Growth patterns of fresh human crystalline lenses measured by in vitro photographic biometry

Abstract

The purpose of the study was to demonstrate and evaluate the use of digital-image photography to measure the central thickness and equatorial diameter of whole fresh human crystalline lenses free of all zonular attachments. Forty-one human donor postmortem intact clear crystalline lenses, with a mean age of 28.5 +/- 16.4 years, were obtained by the contributing eye banks. The lenses were removed by the eye bank and shipped in Optisol-GS, a physiologic preservative storage medium, at 7 degrees C. The lenses were stored at the same temperature and in the same preservative throughout this study. This medium has been demonstrated to maintain the morphometric characteristics of epithelial cells. After freeing the lenses of all residual zonular attachments, digital photographs were obtained within an average of 20.9 +/- 13.4 h after death. The digital images were used to determine the central thickness and equatorial diameter of the crystalline lenses. By carefully calibrating the digital images and maintaining the lenses in physiological storage medium, reliable dimensional measurements were obtained. The dimensions for central thickness for each lens were compared to published, age-matched lenses, measured in vivo, and were found to duplicate these in vivo measurements reliably.

Fig. 1

A profile photograph used to measure central thickness of the human crystalline lens.

Fig. 2

(A) Bland–Altman-style plot of the 50 photographic measurements of the 10 precision spheres, which includes reference lines for the mean and ± 3 standard deviations (3 SD).

Fig. 3

Plot of central thickness of the human crystalline lens vs age. The central thickness of the human crystalline lens decreases in childhood, reaching a minimum at approximately 20 years and then increases with additional age.

Fig. 4

Plot of the equatorial diameter of the human crystalline lens vs age. The equatorial diameter grows rapidly for approximately 20 years and then increases at a slower rate with age.

Fig. 5

Profile photographs of human crystalline lenses of different ages demonstrating, in the horizontal plane, the progressive increase in equatorial diameter with age. The central thickness is measured perpendicular to this equatorial diameter. The thickness, measured vertically, can be seen to decrease after age 3 and increase again after the second decade of life.