I assume "slight asymmetry in optic nerves" refer to the optic nerve ending or the optic disc, which is the part of optic nerve eye doctors can see when we look at the back of the eyes.
Slight asymmetry of the optic disc usually refers to asymmetry of the "cup disc ratio" and is an indication of risk of glaucoma. Glaucoma is a potentially blinding eye disease which affects the elderly more commonly. But signs may be present in the eyes upon careful examination before old age, so responsible doctors usually will inform patients about these findings.
It does not necessarily mean that the eyes are already affected by glaucoma. However, if suspicions are strong, other investigative tests such as a visual field test and an optical coherence tomography (OCT) should be performed before decision for LASIK is made.
If there is no diagnosis of glaucoma, it is perfectly OK to proceed with LASIK. If there is a diagnosis of glaucoma, further discussions regarding the long term management of glaucoma should take priority above LASIK.
Hope this answers your question. Cheerio!
Dr Daphne Han