*Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida; †Duke University Eye Center, Duke University, Durham, North Carolina; and ‡Shiley Eye Center, University of California San Diego, La Jolla, California.
Retina. 2014 Apr;34(4):749-60. doi: 10.1097/IAE.0b013e3182a48784.
To characterize the morphology of patterned scanning laser (PASCAL) panretinal photocoagulation.
In this prospective cohort study, patients with proliferative diabetic retinopathy or severe nonproliferative diabetic retinopathy with high-risk characteristics, who were treated with PASCAL panretinal photocoagulation as part of their indicated clinical course, were serially imaged with spectral domain optical coherence tomography. Thirty eyes of 25 patients were studied from 1 hour to 21 weeks after laser treatment.
Over a quarter (26.1%) of all treatment spots were imaged by spectral domain optical coherence tomography 1 hour after PASCAL panretinal photocoagulation. At 1 hour (±30 minutes) after PASCAL treatment, spectral domain optical coherence tomography demonstrated retinal pigment epithelium detachment in 23 of 27 eyes (85.2%) and in 36.1% of all imaged laser spots. Detachments occurred preferentially at the photocoagulation edges in 48.4% of pigment epithelium detachments (PEDs). Linear regression analysis revealed that average laser power (Pearson's r = 0.671, P < 0.001) and average laser energy (Pearson's r = 0.588, P = 0.001) were significantly associated with PEDs observed 1 hour after treatment. Pigment epithelium detachments occurred at a rate of 9.2% ± 4.9% at an average power of 0 mW to 400 mW, 37.8% ± 9.5% at 401 mW to 800 mW, 42.1% ± 5.6% at 801 mW to 1,200 mW, and 53.6% ± 5.7% at >1,200 mW. By a 1-week follow-up, no PEDs were observed, and the retinal pigment epithelium appeared morphologically similar to its preoperative structure by 3 weeks. Patient characteristics (study eye, sex, race, diagnosis, age, preoperative blood glucose, hemoglobin A1C, duration of diabetes, and body mass index) and other PASCAL parameters (number of laser applications, spot size, pulse duration, and average laser fluence) were not significantly associated with PEDs.
Retinal pigment epithelium detachment occurs 1 hour after PASCAL treatment over a wide range of laser settings. Laser power and energy are positively correlated with the occurrence of PEDs, which are no longer observed by 1-week follow-up. Future studies might examine various acute posttreatment time points and directly compare the morphology of PASCAL burns with that of longer pulse-duration laser modalities.
描述模式扫描激光（PASCAL）全视网膜光凝的形态。
本前瞻性队列研究纳入了接受 PASCAL 全视网膜光凝治疗的增殖性糖尿病视网膜病变或高危特征的严重非增殖性糖尿病视网膜病变患者，这些患者是根据其临床情况进行治疗的。在激光治疗后 1 小时至 21 周，对患者进行了频域光相干断层扫描（OCT）的连续成像。这项研究共纳入了 25 例患者的 30 只眼。
在 PASCAL 全视网膜光凝治疗后 1 小时，26.1%的所有治疗光斑都可以通过频域 OCT 成像。在 PASCAL 治疗后 1 小时（±30 分钟），27 只眼中有 23 只（85.2%）和所有成像激光光斑的 36.1%显示视网膜色素上皮脱离。在 48.4%的色素上皮脱离（PED）中，PED 优先发生在光凝边缘。线性回归分析显示，平均激光功率（Pearson r = 0.671，P < 0.001）和平均激光能量（Pearson r = 0.588，P = 0.001）与治疗后 1 小时观察到的 PED 显著相关。在平均功率为 0 至 400 mW 时，PED 的发生率为 9.2%±4.9%；在 401 至 800 mW 时，PED 的发生率为 37.8%±9.5%；在 801 至 1200 mW 时，PED 的发生率为 42.1%±5.6%；在 1200 mW 以上时，PED 的发生率为 53.6%±5.7%。在 1 周的随访时，没有观察到 PED，PED 在 3 周时视网膜色素上皮的形态与术前结构相似。患者特征（研究眼、性别、种族、诊断、年龄、术前血糖、糖化血红蛋白、糖尿病病程和体重指数）和其他 PASCAL 参数（激光应用次数、光斑大小、脉冲持续时间和平均激光强度）与 PED 无显著相关性。
在广泛的激光设置下，PED 在 PASCAL 治疗后 1 小时发生。激光功率和能量与 PED 的发生呈正相关，1 周随访时不再观察到 PED。未来的研究可能会检查各种急性治疗后时间点，并直接比较 PASCAL 烧伤的形态与较长脉冲持续时间激光治疗模式的形态。
