Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.
Cornea. 2012 Jan;31(1):18-20. doi: 10.1097/ICO.0b013e31821eea97.
To assess whether fluorescein dye in the tear film results in a clinically relevant change in central corneal thickness (CCT), as measured with Scheimpflug imaging (Pentacam HR; Oculus, Wetzlar, Germany). The study was conducted at Moorfields Eye Hospital NHS Foundation Trust.
In this prospective, randomized, controlled, single-center study on healthy volunteers, CCT was measured using rotating Scheimpflug imaging and partial coherence interferometry technique. After 3 baseline measurements of both eyes, a drop of 0.25% fluorescein with 0.5% proxymetacaine hydrochloride dye, as used for measuring intraocular pressure with applanation Goldmann tonometry, was instilled in the first eye and measurements were repeated after 1 minute and 5, 10, 20, 40, and 60 minutes. A fluorescein drop was then instilled in the second eye, and 1 measurement was performed after 1 minute. Immediately afterwards, the second eye was rinsed with 2 ml of balanced saline solution and the CCT measurement was repeated. On a different day, a Schirmer II test was performed.
Thirty eyes of 15 volunteers were included in this study. The average CCT measured with Scheimpflug imaging was 539.1 μm (SD, 32.2 μm), and after instilling fluorescein, CCT values increased by 46.6 μm (SD, 11.4 μm; P < 0.01, paired t test). In 10 of 15 subjects, the fluorescein layer was still present 40 minutes after instilling the drop. Rinsing the eye decreased the fluorescein layer by 49.6% and a value of 24.8 μm (SD, 16.8 μm).
Because CCT measurements are critical for corneal refractive surgery, Scheimpflug imaging should not be performed after use of fluorescein dye for staining of the corneal epithelium or for applanation tonometry.
评估在泪膜中使用荧光素染料是否会导致中央角膜厚度（CCT）发生临床相关变化，该变化通过Scheimpflug 成像（Pentacam HR；Oculus，德国威茨拉尔）进行测量。本研究在 Moorfields Eye Hospital NHS Foundation Trust 进行。
在这项针对健康志愿者的前瞻性、随机、对照、单中心研究中，使用旋转 Scheimpflug 成像和部分相干干涉测量技术测量 CCT。双眼进行 3 次基线测量后，将 0.25%荧光素和 0.5%盐酸普罗卡因染料滴入第一只眼，用于测量眼压的压平式 Goldmann 眼压计，滴入后 1 分钟以及 5、10、20、40 和 60 分钟重复测量。然后将一滴荧光素滴入第二只眼，滴入后 1 分钟进行 1 次测量。之后立即用 2ml 平衡盐溶液冲洗第二只眼并重复 CCT 测量。在不同的一天，进行 Schirmer II 测试。
这项研究共纳入 15 名志愿者的 30 只眼。Scheimpflug 成像测量的平均 CCT 为 539.1μm（标准差，32.2μm），滴入荧光素后 CCT 值增加了 46.6μm（标准差，11.4μm；P<0.01，配对 t 检验）。在 15 名受试者中有 10 名，在滴入滴眼剂后 40 分钟仍存在荧光素层。冲洗眼睛使荧光素层减少了 49.6%，为 24.8μm（标准差，16.8μm）。
由于 CCT 测量对角膜屈光手术至关重要，因此在使用荧光素染料染色角膜上皮或进行压平眼压测量后，不应进行 Scheimpflug 成像。
