Is there any cream or ointment you can put on your stitch lines after an upper blepharoplasty, in the crease?

I am assuming you had your eyelid surgery in the past few weeks. It is very common for eyelid incisions to look bumpy 4-6 weeks after surgery. If the incision was placed in the natural crease, the bumpiness will subside and you will not be able to see the scar in the next month or two. 
It is never recommended to place scar creams or gels on the eyelid incisions. You can create more problems by exposing your eyes to foreign chemicals. Gentle massaging can help a stiff scar, but beyond that, be patient.
In this case, patience is the best remedy for your scar. Let you body's natural healing process take place. Hang in there and your patience should be rewarded with an almost imperceptible scar.
Good Luck.

Typically, I prescribe an antibiotic ointment called Tobradex to apply 10-12 days post operatively to the suture line. This will help the healing process. Consult with your surgeon about what he would recommend. Best of luck, Dr. Heffernan

The usual postop regimen after an upper blepharoplasty is a topical antibiotic ointment such as Fucithalmic for about 10 days followed by a silicon gel for about 3-4 months. But make sure to always discuss it with your surgeon 

The only cream, scientifically proven to prevent scars thickening and lessen redness, is Solution for Scars.  It is available online in the UK from Science of Skin Ltd.

An antibiotic ointment is typically used over the blepharoplasty suture lines for about one week after surgery. You might consider silicone scar removal ointment if the suture bumps are significant. Suture bumps along the crease can be present for several months after surgery.  They typically resolve over time.  Make sure to discuss with your surgeon.