Tunnel vision [Gun barrel vision, tubular vision]

Tunnel vision [Gun barrel vision, tubular vision]: Excerpt from Professional Guide to Signs & Symptoms (Fifth Edition)

Resulting from severe constriction of the visual field that leaves only a small central area of sight, tunnel vision is typically described as the sensation of looking through a tunnel or gun barrel. It may be unilateral or bilateral and usually develops gradually. (See Comparing tunnel vision with normal vision, page 774.)  This abnormality results from chronic open-angle glaucoma and advanced retinal degeneration. Tunnel vision also can result from laser photocoagulation therapy, which aims to correct retinal detachment. Also a common complaint of malingerers, tunnel vision can be verified or discounted by visual field examination performed by an ophthalmologist.

History and physical examination

Ask the patient when he first noticed a loss of peripheral vision, and have him describe the progression of vision loss. Ask him to describe in detail exactly what and how far he can see peripherally. Explore the patient’s personal and family history for ocular problems, especially progressive blindness that began at an early age.

To rule out malingering, observe the patient as he walks. A patient with severely limited peripheral vision typically bumps into objects (and may even have bruises), whereas a malingerer manages to avoid them.

If your examination findings suggest tunnel vision, refer the patient to an ophthalmologist for further evaluation.

Medical causes

Glaucoma, chronic open-angle

Bilateral tunnel vision occurs late in this insidious disorder and slowly progresses to complete blindness. Other late findings include mild eye pain, halo vision, and reduced visual acuity (especially at night) that isn’t correctable with glasses.

Retinal pigmentary degeneration

This group of hereditary disorders, such as retinitis pigmentosa, produces an annular scotoma that progresses concentrically, causing tunnel vision and eventually complete blindness, usually by age 50. Impaired night vision, the earliest symptom, typically appears during the first or second decade of life. An ophthalmoscopic examination may reveal narrowed retinal blood vessels and a pale optic disk.

Special considerations

To protect the patient from injury, be sure to remove all potentially dangerous objects and orient him to his surroundings. Because visual impairment is frightening, reassure the patient and clearly explain diagnostic procedures, such as tonometry, perimeter examination, and visual field testing.

Pediatric pointers

In children with retinitis pigmentosa, night blindness foreshadows tunnel vision, which usually doesn’t develop until later in the disease process.

Patient counseling

If tunnel vision is permanent, teach the patient to move his eyes from side to side when he walks to avoid bumping into objects.

Pictures

Book Source Details

• Book Title: Professional Guide to Signs & Symptoms (Fifth Edition)
• Author(s): Springhouse
• Year of Publication: 2006
• Copyright Details: Professional Guide to Signs & Symptoms (Fifth Edition), Copyright © 2006 Lippincott Williams & Wilkins.

More About Proximal Renal Tubular Acidosis

• Back to disease: Proximal Renal Tubular Acidosis: Introduction
• Next Book Extract About Proximal Renal Tubular Acidosis: Anemia (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)
• More Book Extracts: All Online Books for Proximal Renal Tubular Acidosis

More Medical Textbooks Online about Proximal Renal Tubular Acidosis

Review other book chapters online related to Proximal Renal Tubular Acidosis:

Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.

More About This Book: Title: Professional Guide to Signs & Symptoms (Fifth Edition) Authors: Springhouse Publisher: Lippincott Williams & Wilkins Copyright: 2006 ISBN: 1-58255-510-9

 » Next page: Anemia (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• Anemia (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)
• Fatigue (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)
• Anemia (Field Guide to Bedside Diagnosis)
• Fatigue (Field Guide to Bedside Diagnosis)
• Renal tubular acidosis (Handbook of Diseases)

Tools & Services:

• Bookmark this page
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City