[Anatomical evaluation of the anterior capsular zonular free zone in the human crystalline lens (age range, 50 approximately 100 years)].

It is important to determine the anterior capsular zonular free zone (ZFZ) in order to minimize the risk of zonular disinsertion. From this point of view the size of the ZFZ of normal suspended lenses was directly measured in 199 human eyes obtained postmortem. The cornea was completely excised and the iris removed to allow clear visualization of the anterior surface of the lens to the equator. After measuring lens diameter with a caliper, a 4 mm continuous curvilinear capsulorhexis was performed, and lens substrate was completely removed by phacoemulsification. Care was taken to minimize trauma to the zonules during surgery. The anterior insertion of the zonules was identified at high power magnification; the size of the ZFZ was measured with a caliper. The mean age was 75.5 +/- 10.3 (+/-SD) years (age range, 50 approximately 100 years). The mean diameter of the lenses was 9.72 +/- 0.31 mm. The mean diameter of the ZFZ was 6.83 +/- 0.35 mm. Statistical analysis revealed no significant correlation between the size of the ZFZ and age, or between the size of the ZFZ and lens diameter. The present study indicates that the size of the ZFZ was constant regardless of age or lens diameter.