Endotoxins in Ophthalmic Viscosurgical Devices

Abstract

Purpose To measure the endotoxin concentration (EC) of 25 commercially available, hyaluronic acid- and hydroxypropylmethylcellulose-based (HPMC) ophthalmic viscosurgical devices (OVDs). Methods The in vitro Limulus amebocyte lysate (LAL) assay, which indicates the presence of endotoxins originating from gram-negative bacteria, was used to determine the EC. The procedure was performed according to the European Pharmacopoeia/USP. EC including duplicate determinations, negative controls, dilution series with control standard endotoxin, dilution series with sample extract and positive sample control. Results 16 OVDs (Amvisc®, Amvisc® Plus, Biolon®, Coatel®, Healon®, Healon® GV, Healon®5, HPMC Ophtal® L, Microvisc®, Microvisc® Plus, Ocucoat®, Provisc®, Rayvisc®, Viscoat®, Visco Shield® 2%, Visko® 1.4%) had an EC under 1.2 endotoxin units/mL, five (Adatocel®, HPMC Ophtal® H, LA Gel®, Viscorneal®, Viscorneal® Plus) had an EC ≥ 1.2 and ≤ 24 EU/ml, and four (Biocorneal®, Dispasan® also named Ophthalin, Dispasan® Plus, Visko® 1%) had an EC of > 24 EU/ml. Discussion To avoid viscoelastic-related inflammatory or immunological reactions, the use of pure OVDs is recommended, especially for surgical procedures with an inherent possibility of leaving viscoelastic remnants in the eye (e.g., cataract surgery, viscocanalostomy or penetrating keratoplasty).