Comparison between Topcon SL-45 and SL-45B with different correction methods for factors influencing scheimpflug examination

Topcon Tokyo manufactured the first series of SL-45 in 1980 and a second in 1982/83, which were completed in Bonn with all technical improvements developed so far. In 1987, the SL-45B was manufactured which included all previously added improvements. To compare both camera types, we carried out a test with 10 volunteers and the following technical variables for the SL-45: (1) miosis; (2) mydriasis; (3) flashbulb 1; (4) flashbulb 2; (5) film batch 1; (6) film batch 2, and (7) different types of film. Afterwards, 5 of these volunteers were photographed with the SL-45B. Photographer and reader were identical in all cases. Based on microdensitometry it could be demonstrated that, with the exception of a different film type, all variables can be compensated for by using the corneal peak as an external standard.