Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.
Ophthalmology. 2010 Mar;117(3):538-44. doi: 10.1016/j.ophtha.2009.07.035. Epub 2010 Jan 4.
To analyze immediate in vivo intraretinal morphologic changes secondary to standardized grid photocoagulation using spectral domain optical coherence tomography (SD OCT).
Prospective clinical trial.
Thirteen consecutive patients with treatment-naïve clinically significant diabetic macular edema (DME).
Before and 1 day after standardized grid photocoagulation using the PASCAL system (Pattern Scan Laser, OptiMedica Corporation, Santa Clara, CA), Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) examinations based on an eye-tracking system, infrared fundus imaging, color fundus photography, and biomicroscopy were performed. A standardized visual acuity assessment (Early Treatment Diabetic Retinopathy Study protocol) and fluorescein angiography were performed at baseline.
Morphologic changes secondary to grid laser treatment.
One day after laser therapy, immediate morphologic alterations of only the outer retinal layers, that is, the retinal pigment epithelium (RPE), the photoreceptor layer (PRL), and the outer nuclear layer (ONL), were observed. The shape of the laser-induced lesions did not show a sagittal alteration pattern throughout all 3 of the layers, however, but rather seemed to follow an oblique pathway throughout the ONL, changing direction at the level of the external limiting membrane and proceeding sagittally through the PRL and RPE. These morphologic changes also induced biometric changes, such as a decrease in central retinal thickness combined with local thickening at the lesion site, especially in the PRL.
Spectral domain optical coherence tomography provides new insight into the immediate morphologic changes after laser treatment using the PASCAL laser system. Standardized grid photocoagulation induces characteristic homogenous alteration in the neurosensoric retinal layers. Biometric changes, indicating an immediate effect, were observed within 1 day after treatment.
使用谱域光相干断层扫描（SD OCT）分析标准化格栅光凝后立即发生的视网膜内形态变化。
前瞻性临床试验。
13 例未经治疗的初诊临床显著糖尿病性黄斑水肿（DME）患者。
使用 PASCAL 系统（Pattern Scan Laser，OptiMedica Corporation，Santa Clara，CA）进行标准化格栅光凝之前和之后 1 天，进行基于眼球跟踪系统的 Spectralis OCT（Heidelberg Engineering，Heidelberg，Germany）检查、红外眼底成像、彩色眼底照相和生物显微镜检查。在基线时进行标准化视力评估（早期糖尿病视网膜病变治疗研究方案）和荧光素血管造影。
格栅激光治疗引起的形态变化。
激光治疗后 1 天，仅观察到外视网膜层，即视网膜色素上皮（RPE）、光感受器层（PRL）和外核层（ONL）的即刻形态改变。然而，激光诱导病变的形状并没有在所有 3 层中表现出矢状改变模式，而是似乎在整个 ONL 中沿着斜向路径，在外限膜处改变方向，并通过 PRL 和 RPE 进行矢状延伸。这些形态变化也引起了生物计量学的变化，例如中央视网膜厚度的减少，同时病变部位出现局部增厚，尤其是在 PRL 中。
谱域光相干断层扫描为使用 PASCAL 激光系统治疗后的即刻形态变化提供了新的见解。标准化格栅光凝可引起神经感觉视网膜层的特征性均匀改变。在治疗后 1 天内观察到生物计量学变化，表明即刻效应。
