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Inman et al. (23) report tonopen-derived IOP values for a large colony (n = 400) of DBA/2 mice. These mice develop iris stromal atrophy and iris pigment dispersion leading to elevated intraocular pressure and subsequent optic nerve axon loss. The data reveal a linear increase in mean IOP with age from two to ten months, with a wide range of IOPs within each age group. The authors subsequently selected a small number of ten month-old mice (n = 5) with higher average IOPs and compared axon count, density and limbal corneal thickness (determined histologically) with an equal number of nine month-old mice with lower average IOPs. Further comparison was made with two five month-mice with higher IOP and four five month-old anatomically normal DBA mice with presumed (not measured) normal IOP. Despite some overlap in the IOPs among the groups, the authors demonstrated significant differences in axon counts and peripheral corneal thickness measurements. Linear regression analysis showed that IOP was positively correlated with peripheral corneal thickness and negatively correlated with axon count and density. The low number of mice in the histological part of the study preclude any definite conclusions to be drawn and the relationship between peripheral corneal thickness, lOP and axon number needs to be further evaluated.