When considering the issue of inherited eye disease that can lead to blindness, genetics is central to any deliberation, but what if other factors could be involved, such as gut bacteria?

A surprising potential link between gut bacteria and eye diseases caused by genetics was identified in recent research published in the journal Cell (Peng et al, 2024). 

Retinal degeneration caused by genetic factors is the most common cause of sight loss globally (Broadgate et al, 2017) and among these disorders are around 250 associated genes and clinical phenotypes (Peng et al, 2024).

CRB1 (Crumbs homolog 1) is a gene that gives instructions for making a protein found in the retina and brain needed for normal vision, and mutations in this gene can cause inherited degenerative eye diseases. Mutations of the CRB1 gene are believed to cause various problems, including Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP), accounting for 10 to 15% of LCA and 7% of RP globally (Ehrenberg et al, 2013).

Genetic eye diseases also include congenital eye malformations, congenital cataracts, congenital glaucoma, inherited retinal degenerations (IRDs), optic atrophy, certain types of strabismus with a family history, and colour blindness.

These can have a significant impact on a person’s life, such as causing severe vision loss (Moorfields Private Eye Hospital, 2024), congenital eye malformations such as microphthalmia, anophthalmia and ocular coloboma (Kraff, 2023).

It is estimated that although each genetic eye disease affects only a small percentage of people globally, collectively they affect more than 300 million people (Ophthalmology Center Barcelona, 2024).