Optical coherence tomography for retinal thickness measurement in diabetic patients without clinically significant macular edema

BACKGROUND AND OBJECTIVE: To evaluate the potential of optical coherence tomography (OCT) as a screening method for retinal thickness measurements in diabetic patients. PATIENTS AND METHODS: We used a previously described pattern of six 5 mm OCT scans through the center of fixation in 45 diabetic patients without clinically significant macular edema: 22 patients (group 1) had no diabetic retinopathy (ETDRS classification); 18 (group 2) had nonproliferative retinopathy; 5 patients with peripheral neovascularization did not enter statistical analysis; 25 normal healthy subjects were used as a control group. Retinal thickness was measured at five locations in each scan: in the fovea, at the foveal rim, and outside the macula. Measurements were identified in nonaligned images and taken from raw data A-scans. Locations were grouped into hemispheres, quadrants and rings, and mean values tested for statistically significant differences using Mann-Whitney U-Wilcoxon rank sum W test. RESULTS: Differences in retinal thickness were found to be significant in the macula (controls vs group 2 P = 0.0266), at the foveal rim (controls vs group 1 and 2: P = 0.0386 and P = 0.0193), in the nasal and superior hemisphere (controls vs group 2: P = 0.0251 and P = 0.0187), and in the superior nasal quadrant (controls vs group 1 and group 1 vs group 2: P = 0.0022 and P = 0.0462). CONCLUSIONS: Significant differences of retinal thickness between patients with diabetic retinopathy and normals can be detected by OCT even in the absence of clinically significant macular edema. Significant differences between diabetic patients with and without retinopathy are most likely to be found in the superior nasal quadrant.     

Patterns of diabetic macular edema with optical coherence tomography

PURPOSE: We report cross-sectional images of diabetic macular edema and correlation between tomographic features and visual acuity with best correction by means of optical coherence tomography. METHOD: In a prospective study, optical coherence tomography was performed in 59 eyes of 42 patients with diabetic macular edema and in 10 eyes of 10 normal control subjects. RESULTS: Optical coherence tomography showed three patterns of structural changes in diabetic macular edema: sponge-like retinal swelling (52 [88%] of 59 eyes), cystoid macular edema (28 [47%] of 59 eyes), and serous retinal detachment (9 [15%] of 59 eyes). Some eyes had more than one pathologic change. Retinal swelling was more pronounced in the outer rather than the inner retinal layers. Cystoid macular edema was located mainly in the outer retinal layers. In eyes with long-standing cystoid macular edema, cystoid spaces had fused, resulting in a large cystoid cavity involving almost the entire retinal layer. Hard exudates were seen as highly reflective areas located in the outer retinal layers. The retinal thickness at the central fovea and the visual acuity with best correction showed an intermediate negative correlation in eyes without cystoid macular edema (correlation coefficient: -0.61, P < .01). CONCLUSIONS: Diabetic macular edema involved three structural changes, including sponge-like retinal swelling (88%), cystoid macular edema (47%), and serous retinal detachment (15%). Visual acuity with best correction moderately correlated with retinal thickness regardless of the different tomographic features.     

24-Hour variation of optical coherence tomography-measured retinal thickness in diabetic macular edema

Purpose. To investigate 24-hour variation in retinal thickness in patients with diabetic macular edema (DME) using optical coherence tomography (OCT). Methods. Fifty-three eyes of 53 diabetic patients with clinically significant macular edema and central subfield thickness (CST) >225 μm, 36 eyes of 36 healthy individuals (normal controls), and 22 eyes of 22 diabetic patients without macular pathology (diabetic controls) underwent 5 OCT measurements at 7 am, 10 am, 3 pm, 8 pm, and 1 am. Visual acuity, blood pressure, blood glucose, and body temperature were measured as well. Results. The CST (p<0.0005), total macular volume (p<0.0005), and visual acuity (p<0.0005) showed significant variation in patients. The CST (450 μm at 7 am) reached a minimum at 3 pm (absolute change of -49 μm, relative change of -17%) before increasing again. Thickening changes were higher in more thickened retinas (p<0.0005, p=0.024, absolute and relative change, respectively). Visual acuity was worse in the morning (0.38 logMAR) and improved to a maximum at 8 pm (0.30 logMAR) (p<0.0005). Blood pressure, blood glucose, and body temperature did not vary over time. Conclusions. The 24-hour variation of retinal thickness is observed in a large proportion of patients with DME, with a decrease from morning to afternoon. Time of examination should be taken into account when managing such patients.     

无糖尿病视网膜病变的2型糖尿病患者黄斑区视网膜厚度变化:基于SD-OCT的观察

目的　观察无糖尿病视网膜病变（diabetic retinopathy,DR）的2型糖尿病患者黄斑区视网膜厚度变化。方法　选择2017年8月至10月在我院检查确诊无DR的2型糖尿病患者40例（40眼,无DR组）和健康志愿者70名（70眼,正常对照组）纳入研究。采用频域光学相干断层扫描成像（spectral domain optical coherence tomography,SD-OCT）以及自动化分层技术分别测量黄斑区视网膜全层（retina,R）、视网膜内层（inner retinal layer,IRL）和视网膜外层即感光细胞层（photoreceptor layer,PL）厚度,将黄斑区以中心凹为中心点,分别以直径为1 mm、3 mm和6 mm的3个同心圆进行分区（R总、R-1、R-3、R-6、IRL-1、IRL-3、IRL-6、PL-1、PL-3及PL-6）,对比两组间视网膜厚度差异。结果　无DR组患者PL-1、PL-3厚度分别为（71±4）μm、（66±2）μm,较正常对照组（73±3）μm、（67±2）μm明显变薄（均为P<0.05）。正常对照组中除IRL-6和PL-1外,其余测量区域不同性别间视网膜结构厚度差异显著（均为P<0.05）。无DR组男性患者PL-3、PL-6厚度分别为（67±2）μm、（65±2）μm,较正常对照组的（68±2）μm、（66±2）μm明显变薄（均为P<0.05）。无DR组女性患者PL-3、PL-6厚度分别为（65±2）μm、（63±2）μm,较正常对照组的（67±2）μm、（64±2）μm明显变薄（均为P<0.05）。其余测量区域组间差异均无统计学意义（均为P>0.05）。结论　无DR组黄斑旁中心凹及中心凹周围视网膜PL厚度较正常对照组明显变薄,SD-OCT测量视网膜PL厚度有助于DR早期病变研究,并成为早期监测DR的重要生物学标志。     

Comparing central retinal thickness in diabetic macular edema measured by two different spectral-domain optical coherence tomography devices

Purpose

We evaluated central retinal thickness (CRT) in diabetic macular edema (DME) using two different spectral-domain (SD) optical coherence tomography (OCT) instruments: the Cirrus and Spectralis OCTs.

Methods

CRT was measured in 63 eyes of 32 patients with DME using both instruments on the same day.

Results

CRT measurements were significantly greater for the Spectralis than the Cirrus (p < 0.0003, n = 63, paired t test); mean CRT values were 382 ± 136 ??m with the Cirrus and 394 ± 139 ??m with the Spectralis. In eyes with poor best-corrected visual acuity (BCVA) (<20/40), mean CRT was 378 ± 130 ??m with the Cirrus and 395 ± 139 ??m with the Spectralis (p < 0.007, n = 29). In eyes with good acuity (equal to or better than 20/40), the mean CRT was 385 ± 142 ??m with the Cirrus and 393 ± 140 ??m with the Spectralis (p < 0.005, n = 34).

Conclusions

Foveal retinal thickness measurements may vary among SD-OCT devices. The differences between instruments could affect the results of a multicenter study.     

The variation in optical coherence tomography-measured macular thickness in diabetic eyes without clinical macular edema

PURPOSE: To determine the variation in optical coherence tomography (OCT)-measured macular thickness in diabetic eyes without clinical edema and to investigate factors that might influence variation in macular thickness. DESIGN: Retrospective, observational case series from a clinical practice. METHODS: Review of clinical charts and longitudinal OCT measurements of a consecutive series of 56 eyes of 56 patients with diabetes but no clinical macular edema. Measured variables include OCT central subfield mean thickness (CSMT), total macular volume (TMV), and logarithm of the minimum angle of resolution (logMAR) visual acuity. RESULTS: Over a median follow-up of 17 months, interquartile range (IQR) (9, 23), the median variation in CSMT was 18 microns, IQR (11, 31), and the median variation in TMV was 0.09 mm(3), IQR (0.06, 0.16). Variation in CSMT did not change significantly with increasing CSMT. Absolute, but not relative, variation in TMV increased with increasing baseline values (P = .0127 and P = .1538 for absolute variation and relative variation in TMV, respectively). The variation in CSMT and TMV did not vary with follow-up time and did not vary with age, gender, race, hypertension status, glycosylated hemoglobin, or retinopathy level. CONCLUSIONS: Variation in CSMT and TMV in diabetic eyes without DME over intervals up to 17 months is no greater than OCT measurement variability in eyes without and with DME. A change in the OCT-measured macular thickness greater than 10% of the baseline thickness is likely to represent a true change in the macular thickness and not OCT measurement variability, diurnal variation, or variability occurring over longer time scales.     

光学相干断层扫描血管成像量化分析糖尿病患者黄斑区毛细血管参数

目的：应用光学相干断层扫描血管成像技术(OCTA)量化2型糖尿病患者黄斑区毛细血管的早期变化。方法：回顾性病例研究。分别纳入49名健康受试者、52例无视网膜病变的2型糖尿病患者(noDR)和43例轻度非增殖性糖尿病视网膜病变(mNPDR)患者，并得到在黄斑区3 mm×3 mm浅层毛细血管丛和深层毛细血管丛的OCTA图像。去除大血管后分别计算毛细血管灌注密度、血管长度密度(VLD)和平均血管直径(AVD)并进行比较。应用受试者工作特征曲线评估该参数监测2型糖尿病患者视网膜微血管早期改变的能力。结果：比较三组间VLD和AVD，差异均有统计学意义(P&#x003C;0.001)。与健康受试者相比，noDR组的AVD均显著增加(P&#x003C;0.05)。mNPDR组患者深层及浅层的VLD较noDR组显著下降(均P&#x003C;0.01)。深层AVD鉴别noDR组与健康受试者的曲线下面积(AUC)为0.796，鉴别mNPDR组和健康受试者的AUC最高为0.920，其次为深层VLD(AUC=0.899)，显著高于其他参数。结论：在糖尿病视网膜病变的临床前阶段，2型糖尿病患者的深层及浅层AVD均显著高于健康人，VLD均显著高于mNPDR患者。与健康人相比，深度AVD较其他参数更能检出noDR患者早期视网膜毛细血管的变化。     

频域相干光断层扫描对糖尿病黄斑区厚度的应用研究

目的 利用频域相干光断层扫描(OCT)测量并分析糖尿病( DM)患者的黄斑区视网膜厚度.方法 DM组90例(90只眼),并分为分无糖尿病视网膜病变(NDR) 、非增殖期(NPDR) 及增殖期(PDR) 病变3组,每组各30例(30只眼),正常对照组30例(30只眼).分别行最佳矫正视力(BCVA)、裂隙灯、眼底彩照、荧...     

Optical coherence tomography after laser photocoagulation for clinically significant macular edema

BACKGROUND AND OBJECTIVE: To demonstrate the utility of optical coherence tomography (OCT) for documenting an early response to laser photocoagulation in clinically significant macular edema (CSME) secondary to diabetes. PATIENTS AND METHODS: Five eyes of four patients were selected for review based on the diagnosis of CSME. All eyes had a clinical diagnosis of CSME based on slit lamp biomicroscopy. All eyes underwent focal/grid laser photocoagulation to areas of retinal thickening detected by OCT and clinical exam. Pre and post-treatment optical coherence tomograms were obtained for all patients. RESULTS: All eyes selected for review had an early positive response to focal laser photocoagulation. OCT was useful for demonstrating areas of retinal thickening prior to laser treatment. Serial macular maps demonstrated the resolution of retinal thickening after laser photocoagulation in all eyes. CONCLUSION: OCT is a useful tool for evaluating and documenting CSME both before and after focal/grid laser photocoagulation. OCT is capable of detecting an early positive response to photocoagulation for macular edema.     

应用光学相干断层扫描血管成像（OCTA）评估糖尿病患者早期黄斑区视网膜微循环

目的　应用光学相干断层扫描血管成像（optical coherence tomography angiography,OCTA）观察糖尿病患者早期黄斑中心凹无血管区（foveal avascular zone,FAZ）面积和黄斑区血流密度（macular vascular density,MVD）的改变及其临床意义。方法　回顾性病例研究。收集33例46眼糖尿病患者纳入研究,依据糖尿病视网膜病变国际临床分期标准将患眼分为两组,其中无糖尿病视网膜病变（no-diabetic retinopathy,NDR）组13例20眼和非增生期糖尿病视网膜病变（nonproliferative diabetic retinopathy,NPDR）组20例26眼。另选取年龄相匹配的26人（40眼）健康者作为对照组。所有受试者均接受OCTA对黄斑区视网膜行3 mm×3 mm 范围的模式扫描,获得4个层面黄斑血流密度图,同时测量FAZ面积和MVD。结果　NDR组和NPDR组FAZ面积分别为（0.392±0.028）mm²、（0.410±0.019）mm²,与对照组（0.314±0.025）mm²相比差异均有统计学意义（均为P=0.000）;NDR组和NPDR组之间的FAZ面积比较,差异有统计学意义（P=0.010）。NDR组和NPDR组的表层视网膜、深层视网膜、外层视网膜及脉络膜毛细血管层的MVD分别是0.500±0.012、0.553±0.007、0.393±0.005、0.651±0.006和0.484±0.012、0.522±0.007、0.397±0.007、0.642±0.007,与对照组（0.518±0.014、0.572±0.008、0.385±0.005、0.666±0.007）比较,差异均有统计学意义（均为P=0.000）;NDR组和NPDR组表层视网膜、深层视网膜及脉络膜毛细血管层MVD比较,差异均有统计学意义（均为P=0.000）,但两组外层视网膜MVD比较,差异无统计学意义（P=0.065）。结论　应用OCTA检查提示糖尿病患者早期黄斑区视网膜的微循环障碍,且随着病情的进展而变化。     

The correlation between fluorescein angiographic and optical coherence tomographic features in clinically significant diabetic macular edema

PURPOSE: To assess the correlation between the features of optical coherence tomography (OCT) and fluorescein angiography in clinically significant diabetic macular edema. DESIGN: Retrospective observational case series. METHODS: This study involved 145 eyes (91 patients) with clinically significant diabetic macular edema. The fluorescein angiography features were categorized into focal leakage type, diffuse leakage type, and diffuse cystoid leakage type. The OCT features were categorized into four types: type 1, thickening with homogeneous optical reflectivity; type 2, thickening with markedly decreased optical reflectivity in the outer retinal layer; type 3A, foveolar detachment without traction; and type 3B, foveolar detachment with apparent vitreofoveal traction. The correlation between fluorescein angiography types and OCT types were analyzed, and their associations with visual acuity, central foveal thickness. and stages of diabetic retinopathy were evaluated. RESULTS: The prevalence of OCT type 1 was higher in the focal leakage type (73.0%) and in the diffuse leakage type (58.9%) than in the diffuse cystoid leakage type (3.8%) of fluorescein angiography (P <.0001). The prevalence of OCT type 2 and 3A was higher in the diffuse cystoid leakage type (57.7% and 34.6%, respectively) than in the focal leakage type (20.6% and 3.2%) or diffuse leakage type(28.6% and 10.7%; P <.0001). The stages of retinopathy correlated with fluorescein angiography types (P =.016). Optical coherence tomography type 1 and the focal leakage type of fluorescein angiography showed the least foveal thickness and the best visual acuity (P <.05). CONCLUSIONS: There was a significant correlation between the features of OCT and fluorescein angiography in clinically significant diabetic macular edema. The combined data from both OCT and fluorescein angiography may provide a clearer understanding of the anatomic and physiologic characteristics of clinically significant diabetic macular edema.     

Intravitreal triamcinolone acetonide: valuation of retinal thickness changes measured by optical coherence tomography in diffuse diabetic macular edema

PURPOSE: The authors studied the efficacy of intravitreal triamcinolone acetonide in a case series of patients with diffuse diabetic macular edema without evidence of vitreous-macular traction refractory to laser photocoagulation. METHODS: Six eyes with clinically diffuse diabetic macular edema that failed to respond to at least two previous sessions of laser photocoagulation were included. The mean age of selected patients was 72.5+/-13.8 years, with a preoperative best-corrected visual acuity reduced to 1.48+/-0.18 logMar and a mean baseline intraocular pressure (IOP) of 15.17+/-2.64 mmHg. The authors also studied macular thickness measured by optical coherence tomography (OCT 2000 scanner, Humphrey Instruments, San Leandro, CA) - in the preoperative period it was 640.8+/-171.1 microm - and the fluorangiographic (Heidelberg Retina Angiograph, Heidelberg Engineering GmbH, Heidelberg, Germany) patterns, which showed pooling in tardy phases and leakage. Mean follow-up was 4 months. RESULTS: In each patient the authors observed a significant improvement, both functionally and anatomically. Mean best-corrected visual acuity increased in the postoperative period to 0.94+/-0.53 logMar. No patient showed decline of visual acuity at the end of follow-up. Base line macular thickness was reduced in the postoperative period to 312.2+/-157.65 microm measured by OCT and fluorangiographic patterns showed a reduction of pooling and of leakage. The most common complications described in the literature were not observed and the increase of mean IOP in the postoperative period to 18.76+/-5.72 mmHg was not significant. CONCLUSIONS: Intravitreal triamcinolone acetonide may decrease macular edema and improve visual acuity in eyes with diffuse diabetic macular edema.     

应用光学相干断层扫描量化评估糖尿病黄斑水肿的临床研究

目的 探讨糖尿病黄斑水肿患者在光学相干断层扫描(optical coherence tomography,OCT)中四个量化指标的变化.方法 纳入糖尿病视网膜病变患者89例(155眼),按照有无黄斑水肿分为阳性组(33例55眼)及阴性组(56例100眼),另收集正常志愿者23例(42眼)为正常对照组.所有试验对象经OCT检查,测量并分析各组黄斑中心凹视网膜厚度(central retinal thickness,CRT)、黄斑中心凹下脉络膜厚度(subfoveal choroidal thickness,SFCT)的差异,观察各组黄斑区外界膜(external limiting membrane,ELM)、椭圆体带(inner segment/outer segment,IS/OS)的连续性.结果 正常对照组、阴性组、阳性组CRT分别为(219.048±16.798) μm、(217.775±26.866) μm、(280.418±74.187)μm,3组间差异有统计学意义(P ＜0.001);3组SFCT分别为(312.893±140.559) μm、(302.080±125.287) μm、(293.745±140.517) μm,3组间差异无统计学意义(P=0.781);阴性组中黄斑区ELM连续97眼、中断3眼,阳性组连续47眼、中断8眼,两组间ELM连续性差异有统计学意义(P=0.019);阴性组中黄斑区IS/OS连续95眼、中断5眼,阳性组连续36眼、中断19眼,两组间IS/OS连续性差异有统计学意义(P＜0.001).结论 糖尿病黄斑水肿患者CRT增加,黄斑区ELM、IS/OS连续性遭到破坏,CRT、ELM连续性及IS/OS连续性可用于量化评估糖尿病黄斑水肿.     

光学相干断层扫描技术在糖尿病黄斑水肿的应用

光学相干断层扫描技术是一种高分辨率,非接触性的生物组织成像技术,能在活体上动态的观察一些眼底疾病发生发展的过程,近年来光学相干断层扫描技术在对糖尿病黄斑水肿的临床诊治和研究工作中发挥了很大的作用。本文就光学相干断层扫描技术对糖尿病黄斑水肿的应用作一综述。     

Optical coherence tomography for assessment of diabetic macular edema

Optical coherence tomography (OCT) is a noninvasive objective diagnostic technique that has become a powerful method for the clinical assessment of diabetic macular edema. It is a very useful imaging technique to diagnose and follow-up diabetic macular edema (DME). The present paper aims to present an overview of the principles, progress, and uses of OCT in the diagnosis and management of DME.