Police were called to reports of a fight on Walnut Road, E10, at 8.25pm on Saturday, June 18, where they found the 18-year-old injured.
His condition is not thought to be life-threatening, but he is thought to have suffered life-changing injuries.
Detectives from the North East Command Unit are currently investigating and have appealed for anyone who was in the Larch Road and Walnut Road area on June 18 to come forward.
The police would also like to speak to people with dash cam, CCTV or doorbell footage captured between 8pm and 9pm.
Anyone with information can call 101 or tweet @MetCC, quoting the reference CAD 7403/18Jun.
Alternatively, details can be provided anonymously via Crimestoppers, an independent charity, on 0800 555 111.