“…The laser spot is inversely related to the axial length and varies between 3.2 and 5 mm with the Mainster Standard, 2.9-4.4 mm with the Mainster Wide Field, 2.7-4.3 mm with the Volk Transequator, and 2.8-4.3 mm using the Volk PDT Laser lens.The 95% confidence intervals for repeated measurements were from +2.25 to −1.76% (refraction-corrected measurement software), +3.35/−2.87% (manual measurement), +2.97/−2.32% (Mainster Standard), +2.45/−2.88% (Mainster Wide Field), +2.64/−2.94% (Volk Transequator), and +2.78/−2.56% (Volk PDT Laser). These are expressed as percentage of the spot size and are within acceptable limits[1].Figures 4,5 show the differences between laser and calculated spot sizes for the 4-mm spot in relation to axial length. The spot size differences calculated with the refraction-corrected measurement software varied between −0.76 and +0.57 mm with the Mainster Standard, −0.16 and +0.92 mm with the Mainster Wide Field, −0.06 and +1.07 mm with the Volk Transequator, and −0.06 to +1.02 mm using the Volk PDT Laser lens…”