An almost two-fold range of IOP between genetically distinct mouse strains. Mean IOP ± SEM is shown for each strain. Twelve to 25 mice were analyzed for each strain (typically 18 to 20), except for RIIIS/J (7 mice). Mice of most strains were 6 to 12 months old, except for SEC/1ReJ and SB/Le that were 2 to 3 months old. Approximately half of the CE/J and one third of the BUB/BnJ mice were 16 months old and were pooled with the younger mice, as the IOPs of both ages were the same. Strain name CBA/CaHN-Btkxid/J is abbreviated to CBA/CaHN.