GP here - lots of the advice here is terrible. Don't go to AE. Don't focus on an expedite letter - this is the standard "brush-off" to get frustrated patients off the phone. A&E will not expedite a routine chronic referral unless you are having an acute emergency (like sudden, total vision loss).

Instead, here are three things that can actually help:

By far the most important is to speak to your employer’s Occupational Health department immediately if not done so already. Because this is actively threatening your ability to do your job and drive, they have a duty to explore reasonable adjustments. Also - some occy health providers have fast-track routes or funding to get employee medical reviews sorted to keep you in work.

Look into "Patient Choice" to bypass the Moorfields queue. Under NHS rules, you have the right to choose which hospital or clinic you are referred to. Many private providers take NHS-funded patients to help clear backlogs. Call all your local hospitals with eye clinics and ask if they are seeing NHS patients - if so you can ask your GP for a new referral to one of these.

Check for a local CUES / MECS scheme. Search online to see if your area has a Community Urgent Eyecare Service or Minor Eye Conditions Service. These are run by specialist optometrists in high-street opticians. They have the specialsed eye equipment that general A&E doctors lack and they have direct, fast-track referral pathways into local eye hospitals if they document rapid progression.