Nyctalopia in Vitamin A Deficiency

Definition

Nyctalopia is the medical term for night blindness. This is an eye defect where the person cannot see properly at night or in dim light, though the person still has some visual. One of the chief causes of this condition is vitamin A deficiency. A form of vitamin A called “retinol” works together with eye proteins to produce rhodopsin (a photosensitive pigment). This “retinol” is continually used by the eyes and therefore must be replaced by taking in adequate amounts of vitamin A. Lack of this replacement gradually leads to nyctalopia.

High-risk Populations

Children and pregnant women are at the highest risk of not having all the necessary nutrients, and vitamin A in particular. Globally, the most deficient regions are sub-Saharan Africa, south and east Asia, Central America, and some parts of South America. Many international organizations over the past few decades have joint efforts to eradicate vitamin A deficiency and its effects. The chart below shows the countries that are still not adequately covered.

Driving at Night

Nyctalopia greatly reduces your ability to see properly at night. For this reason, night-time driving should be avoided—take a cab or have a friend drive you instead. For less severe or milder cases of nyctalopia, prescription glasses for night driving are available and can be prepared by your optician. In addition, visibility can be increased by cleaning you headlights and windshield, and driving at a reasonable speed.

 

Measures for Treatment

The kind of night blindness caused by vitamin A deficiency is treatable and reversible. A simple blood test will let your healthcare practitioner know the amount of vitamin A in your system. There are two parts to treatment: (1) Food: the food sources of vitamin A are either animal foods or plant foods. Animal sources include liver, eggs, milk, chicken, fish, beef, and butter. Plant sources include leafy green vegetables, as well as many yellow/orange coloured fruits like mangos, papaya, carrots, and sweet potatoes. (2) Supplements: the doctor will prescribe the adequate dosage and frequency of vitamin A supplements according to the individual.

Prevention from Childhood

Vitamin A deficiency and subsequent night blindness can be prevented beginning as early as when the baby is in the mother’s womb. An undernourished mother will not have enough nutrients to transfer to the foetus or developing baby. The child born in this state is already at a disadvantage and high- risk of developing nyctalopia. Furthermore, the issue of breastfeeding is critical. A well-nourished mother’s breastmilk is rich in vitamin A, while that of an undernourished mother isn’t. According to the World Health Organization, a person’s needs for vitamin A are highest during times of rapid growth (from the womb to infancy, early childhood, and adolescence). Nyctalopia and related complications are best prevented at these early stages of life.