' s ▁toler ance , ▁however , ▁would ▁have ▁allowed ▁work ▁to ▁ 1 0 0 0 th ▁mill imet re . ▁The ▁operation ▁proved ▁the ▁effic acy ▁of ▁the ▁new ▁techn ologies ▁available , ▁allowing ▁the ▁possibility ▁of ▁explo iting ▁their ▁potential ▁to ▁new ▁scientific ▁and ▁a ▁medical ▁ends : ▁Mac L aren ▁said ▁that ▁with ▁robot ic ▁systems , ▁a ▁whole ▁new ▁chapter ▁of ▁eye ▁surg ery ▁had ▁just ▁begun . ▁▁ 2 0 1 7 ▁X - link ed ▁Ret init is ▁P ig ment osa ▁Gene ▁Ther apy ▁Tri al ▁Mut ations ▁in ▁the ▁X - link ed ▁R P GR ▁gene ▁are ▁the ▁most ▁common ▁cause ▁of ▁severe ▁sight ▁loss ▁in ▁ret init is ▁p ig ment osa . ▁The ▁R P GR ▁gene ▁contains ▁a ▁highly ▁repet itive ▁sequence ▁of ▁pur ine ▁bases ▁in ▁the ▁DNA ▁with ▁a ▁large ▁section ▁compr ising ▁almost ▁exclus ively ▁Gu an ine ▁or ▁A den ine ▁nucle ot ides , ▁which ▁made ▁it ▁very ▁difficult ▁to ▁clone ▁it ▁for ▁gene ▁ther apy . ▁Using ▁a ▁form ▁of ▁gene ▁editing ▁known ▁as ▁cod on - optim isation , ▁Mac L aren ▁and ▁members ▁of ▁his ▁research ▁team ▁were ▁able ▁to ▁engineer ▁a ▁stable ▁version ▁of ▁R P GR ▁that ▁was ▁expressed ▁highly ▁efficiently ▁in ▁an ▁A AV ▁vector . ▁This ▁led ▁to ▁the ▁first ▁gene ▁ther apy ▁trial ▁for ▁X - link ed ▁ret init is ▁p ig ment osa ▁spons ored ▁by ▁Night star ▁and ▁with ▁Mac L aren ▁as ▁the