Drum Bruce A
Division of Ophthalmic and ENT Devices, Office of Device Evaluation, Center for Devices and Radiological Health, Food and Drug Administration, 9200 Corporate Boulevard, HFZ-460, Rockville, MD 20850, USA.
J Refract Surg. 2003 Sep-Oct;19(5):S588-91. doi: 10.3928/1081-597X-20030901-16.
Manufacturers of refractive surgical lasers are seeking Food and Drug Administration (FDA) approval for refractive surgery based on wavefront measurements rather than manifest refractions. This article draws attention to the need for better understanding of the relationship between aberrations and visual function and better testing methods for evaluating safety and effectiveness of wavefront-guided refractive surgery.
Before U.S. market approval for a new medical device, the FDA must determine whether the manufacturer has provided reasonable assurance that the device is safe and effective for its intended use, based on valid scientific evidence. The issues discussed here are based on FDA reviewers' experiences in evaluating Investigational Device Exemption (IDE) and Premarket Approval (PMA) applications for wavefront-guided refractive lasers.
Even an optimal wavefront correction can provide only a marginally greater visual function benefit than a conventional spherocylindrical correction in a normal eye. Actual benefits are even smaller or nonexistent because variability from uncontrollable sources (eg, healing, aging, accommodation, pupil size, or ocular biomechanical effects) are typically larger than the errors treated. The effects of higher order aberrations and aberration changes on visual function are complex and poorly understood.
The FDA's need for better tools to assess safety and effectiveness of wavefront-guided refractive surgery has stimulated major research efforts within the vision, ophthalmic, and optometric research communities. More research is needed to better understand the relationship between aberrations and visual function, and to be able to predict the visual effects of specific aberration changes in individual eyes. This research would have been more appropriately done before rather than after clinical trials for wavefront-guided refractive lasers.
屈光手术激光制造商正在寻求美国食品药品监督管理局（FDA）批准基于波前测量而非显验光的屈光手术。本文提请注意需要更好地理解像差与视觉功能之间的关系，以及需要更好的测试方法来评估波前引导屈光手术的安全性和有效性。
在美国市场批准一种新的医疗器械之前，FDA必须根据有效的科学证据确定制造商是否提供了合理的保证，即该器械对于其预期用途是安全有效的。这里讨论的问题基于FDA审评员在评估波前引导屈光激光的研究性器械豁免（IDE）和上市前批准（PMA）申请方面的经验。
即使是最佳的波前矫正，在正常眼中也只能比传统的球柱镜矫正略微提供更大的视觉功能益处。由于不可控因素（如愈合、衰老、调节、瞳孔大小或眼部生物力学效应）引起的变异性通常大于所治疗的误差，实际益处甚至更小或不存在。高阶像差和像差变化对视觉功能的影响复杂且了解甚少。
FDA对更好的工具来评估波前引导屈光手术的安全性和有效性的需求，刺激了视觉、眼科和验光研究领域的重大研究工作。需要更多的研究来更好地理解像差与视觉功能之间的关系，并能够预测个体眼睛中特定像差变化的视觉效果。这项研究在波前引导屈光激光的临床试验之前进行会比之后进行更为合适。
