Eye Deceases

(H53.6) Nyctalopia

Nyctalopia Information

Nyctalopia is an eye disorder commonly known as night blindness. It is the vision impairment or difficulty to see in dim light or at night. It is actually a symptom of the disorder which is not treated. Nearsightedness, if not treated proceeds to night blindness or Nyctalopia.

Nyctalopia can reduce the capability of the driver to drive at night due to poor vision. People with Nyctalopia cannot see stars at night and sometimes they are not able to walk in a dark room.

ICD-10 H53.6
ICD-9 368.6

An individual with Nyctalopia can also have a deeply reduced contrast vision and can be the reason for difficulties in passing through a pedestrian street with poor street lights.

Symptoms Observed in Nyctalopia

The most obvious symptoms observed in Nyctalopia are difficulty to see at night while driving and walking in dim light.

Tests and Treatment of Nyctalopia

To detect Nyctalopia, several tests are performed as

  1. Color vision testing
  2. Pupil light reflex
  3. Refraction
  4. Retinal exam
  5. Slit lamp examination
  6. Visual acuity
  7. Electroretinogram
  8. Visual field tests

Treatment usually includes changing the eye glasses or wearing eye glasses that can help to improve the vision.

Nyctalopia caused due to cataracts can be treated by surgery of the cataract.

Night blindness can be caused due to Vitamin A deficiency. Hence proper intake of products enriched in Vitamin A and maintaining the levels in the body can help to reduce the deficiency. Your doctor may recommend daily doses of Vitamin A to recover the Vitamin A deficiency.

While it takes extra time for the individual with nyctalopia to change from a well-lit room to a faintly-lit room, it is best to keep on with that person for a while to stay away from the accidents of falls and injury.

Nyctalopia Causes

Nyctalopia may be observed in the new born or may also be caused due to injuries or improper nutrition.

But mostly Nyctalopia is associated with retinitis pigmentosa, a genetic disorder which progresses gradually to damage of rod cells in the retina.

Deficiency of vitamin A, retinol is also the major cause of Nyctalopia. Reduced intake of vitamin enriched products like fish oils, dairy products, liver reduces the vitamin A levels in the body.

Cataract and near sightedness if not treated always cause night blindness.

Rod cells present in the retina are responsible for the illumination of light. The pigment rhodopsin is deficient in rod cells. Night blindness hence leads to poor vision at night or dim light.

Diseases like choroidoretinitis and glaucoma are also some reasons to cause night blindness.

Causes of Nyctalopia

  • Vitamin A deficiency
  • Retinitis pigmentosa
  • Congenital night blindness
  • Sorsby's fundus dystrophy
  • Pathological myopia
  • Peripheral cortical cataract
  • Oguchi disease
  • Refractive surgery (RK, PRK, LASIK)

Types of Nyctalopia

  1. Congenital Stationary Nyctalopia – It is already present at birth as it is inherited from the parent.
  2. Progressive Nyctalopia - It gradually progresses and increases with time if not treated. Usually caused due to Vitamin A deficiency and some drugs such as quinine.
  3. Nyctalopia due to Surgery - Some individuals who need to go for an obesity surgery can be affected by Nyctalopia due to less intake of nutritional supplements after surgery.