Stem Cells Cure Blindness | Serendip Studio

The Controversy

Earlier this November, scientists from the University College London Institutes of Ophthalmology and Child Health and Moorfields Eye Hospital were able to restore vision to blind lab mice. This scientific breakthrough signifies that millions of people with optical conditions such as macular degeneration (loss of sight experienced by the elderly), diabetic retinopathy, and a variety of other forms of blindness could be able to regain sight through a remarkably simple procedure. However, the fact that the procedure requires stem cells from foetusescurrently viewed as a highly controversial method by many politicianshas prevented this procedure from becoming more publicized in the U.S. (1).

The Breakthrough

Researchers have identified certain cells on the margin of adult retinas that are similar to stem cells. Additionally, retinal cell replacement may be the most effective method of "cell transplant therapy because photoreceptor loss initially leaves the rest of the wiring to the brain intact (1). In other words, major surgical reconstruction is not necessary. Any surgical procedure would only involve the superficial layer of the retina and not the particularly sensitive optic nerve wiring at the back of the eye. However, in order to attain human retinal cells at the necessary stage of development, stem cells would need to be extracted from a foetus during the second trimester of pregnancy (1). Because stem cells are able to proliferate and develop into many other types of cells within the human body, they can be extracted from any part of the foetus. However, the timing is imperative if the procedure is to work.

Three Blind Mice See How the Procedure Works...

1. Early stage retinal stem cells were extracted from a 3 to 5 day old newborn mouse (1).

2. The retinal cells were transplanted onto the retinal surface of a blind mouse whose condition was genetically programmed to resemble the gradual loss of sight characteristic to the human disease retinitis pigmentosa or age-related macular degeneration (1).

3. The cells embed themselves and connected with other cells on the retina of blind mouse. Within 30 minutes the photoreceptors from the retinal stem cells implanted themselves and fused electrical connections with the animals' existing retinal nerve cells (3). As a result, the formerly blind mice's pupils began to respond to light and there was activity in the optic nerve (indicating that the eye was transmitting signals to the brain) (1).

Anatomy & Physiology of the Eye: Photoreceptors

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Stem Cells Cure Blindness | Serendip Studio