I would assume it probably could. Too much of one thing is generally not good. The father of my little brothers did not work for winter so he sat on the computer or watching the tv for 5 months every year for the past 3-5 years. It ended up putting him in what we called a "funk" he became very selfish and bitter. (My mother and him are in the devorce process as we speak) If there is anyway you can get off the computer even if for a few moments and do something like walk in the sun or hang out with a couple friends, or work on any relationship in your life that would probably be a good thing.
I'm sure you two are very different people and it sounds like your computer use is perhaps job related. Maybe try getting up earlier and walking to work if its not too far. Or find a nice park to walk to for lunch. Eat healthy and try to get up as much as you can.
My mom also has a job where she uses the computer alot the difference between her and her soon to be ex husband is in her time off she avoided the computer and tv like a plague lol. I find she is generally happier when she is on the computer less.
It can damage your eyesight, that's about it. However the other things you're neglecting like healthy exercise, exposure to sunlight and contact with other people are the things that prevent your body from deteriorating and falling out of balance and your mind from slipping into insanity. It's probably safe to think of things this way. A day spent inside, jacked into your computer removes 24 hours from your lifespan, give-or-take 48 hours.