Aspiration curette for anterior capsule polishing: laboratory and clinical evaluation

Abstract

Capsular fibrosis or fibrotic after-cataract results from transdifferation of anterior lens epithelial cells into myofibroblasts with consequent contraction and collagen deposition. To avoid possible complications, an instrument was designed for efficient and safe polishing of the anterior capsule leaf. The curette features an upward-facing slit with sharp-edged flanks and rounded turning points and an optional bypass hole. It is introduced through 3 equidistant 20-gauge paracentesis openings. In a laboratory test, vacuum rise time and vacuum levels under occlusion and the effect of adding a bypass hole were investigated for various pump settings. In a clinical pilot series, efficiency and safety of various designs were tested and vacuum and flow settings titrated for optimum performance; the clinical effect was determined in prospectively randomized bilateral studies. Optimum pump settings were 5 mL/min and 10 mm Hg with the nonventing curette and 7 to 10 mL/min and 50 mm Hg with the venting curette. A bypass hole delayed the vacuum rise and reduced the mean vacuum level on full occlusion. It also allowed fine-tuning the vacuum at the slit by varying the flow rate with the foot pedal. Anterior capsule polishing significantly decreased capsule fibrosis and is recommended when posterior capsulorhexis and optic buttonholing are combined.