Through-Focus Letter Images Predict Visual Performance With Corneal Inlay to Treat Presbyopia
Purpose
To estimate the distance, intermediate and near visual performance of the Raindrop Near Vision Inlay by raytracing a customized schematic eye model.
Methods
The inlay introduces a progressive change in corneal power that extends into the mid-periphery. This induced change is modeled in a schematic eye by modifying the corneal elevation to match corneal topography data. Average levels of ocular aberration are incorporated into the model as well. Exact raytracing is used to determine the optical changes induced by the inlay. Through-focus simulated letter charts are created to assess visual performance for different levels of preoperative MRSE. Visual acuity and depth of focus are predicted from the letter charts.
Results
The simulations demonstrate that good near vision (~20/25) can be obtained for patients who were preoperatively between -0.5 D and +1.5 D MRSE. For patients who are slightly myopic two to three lines of distance vision loss is predicted, but this effect reduces for more hyperopic patients. Furthermore, the simulations suggest that the depth of focus for this procedure is enhanced due to the progressive nature of the corneal power change. This effect suggests improved intermediate vision when compared to the pre-operative eye. The simulation results are similar to clinical findings which lends credence to the validity of the model.
Conclusion
High quality distance, intermediate and near visual acuity is expected with the corneal inlay due to its progressive nature and smooth transition for patients with pre-operative MRSE between -0.5 D and +1.5 D.
* CAUTION: Investigational device. Limited by Federal United States law to investigational use.