Purpose
The increased elasticity of the lens capsule in children complicates the successful completion of the continuous curvilinear capsulorhexis (CCC) during pediatric cataract surgery. Trypan blue reduces the elasticity of the lens capsule, possibly facilitating the creation of the CCC in pediatric patients. We investigated the effects of trypan blue on ease of completion of capsulorhexis, lens capsule elasticity and intralenticular pressure.
Methods
24 lenses were excised from fresh sheep whole globes. 12 lenses were immersed in trypan blue for 2.5 minutes and 12 lenses were immersed in BSS for 2.5 minutes. Ease of completion of capsulorhexis was assessed using our grading system (1=difficult, 4=undemanding), and intralenticular pressure was quantified using a Schiotz Tonometer.
Results
Lenses immersed in trypan blue averaged a score of 2.58 out of 4. Capsulorhexis was successfully completed in 91.7%. Lenses immersed in BSS averaged a score of 1.5 out of 4 (p = 0.031) with a success rate of 58.3%. Immersion in tyrpan blue decreased the intralenticular pressure by an average of 4.5mmHg (p = 0.025).
Conclusions
Our data confirmed that the graded ease of completing a continuous curvilinear capsulorhexis was significantly improved with trypan blue, not only by allowing the surgeon to distinguish the lens capsule, but also by decreasing lens capsule elasticity. Additionally, intralenticular pressure was significantly decreased possibly due to the osmotic effect of the dye.