New self-retaining sutureless cellulose flanged disposable contact viewing system for vitreoretinal surgery.

The Super View HTC Hassan Tornambe Disposable Contact Lens (Insight Instruments, Stuart, FL) is a disposable flat contact lens with a cellulose flange and four cellulose footplates. The circular lens is manufactured from high-index optical grade thermoplastic material, with a lens diameter of 13 mm and edge thickness of 4.8 mm (Figure 1A). The anterior surface is flat, whereas the concave posterior surface has an 8 mm radius of curvature with rounded edges for atraumatic corneal contact. The field of view is approximately 36° depending on the pupil diameter and intraocular optical aberrations. The key novel feature of the new lens is the fixed circumferential absorbent synthetic foam flange (Figure 1B). It has 4 tapered legs that are symmetrically arranged, with a dry outside diameter of 18 mm. The overall weight of the viewing system is 0.5 g. Because the flange and footplates are made from deformable foam, they contact the peripheral cornea, corneoscleral limbus, and sclera at the exact angle that exists at the junction of the lens and these anatomical structures. As a result, the lens sits flush with the ocular surface without any underlying space. The viewing system is compatible with any gauge instrumentation. Pars plana vitrectomy ports (cannulated or not) are placed in the usual fashion (Figure 2A). A small amount of viscoelastic material is placed on the concave surface (Figure 2B), and the lens is placed on the cornea, its position maintained by the viscoelastic material’s surface tension and negative suction (Figure 2C). The ocular surface hydrates the footplates (Figure 2D), and capillary action provides further adhesion of the foam ring and footplates to the ocular surface, and ultimate stabilization of the viewing system (Figure 2E), to allow macular surgery with more stable centration of the lens (Figure 2F). The flexible cellulose foam material conforms to a wide range of curvatures (Figure 3), which is particularly beneficial for use with ectatic ocular surfaces, and ultimately allows maximum contact to the globe for consistent stabilization when used in most cases. The footplates are thus able to maintain positioning through their adhesion to the conjunctiva and sclera independently rather than through their apposition to the cannulas.