Experimental Therapy Injected in One Eye Unexpectedly Improves Vision in The Other 15 DECEMBER 2020 In a development that could restore sight to thousands of people with an inheritable condition called Leber's Hereditary Optic Neuropathy (LHON), scientists have been able to improve vision in both eyes in a majority of patients – even though only one eye was actually treated.
The treatment is an experimental type of gene therapy, where tailored genetic material is injected to counteract genes that are defective or malfunctioning. With LHON, a m.11778G>A mutation in the MT-ND4 gene is the target. In a phase 3 clinical trial, 37 patients were treated with a modified viral vector rAAV2/2-ND4 in one eye only, leading to an average vision improvement of 15 letters on the standard ETDRS chart you might have spotted at an optician's clinic.