Profocal Cornea Created by Transparent Hydrogel Corneal Inlay: Mechanism of Action and Clinical Implications
Purpose
To demonstrate, through clinical data and ray-trace simulations, how a profocal cornea provides a functional range of vision.
Methods
This study included 188 presbyopes implanted with a hydrogel corneal inlay in their non-dominant eye (Raindrop Near Vision Inlay), at two OUS clinical sites. Uncorrected ETDRS visual acuities for distance, intermediate, near, and patient satisfaction using self-administered questionnaire were used as clinical outputs. Using ray-trace (Zemax) in a finite eye model, we simulated letter charts to observe the dynamics of rays in order to understand the range of good near VA as a function of pupil size and spectacle defocus. The inlay induced anterior corneal surface change as was derived from the difference between postop and preop wavefront measurements.
Results
Mean preop UNVA was (logMAR) 0.51 and by 3 months improved to 0.06 (p<0.001). Similarly, UIVA improved 2.5 lines (0.38 preop to 0.12 at 3 months, p<0.001). Near satisfaction improved after inlay implantation (p<0.001). Zemax simulations in bright light (3.5 mm pupil), predicts that the change in cornea provides enough power for near, intermediate, and distance vision in a wide range of preoperative refractive powers (-0.50 D to +1.50 D).
Conclusion
Raindrop creates a smooth steepening in the central cornea (Profocal cornea), which generates a gradient of power. This smooth elevation provides good range of vision and patient satisfaction.
* CAUTION: Investigational device. Limited by Federal United States law to investigational use.