How isolate PC connected Arduino from WS2812B LED matrix?

Hi,
I want to control 8x8 WS2812B led matrix from PC. Arduino is connected to PC by USB. I need isolate Arduino part of circuit from LED "power" side of circuit.
I'm stuck with my current research, because more I know, the solution became out of my capabilities with electronic.

Current state:
I will be using 5V 5A power supply.
So far I think about high speed optocoupler, but I'm confused about no load on output side. The second thing is that I find information about optocoupler to be really fast,there is need to have more complicated output circuit to keep transistor satured to be more sensitive and fast.
I want to control that matrix 30+ Hz(if possible), so there will be tons of data flowing thru Arduino output pin.

I'm open to any ideas and any suggestion. Circuit examples are welcomed.

evilmiky:
I want to control 8x8 WS2812B led matrix from PC. I need isolation on output pin, because I dont want to damage my PC hw by connected grounds.

Sorry, doesn't make sense.

Changed the post to be more accurate.

It's the part of "I dont want to damage my PC hw by connected grounds" that doesn't make sense.

Oh... I removed confusing part because I dont know ho to describe it better.

Explain, in a new post not by editing a previous post as mentioned in the rules How to use this forum

Now say why you want to isolate your PC and why you think connecting grounds gives you trouble. Hint, it does not.

Maximum consumed by LEDs is almost 4Amps and thats quite a lot.
Arduino will always be connected to USB. This means that ground/negative of power supply will be grounded with my USB Port. I dont like it and if the ground will be disconnected somewhere between Arduino and LEDs (by accident like bended cable, cold connection somewhere, etc.) this will burn my motherboard. I burn 2 notebooks in work in similar conditons(different device connected by USB RS232 convertor, power supply ground disconnected).

I dont like it

Get over it, that is how electronics works.

and if the ground will be disconnected somewhere between Arduino and LEDs (by accident like bended cable, cold connection somewhere, etc.) this will burn my motherboard.

No it won't.

I burn 2 notebooks in work in similar conditons(different device connected by USB RS232 convertor, power supply ground disconnected).

No idea what that means but you are clearly not understanding basic electricity.

See this:-
http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html

evilmiky won't be here for a few days.

AWOL:
evilmiky won't be here for a few days.

Now you have us wondering!

Bad language timeout.

Ah! Kind of suspected that much.

It seems that powers of judgement generally overlap many fields.

Galvanic USB Isolator ?

http://www.ebay.co.uk/itm/USB-Galvanic-Signal-Insulator-USB-Digital-Isolator-Isolation-Ground-Noise-A30-/221721409261?hash=item339fa036ed:g:rG0AAOSwNSxVXMMr

. . . and now evilmiky is enjoying a timeout of a more permanent nature.

I am making some Galvanic-Isolated differential drivers for my WS2812 system, which partly runs on USB connection and partly on Ethernet connections (my ethernet boards dont have isolators)