Reconstruction and correction of four historical biometry data sets.

PURPOSE

To reconstruct and correct four historical biometry data sets.

METHODS

The data sets measured by Stenström (1946), Sorsby (1957), Zeeman (1911), and Awerbach (1900) are of great historical interest but have issues that need to be dealt with before they may be of practical use in comparative studies. These issues range from only publishing statistical descriptors instead of the numerical data (Stenström) to assuming an equivalent refractive index of the crystalline lens that was constant with age (Sorsby) and calculation errors (Awerbach and Zeeman). These issues were corrected by only considering subjects with ages ranging between 20 and 35 years and refraction within ±8D. This left 86 eyes for Sorsby, 73 for Zeeman, and 54 for Awerbach that could be used for further study. For the Stenström data set, the statistical descriptors of 983 eyes were used to generate data that are statistically indistinguishable from the original data through multivariate Gaussian modeling.

RESULTS

After verification that all biometric parameters, except refraction, could be well approximated by a Gaussian distribution, a statistical eye model was defined for the Stenström data set. By means of the "two-one-sided t test" procedure, it was demonstrated that the data generated by the model are statistically indistinguishable from the original data at a confidence level of 99%.

CONCLUSIONS

These results provide the best possible correction and reconstruction of the historical data sets. Provided one acknowledges the limitations of the data acquisition at the time, these data may be of use in studies on how ocular biometry has changed in the past century.