The Relationship Between Blue Light and Macular Degeneration

Macular degeneration affects more than 10 million Americans, which is more than the total number of patients of glaucoma and cataracts. There is an estimate that by 2050, nearly 22 million Americans will face this condition.

Age-related degeneration of macula is directly linked with bluish light exposure. You might have heard about bluish light hazard which is responsible for this number one vision loss disease.

Bluish light is high energy visible light (HEV) with a wavelength that ranges from 380-500 nm (nanometers). Sun is the source of natural light of this type while LED’s, computers, Televisions, smartphones, and tablets are sources of artificial bluish light.

There are strong evidence and studies that bluish light is responsible for age-related degeneration macula. OR It may aggravate this condition directly or indirectly in most of the people.

Macular Degeneration Causes

Several factors contribute to degeneration of macula. These factors include.

  • Age-related factor
  • Environment and lifestyle
  • Genetics
  • Smoking
  • Diet lacking in specific nutrients and vitamins
  • And most importantly, The Blue type of light.

Pathogenesis of (AMD)

Macula is a spot in the very center of the eye. It has a light-absorbing pigment named as macular pigment. The macular pigment has photoreceptors that are responsible for the absorption of hazardous light.

Macular pigment degenerates with age and with exposure to blue light. The retinal pigment epithelium (RPE) and photoreceptors are non-replicating (post-mitotic). Eyes are at regular risk of oxidative stress, and these two are responsible for combating oxidative stress for a lifetime. 

These anti-oxidative stress mechanisms break down by middle age, and our eyes become at more risk towards AMD (age related degeneration of macula).

We can take oxidative stress simply as the number of reactive oxygen species produced due to the absorption of visible light by photoreceptors. when photoreceptors absorb visible light than a toxic indigestible compound known as A2E is produced.   

A2E, when exposed to blue light, produces damaging reactive oxygen species (ROS). Peak production of ROS related to A2E occurs at wavelength 440nm. Excessive production of these ROS is responsible for irreversible damage to eyes, sometimes leading to permanent loss of vision by contributing to AMD.

When retinal pigment epithelium (RPE) is exposed to high energy visible light like blue light, it also produces a toxic compound named lipofuscin. When lipofuscin is exposed to light, it produces reactive oxygen species (ROS), leading to cell death and apoptosis of retinal pigment epithelium.

Types

There are two types of AMD. One is dry degeneration (widespread), and second is wet degeneration (less common).

Dry Type

One of the commonly occurring types of this disease, affecting 85-90% of the people, is dry type of this disease. It is less severe and comparably easy to treat. When retinal pigment epithelium can not store more lipofuscin, it releases lipofuscin into intracellular spaces between RPE and Bruch’s membrane.

This results in the formation of a substance known as drusen. Drusen don’t allow the proper supply of oxygen and nutrients to RPE cells. This results in the death of photoreceptors at the macula area of the retina. This leads to the type of blindness known as geographic atrophy or the dry form of AMD.

Wet Macular Degeneration

It is a more severe form of AMD affecting about 10-15% of people. It is also known as exudative AMD. In it, abnormal blood vessels grow from the choriocapillaris through the retinal pigment epithelium (RPE), resulting in hemorrhage, exudation, and serous retinal detachment.

Wet AMD is also related to the production of reactive oxygen species by chromophores in lipofuscin and drusen. These ROS are responsible for lesions in the blood-retinal barrier resulting in sudden blindness when they leak or break. 

Symptoms of Macular Degeneration

Dry macula degeneration symptoms include.

  • Straight lines appear distorted when you see
  • Decrease central vision
  • You need bright lighting for observing anything
  • Dark, blurry areas
  • Difficulty in recognizing faces

Wet type symptoms also match these dry macula degeneration symptoms of this disease. Additionally, there could be the following symptoms.

  • Blurry spot
  • Rapidly worsening symptoms

Prevention Tips

Prevention is better than cure. You should go for preventive measures instead of macular degeneration treatment.

  • Always use protection filters or glasses for bluish light whenever using a computer or mobile phone, especially during nighttime.
  • Supplement your diet with carotenoids like lutein, zeoxanthin, and meso-zeoxanthin. These are responsible for the development of macular pigment.
  • Take frequent breaks if you work the whole day sitting in front of a computer.
  • Try to adopt the 20-20-20 rule while working on the computer. After every 20 minutes of screen exposure, it means to look at anything natural 20 feet away for 20 seconds.

Some people still deny the fact that blue light causes macular degeneration. But it is much supported by scientific evidence and studies that bluish light contributes to degeneration of macula. It would help if you adopted prevention strategies to keep yourself safe from any vision loss problem.

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