Fluorescein-conjugated hyaluronic acid enables visualization of retained ophthalmic viscosurgical device in anterior chamber.

Abstract

Purpose: To develop and assess the utility of an ophthalmic viscosurgical device (OVD) manufactured with fluorescein-conjugated hyaluronic acid (conjHA).

Setting: Department of Biomedical Engineering and the Wilmer Eye Institute, Johns Hopkins University and School of Medicine, Baltimore, Maryland.

Design: Laboratory study.

Methods: ConjHA and unconjugated HA (unconjHA) at varied ratios were used to produce OVD (conjOVD) with varied fluorescence intensity. The conjHA:unconjHA ratio was optimized to maximize clarity under white light and fluorescence intensity under cobalt blue light (CBL), allowing for conditional visualization. The effect of conjugation on conjOVD viscosity was assessed by rotational rheometry. Intraocular lenses (IOLs) were immersed in conjOVD for 4 hours to assess staining of IOLs. A proof-of-concept study was performed in ex vivo porcine eyes. After injection and visualization, the OVDs were removed from the eyes by irrigation/aspiration (I/A).

Results: 0.5 mg/mL of conjHA (degree of substitution = 0.005) enabled robust fluorescence of conjOVD under CBL. Fluorescein conjugation did not significantly affect conjOVD viscosity ( P > .05 for mean difference in viscosity at all shear rates tested). No staining of IOLs was appreciated. ConjOVD was visualized under CBL when injected ex vivo and maintained clarity of the anterior chamber under white light. Importantly, conjHA enabled delineation of retained OVD after I/A.

Conclusions: Use of OVD composed of fluorescein-conjugated HA is a feasible method to enable conditional visualization of OVD intraoperatively without nonspecific staining of ocular structures. Further development of this technology may enable accelerated OVD removal in ocular surgery or decreased OVD retention postoperatively.