Objective evaluation of static and dynamic behavior of different toric silicone-hydrogel contact lenses

Abstract

The present study aimed to estimate how orientation position, recovery time, and contact lens decentration, associated with visual performance, may vary on several designs of the most recent toric siliconehydrogel toric contact lenses in two-time different moments. Methods: To evaluate the toric silicone-hydrogel toric contact lens position and stability, it was conducted with a prospective, observational, randomized, and single-center case series including 95 astigmatic eyes wearing four toric silicone-hydrogel toric contact lenses for two weeks. Orientation and decentration were analyzed with ImageJ software from video-frames extracted with a Python application. Recovery time was evaluated after 45 degrees of inferior-temporal misorientation. Results: Evaluation of misorientation after 20 min of wear revealed the highest amount for Saphir RX, − 20.41 ± 10.84 deg, and lowest for Air Optix Aqua for Astigmatism, − 1.43 ± 7.48 deg. The highest horizontal misalignment was found for Air Optix Aqua for Astigmatism, − 0.627 ± 0.330 mm, and lowest for Biofinity Toric, 0.004 ± 0.270 mm. Vertical misalignment presented the highest value for Acuvue Vita for Astigmatism, − 0.652 ± 0.369 mm, and lowest for Air Optix Aqua for Astigmatism, − 0.126 ± 0.231 mm. Recovery time showed the highest amount for Saphir RX, 80.70 ± 33.26 s, and lowest for Biofinity Toric 43.67 ± 23.70 s. Only Air Optix Aqua for Astigmatism presented significant differences after two-week of wear for misorientation (P = 0.02) and horizontal misalignment (P < 0.001). When pairwise comparisons are made between toric silicone-hydrogel toric contact lenses, significant differences (P < 0.001) are found. Conclusions: Although there was acceptable fitting, based upon decentration, orientation, and recovery with the study contact lenses, the stabilization and profile design used in the Air Optix Aqua for Astigmatism helped to minimize rotation and vertical misalignment. In addition, the peri-ballast and thickness profile of the Biofinity Toric improved rotational recovery and horizontal misalignment compared to the other contact lenses. Finally, lenses with a better fitting profile showed better visual performance.

Epithelial and stromal thickness profile and lens decentration in myopic orthokeratology

“… 12 , 33 , 34 The main reason for this tendency may be that the temporal corneal shape is commonly steeper than the nasal one, and the lenses tended to drift to the steeper side. 29 , 35 So, the asymmetric compression pattern observed in this study, can be attributable to inherent Ortho-k effect on asymmetric corneal surface. 36 Simple linear regression analysis showed that there was no association between vertical lens decentration and regional ET or ST changes, but there was association between post Ortho-k ET and the magnitude of horizontal lens decentration.…”

Unraveling the New Perspectives on Antimicrobial Hydrogels: State-of-the-Art and Translational Applications

“…According to some research, a novel class of optically clear silicone thermoplastic hydrogel materials could be used to make contact lenses [ 180 , 181 ]. The polymers’ general formula includes a section made of silicone and produced from polyciliate that is joined by hydroxyl or amino groups [ 182 ]. In addition, among the variety of their applications in vision correction, soft contact lenses may also be utilized to administer medications to the eye [ 183 , 184 ].…”

LIDAR-based SLAM system for autonomous vehicles in degraded point cloud scenarios: dynamic obstacle removal

“…Another method is ray tracing-based (Wang et al , 2022). Such methods are typically implemented in conjunction with a grid (Sánchez-García and González-Pérez, 2021), either an ordinary occupying grid or an octree grid. The basic principle is that when a laser misses a cell, the hits count adds one, and when the laser beam passes through the cell, the misses count adds one.…”