversed.

References:

  • Double Vision (Diplopia) (https://www.health.harvard.edu/a_to_z/double-vision-diplopia-a-to-z)
  • Diplopia: Diagnosis and Management (https://www.aao.org/focalpointssnippetdetail.aspx?id=8eb21322-ab3c-49f9-a772-b9ba8bd9783f)