As Sue said, "LIGHTNER" is just the anglicized (phonetically identical) version of "LEITNER". My family made the spelling switch in the early 19th century, but even earlier records show the name spelled "LEUTNER". Today, and probably then in some German dialects, the latter spelling would be pronounced "loytner", but in the Pennsylvania German dialect "eu" was pronounced as a long "i". This is evident in the way they said "Pennsylfanisha Dightch" for Pennsylvanische Deutch. I've also seen it in the spelling of other names: NEUN/NEIN/NINE, BREUTIGAM/BREITIGAM, etc.
LEIDNER and LEYDNER both appear occasionally in Pennsylvania records and are the same "LIGHTNER" pronunciation - "d" is just a voiced "t" or a "t" is a voiceless "d". This is one of a number of consonant shifts that occurred in spoken Old High German centuries ago ( http://en.wikipedia.org/wiki/High_German_consonant_shifthttp://en.wikipedia.org/wiki/High_German_consonant_shift ) - Old English was unaffected. "T" and "D" were used interchangeably (seemingly) in spelling even as late as the 19th century. In a single German parish record the first name of one man was alternately spelled "Dielmann" and "Tielmann/Thielmann", the latter likely being how an English ear would hear it.