Noncontact optical measurement of lens capsule thickness in human, monkey, and rabbit postmortem eyes.
OBJECTIVE
To measure interspecies thickness differences in the central anterior and posterior capsules of postmortem crystalline lenses, by a technique that maintains the anatomic integrity of the lens.


METHODS
Central capsule thickness was measured with a custom-built, noncontact optical system, using a focus detection technique. Anterior and posterior lens capsule thickness measurements were performed on 22 human, 29 monkey, and 34 New Zealand White rabbit intact postmortem lenses in situ. Eyes were prepared for optical measurements by bonding a PMMA ring to the sclera in the region of the ciliary body after the conjunctiva, adipose, and muscle tissues were removed. The posterior pole was removed by making a circumferential incision through the sclera approximately 7 mm posterior to the limbus. Excess vitreous was removed to expose the posterior capsule surface, and the eye assembly was placed on a Teflon slide. The cornea and iris were sectioned to expose the anterior capsule surface. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Lens capsule thickness was measured from the histologic slides and compared to the optical


RESULTS
results. Central anterior lens capsule thickness was 8.2 +/- 5.5 (human), 7.5 +/- 4.4 (monkey), and 10.7 +/- 4.2 (rabbit) microm optically and 12.4 +/- 2.5 (human), 10.7 +/- 3.7 (monkey), and 10.4 +/- 2.0 (rabbit) microm histologically. Central posterior capsule thickness was 6.3 +/- 2.2 (human), 5.9 +/- 1.7 (monkey), and 7.8 +/- 2.3 (rabbit) microm optically and 4.1 +/- 1.5 (human), 3.5 +/- 1.6 (monkey), and 4.7 +/- 2.5 (rabbit) microm histologically.


CONCLUSIONS
The central anterior and posterior lens capsule thicknesses do not appear to vary considerably among human, rabbit, and monkey eyes. There were significant differences between optical in situ measurements and histology, which indicates that histologic preparation may affect lens capsule thickness.
Ziebarth
Noël M
NM
Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, FL 33136, USA.
Manns
Fabrice
F
Uhlhorn
Stephen R
SR
Venkatraman
Anna S
AS
Parel
Jean-Marie
JM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001837:Body Weights and Measures; D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D007903:Lens Capsule, Crystalline / Q000033:anatomy & histology*; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008875:Middle Aged; D011817:Rabbits; D013045:Species Specificity