double vision with lobulated paranasal sinus thickening

My son has double vision, lasting 3 months now. We saw neuro-optho. Sons vision has changed dramatically from one and a half year ago exam. His vision was near perfect prior. He now is near and farsighted/ He has a stigmatism? Doc. was unable to correct vision in one eye. Double vision no correction yet. Son had flashing light test? One eye not normal.Doc. wants to think about this. We are re-peating test in one month. Doc prescribed glasses. He is re-examing when we go back in one month.
Doc ordered mri. Results; Moderate lobulated paranasal sinus thickening is most pronounced in left maxillary compartment.
I was reading up on this, could this be the root of vision changes?
My son 8 months ago had a bad motorcycle crash. He broke his back. He has some cord issues. He is most likely on low end of ASIA SCALE. Asia c or d incomplete.Most damage was thoracic.(t5 thru tCool Some of his loss is highly suggestive of injury higher than t-5.( Autonomic-disreflexia on two occassions now) Loss of feeling of bladder, etc. Although nothing has shown above this level.
I was thinking double vision could be csf leak. But this did not show on brain mri.
I am now wondering about this sinus thing? How is it treated? What is the likelyness that this is root of vision problems? Also, if you know this..One indicator of cord involvement is the constant clearing of throat. Son does this continually.
I did not focus on this, at time of injury as there were way to many other issues.
Any theories appreciated!
Diana