Abstract
Purpose: :
To evaluate and visualize anterior chamber maintenance by Scheimpflug photography for Vitrax II OVD + Healon GV OVD and Vitrax II OVD + Healon OVD (Abbott Medical Optics Inc.) along with DuoVisc (Viscoat + Provisc, Alcon Inc.) during simulated cataract surgery with softshell technique.
Methods: :
Cataract surgery was simulated ex vivo in porcine eyes, using dual injection of OVDs according to the softshell technique. Dispersive and cohesive OVDs were stained with fluorescein, 10 µg/ml and 6 µg/ml respectively, for detection purposes. Anterior chamber depth (ACD) was measured before surgery, after injection of dispersive OVD, after injection of cohesive OVD, and after phacoemulsification (Sovereign® Compact system, AMO) as monitored by Scheimpflug photographs (Pentacam HR, Oculus) and presented as relative ACD of each eye before surgery. The thickness of the OVD layers after each injection, as well as after phacoemulsification, was recorded. Results were grouped according to product used at each step of the surgical procedure. The Kruskal-Wallis test was used to evaluate differences between the products at each step of the surgical procedure.
Results: :
The Scheimpflug photographs visualizes the dual OVD distribution within the anterior chamber in a unique way, 85-90% of ACD was filled with cohesive OVD covered by a smooth layer of dispersive OVD along cornea. Injection of Vitrax II OVD + Healon OVD gives a significantly thicker layer of dispersive OVD (P<0.05) than the other two product combinations. After phacoemulsification the thickness of the OVD layer of Vitrax II OVD + Healon OVD and DuoVisc were equal while the Vitrax II OVD + Healon GV OVD combination was retained to a larger extent in the AC (P<0.05). The medians of relative ACDs after phacoemulsification did not vary significantly. Before phacoemulsification no significant variation between the three groups was observed regarding relative ACDs.
Conclusions: :
Both Vitrax II OVD + Healon GV OVD and Vitrax II OVD + Healon OVD are equivalent to DuoVisc in creating and maintaining the anterior chamber depth. The Vitrax II OVD + Healon GV OVD combination was superior in OVD retention capacity during phacoemulsification in the simulated cataract surgery.
Keywords: cataract • anterior chamber • training/teaching cataract surgery