EyeWorld China December 2019 Issue

The Optiwave Refractive Analysis (ORA™) system with VerifEye+ technology is an intraoperative aberrometry that provides unique information to improve refractive outcomes. It allows true measurement of complete refractive error by including the effect of posterior corneal curvature and surgically induced astigmatism for each eye. It provides IOL sphere, cylinder and alignment suggestions. ORA™ also indicates the residual refractive after IOL insertion and allows refinement of toric IOL axial placement before leaving the operating room, highlighted Dr. Vilavun Puangsricharern. A study that compared ORA™ system wavefront aberrometers with surgeon best preoperative choice, the Haigis L, and the Shammas IOL formulas in in eyes undergoing cataract surgery after prior myopic LASIK, showed that that IOL power was most effectively predicted by ORA™ system. (67% in ORA™ group had mean absolute error within 0.5 D vs. 46% in conventional method group). The mean absolute error was 0.35D in ORA™ vs. 0.6D in conventional method. 13 Another study compared the accuracy of ORA™ versus pre-operative biometry in predicting residual refractive error after cataract surgery in axial myopia. SRK/T, Holladay 1, AL-optimized Holladay 1, Holladay 2, Barrett Universal II, and Hill-RBF formulas were used for pre-operative prediction of residual refractive error. The study showed that ORA™ was as effective as AL-optimized Holladay1 formula, and better than all other formulas based on preoperative biometry in predicting residual refractive error and reducing hyperopic outcomes. 14 Achieving Target Refractive outcomes with ORA ® VerifEye+ Vilavun Puangsricharern ORA™ system with VerifEye+ technology facilitates intraoperative measurement and analysis of the refractive power of the eye and provides assurance through empowered decisions, which help surgeons to improve refractive outcomes and avoid refractive surprises. Though femtosecond laser assisted cataract surgery (FLACS) results in less deviation from target refraction, faster visual recovery, earlier stabilization of refraction and lower incidence of higher order aberrations, recent research has shown that femtosecond laser- created clear corneal incisions (CCIs) during cataract surgery were associated with more surgically induced astigmatism (SIA) than manually created CCIs. 15-17 The SIA during femtosecond laser-created CCIs is believed to be due inaccurate or uncertain corneal incision positioning of the femtosecond machine. 18 This is where LenSx ® femtosecond laser platform comes in to action, as it is designed to increase the safety and efficiency of cataract surgery by offering enhanced automation, precise and customizable incision architecture and precise capsulotomies. One of the unique features of LenSx ® is the curved contact lens patient interface (PI) as opposed to noncontact liquid optical interface in other laser platforms. 18 LenSx ® allows the surgeon to choose the position and architecture of the corneal incisions, centration, diameter of the anterior capsulotomy and depth and type of fragmentation pattern. 18 Furthermore, incisions with LenSx ® are more consistent and closer to the target incision geometry, explained Prof. Zhao Ping. He also provided several practical tips on creating successful CCIs with femtosecond laser. (Table 4) Arecent LenSx ® softwareupdateoffersenhanced incisionvisualization and easier incision placement. Future software update with planning for swept source optical coherence tomography (OCT) to allow real-time high definition images and dynamic display of incision is expected to elevate the level of precision in cataract surgery, added Prof. Zhao Ping. Bringing Precision to a higher level with LenSx ® Zhao Ping Table 4: Tips to make successful CCIs 1. Adjust the illumination to get better recognition of limbus 2. Understand the influence of side cut angle 3. Avoid decentered suction during docking 4. Use sharp instrument to open the incision 5. In case of incomplete incision, use keratome to finish the incision 6. Protect the incision and avoid distortion to minimize SIA LenSx ® femtosecond laser features enhanced capabilities with multi-curvature patient interface and offers superior precision with clean and customizable incisions enhancing the safety and efficiency of cataract surgery.