Hunter D G, Guyton D L
Wilmer Ophthalmological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-9028, USA.
Arch Ophthalmol. 1998 Jun;116(6):767-71. doi: 10.1001/archopht.116.6.767.
To improve the clinical documentation of strabismus by mathematically predicting and clinically verifying the location of a fixation target that produces a vertically centered corneal light reflex (first Purkinje image) in clinical photographs of the eye using a standard photographic flash unit.
Mathematical modeling of the corneal light reflex during clinical photography was based on the schematic eye. Clinical photographs were taken using a range of fixation targets located between the center of the camera lens and the center of the flash. Image quality was also assessed subjectively.
Optimum vertical centration of the corneal light reflex was predicted and produced when the fixation target was located one fifth of the distance from the center of the flash to the center of the camera lens. Placement of the flash below, rather than above, the camera lens provided more uniform illumination of the patient's eyes and face. Decreasing the distance between the camera lens and the flash minimized the severity of these artifacts.
A poorly positioned corneal light reflex makes it difficult to identify the fixing eye in photographs of patients with strabismus, especially when vertical strabismus is present. Adoption of the aforementioned protocol will reproduce the appearance of coaxially viewed corneal light reflexes and provide much-needed standardization for strabismus case presentation.
通过数学预测并临床验证在使用标准摄影闪光灯单元拍摄的眼部临床照片中，能产生垂直居中角膜反光（第一普尔钦耶图像）的注视目标位置，以改善斜视的临床记录。
临床摄影期间角膜反光的数学建模基于简化眼。使用位于相机镜头中心与闪光灯中心之间的一系列注视目标拍摄临床照片。还主观评估了图像质量。
当注视目标位于从闪光灯中心到相机镜头中心距离的五分之一处时，可预测并产生角膜反光的最佳垂直居中。将闪光灯置于相机镜头下方而非上方，可为患者的眼睛和面部提供更均匀的照明。减小相机镜头与闪光灯之间的距离可使这些伪影的严重程度降至最低。
角膜反光位置不佳会使在斜视患者照片中难以识别注视眼，尤其是存在垂直斜视时。采用上述方案将重现同轴观察到的角膜反光外观，并为斜视病例呈现提供急需的标准化。
