There's actually a lot of confusion of deer, Lyme's disease and ticks.
First, contrary to what most people think, deer are NOT the primary cause of ticks...or deer ticks. Small rodents such as mice, chipmunks, squirrels, etc are the primary carrier of ticks. This is why keeping deer of your property will have very little impact on reducing the tick population. Yes, keeping deer off your property can have many benefits as they can be destructive to flowers, shrubs and other foliage, but keeping them off the property will have a negligle effect on ticks. Instead, look for ways to reduce the number of rodents on your property and consider other methods such as aracides. You can read more in this article about ways to reduce and control the tick population in your back yard.
Furthermore, ticks do not actually get Lyme disease from deer as many people believe. Rather, the ticks contract Lyme's disease when they are larvae and they often feed on infected mice. When, the ticks get older, they need the deer to lay their eggs (and hence the name deer tick), but the deer to not become infected with the disease, nor cause the disease in the ticks.
So, while deer ticks can carry Lyme disease (and note that not all of them do), deer themselves are not the cause of Lyme disease nor the main carrier for ticks. Instead look for ways to reduce rodents on your property by keeping your lawn clean and well trimmed. Try to avoid wood piles or leaf piles (or mulch) as mice and chipmunks like to congregate there.
Also, be aware that even if a tick has Lyme's disease and you or your pet gets a tick, if you remove it quickly (often within 24 hrs), your likelihood of you or your pet contracting Lyme disease greatly declines. See this article on how to remove a tick from a dog or cat, in case your pet gets one. The key is quick detection and removal.