What does a borderline oct rnfl classification in an eye exam mean in a non glaucoma patient.

Probably nothing: In the absense of other findings, it probably doesn't mean anything. I would just repeat it in the future.

RNFL layer artifacts: Rnfl layer is just one parameter in diagnosing glaucoma. In some patients without glaucoma , rnfl layer can be borderline thin; conversely, in some patients with glaucoma, the nfl can be "normal". For e.g., in highly myopic people, the rnfl is often "borderline, " but these patients can be normal. How? Rnfl is a thickness measurement of the tissue and not an absolute measure of the optic nerve.

RNFL is thin: Then oct measures an individual retinal nerve fiber layer and compares it to normals your age. If 95% of normals have a thicker nerve fiber than you then your test is flagged as abnormal but not necessary pathologic or indicative of disease. Normal variants exist without evidence of pathology whose measurements are outside the normal distribution of 95% of normals.

Probably not much: If you are not a glaucoma patient and are not otherwise suspicious for glaucoma why did you have an oct nerve fiber layer analysis in the first place? Oct nfl testing is a very poor screening tool and will produce way more false positives then real positives in people who are otherwise not a glaucoma patient or glaucoma suspect. Headaches alone are not usually reason for an oct.