Octaves in Tcherepnin's Bagatelle Op. 5 No. 1

[maplecleff1215]

I'm struggling with the octave section in the piece (measures 6 and 7). I have fairly small hands, reaching an okay octave at best and barely a ninth at the most. I have no problem playing slower octaves, but this piece has them jumping in fast fourths right next to each other (and they're fortissimo). Does anyone have any tips of reducing tension when playing the octaves in this particular piece?

(octaves at 0:14-0:23)

[themeandvariation]

The visual field is wide at the octave jumps.. Narrow your visual focus to the thumbs - they are next to each other, and just feel the 5th finger in each hand..  Don't play ff while practicing.. Keep wrists loose.. It is harder to keep wrists loose of you feel the octave to be an uncomfortable stretch - at the limit of your extension.. Still give it a try. Not too fast at first, as your eyes need to adjust as well..