The College of Optometrists

Has anyone seen one as it starts? How would it present itself in practice? It seems rare - is it? Any particular age or gender at risk? Would be an emergency? Sorry for all the questions - but I have never seen one and would like to know more. thanks

Sixth nerve palsy is usually a vascular problem causing a sudden esotropia usually in the elderly or diabetic patient. Usually referral promptly is indicated especially for help with diplopia. Can also be due to tumour which can grow in the cerebellopontine angle. But these usually cause other cranial nerve problems. A common one is an vestibular schwannoma, which travels down the 8th nerve, attaching also to the facial nerve and maybe also abducens and trigeminal. So look out symptoms of deafness, balance problems, facial weakness and inability to blink and test corneal sensation for lack of sensitivity. Rare to affect 6th nerve but surgery to remove tumour can.

Sixth nerve palsy is usually a vascular problem causing a sudden esotropia commonly in the elderly or diabetic patient. Referral promptly is indicated especially for help with diplopia. Can also be due to tumour which can grow in the cerebellopontine angle. But these usually cause other cranial nerve problems. A common one is an vestibular schwannoma, which travels down the 8th nerve, attaching also to the facial nerve and maybe also abducens and trigeminal. So look out symptoms of deafness, balance problems, facial weakness and inability to blink and test corneal sensation for lack of sensitivity. Rare to affect 6th nerve but surgery to remove tumour can.

Thank you,

So its like a bells palsy with a squint? Is it sudden onset or does it come and go. In diabetics - how does that start - have you seen one? Does it have any blurring secondary to the induced diplopia? Is there is head tilt or twist to compensate ? (or does the angle of squint vary)

The sudden onset just gives a convergernt squint with diplopia. No pain is present and yes have seen at least a few of these in 10 years. The Bells palsy etc is only if facial nerve involved also which is more likely in tumour growth so are slow onset. After surgery they can be present due to damage at tumour removal or secondary swelling. Hopefully if down to swelling these should improve rapidly. If damage then sometimes facial nerve can regrow but takes upto 18 months for improvement in face. Often need to take care of exposed cornea.

-so occlude the squinting eye and refer urgently and directly?