What can I do for low hair density in donor area 10 weeks after FUE? (photos)

It appears you have focal areas of alopecia given the large number of grafts that were obtained in one procedure.  It is still early in the healing process and some of the areas may have experienced shock loss.  You can give it some more time to allow for the hair in the donor area to regrow and if you feel that the donor area continues to appear depletd you may want to consider scalp micropigmentation.  

Your donor area will always look "thinner" proportionate to the number of hairs taken out after a FUE harvesting surgery.  The hairs will NOT grow back from the donor area (where it was taken). If it all goes to plan the donor hairs will grow in the area it was transplanted.

In FUE transplants the only donor area that may grow are resected hair bulbs i.e. - errors in graft excisions. Having had 5100 hair follicles removed, it is very possible you may have permanent low density in certain portions of the donor area. Consult ISHRS.org (take link to finesteride) to get honest "pros and cons" of it. Using minoxidil and finesteride may help the donor area.

I would wait until the 6 month mark to see if any of the hair was loss due to shock loss.  If density doesn't get better you should consider SMP (Scam Micropigmentation) to fill in the scarring that could camouflage the donor area.

At this point, there are two main possibilities: the donor area was over-harvested or you have shock loss in the donor area. Shock loss in the donor area happens occasionally and hopefully this is the reason for the thinned appearance. 
At this point, it is best to give this another 4-10 months to see if this improves spontaneously. If not, you may need to consider scalp micro-pigmentation to camouflage the affected areas. 
The last option might be to carefully transplant FUE grafts from other areas into the depleted areas and refill them but this might require quite a few grafts. 
Dr. Thomas Nakatsuu

Harvesting 5000 grafts may have depleted your donor zone. If your surgeon has ruled out shock loss following transplantation I would look to have scalp micropigmentation to conceal areas of donor area depletion. 

You have received 5000 follicle, but your donor looks more depleted than expected. You might have lost donor hair due to the shock loss which should be reversible after a few months. I think you still need to be evaluated for the degree of depletion which seems to be too much if this is the first hair transplant. 

From the photos you provide, you may be suffering from shock loss, or the donor area may have been over harvested.  I'd give it some time to see if there is any recovery.  If the area doesn't improve with time, scalp micropigmentation may be an option to improve the appearance of your donor area.

Your donor area is depleted as I don't believe that 99% of people who get 5000 FUE grafts can support that number without getting a see-through donor area. Your residual donor density is probably too low for reasonable coverage. You can never grow out the missing hair. Scalp Micropigmentation works nicely to COVER it up, but it is a tattoo not hair

We do not recommend to do a mega session using FUE technique as it may cause donor depletion. In your case that is what I suspect happened. You need to see your doctor for follow up and see what they suggest.