術後可調整度數及散光的人工水晶體 RxSight，正式被美國FDA通過，如果未來能在台灣上市，將是眼科醫師與患者的一大福音！
美國食品藥物管理局(FDA)昨(22)日批准了RxSight的光調節水晶體(light adjustable lens)和光傳遞設備(light delivery device, LDD)，這是第一個可以在白內障手術後，對人工水晶體(intraocular lens, IOL)進行小幅度調整的醫療器械系統，幫助患者不戴眼鏡也能擁有良好視力。
白內障通常是由於年紀增長，水晶體變硬或混濁，影響患者視力。也有些是由於外傷性、併發性(如青光眼)、代謝性(如糖尿病)等引起的白內障。
解決療法之一便是進行人工水晶體置換手術，然而許多患者會有些微屈光不正，需要使用眼鏡或隱形眼鏡矯正。
為了替患者解決人工水晶體不當聚焦的問題，RxSight 建構獨特材料IOL，在手術後17至21天，對LDD發出的紫外線進行反應。根據所需調整量，患者在1到2周內接受3或4次光照治療，每次約40-150秒。
白內障手術開始到光療結束，患者必須配戴特殊眼鏡防護紫外線，保護新水晶體免受紫外線照射影響。
FDA批准是基於針對此產品所做的試驗成果，該研究隨機性地在17個研究地點挑選600名患有散光的患者，比較了光調節水晶體與現有的單焦點水晶體。
使用光調節水晶體的患者接受輕度LDD治療，術後6個月的裸眼視力(uncorrected visual acuity, UCVA)達到20/20或更高，是接受單焦點水晶體患者的兩倍。與使用傳統IOL相比，患者平均遠距離裸眼視力在視力表上可多看清楚一行。
75%的患者散光也有所減少，91.8%使用光調節水晶體的患者也達到目標驗光球鏡度數(manifest refraction spherical equivalent)0.5D以內的結果，這與近期LASIK研究中所見屈光準確性相似。
FDA醫療器械暨輻射健康中心(Center for Devices and Radiological Health)眼科和耳鼻喉科部門主任Malvina Eydelman表示，到今天為止，白內障手術常見的屈光不正問題，都還得透過眼鏡矯正。不過這個系統為部分患者提供了一個新的選擇，使醫生在初次手術後，可進行多次，可在辦公室內操作的步驟，對植入的水晶體做些調整，提高不戴眼鏡的視力。
RxSight執行長Eric Weinberg指出，我們很高興全球首個手術後可調式IOL成功到達另一個里程碑，這對期待屈光人工水晶體技術再度突破的患者、外科醫生和驗光師來說，是一個相當令人振奮的機會。我們很感謝所有參與這項工作的人員，包括協助研究的臨床工作人員，以及準備審查監管報告的雙方(RxSight和FDA)工作人員。
感謝 David 提供中文翻譯。
資料來源：
https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm586405.htm
The U.S. Food and Drug Administration today approved the RxSight Inc. Light Adjustable Lens and Light Delivery Device, the first medical device system that can make small adjustments to the artificial lens’ power after cataract surgery so that the patient will have better vision when not using glasses.
Cataracts are a common eye condition where the natural lens becomes clouded, impairing a patient’s vision. Following cataract surgery, during which the natural lens of the eye that has become cloudy is removed and replaced with an artificial lens (intraocular lens, or IOL), many patients have some minor residual refractive error requiring use of glasses or contact lenses. Refractive error, which is caused when the artificial lens does not focus properly, causes blurred vision.
“Until now, refractive errors that are common following cataract surgery could only be corrected with glasses, contact lenses or refractive surgery,” said Malvina Eydelman, M.D., director of the Division of Ophthalmic, and Ear, Nose and Throat at the FDA’s Center for Devices and Radiological Health. “This system provides a new option for certain patients that allows the physician to make small adjustments to the implanted lens during several in-office procedures after the initial surgery to improve visual acuity without glasses.”
The RxSight IOL is made of a unique material that reacts to UV light, which is delivered by the Light Delivery Device, 17-21 days after surgery. Patients receive three or four light treatments over a period of 1-2 weeks, each lasting about 40-150 seconds, depending upon the amount of adjustment needed. The patient must wear special eyeglasses for UV protection from the time of the cataract surgery to the end of the light treatments to protect the new lens from UV light in the environment.
A clinical study of 600 patients was conducted to evaluate the safety and effectiveness of the RxSight Light Adjustable Lens and Light Delivery Device. Six months after the procedure, patients on average saw an improvement of about one additional line down the vision chart, for distance vision without glasses, compared to a conventional IOL. Six months after surgery, 75 percent also had a reduction in astigmatism.
The device is intended for patients who have astigmatism (in the cornea) before surgery and who do not have macular diseases.
The device should not be used in patients taking systemic medication that may increase sensitivity to UV light such as tetracycline, doxycycline, psoralens, amiodarone, phenothiazines, chloroquine, hydrochlorothiazide, hypercin, ketoprofen, piroxicam, lomefloxacin and methoxsalen. Treatment in patients taking such medications may lead to irreversible eye damage. The device is also contraindicated in cases where patients have a history of ocular herpes simplex virus.
The FDA approved the Vision Light Adjustable Lens and the Light Delivery Device to RxSight Inc.
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency is also responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.
