Early postoperative capsular block syndrome related to saccadic-eye-movement-induced fluid flow into the capsular bag

To determine the relationship between saccadic eye movements and the development of early postoperative capsular block syndrome.

Fundacion Oftalmologica, Los Andes, Santiago, Chile.

An artificial experimental setup was designed to reproduce the anatomical, hydrodynamic, and kinetic conditions of an early postoperative pseudophakic eye with a capsulorhexis and intracapsular intraocular lens (IOL) implantation. An electromechanical transducer driven by a digital-to-analog converter was used to mimic saccadic eye movements at physiological speeds and accelerations. Position information and differential pressure measurements between the intracapsular space and the extracapsular space were digitized. Various anterior capsule-IOL configurations were tested including partial adhesion of the anterior capsule to the lens.

Saccadic movements increased intracapsular pressure by displacing fluid into the capsular bag. This finding was inconstant and only observed when the capsular rim adhered to the IOL optic by more than 70%. Development of positive intracapsular pressure was noted above 4 mm Hg.

A valve-like mechanism formed by the capsulorhexis rim partially adhered to the IOL optic can occur postoperatively. Under these conditions, saccadic eye movements can increase intracapsular pressure by a unidirectional inertial displacement of fluid into the capsular bag.