forgot to mention I'm 31 years of age
well yes and no. yes, heavy computer use does usually cause increase in myopia from accommodative spasm. it also IMO accellerates myopia progression in children.
but it has nothing to do with "myopic degeneration" or retinal thinning from having an excessively large eye.
so while it probably did contribute to your Rx changing from -14 to -15, it is not affecting your retina. i only mention retinal problems not b/c you mention them, but b/c the term "myopic degeneration" generally refers to retinal problems associated with myopia (but not computer use)