Evaluation of the iridocorneal angle with accommodation using optical coherence tomography

The changes in the iridocorneal angle structure during accommodation are assessed by means of anterior segment optical coherence tomography. Thirteen right eyes were included in the study. The device used for the measurement was the Visante® omni system. The stimuli were set up at different vergences (0.0 D, -1.5 D, and -3.0 D). The angle opening distance 500 and 750, the trabecular iris space area 500 and 750, and the scleral spur angle parameters were assessed at the nasal and temporal regions. The results in the iridotrabecular angle comparing the three accommodative states of the eye did not yield any statistically significant difference at nasal or temporal angle sections. In light of our results and in the conditions of our study, the structures of the iridocorneal angle are not significantly changed with accommodation.     

[In Press] Evaluation of the iridocorneal angle with accommodation using optical coherence tomography

The changes in the iridocorneal angle structure during accommodation are assessed by means of Anterior Segment Optical Coherence Tomography. Thirteen right eyes were included in the study. The device used for the measurement was the Visante® omni system. The stimuli were set up at different vergences (0.0 D, -1.5 D, and -3.0 D). The Angle Opening Distance 500 and 750, the Trabecular Iris Space Area 500 and 750, and the Scleral Spur Angle parameters were assessed at the nasal and temporal regions. The results in the iridotrabecular angle comparing the three accommodative states of the eye did not yield any statistically significant difference at nasal or temporal angle sections. In light of our results and in the conditions of our study, the structures of the iridocorneal angle are not significantly changed with accommodation.     

Lens diameter and thickness as a function of age and pharmacologically stimulated accommodation in rhesus monkeys

Uncertainty exists regarding accommodative and age changes in lens diameter and thickness in humans and monkeys. In this study, unaccommodated and accommodated refraction, lens diameter, and lens thickness were measured in rhesus monkeys across a range of ages. Iridectomized eyes were studied in 33 anesthetized monkeys aged 4-23 years. Refraction was measured using a Hartinger coincidence refractometer and lens thickness was measured with A-scan ultrasound. Lens diameters were measured with image analysis from slit-lamp images captured via a video camera while a saline filled, plano perfusion lens was placed on the cornea. Accommodation was pharmacologically stimulated with 2% pilocarpine via the perfusion lens in 21 of the monkeys and lens diameters were measured until a stable minimum was achieved. Refraction and lens thickness were measured again after the eye was accommodated. Unaccommodated lens thickness increased linearly with age by 0.029 mm/year while unaccommodated lens diameter showed no systematic change with age. Accommodative amplitude decreased by 0.462 D/year in response to pilocarpine. The accommodative increase in lens thickness decreased with age by 0.022 mm/year. The accommodative decrease in lens diameter declined linearly with age by 0.021 mm/year. Rhesus monkeys undergo the expected presbyopic changes including increasing lens thickness and a decreasing ability of the lens to undergo changes in thickness and diameter with accommodation, however without an age-related change in unaccommodated lens diameter. As in humans, the age-related decrease in accommodative amplitude in rhesus monkeys cannot be attributed to an age-related increase in lens diameter.     

Lens thickness assessment: anterior segment optical coherence tomography versus A-scan ultrasonography

AIM: To assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT) in comparison with A-scan ultrasonography (A-scan US). METHODS: There were 218 adult subjects (218 eyes) aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III). Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA). The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US. RESULTS: Interclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74). Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001), and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001) CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.     

全视场光学相干层析技术的角膜高分辨率成像

目的:针对活体共聚焦显微镜(in vivo confocal microscopy,IVCM)和传统光学相干层析技术(optical coherence tomography,OCT)在人眼角膜成像各自存在成像视野小或无法细胞成像的限制,开发具有高分辨率的非接触全视场光学相干层析系统(full-field optica...     

光学相干断层扫描血管造影(OCTA)在角膜厚度测量中的临床研究

目的 利用光学相干断层扫描血管造影(optical coherence tomography angiography,OCTA)技术分析健康受试者角膜及角膜上皮各区域的厚度.方法 利用OCTA分析100例(男女各50例)年龄20～30岁的健康受试者,使用AngioVue OCTA系统的视网膜成像模式,并采用SSADA算法进行成像,测量角膜中央9 mm直径范围各区域角膜及角膜上皮厚度,比较不同性别各区域角膜及角膜上皮厚度的差异性.结果 男女两组受检者角膜中央总厚度分别为(559.92±33.26) μm、(540.06±31.63)μm,角膜上皮总厚度分别为(57.78±4.88) μm、(56.88±4.57) μm,男性角膜中央总厚度及角膜上皮厚度均大于女性,差异均有统计学意义(t=3.06、2.10,均为P＜0.05).男性各环角膜总厚度均在S5、S7、SN9处最厚,与女性相比,只有在S5、S7处差异显著(t=2.93、2.83,均为P＜0.05),女性各环在S5、SN7、SN9处最厚,与男性相比只在S5处差异显著;男性受检者角膜在IT处最薄,与相同区域的女性受检者相比只有在IT5处差异有统计学意义(t=2.02,P＜0.05);女性受检者角膜在T5、IT7、T9处最薄,与同区域的男性受检者相比只在T5、T9处差异均有统计学意义(=2.63、2.20,均为P＜0.05);在ST处男女角膜厚度差异显著(t=3.11、2.79、2.33,均为P＜0.05);男性受检者角膜上皮在IT5、I7、I9处最厚,在S5、S7、S9处最薄,与同区域的女性相比差异均无统计学意义(均为P ＞0.05),女性受检者角膜上皮在IT5、T7、N9处最厚,在SN5、S7、S9处最薄;除M2、SN5外,角膜上皮在男女组间差异均无统计学意义(均为P＞0.05).角膜中央上皮占角膜总厚度的百分率最大,并且由内向外逐渐减小.结论 OCTA能够用于测量角膜及角膜上皮各区域的厚度.     

OCT黄斑区厚度测量对青光眼早期诊断的研究

相干光断层扫描(optical coherence tomography,OCT)具有非接触性、可重复性好、获取眼部图像快等优点,已在眼科领域广泛应用.以往的研究显示OCT测量视乳头旁视网膜神经纤维层(circumpapillary retinal nerve fibre layer,cpRNFL)厚度和视盘参数对青光眼具有较好的诊断价值.传统时域OCT可对黄斑区神经上皮层厚度进行测量,目前频域OCT能提供更高的图像分辨率,还可对黄斑区视网膜神经节细胞复合体的厚度进行测量,因其在正常人的变异较小,更有利于青光眼的早期诊断.     

傅立叶OCT对不同年龄正常人群角膜厚度的测量研究

目的:研究傅立叶域光学相干断层成像系统(Fourier-domain optical coherence tomography,FD-OCT)测量不同年龄人群角膜厚度正常值。方法:选取健康受试者210例420眼,分为3组,青年组(18～40岁)70例140眼;中年组(41～60岁)70例140眼;老年组(≥61岁)70例140眼。用傅立叶OCT检测受试者双眼角膜中心区、内环区和外环区角膜厚度及平均角膜厚度。结果:通过FD-OCT测量的不同区域角膜厚度最薄处位于角膜中心区,平均厚度527.19±1.72μm;最厚处在外环上方,平均厚度582.42±2.50μm;左右眼不同区域间角膜厚度差异没有统计学意义(P>0.05)。通过FD-OCT测量的平均角膜厚度在三个不同年龄组间具有很好的一致性及相关性(右眼:青年组-中年组:r=0.949,中年组-老年组:r=0.924,青年组-老年组:r=0.981;左眼:青年组-中年组:r=0.996,中年组-老年组:r=0.901,青年组-老年组:r=0.876)。结论:采用FD-OCT前节功能测量角膜厚度具有可重复性、可信性、方便性,可以更好地代表实际上的角膜厚度。     

Reflectivity and thickness analysis of epiretinal membranes using spectral-domain optical coherence tomography

AIM: To compare thickness and reflectivity spectral domain optical coherence tomography (SD-OCT) findings in patients with idiopathic epiretinal membranes (ERMs), before and after ERM peeling surgery, with normal controls. METHODS: A retrospective study analyzed SD-OCTs of eyes with ERMs undergoing ERM peeling surgery by one surgeon from 2008 to 2010 and normal control eyes. SD-OCTs were analyzed using a customized algorithm to measure reflectivity and thickness. The relationship between the SD-OCT findings and best corrected visual acuity (BCVA) outcomes was also studied. RESULTS: Thirty-four ERM eyes and 12 normal eyes were identified. Preoperative eyes had high reflectivity and thickness of the group of layers from the internal limiting membrane (ILM) to the retinal pigment epithelium (RPE) and the group of layers from the ILM to the external limiting membrane (ELM). The values of reflectivity of these two groups of layers decreased postoperatively, but were still higher than normal eyes. In contrast, preoperative eyes had lower reflectivity of two 10×15 pixel regions of interest (ROIs) incorporating: 1) ELM + outer nuclear layer (ONL) and 2) photoreceptor layer (PRL) + RPE, compared to controls. The values of reflectivity of these ROIs increased postoperatively, but were still lower than normal controls. A larger improvement in BCVA postoperatively was correlated with a greater degree of abnormal preoperative reflectivity and thickness findings. CONCLUSION: Quantitative differences in reflectivity and thickness between preoperative, postoperative, and normal SD-OCTs allow assessment of changes in the retina secondary to ERM. Our study identified hyperreflective inner retina changes and hyporeflective outer retina changes in patients with ERMs. SD-OCT quantitative measures of reflectivity and/or thickness of specific groups of retinal layers and/or ROIs correlate with improvement in BCVA.     

Comparison between central corneal thickness measurements by ultrasound pachymetry and optical coherence tomography

PURPOSE: Measurement of central corneal thickness (CCT) plays an important role in both diagnostic and therapeutic assessment of ocular diseases. Although ultrasound pachymetry (U-PACH) is regarded as the golden standard for measurement of CCT, optical coherence tomography (OCT) may offer advantages as it can locate the central cornea with precision with no corneal touch. Nevertheless, the agreement of OCT with U-PACH has not yet been gauged by Bland-Altman analysis. This study compares CCT measurement by OCT with that by U-PACH. METHODS: Healthy subjects without ocular abnormality (except refractive errors less than or equal to -6.0 D), contact lens wear or ocular surgery were recruited. CCT was measured in one eye of normal subjects using OCT and U-PACH. Results were compared using correlation and Bland-Altman plots. RESULTS: Fifty subjects were recruited. Mean +/- SD CCT measured by OCT was 565 +/- 33 microm. This was highly correlated (Pearson's coefficient = 0.934) with the mean thickness measured by U-PACH (543 +/- 33 microm). The coefficients of variation were good and comparable at 7.9% for U-PACH and 3.5% for OCT. Compared with U-PACH, OCT consistently overestimated the CCT by a mean of 23 microm as shown on Bland-Altman plot. CONCLUSION: CCT measured by OCT and U-PACH is highly correlated. With appropriate adjustment factor, OCT agrees well with U-PACH and is a reliable alternative for CCT measurement.     

白内障术后黄斑区光学相干断层扫描动态观察

目的：观察白内障术后黄斑厚度的改变。方法：将126例白内障患者分为两组,分别行常规白内障超声乳化联合人工晶状体植入术64例和小切口非超声乳化联合人工晶状体植入术62例。两组术前、术中无并发症,术前及术后1,3mo黄斑区行OCT检查,观察两组术后黄斑厚度及视力变化。本研究采用SPSS 17.0统计学软件处理,每组术前、后采用配对t检验对数据进行统计学处理; 两组间术前、后分别采用独立样本t检验对数据进行统计学处理,取α=0.05检验水准。结果：两组术后黄斑厚度变化：超声乳化组：术前、术后1,3mo黄斑厚度分别为241.3±10.9, 279.7±16.5,245.6± 12.6μm。术后1mo与术前比较差异有显著差异（P〈0.01）; 术后3mo与术前比较,差异无统计学差异（P〉0.05）; 术后1mo与3mo比较有统计学差异（P〈0.05）。有3例术后1mo出现黄斑囊样水肿,2例术后3mo完全消退。小切口非超声乳化组：术前、术后1,3mo黄斑厚度分别为240.5±11.9,280.9±16.8,246.6±13.2μm。黄斑厚度术后1mo与术前比较有显著统计学差异（P〈0.01）; 术后3mo与术前比较,无统计学差异（P〉0.05）; 术后1mo与3mo比较有统计学差异（P〈0.05）。有2例术后1mo出现黄斑囊样水肿,2例术后3mo完全消退。超声乳化组与小切口非超声乳化组,两组间术前、术后1,3mo分别比较均无统计学差异（P均〉0.05）。结论：无论选择白内障超声乳化还是小切口非超声乳化白内障联合人工晶状体植入,术后1mo黄斑厚度明显增加,证明术后造成黄斑水肿; 术后3mo厚度基本恢复术前。黄斑增厚与术式选择无明显关系。     

Intraoperative optical coherence tomography in anterior segment surgery

Intraoperative optical coherence tomography (iOCT) enables real-time visualization of ocular structures during surgery and enhances our understanding of intraoperative dynamics. iOCT aids in decision-making during various anterior segment surgeries, and its efficacy and feasibility in anterior lamellar keratoplasty and endothelial keratoplasty is well established. The landmark DISCOVER study observed that iOCT altered the surgeon decision in 38% of cases undergoing lamellar keratoplasty and provided guidance regarding the need for secondary surgical intervention. iOCT also finds an application in phacoemulsification wherein it helps to assess corneal incisions, intralenticular pressure, and posterior capsule integrity during nuclear emulsification. iOCT aids in the visualization of angle structures during placement of tubes and shunts in glaucoma surgeries and allows precise creation of partial thickness scleral flaps. In addition, iOCT helps in establishing a diagnosis, as well as provide intraoperative guidance, in pediatric patients who are not cooperative for examination. The role of iOCT in refractive surgeries and ocular surface disorders is increasingly being evaluated. The limitations of present-day iOCT systems are related to instrument compatibility, automated tracking of the surgical field, and on-table volumetric analysis of the real-time images. Technological advances may facilitate complete integration of OCT in the surgical microscopes for all surgical procedures.     

白内障超声乳化吸除术前后黄斑区厚度变化的OCT观察

目的：：观察白内障超声乳化联合人工晶状体植入术对白内障患者黄斑中心凹视网膜厚度变化的影响。方法：将60例白内障患者的手术眼作为手术组,对侧眼作为对照组,两组术前、术中无并发症,术前和术后1 wk;1,3,6 mo黄斑区行OCT测量,观察两组术后黄斑中心凹视网膜厚度变化。结果：手术组：术后1 wk和1,3 mo黄斑中心凹视网膜厚度与术前相比,均有统计学差异(P<0.05),术后6mo黄斑中心凹视网膜厚度与术前相比,无统计学差异(P>0.05),术后1 mo黄斑中心凹视网膜厚度明显高于其他组(P<0.05)。其中12眼术后出现黄斑水肿,均发生于术后2~4wk,包括10眼中心凹增厚及2眼黄斑囊样水肿,其中11眼于6 mo内自愈。对照组：术前黄斑中心凹视网膜厚度与术后1 wk;1,3,6 mo相比,均无统计学差异(P>0.05)。手术组与对照组：两组术前、术后6mo黄斑中心凹视网膜厚度对比,均无统计学差异(P>0.05),两组术后1 wk和1,3 mo黄斑中心凹视网膜厚度对比,均有统计学差异(P<0.05)。结论：白内障超声乳化联合人工晶状体植入术后黄斑中心凹视网膜厚度显著增加,少数患者会出现黄斑水肿,但绝大多数患者可自愈,预后良好。     

In vivo quantification of human aqueous veins by enhanced depth imaging optical coherence tomography and optical coherence tomography angiography images

AIM: To investigate the aqueous vein in vivo by using enhanced depth imaging optical coherence tomography (EDI-OCT) and optical coherence tomography angiography (OCTA). METHODS: In this cross-sectional comparative study, 30 healthy participants were enrolled. Images of the aqueous and conjunctival veins were captured by EDI-OCT and OCTA before and after water loading. The area, height, width, location depth and blood flow of the aqueous vein and conjunctival vein were measured by Image J software. RESULTS: In the static state, the area of the aqueous vein was 8166.7±3272.7 μm2, which was smaller than that of the conjunctival vein (13 690±7457 μm2, P<0.001). The mean blood flow density of the aqueous vein was 35.3%±12.6%, which was significantly less than that of the conjunctival vein (51.5%±10.6%, P<0.001). After water loading, the area of the aqueous vein decreased significantly from 8725.8±779.4 μm2 (baseline) to 7005.2±566.2 μm2 at 45min but rose to 7863.0±703.2 μm2 at 60min (P=0.032). The blood flow density of the aqueous vein decreased significantly from 41.2%±4.5% (baseline) to 35.4%±3.2% at 30min but returned to 45.6%±3.6% at 60min (P=0.021). CONCLUSION: The structure and blood flow density of the aqueous vein can be effectively evaluated by OCT and OCTA. These may become biological indicators to evaluate aqueous vein changes and aqueous outflow resistance under different interventions in glaucoma patients.     

Renal function and choroidal thickness using swept-source optical coherence tomography in diabetic patients

AIM: To assess the relationship between choroidal thickness and renal function in diabetic patients. METHODS: Cross-sectional retrospective clinical study of 42 eyes of 21 ocular treatment-naïve diabetic patients. Demographic data included: age, sex, type and course of diabetes. Ocular data included: severity of diabetic retinopathy; retinal thickness at the central macular region, as well as choroidal thickness at the central and paracentral quadrants, using automatically generated maps by swept-source optical coherence tomography; presence of cystic macular edema; and ocular axial length (AXL). Lab-test parameters included: glycated hemoglobin (HbA1c), albuminuria, albumin/creatinine ratio in urine, and glomerular filtration rate. RESULTS: A significant negative correlation was mainly observed between several choroidal thicknesses, age (P<0.020) and ocular AXL (P<0.030). On the contrary, a significant positive correlation was found between all choroidal thicknesses, HbA1c (P<0.035) and albuminuria (P<0.040). CONCLUSION: Choroidal thickness can represent an additional tool to help clinicians predicting the renal status in ocular treatment-naïve diabetic patients.     

Peripapillary choroidal thickness in glaucoma measured with optical coherence tomography

As choroidal changes have been suggested in glaucoma, we examined peripapillary choroidal thickness (CT) in patients with and without primary open-angle glaucoma (POAG) using spectral-domain optical coherence tomography (SD-OCT). We collected measurements retrospectively on 70 eyes of 70 patients consecutively undergoing SD-OCT. POAG (n = 31) and suspect eyes (n = 39) had two reliable and repeatable Humphrey 24-2 visual fields with glaucoma hemifield test outside or within normal limits, respectively. A 360-degree peripapillary scan was performed using the standard protocol for retinal nerve fiber layer (RNFL) assessment. Using provided software, two independent masked investigators manually segmented CT as the area of visible choroidal vasculature. Agreement between investigators was determined using Lin’s concordance correlation coefficient (CCC). A single masked observer determined clock hours of parapapillary atrophy (PPA) and the presence of ßPPA for each optic nerve quadrant. Correlation between RNFL and CT was assessed; two-sample t-tests were used to determine differences in RNFL and CT between POAG and suspect eyes; and linear regression was used to model changes in RNFL and CT. We found that independent measurements of CT by two observers were highly correlated (Lin’s CCC for global CT; ρ_c = 0.93, p < 0.001). RNFL and CT measurements were not significantly correlated for any peripapillary location (|r| ≤ 0.15, p ≥ 0.22). Global CT (ß = −1.94, 95% confidence interval [CI] −2.76, −1.13) but not RNFL thickness (ß = −0.18, 95% CI −0.58, 0.22) decreased significantly with age. Compared to suspect eyes, eyes with POAG had significantly thinner RNFL measurements at all locations (p ≤ 0.005) but CT measurements did not differ between groups for any location (p ≥ 0.13). Adjusting for glaucoma status and age, total (ß = 3.15 95% CI −0.24, 6.53) and ß clock hours of PPA (ß = 1.33, 95% CI −1.72, 4.38) were not significantly associated with global CT; the spatial distribution of PPA was not associated with underlying CT, though PPA was graded subjectively and may have been subject to spatial mismatch with a singular peripapillary eccentricity on SD-OCT. We conclude that eyes with POAG did not demonstrate reduced CT nor was there a correlation between RNFL and CT maps. This study does not support the use of CT assessment in glaucoma diagnosis or management.     

Peripapillary choroidal thickness in Chinese children using enhanced depth imaging optical coherence tomography

AIM: To evaluate the peripapillary choroidal thickness (PPCT) in Chinese children, and to analyze the influencing factors. METHODS: PPCT was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) in 70 children (53 myopes and 17 non-myopes) aged 7 to 18y, with spherical equivalent refractive errors between 0.50 and -5.87 diopters (D). Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc. PPCT was measured by EDI-OCT in six sectors: nasal (N), superonasal (SN), superotemporal (ST), temporal (T), inferotemporal (IT) and inferonasal (IN), as well as global RNFL thickness (G). RESULTS: The mean global PPCT was 165.49±33.76 µm. The temporal, inferonasal, inferotemporal PPCT were significantly thinner than the nasal, superonasal, superotemporal segments PPCT were significantly thinner in the myopic group at temporal, superotemporal and inferotemporal segments. The axial length was significantly associated with the average global (β= -0.419, P=0.014), superonasal (β= -2.009, P=0.049) and inferonasal (β= -2.000, P=0.049) PPCT. The other factors (gender, age, SE) were not significantly associated with PPCT. CONCLUSION: PPCT was thinner in the myopic group at temporal, superotemporal and inferotemporal segments. The axial length was found to be negatively correlated to PPCT. We need more further studies about the relationship between PPCT and myopia.     

Artifacts in optical coherence tomography

Optical coherence tomography (OCT) is now an integral part of management for numerous retinal diseases for diagnosis, treatment planning and follow up. OCT interpretation must involve the understanding of the associated artifacts. These artifacts can mislead physicians to wrong diagnosis or inappropriate management. This review article discusses the various types of artifacts in OCT scans obtained from various devices in various retinal diseases. This article would help to improve the understanding about the various artifacts and their clinical importance.     

Filtering blebs imaging by optical coherence tomography

PURPOSE: To assess the ability of standard optical coherence tomography to visualize filtering blebs after glaucoma surgery. METHODS: A prospective interventional case series was conducted in a private practice. Twenty-nine eyes of 24 patients (21 with good, 2 with fair and 6 with poor intraocular pressure [IOP] control) were investigated. After the focus was manually adjusted on the conjunctiva, blebs were scanned perpendicularly to the limbus. RESULTS: Hyporeflective fluid-filled spaces were detected in 19 out of the 21 eyes with good IOP. Within this group, blebs were classified into three different categories according to their optical coherence tomography pattern: type A (featuring a thick wall and a single large fluid-filled space), type B (featuring a thin wall and multiple large fluid-filled spaces) and type C (featuring multiple, irregular and flattened fluid-filled spaces). Fluid-filled spaces were not observed in three out of the six eyes with poor IOP control. Trabeculectomy without antimetabolites was associated with type A blebs (P = 0.015, Fisher's exact test), mitomycin-C trabeculectomy with type B blebs (P = 0.0025) and mitomycin-C phacotrabeculectomy with type C blebs (P = 0.0173). CONCLUSIONS: Although it was not developed to evaluate the anterior segment of the eye, standard optical coherence tomography can visualize filtering blebs and reveal interesting details of their morphology. Clinicians using optical coherence tomography to diagnose glaucoma can take advantage of this ability of the instrument to obtain more information about their patients in the postoperative course of trabeculectomy and phacotrabeculectomy.