Effect of trypan blue staining on the elastic modulus of anterior lens capsules of diabetic and nondiabetic patients.

ABSTRACT

PURPOSE: To determine whether trypan blue causes a significant difference in the biomechanical properties (stiffness) of diabetic and nondiabetic anterior lens capsules and to determine whether diabetes significantly alters the stiffness of anterior lens capsules. SETTING: Veterans Administration Boston Healthcare Center System, Jamaica Plain, Massachusetts, USA. METHODS: In this unmasked prospective randomized controlled experimental study, anterior lens capsules were obtained from diabetic and nondiabetic patients approved for cataract surgery. Four treatment groups were created (1) capsules of nondiabetic patients without trypan blue; capsules of nondiabetic patients with trypan blue; (3) capsules of diabetic patients without trypan blue; (4) capsules of diabetic patients with trypan blue. Anterior lens capsule stiffness as a function of elastic (Young's) modulus (kilopascals) was measured with the Hysitron TriboIndenter. RESULTS: The use of trypan blue led to significantly stiffer anterior lens capsules (P= .036). Trypan blue had the greatest effect on the stiffness of diabetic lens capsules (P= .046). CONCLUSION: Trypan blue contributed to increased capsule stiffness during capsulorhexis, especially in diabetic patients.