Zhuo Yueming, Bhuckory Mohajeet, Li Huakun, Hattori Junya, Pham-Howard Davis, Veysset David, Ling Tong, Palanker Daniel
Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA.
Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, 94305, USA.
Light Sci Appl. 2025 Apr 2;14(1):151. doi: 10.1038/s41377-025-01798-x.
Controlling the tissue temperature rise during retinal laser therapy is essential for predictable outcomes, especially at non-damaging settings. We demonstrate a method for determining the temperature rise in the retina using phase-sensitive optical coherence tomography (pOCT) in vivo. Measurements based on the thermally induced optical path length changes (ΔOPL) in the retina during a 10-ms laser pulse allow detection of the temperature rise with a precision less than 1 °C, which is sufficient for calibration of the laser power for patient-specific non-damaging therapy. We observed a significant difference in confinement of the retinal deformations between the normal and the degenerate retina: in wild-type rats, thermal deformations are localized between the retinal pigment epithelium (RPE) and the photoreceptors' inner segments (IS), as opposed to a deep penetration of the deformations into the inner retinal layers in the degenerate retina. This implies the presence of a structural component within healthy photoreceptors that dampens the tissue expansion induced by the laser heating of the RPE and pigmented choroid. We hypothesize that the thin and soft cilium connecting the inner and outer segments (IS, OS) of photoreceptors may absorb the deformations of the OS and thereby preclude the tissue expansion further inward. Striking difference in the confinement of the retinal deformations induced by a laser pulse in healthy and degenerate retina may be used as a biomechanical diagnostic tool for the characterization of photoreceptors degeneration.
在视网膜激光治疗过程中控制组织温度升高对于获得可预测的结果至关重要，尤其是在非损伤性设置下。我们展示了一种在体内使用相敏光学相干断层扫描（pOCT）来确定视网膜温度升高的方法。基于10毫秒激光脉冲期间视网膜内热诱导光程长度变化（ΔOPL）的测量能够以小于1°C的精度检测温度升高，这足以针对患者特异性非损伤性治疗校准激光功率。我们观察到正常视网膜和退化视网膜之间视网膜变形的局限存在显著差异：在野生型大鼠中，热变形局限于视网膜色素上皮（RPE）和光感受器内段（IS）之间，而在退化视网膜中，变形则深入到视网膜内层。这意味着健康光感受器内存在一种结构成分，可抑制由RPE和色素性脉络膜激光加热引起的组织扩张。我们推测连接光感受器内段和外段（IS，OS）的细而柔软的纤毛可能吸收OS的变形，从而防止组织进一步向内扩张。健康视网膜和退化视网膜中激光脉冲引起的视网膜变形局限的显著差异可作为一种生物力学诊断工具，用于表征光感受器退化。
