GPs often provide superior visual acuity as compared with soft toric lenses albeit with a longer period of adaption and perhaps a bit less comfort (Chang and Lam, 2013). Hybrid contact lenses, which incorporate the sharp vision of a GP with the comfort of a hydrogel lens, may truly be “the best of both worlds.”

The early generations of hybrids suffered from the soft skirt tearing away from the rigid portion of the lens. These soft skirts were made from hydroxyethyl methacrylate (HEMA) plastic, and the low Dk of 9.3 often resulted in neovascularization of the cornea (Papas, 2006).

Not only are the current generation of hybrids made of high-Dk materials (silicone-hydrogel skirts; fluorosilicone acrylate optical center), but the skirts are now bonded covalently to the GP (Sonsino, 2014).

The recent pandemic led to concerns with the usage and disinfection of diagnostic contact lenses that were to be reused (Barnett, 2020). Leading hybrid lens manufacturers now recommend fitting hybrid lenses empirically, utilizing central keratometry measurements and horizontal visible iris diameter (HVID) (SynergEyes iD Practitioner Brochure, 2021). The latest, or third generation, relies on the HVID measurement as a metric for designing the lens skirt. The new skirt is linear rather than the curved designs of earlier generations. The linear, or straight, landing zone more closely matches the tangent angles of the sclera (Otten et al, 2018).

When a multifocal lens is required, a unique, proprietary design which is “non-monotonic” and “aperiodic” creates an extended depth of focus (EDOF).

Hybrid lenses are perceived to be more comfortable in many cases than GP lenses (Frogozo et al, 2022). The soft skirt provides a comfortable landing zone and helps keep the GP portion centered over the central cornea. The reduced movement and lid interaction means that adaptation will be quicker than a traditional GP.

Hybrid lenses are typically designed to be replaced every six months. The combination of superior visual acuity, improved comfort, less chair time required in empirical fitting, and increased profitability makes hybrids a valuable addition to the contact lens toolbox. CLS

REFERENCES:

1. Arnold T. Heads or Tails. Contact Lens Spectrum. 2022 Apr;37:12.
2. Chang A, Lam D. A Toric GP Primer. Contact Lens Spectrum. 2013 Dec;28:22-27.
3. Papas E. Corneal neovascularization and contact lenses. Arc Soc Esp Ofalmol. 2006 Jun;81:309-12.
4. Barnett M. In-Office Contact Lens Disinfection. Contact Lens Spectrum. 2020 Jan;35:17.
5. Synergeyes iD Practitioner Brochure. Available at https://synergeyes.com/wp-content/uploads/2021/02/SynergEyes-iD-Practitioner-Brochure-SV-MF.pdf . Accessed on Nov. 1, 2022.
6. Otten HM, van der Linden BJJJ, Visser E-S. Clinical performance of a new bitangential mini-scleral lens. Optom Vis Sci. 2018 Jun;95:515-522.
7. Frogozo M, Harthan J, Sonsino J. Custom soft vs. hybrid vs. rigid lens modalities. CL Spectrum. 2022 Oct:32-43,36,37.