The silicone rubber contact lens: clinical indications and fitting technique

Novel silicone elastomer contact lenses designed for simultaneous viewing of distance and near eye displays

SIGNIFICANCE

As technology advances, there is a need for a safe and well-fitting contact lens that can be utilized to carry embedded components without concerns of decreasing oxygen permeability to the eye.

PURPOSE

The purpose of this study was to assess fitting characteristics, vision and performance of a novel ultra-high Dk silicone elastomer contact lens having a fully encapsulated two-state polarizing filter and a high-powered central lenslet that allows viewing at distance and viewing of a near eye display, while managing the concomitant high water vapor permeability of the material.

METHODS

15 participants were fit with the silicone elastomer study lenses. Biomicroscopy was conducted before and after lens wear. Visual acuity with manifest refraction and visual acuity with an over-refraction while wearing the plano-powered study lenses were measured. Participants wore spectacles with micro-displays at the focal length of the lenslet on each eye. Lens fit was assessed including ease of lens removal. Subjective assessments of viewing the micro-displays were completed on a 1(unable) to 10(immediate/profound/stable) scale.

RESULTS

Biomicroscopy revealed no eyes had moderate or severe corneal staining after study lens wear. Mean (±standard deviation) LogMAR acuity for all eyes was -0.13(0.08) with best corrected refraction and -0.03(0.06) with the study lenses and over-refraction. Mean spherical equivalent of the manifest refraction for both eyes was -3.12 D and was -2.75 D over the plano study lenses. Subjective assessments revealed a mean score of 7.67(1.91) for ease of obtaining fusion; 8.47(1.30) for ease of observing three-dimensional vision, and 8.27(1.49) for stability of the fused binocular display vision.

CONCLUSION

The silicone elastomer study lenses with a two-state polarizing filter and central lenslet allow for vision at distance and on spectacle mounted micro-displays.

Applications of contact lens devices in the management of corneal disease

Contact lens devices have a variety of therapeutic applications in the management of corneal diseases. A wide range of devices is available, some with very specific indications for use, including scleral lenses, silicone elastomer, collagen shields, large diameter corneal lenses, and silicone hydrogels. The traditional hydrogel contact lens is the most frequently used device and is indicated in at least 80% of cases. Common indications for use are relief of pain, promotion of corneal healing, mechanical protection and support, and control of corneal hydration, often a combination of effects being achieved. Visual improvement may be achieved but this is not the primary role of such devices.