Quantitative assessment of retinal thickness in diabetic patients with and without clinically significant macular edema using optical coherence tomography

PURPOSE: To assess patients with diabetic macular edema quantitatively using optical coherence tomography (OCT). METHODS: OCT was performed in 14 eyes with diabetic retinopathy and ophthalmoscopic evidence of clinically significant macular edema (CSME) and in 19 diabetic eyes without CSME. Retinal thickness was computed from the tomograms at fovea and other 36 locations throughout the macula. RESULTS: The mean +/- standard deviation foveal thickness was 255.6 +/- 138.9 microm in eyes with CSME, and 174.6 +/- 38.2 microm in eyes without CSME (p = 0.051). Within 2000 microm of the center of the macula, eyes with CSME had significantly thicker retina in the inferior quadrant than those without CSME (p < 0.01). The foveal thickness was correlated with logMAR visual acuity (gamma = 0.68, p < 0.01). OCT identified sponge-like retinal swelling and/or cystoid macular edema in 11 (58%) eyes without CSME, and in 12 (86%) eyes with CSME. CONCLUSIONS: Criteria of CSME seem to be insufficient in really identifying macular edema. OCT may be more sensitive than a clinical examination in assessing diabetic macular edema and is a quantitative tool for documenting changes in macular thickening.     

Precision and reliability of retinal thickness measurements in foveal and extrafoveal areas of healthy and diabetic eyes

PURPOSE: To determine the precision and reliability of retinal thickness measurements with an optical coherence tomograph (Stratus OCT 3; Carl Zeiss Meditec, Dublin, CA) and a retinal thickness analyzer (RTA; Talia Technology Ltd., Neve-Ilan, Israel) in foveal, parafoveal, and perifoveal areas. METHODS: Three measurements of all areas were performed within 1 hour on the same day with each instrument in the eyes of healthy volunteers and diabetic patients. The latter group was divided into eyes with and without macular edema. RESULTS: Measurement precision, expressed as the 95% limits of agreement (LA 95%), was significantly higher (i.e., a lower LA 95%, P < 0.01) for the OCT in comparison to the RTA in virtually all areas of the retina. Moreover, measurement reliability, expressed as the intraclass correlation coefficient, was high with the OCT (>0.90) and moderate to low with the RTA (0.26-0.89). A direct influence of macular edema itself on measurement precision of para- and perifoveal areas was found in the OCT measurements. CONCLUSIONS: The high measurement precision and reliability of the OCT suggests that this instrument is currently the most suitable technique for detection and follow-up of diabetic macular edema. When macular edema is present, the OCT can reliably detect changes of at least 36 microm at the fovea, 55 microm in parafoveal areas below a thickness of 744 microm, and 42 microm in perifoveal areas below a thickness of 1011 microm.     

Arteriovenous sheathotomy for persistent macular edema in branch retinal vein occlusion

PURPOSE: To evaluate the efficacy of arteriovenous (AV) sheathotomy with internal limiting membrane peeling for persistent or recurrent macular edema after intravitreal triamcinolone injection and/or laser photocoagulation in branch retinal vein occlusion. METHODS: Twenty-two eyes with branch retinal vein occlusion (BRVO) with recurrent macular edema underwent vitrectomy with AV sheathotomy and internal limiting membrane peeling. All eyes had previous intravitreal triamcinolone injection and/or laser photocoagulation for macular edema. The best corrected visual acuity (BCVA), fluorescein angiography and optical coherence tomography (OCT) before and after surgery were compared. RESULTS: The mean preoperative BCVA (log MAR) were 0.79 +/- 0.29 and postoperative BCVA (log MAR) at 3 months was 0.57 +/- 0.33. And improvement of visual acuity > or = 2 lines was observed in 10 eyes (45%). The mean preoperative fovea thickness measured by OCT was 595.22 +/- 76.83 microm (510-737 microm) and postoperative fovea thickness was 217.60 +/- 47.33 microm (164-285 microm). CONCLUSIONS: Vitrectomy with AV sheathotomy can be one treatment option for the patients with recurrent macular edema in BRVO.     

Bestimmung der Netzhautdicke in Abhängigkeit von Alter und Achsenlänge mit Hilfe der optischen Kohärenztomographie

PURPOSE: It is unknown whether the thickness of the retina depends on axial length or on age. We therefore used optical coherence tomography (OCT) to study this relationship. METHODS AND MATERIALS: We recruited 159 subjects aged 13-92 years (205 eyes) without macular pathology. OCT measurements included three horizontal scans and one vertical scan through the fovea. Axial length was determined by an analog high-resolution biometric unit. RESULTS: There was no correlation between retinal thickness and either axial length or age. Mean retinal thickness in the fovea was 142 +/- 18 microns. In the nasal retina thickness was significantly increased to 266 +/- 17 microns, compared to 249 +/- 18 microns in the temporal retina. Retinal thickness in subjects' two eyes was significantly correlated. CONCLUSIONS: Since retinal thickness does not depend upon age or length of the eye, no corrections are necessary when analyzing pathological retinal thickening, such as in diabetic retinal disease.     

Tomographic assessment of vitreous surgery for diabetic macular edema

PURPOSE: To evaluate the retinal structure before and after vitrectomy for diabetic macular edema and to assess the correlation between thickness of neurosensory retina and best-corrected visual acuity. METHODS: Tomographic features of 13 eyes (nine patients) with diabetic macular edema were prospectively evaluated with optical coherence tomography before and after vitrectomy. The foveal thickness (the distance between the inner retinal surface and the retinal pigment epithelium) and the retinal thickness (thickness of neurosensory retina) were measured by optical coherence tomography preoperatively and postoperatively. The correlation of the best-corrected visual acuity with foveal and retinal thickness was determined. RESULTS: All 13 eyes had retinal swelling with low intraretinal reflectivity. In addition to retinal swelling, there were cystoid spaces in five (38%) of 13 eyes, a serous retinal detachment in three (23%), and both cystoid spaces and serous detachment in three (23%). Six months postoperatively, the mean foveal thickness significantly decreased from 630 +/- 170 to 350 +/- 120 microm (P <.01, paired t test) and the mean thickness of neurosensory retina decreased from 540 +/- 160 to 320 +/- 140 microm (P <.01, paired t test). A serous retinal detachment occurred transiently in 3 eyes. Compared with the preoperative level, the postoperative best-corrected visual acuity level improved by more than 2 lines in five of the 13 eyes (38%), remained the same in seven eyes (54%), and decreased in one eye (8%). The postoperative thickness of neurosensory retina at the fovea and best-corrected visual acuity level at the sixth postoperative month had a strong negative correlation (correlation coefficient, -0.76; P <.01, Spearmans rank test). CONCLUSIONS: Vitrectomy was generally effective in treatment of diabetic macular edema. Optical coherence tomography demonstrated the intraretinal changes of macular edema and the process of edema absorption. During the process of macular edema absorption, intraretinal fluid appeared to move into the subretinal space in some cases. Best-corrected visual acuity improvement was greater in eyes with less preoperative increase in thickness of neurosensory retina.     

OCT对糖尿病视网膜病变光感受器细胞层的检测

目的:应用频域光学相干断层扫描(optical coherence tomography,OCT)在健康人群及各期糖尿病视网膜病变患者中测量外核层(ONL)、内节和外节层(IS/OS)、光感受器细胞层的厚度.方法:选择健康人群50例100眼作为对照组,选择2型糖尿病患者178例300眼为研究对象,分为3组:糖尿病正常视网膜组(NDR)100眼、非增生性糖尿病视网膜病变组(NPDR)100眼、增生性糖尿病视网膜病变组(PDR)100眼.用频域OCT对4组进行测量中心凹和旁中心凹(鼻侧、颞侧)ONL、IS/OS层、光感受器细胞层的厚度.结果:对照组、NPDR组、PDR组中心凹、旁中心凹颞侧ONL、光感受器细胞层厚度比较差异均有统计学意义(P<0.05);NDR组中心凹、旁中心凹颞侧各层与对照组比较差异无统计学意义(P>0.05);中心凹、旁中心凹颞侧各组IS/OS层厚度比较差异无统计学意义(P>0.05);旁中心凹鼻侧各组各层比较差异无统计学意义(P>0.05).结论:黄斑中心凹和旁中心凹颞侧ONL、光感受器细胞层在DR中均有增厚,随DR病程的进展呈动态变化;光感受器细胞层厚度的变化主要发生在ONL层,IS/OS层无变化;旁中心凹颞侧的改变显于鼻侧;频域OCT能定量定性地观察糖尿病患者黄斑区的细微变化,为糖尿病患者黄斑病变早期诊断及治疗提供可靠的检测手段.     

黄斑水肿的光相干断层扫描分析

目的 观察黄斑水肿的光相干断层扫描（OCT）图像特征；探讨黄斑中心凹厚度与最佳矫正视力之间的关系。 方法 对50例正常对照者以及47例54只经直接、间接检眼镜、三面镜及荧光素眼底血管造影（FFA）诊断为黄斑水肿的患眼进行OCT检查，通过黄斑中心凹的水平或垂直方向线性扫描，测量黄斑中心凹的厚度，对比分析两组受检者的黄斑形态及中心凹厚度值，根据形态学特点对黄斑水肿者的OCT图像进行分类并将其中心凹厚度与其最佳矫正视力进行相关分析。 结果 正常对照组与黄斑水肿组黄斑形态及中心凹厚度差异有显著性的意义。黄斑水肿患眼的OCT图像表现为3种特征，20只眼表现为黄斑区视网膜海绵样肿胀，占37.1%；26只眼表现为黄斑囊样水肿，占48.1%；8只眼表现为浆液性视网膜神经上皮脱离，占14.8%。黄斑水肿者黄斑中心凹厚度与其最佳矫正视力呈负相关（r=－0.569, P=0.000）。 结论 黄斑水肿的OCT图像主要包括视网膜海绵样肿胀、黄斑囊样水肿及神经上皮浆液性脱离。黄斑水肿患者的黄斑中心凹厚度明显增厚，黄斑中心凹厚度越厚，视力越差。 （中华眼底病杂志，2004，20：152-155）     

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.     

Retinal thickness in diabetic retinopathy: comparison of optical coherence tomography, the retinal thickness analyzer, and fundus photography

BACKGROUND: Optical coherence tomography (OCT) and the retinal thickness analyzer (RTA) have proved their ability to measure retinal thickness in healthy subjects and diabetics reliably. In the present study, both techniques were compared for the same study population of diabetic patients, and the findings were related to macular edema shown by stereo fundus photography (SFP). METHODS: Maculas of 124 eyes from 69 patients with diabetes mellitus were examined with OCT and the RTA. Measurements of retinal thickness were compared with signs of macular edema shown by SFP. For each eye, nine different sectors were analyzed (a foveal sector, four parafoveal sectors, and four extrafoveal sectors). Thirteen eyes with a normal macula served as controls. Sensitivity and specificity of detecting clinically significant macular edema (CSME) were calculated. RESULTS: Of 111 eyes, 64 showed signs of CSME by SFP. Mean retinal thickness +/- SD of the foveal sector was 249 +/- 104 microm by RTA and 295 +/- 124 microm by OCT measurements. There was a moderate overall correlation between OCT and the RTA (r = 0.66). The correlation was best in the foveal sector (r = 0.82). Overall correlation with SFP was better for OCT (r = 0.77) than for the RTA (r = 0.62). Sensitivity of detecting CSME was consistently higher with OCT, while the RTA showed higher specificity. CONCLUSION: Both measuring techniques yielded similar results when examining eyes of patients with diabetes, although absolute values differed. OCT seems to be more suitable in the clinical screening for macular edema due to its high sensitivity (>90%) with appropriate analysis parameters. The RTA is more prone to erroneous or missing thickness readings particularly under difficult measuring conditions.     

无黄斑水肿的NPDR患者中心凹区mfERG与视网膜厚度的研究

目的：分析非增生性糖尿病视网膜病变(nonproliferative diabetic retinopathy,NPDR)无黄斑水肿的患者黄斑中心凹区视网膜功能及厚度间的关系。

方法：选取NPDR患者20例35眼患眼为糖尿病视网膜病变(diabetic retinopathy,DR)组,行多焦视网膜电图(multifocal electronic retinography, mfERG)及Spectralis 相干断层扫描(Spectralis optical coherence tomography,Spectralis OCT)检查。以15例20眼正常眼为OCT对照组,以19例20眼正常眼为mfERG对照组,OCT对照组做Spectralis OCT检查,mfERG对照组做mfERG检查。

结果：与对照组相比,DR组黄斑中心凹mfERG1环的P1波反应密度减小,P1波及N1波隐含期改变无统计学意义; DR组无水肿的黄斑中心凹视网膜厚度、神经上皮层厚度仍有显著增加。

结论：应用mfERG可以在视网膜无可见明显结构改变之前发现视网膜功能上的异常变化; Spectralis OCT可以测量视网膜各层厚度,反映视网膜精细结构变化,验证视网膜功能上的异常改变,二者联合应用为极早期发现糖尿病视网膜病变视功能改变提供有效的证据,并为及时治疗提供资料。     

上海北新泾社区2型糖尿病患者黄斑水肿患病情况调查

目的 了解社区糖尿病视网膜病变患者黄斑水肿的患病情况。方法对上海北新泾街道社区100例（151只眼）15岁以上2型糖尿病患者进行直接检眼镜、眼底照相、超声波及相干光断层扫描（OCT）检查,并对检查结果进行统计学分析。结果实际调查对象795人,发现有糖尿病视网膜病变者215例,随机抽取100例糖尿病患者,有151只眼发生糖尿病视网膜病变,其黄斑中心凹平均厚度195．7μm;有46只眼的黄斑增厚,其中黄斑视网膜海绵样肿胀35只眼（76．1％）,黄斑囊样水肿8只眼（17．4％）,神经上皮层脱离3只眼（6．5％）。黄斑中心凹厚度与最佳矫正视力的负对数之间有相关性（r=0．2869,P=0．0004）。不同程度糖尿病视网膜病变者其黄斑水肿的患病情况有所不同（P=0．0003）。糖尿病黄斑水肿的发生与玻璃体后脱离情况的关联无统计学意义（P=0．472）。结论社区糖尿病视网膜病变患者中黄斑水肿患病率为37．1％。患眼的OCT图像归为三种类型：视网膜海绵样肿胀、黄斑囊样水肿及神经上皮层脱离。糖尿病视网膜病变的程度越重,发生黄斑水肿的可能性越大。糖尿病黄斑水肿与有无玻璃体后脱离无明显联系,与总胆固醇水平呈负相关。（中华腰科杂志．2007,43：626-630）     

Optical coherence tomography images of retinitis pigmentosa

The retinas of 3 patients with typical retinitis pigmentosa (RP) were evaluated by optical coherence tomography (OCT), fluorescein angiography (FA), and fundus photography (FP). OCT showed that retinal thickness was decreased in the areas of the retina affected by RP, and nearly normal in the unaffected macular area. Reflectivity was partially decreased in the affected retinal areas and pigment masses were hyper-reflective. Reflectivity of the macular area was nearly normal except in the fovea, where it was decreased because of edema. Cystic spaces of the fovea were evident in Patient 1.     

血管内皮生长因子抑制剂球内注射治疗糖尿病性黄斑水肿

目的:评价玻璃体腔内注射1.25mg avastin治疗糖尿病性黄斑水肿(diabetic macular edema,DME)(糖尿病视网膜病变Ⅳ期和中期以上黄斑水肿)的临床效果与安全性。方法:选择我科2009-01/2010-12诊断为视力下降有临床治疗意义的糖尿病病变的患者60例(眼底荧光造影显示糖尿病视网膜病变Ⅳ期,以OCT检查显示中度以上黄斑水肿,黄斑水肿病史不超过3mo)。观察治疗前最佳矫正视力、眼压、裂隙灯及间接检眼镜检查,行彩色眼底照相、FFA,OCT检查。再观察治疗后第1,2,3d;3wk;3,6mo,视力的变化,眼压、晶状体、玻璃体、行眼底荧光造影观察视网膜渗漏情况,用TOPCON 3D-OCT检查术后视网膜的厚度进行比较。结果:玻璃体腔内注射avastin后,患者视力明显提高,视网膜中心黄斑平均厚度明显减低,由术前(395.933±119.784)μm至末次随诊为(314.200±60.528)μm,与术前相比差异有统计学意义。随访中未见眼压的异常改变,未发现白内障的加重,未发现与药物有关的视网膜毒性反应及其他局部和全身不良反应。结论:玻璃体腔内注射avastin糖尿病视网膜病变患者视力稳定提高,黄斑水肿明显消退,必要时可以连续注射治疗,但其远期治疗效果需要大样本的实验来进一步证实。     

Serous macular detachment secondary to distant retinal vascular disorders

PURPOSE: To report tomographic features of macular edema associated with distant retinal vascular disorders. METHODS: Six eyes with macular edema (three with extramacular branch retinal vein occlusion and three with Coats disease) underwent fluorescein angiography to detect dye leakage and optical coherence tomography to evaluate the macular features and measure the foveal height (distance between inner retinal surface and retinal pigment epithelium) and the retinal thickness (thickness of neurosensory retina) at the central fovea. RESULTS: Fluorescein angiography showed widespread nonperfusion and retinal vein staining in the eyes with a branch retinal vein occlusion not involving the macula. In eyes with Coats disease, nonperfused areas, telangiectatic retinal vessels, and aneurysms were seen in the peripheral fundus on fluorescein angiography. In one eye with Coats disease, telangiectatic vessels and aneurysms were seen in the nasal mid periphery of the optic disk. There was no dye leakage in the macular area in any eyes. Optical coherence tomography showed subretinal fluid and retinal swelling at the fovea in all eyes. The foveal height ranged from 300 to 697 microm (mean, 478 microm) and retinal thicknesses ranged from 170 to 280 microm (mean, 233 microm). CONCLUSION: Distant retinal vascular leakage causes serous retinal detachment in the macula. The macula is predisposed to collect subretinal fluid although retinal vascular leakage is far from the macula.     

Macular thickness measured by optical coherence tomography (OCT) in diabetic patients

PURPOSE: 1) To compare macular thickness (MT) by optical coherence tomography (OCT) in diabetics and controls; 2) to assess the relationship between MT and stage of diabetic retinopathy (DR) and macular edema (ME); 3) to quantify MT changes after laser treatment for ME. METHODS: One-hundred and thirty-seven patients with diabetes mellitus (216 eyes) were admitted to the study and examined by stereo-color fundus photos, retinal fluorangiography and OCT. DR was classified as: 1) no DR (46 eyes: 21.3%); 2) background DR (66 eyes: 30.6%); 3) pre-proliferative DR (50 eyes: 23.1%); 4) proliferative DR (54 eyes: 25%). The study group was then divided into three ME groups: 1) no edema (65 eyes: 30.1%); 2) not clinically significant ME (no CSME) (45 eyes: 20.8%); 3) clinically significant macular edema (CSME) (106 eyes: 49.1%). Three-month follow-up tomograms were taken to evaluate eyes laser-treated only for ME. The control group consisted of 50 eyes of 50 non-diabetic, age- and sex-matched subjects. RESULTS: MT was 369.3 +/- 163.2 microm in diabetics and 161.9 +/- 12.9 microm in controls (p < 0.001). In the four DR groups it was: 1) 211.0 +/- 37.6 microm; 2) 370.8 +/- 159.6 microm; 3) 419.1 +/- 138.2 microm; 4) 456.1 +/- 162.0 microm (p<0.001). In the three ME groups, MT was: 1)227.8 +/- 53.4 microm; 2) 321.8 +/- 124.2 microm; 3) 476.2 +/-146.6 microm (p < 0.001). In the 52 eyes treated with laser photocoagulation of the posterior pole only and with a follow-up > 3 months, MT before and after treatment was 468.2 +/- 83. 17 microm and 372.1 +/- 120.63 microm. CONCLUSIONS: MT was greater in diabetics than controls and tended to increase with DR and ME severity. OCT is a sensitive technique for detecting early diabetic macular abnormalities and quantifying their reduction after laser treatment.     

Retinal thickness in healthy and diabetic subjects measured using optical coherence tomography mapping software

PURPOSE: To define the normal retinal thickness in healthy subjects using optical coherence tomography (OCT) mapping software and to assess the ability of OCT to detect early macular thickening in diabetic patients. METHODS: Six radial scans centered on the fixation point were done on 60 healthy eyes and 70 eyes of 35 diabetic patients without macular edema on biomicroscopy. Retinal thickness was measured automatically with OCT mapping software. Mean retinal thickness was compared in subgroups of healthy patients based on age, sex, and eye, and in the eyes of diabetic patients and healthy subjects. Thickening was diagnosed if mean retinal thickness of an area was greater than the mean thickness + 2SD in the corresponding area in healthy subjects; or if the difference between right and left eye exceeded the mean difference + 2 SD in a given area in healthy subjects. RESULTS: In healthy subjects, mean retinal thickness in the central macular area 1000 microm in diameter was 170+/-18 microm. There was no significant difference according to age, or left or right eye, but central macular thickness was significantly greater in men than women (p=0.0139). No difference was observed between the eyes of healthy subjects and diabetic patients without macular edema on biomicroscopy, but OCT detected early macular thickening in 12 diabetic eyes. CONCLUSIONS: In this study average retinal thickness and mean local variations in a normal population were defined using a commercially available mapping software. OCT seems a sensitive tool for detecting early retinal thickening.     

特发性黄斑视网膜前膜的光学相干断层扫描

目的观察特发性黄斑视网膜前膜(idiopathic macular epireti nal membranes, IMEM)的光学相干断层扫描(optical coherence tomography, OCT)图像 特征,探讨IMEM患眼黄斑中心凹厚度与视力之间的关系。方法对67例73只经直接或间接检眼镜、三面镜、眼底彩色照相或荧光素眼底血管造影(fundus fluorescein angiogrphy, FFA)检查诊断为IMEM的患眼进行经黄斑中心凹的OCT线性扫描, 测量黄斑中心凹厚度,并与视力进行相关分析。结果32只眼表现为视网膜前膜(Epiretinal menmbrabces, ERMs)伴黄斑水肿;20只眼表现为增生性ERMs,14只眼表现为ERMs伴假性黄斑裂孔;7只眼表现为ERMs伴板层黄斑裂孔。73只眼中27只眼可见ERMs与视网膜内层分离,占38.36%。增生性ERMs者黄斑中心凹厚度 最厚,ERMs伴板层黄斑裂孔者黄斑中心凹厚度最薄。黄斑中心凹厚度与视力呈负相关(r=－0.454,P=0.000)。结论IMEM 的 OCT图像主要有ERMs伴黄斑水肿、增生性ERMs、ERMs伴假性裂孔与板层裂孔改变;ERMs患者黄斑中心凹厚度越厚视力越差。(中华眼底病杂志,2001,17:115-118)     

Comparison of foveal thickness measured with the retinal thickness analyzer and optical coherence tomography.

PURPOSE: To assess and compare the reliability and reproducibility of retinal thickness measurements for the retinal thickness analyzer (RTA) and optical coherence tomography (OCT) in normal and edematous retina. METHODS: The authors measured the foveal thickness of 21 normal eyes and 9 eyes with macular edema with both methods in random order. With the RTA, the fovea was measured 10 times; with the OCT, six scans (one horizontal and five vertical cross-sections) of the fovea were obtained. RESULTS: Mean foveal thickness of normal eyes measured 153 microm with OCT and 181 microm with RTA (median for both methods 150 microm). Coefficients of variation (CV) within the same subjects were 10% (OCT) and 9% (RTA) reducing to 9% (OCT) and 7% (RTA) when scans were repeated only five times for both methods. The RTA, however, yielded an interpatient CV of 33% (OCT 17%), which was caused by several falsely high readings in normal individuals. In eyes with retinal thickening the OCT measured a mean of 324 microm with 15% intra- and 58% interpatient CV. The RTA yielded a mean of 403 microm with CV of 18% and 73%, respectively. CONCLUSION: Both methods yield reproducible measurements of foveal thickness in normal individuals and individuals with macular edema. However, falsely high measurements may occur with the RTA, reducing its reliability as compared to the OCT.     

Retina tomography after vitrectomy for macular edema of central retinal vein occlusion

PURPOSE AND OBJECTIVE: To report retina tomography after vitrectomy for macular edema in central retinal vein occlusion (CRVO). PATIENTS AND METHODS: Five patients with macular edema caused by CRVO were examined using optical coherence tomography (OCT) through their clinical courses. RESULTS: The retinal thickness through the fixation was reduced in all 5 eyes. Preoperatively, the retina thickness at the foveola was more than 500 microm in three eyes and more than 1000 microm in 2 eyes. The retina thickness was reduced to 311+80 microm within two weeks on average. Visual acuity was improved by two or more lines in 3 of 5 eyes. CONCLUSION: Vitrectomy is worthy of consideration when macular edemas are prolonged in patients of CRVO. OCT is a useful instrument for management and treatment of macular edema.     

Macular traction detachment and diabetic macular edema associated with posterior hyaloidal traction

PURPOSE: To review the clinical, photographic, fluorescein angiographic, and optical coherence tomographic findings in patients with the diabetic macular traction and edema (DMTE) associated with posterior hyaloidal traction (PHT). METHODS: We performed a prospective review of nine eyes of nine patients with diabetic macular edema (DME) and PHT on clinical examination. The patients had a comprehensive ophthalmic history and examination, color photographs, fluorescein angiography, and optical coherence tomography (OCT). RESULTS: All patients had diabetic retinopathy and DME. Of the nine eyes, eight patients had previous focal or grid photocoagulation. All nine eyes had a thickened, taut, glistening posterior hyaloid on clinical biomicroscopic examination with no posterior vitreous separation. Fluorescein angiography was performed on seven eyes, and all had early hyperfluorescence with deep, diffuse, late leakage in the macular area consistent with DMTE associated with PHT. Optical coherence tomography scans of the macular region revealed retinal thickening in all eyes with a mean retinal thickness of 556.9 +/- 114.7 microns. In addition, eight of the nine eyes had a shallow macular traction detachment associated with PHT. CONCLUSION: Eyes with DME associated with PHT may have a shallow, subclinical, macular detachment. Optical coherence tomography may be useful in evaluating patients with DME to see if a macular detachment is present.