Comparison of the Simulated Negative Dysphotopsia of an IOL to Published Clinical Observations
Purpose
Evaluate the similarities and dissimilarities of theoretically simulated pseudophakic negative dysphotopsia with that in published clinical case reports of an implanted IOL.
Methods
ZEMAX (ZEMAX LLC) was utilized to build 2 cases of artificial eyes mimicking the pseudophakic eyes that were reported having persistent negative dysphotopsia. The assembled eyes used clinically relevant biometric parameters with a centered and symmetrically designed IOL having a truncated square edge and the same diopters as the reported. A 3mm pupil was used for a common pupil in bright light environment where negative dysphotopsia occurred. The light glared into the eye from angles from zero on axis up to 93 degrees at the temporal. The retinal images were analyzed and compared to the clinical observations.
Results
For sampled small glare angles there seemed only a primary image formed due to that no rays were interacting with the IOL edge. With the glare angle gradually increased to a larger temporal angle in a full field of view, additional multiple images formed on the retina: one formed by rays passing by the IOL edge, one primary image and one formed by rays refracted through the edge. After analyzing and comparing the retinal image location, intensity and contrast to the clinical observations, it was found the simulated images were consistent with the clinical descriptions of the negative dysphotopsia.
Conclusion
Theoretical simulations mimicking clinically reported pseudophakic negative dysphotopsia were conducted with a full field of view and the results were consistent with the clinical observations, thus suggesting that the IOL can be a significant optical source for the persistent pseudophakic negative dysphotopsia.