UK researchers have demonstrated that gene therapy can significantly improve vision in young children with retinal dystrophy caused by genetic deficiency of AIPL1.1
Without treatment, this severe retinal dystrophy causes rapidly progressive impairment of sight from birth.
Scientists from the NIHR Moorfields Biomedical Research Centre and University College London administered a single subretinal injection of a viral vector carrying the AIPL1 gene into one eye in each of four children aged between one and 2.8 years.
Over the following three to four years, all four children experienced significant improvements in their treated eye while losing sight in the untreated eye.
Prior to intervention, the children’s binocular visual acuities were limited to perception of light. However, the researchers reported that 3.5–4 years following, visual acuities in the children’s treated eyes had significantly improved “to a mean of 0.9 logarithm of the minimal angle of resolution ([logMAR] range 0.8–1.0)” and untreated eyes had become unmeasurable at the final follow-up.
An objective test of visual acuity in two children identified “improvements in visual function, and measurement of visual evoked potentials showed enhanced activity of the visual cortex, specific to the treated eyes”.
In the treated eyes, structural lamination of the outer retina was better preserved in three children, and retinal thickness appeared better preserved in all four children.
One child developed cystoid macular oedema in their treated eye. No other safety concerns were identified.
Reference
Michaelides M, Laich Y, Bainbridge JWB, et al. Gene therapy in children with AIPL1-associated severe retinal dystrophy: an open-label, first-in-human interventional study. Lancet. 2025;405(10479):648-657. doi: 10.1016/S0140-6736(24)02812-5.
