Anterior Segment Optical Coherence Tomography Examination Research Articles

Anterior Segment Optical Coherence Tomography Imaging of the Lacrimal Gland in Patients With Chronic Ocular Graft-Vs-Host Disease.

The purpose of this study was to explore the image characteristics of the palpebral lobe of the lacrimal gland in patients with chronic ocular graft-vs-host disease (coGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) using anterior segment optical coherence tomography (AS-OCT). This comparative cross-sectional study included 32 patients with coGVHD, 21 patients with severe aqueous tear deficiency dry eye, and 20 healthy control subjects. All subjects underwent an AS-OCT examination on the palpebral lobe of the lacrimal gland. The main outcomes are the number of visible gland lobules, ducts, and blood vessels and the proportions of mille crêpe-like structures in the AS-OCT images. Compared with the other 2 groups, patients with coGVHD had significantly more blood vessels and slightly less visible lobules and ducts (all P <0.05) in the palpebral lacrimal gland. Mille crêpe-like structures were observed only in the coGVHD group. Number of blood vessels was positively correlated with time after allo-HSCT (β: 0.14, 95% confidence interval [CI], 0.01-0.26). Mille crêpe-like structure was positively correlated with coGVHD severity (odds ratio: 9.07, 95% CI, 1.75-16.38) and time after allo-HSCT (odds ratio: 0.13, 95% CI, 0.03-0.23). We reported the AS-OCT characteristics of the palpebral lacrimal gland in coGVHD and found an increased number of blood vessels and mille crêpe-like structures. AS-OCT has the potential in the disease monitoring of coGVHD.

Anterior-Segment Optical Coherence Tomography-Based Evaluation of the Journey of a Bleb in the Early Postoperative Period.

Introduction In the early postoperative period following trabeculectomy, monitoring the journey of bleb formation is crucial for assessing surgical success. Anterior-segment optical coherence tomography (AS-OCT) emerges as a powerful tool in this pursuit, offering high-resolution imaging of bleb morphology and dynamics. This study aims to evaluate the internal structure of blebs through their maturation phases using AS-OCT. Methods Fifty-five eyes undergoing trabeculectomy were enrolled in a prospective observational study. Serial AS-OCT examinations were done on day 1, week 1, week 3, and week 6 postoperatively; bleb parameters were calculated and correlated with intraocular pressure (IOP). Results IOP control was seen in 45 eyes six months of post-trabeculectomy. Multiform bleb wall reflectivity (BWR) statistically correlates with the success of trabeculectomy. Blebs were successful if BWR showed no change from day 1 to week 6. BWR remained the same on all follow-ups if week 1 bleb wall thickness (BWT) was less than 129.5 microns with 82.6% sensitivity and 83.3% specificity. The cumulative hazard of change in BWR is estimated to be approximately 5.6%, 15.7%, and 17.9% at week 1, week 3, and week 6 follow-ups, respectively. Conclusions Successful blebs showed consistent BWR from day 1 to week 6 of follow-up. Serial AS-OCT examination for changes in BWR in early stages can be done to predict the fate of bleb. The maximum change in BWR occurs between the week 1 and week 3 follow-up periods requiring close follow-up.

Bleb analysis using anterior segment optical coherence tomography after trabeculectomy with amniotic membrane transplantation.

Little has been known about the intrableb structures associated with bleb function after trabeculectomy with amniotic membrane transplantation (AMT). The aim of this study is to analyze the characteristics of intrableb structures using anterior segment optical coherence tomography (AS-OCT) after trabeculectomy with AMT. A total of 68 eyes of 68 patients with primary open-angle glaucoma who underwent trabeculectomy with AMT were included. Surgical success was defined as intraocular pressure (IOP) ≤ 18 mmHg and IOP reduction of ≥ 20% without medication on AS-OCT examination. Intrableb parameters, including bleb height, bleb wall thickness, striping layer thickness, bleb wall reflectivity, fluid-filled space score, fluid-filled space height, and microcyst formation were evaluated using AS-OCT. Logistic regression analysis was performed to determine factors associated with IOP control. Of the 68 eyes, 56 eyes were assigned to the success group and 12 eyes to the failure group. In the success group, bleb height (P = 0.009), bleb wall thickness (P = 0.001), striping layer thickness (P = 0.001), fluid-filled space score (P = 0.001), and frequency of microcyst formation (P = 0.001) were greater than those in the failure group. Bleb wall reflectivity was higher in the failure group than in the success group (P < 0.001). In the univariate logistic regression analysis, previous cataract surgery was significantly associated with surgical failure (odds ratio = 5.769, P = 0.032). A posteriorly extending fluid-filled space, tall bleb with low reflectivity, and thick striping layer were characteristics of successful filtering blebs after trabeculectomy with AMT.

Comparison of the Intrableb Characteristics of Anterior Segment Optical Coherence Tomography Imaging in Trabeculectomy according to Amniotic Membrane Transplantation

Introduction: The purpose of this study was to compare the characteristics of filtering bleb with anterior segment optical coherence tomography (AS-OCT) according to amniotic membrane transplantation (AMT). Methods: One hundred and sixteen eyes of 103 glaucoma patients who underwent trabeculectomy with (AMT group; 85 eyes) or without AMT (control group; 31 eyes) were included. Intrableb parameters were evaluated with AS-OCT. Surgical success was defined as an intraocular pressure (IOP) ≤18 mm Hg and IOP reduction ≥20% without medication at the time of AS-OCT examination. Logistic regression analyses were performed to determine factors associated with IOP control. Results: In the eyes with successful IOP control, the fluid-filled space area, score, and height were greater for the AMT group than the control group (all ps < 0.001), while stripping layer thickness was greater and bleb wall reflectivity was lower for the control group than the AMT group (all ps < 0.001). Surgical success in the AMT group was associated with greater fluid-filled space score, lower bleb wall reflectivity, and microcyst formation (odds ratio [OR] = 8.016, 0.913, and 16.202, respectively, all ps ≤ 0.041). Lower bleb wall reflectivity alone was associated with surgical success in the control group (OR = 0.815, p = 0.019). Conclusion: The extent of the fluid-filled space was associated with successful IOP control after trabeculectomy with AMT. Hyporeflective bleb wall was associated with successful IOP control in AMT and control groups.

Is anterior segment OCT superior to slit-lamp biomicroscopic examination for Kayser Flesicher ring in Wilson's disease?

Detection of the Kayser-Fleischer (KF) ring in the diagnostic scoring and treatment follow-up of Wilson's Disease (WD) is important. Slit lamp (SL) biomicroscopic examination has traditionally been used in the evaluation of the KF ring. The role of Anterior Segment Optical Coherence Tomography (AS-OCT), which is used in various corneal diseases, in the detection of KF rings has attracted attention in recent years. In our study, we tried to demonstrate the effectiveness of AS-OCT in detecting the KF ring by comparing it with SL biomicroscopic examination. 64 of 356 patients followed in our outpatient clinic due to WD were included in the study in the order of their admission to the outpatient clinic. The KF ring was evaluated in both eyes by SL-biomicroscopic examination and AS-OCT. Ophthalmic examination, and findings were performed by the same physician. Age range was 18-67 years, mean 33.06±10.83 years, gender was 39.1% (n: 25) female. At the time of diagnosis, the mean age was 19.48 ± 9.36 years, range was minimum 5 years and maximum 51 years. Clinical presentation was mixed type involvement n: 18 (28.1%), hepatic involvement n: 32 (50%), neurological involvement n: 14 (21.9%). The follow-up period was 2-257 months (74.6±76.16). The presence of KF ring was evaluated together with both AS-OCT and slit-lamp examination, the presence of KF could be detected in both AS-OCT and SL biomicroscopic examination in 10 patients (15.6%), in 12 (18.8%) of the cases KF ring is positive in AS-OCT but was negative in Slit-lamp biomicroscopic examination, in 65.6 (n: 42) of the cases OCT and slit-lamp biomicroscopic examination results were negative. The sensitivity of AS-OCT in detecting the KF ring was higher than the slit-lamp biomicroscopic examination. AS-OCT can detect early stage of KF rings in Wilson's Disease patients, so that diagnosis and treatment accuracy can be evaluated effectively.

Role of anterior segment optical coherence tomography in the evaluation of microbial keratitis

Anterior segment optical coherence tomography (AS-OCT) is a newer technology that provides two-dimensional images of corneal infiltration. This study was undertaken to assess whether AS-OCT can aid objective evaluation and response to treatment in resolving microbial keratitis. This prospective study was performed on 17 patients of who underwent slit lamp and AS-OCT examination at presentation and follow up on days 3, 7, 14, 28 and 6 weeks. A standardized scanning protocol was used to measure the corneal thickness (CT) and infiltrate thickness (IT) using the caliper tool of a commercially available AS-OCT device. The mean CT in the infiltrated area and mean IT, both were thickest at presentation (710.88 um and 288.76 um respectively). The mean CT decreased to 665.12 µm, 650.24 µm, 584.35 µm, 549 µm, 507.47 µm on days 3, 7, 14, 28 and 6 weeks respectively. Similarly, the mean IT decreased to 287.24 µm, 244.41 µm, 197 µm, 174.59 µm and 154.82 µm. Paired t- test was used to calculate the statistical change in CT and IT, which was significant (p&amp;#60;0.0001) at 6 weeks, at the rate of 0.67% and 1.01% per day. AS-OCT can show morphological characteristics of microbial keratitis and give quantitative assessment at every follow up.

The change of anterior chamber angle parameters after cataract surgery in diabetic patients.

Purpose:The purpose of this study is to investigate the change of anterior chamber angle morphology after cataract surgery in patients with type 2 diabetes mellitus (DM2) using anterior segment optical coherence tomography (AS-OCT).Methods:In this prospective and comparative study, 57 eyes of the patients with cataract were investigated. The patients were divided into two groups. The DM2 group included cataractous type 2 diabetic patients without diabetic retinopathy (n = 30) and the non-DM2 group included nondiabetic participants with cataract (n = 27). The AS-OCT examinations were performed at baseline and 1 month after the cataract surgery. The corrected distance visual acuity (CDVA), intraocular pressure (IOP), angle-opening distance at 500 µm (AOD-500) and trabecular iris space area at 500 µm (TISA-500), and scleral spur angle (SSA) in temporal quadrant were analyzed.Results:The mean age, sex, and axial length values were similar in both groups (p > 0.05 for all). The CDVA was significantly improved in both groups (p < 0.001). The mean AOD-500, TISA-500, and SSA were increased and the mean IOP was decreased after cataract surgery in both groups (p < 0.001 for all). There were not any statistically significant intergroup differences in CDVA, IOP, and AS-OCT measurements between the DM2 and non-DM2 groups (p > 0.05 for all).Conclusion:Cataract surgery showed significant increases in mean anterior chamber angle parameters and reductions in IOP values in both diabetic and nondiabetic patients without intergroup significant differences. These results suggested the safety and effectiveness of cataract surgery, especially regarding anterior chamber angle parameters and so IOP changes.

Detection of primary angleclosure suspect with different mechanisms of angle closure using multivariate prediction models.

PurposeWe had found that a multivariate prediction model used for the detection of primary angle‐closure suspects (PACS) by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters had an area under the receiver operating characteristic curve (AUC) of 0.844. We undertook this study to evaluate this method in screening of PACS with different dominant mechanisms of angle closure (AC).MethodsThe right eyes of subjects aged ≥40 years who participated in the 5‐year follow‐up of the Handan Eye Study and had undergone gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analysed by the Zhongshan Angle Assessment Program. The dominant AC mechanism in each eye was determined to be pupillary block (PB), plateau iris configuration (PIC) or thick peripheral iris roll (TPIR). Backward logistic regression (LR) was used for inclusion of variables in the prediction models. LR, Naïve Bayes’ classification (NBC) and neural network (NN) were evaluated and compared using the AUC.ResultsData from 796 subjects (413 PACS and 383 normal eyes) were analysed. The AUCs of LR, NBC and NN in the PB group were 0.920, 0.918 and 0.917. The AUCs of LR, NBC and NN in the PIC group were 0.715, 0.708 and 0.707. The AUCs of LR, NBC and NN in TPIR group were 0.867, 0.833 and 0.886.ConclusionsPrediction models showed the best performance for detection of PACS with PB mechanism for AC and have potential for screening of PACS.

Establishment and Comparison of Algorithms for Detection of Primary Angle Closure Suspect Based on Static and Dynamic Anterior Segment Parameters.

PurposeTo establish and evaluate algorithms for detection of primary angle closure suspects (PACS), the risk factor for primary angle closure disease by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters.MethodsObservational, cross-sectional study. The right eyes of subjects aged ≥40 years who participated in the 5-year follow-up of the Handan Eye Study, and underwent gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analyzed by Zhongshan Angle Assessment Program. Backward logistic regression (BLR) was used for inclusion of variables in the prediction models. BLR, naïve Bayes’ classification (NBC), and neural network (NN) were evaluated and compared using the area under the receiver operating characteristic curve (AUC).ResultsData from 744 subjects (405 eyes with PACS and 339 normal eyes) were analyzed. Angle recess area at 750 µm, anterior chamber volume, lens vault in light and iris cross-sectional area change/pupil diameter change were included in the prediction models. The AUCs of BLR, NBC, and NN were 0.827 (95% confidence interval [CI], 0.798-0.856), 0.826 (95% CI, 0.797-0.854), and 0.844 (95% CI, 0.817-0.871), respectively. No significant statistical differences were found between the three algorithms (P = 0.622).ConclusionsThe three algorithms did not meet the requirements for population-based screening of PACS. One possible reason could be the different angle closure mechanisms in enrolled eyes.Translational RelevanceThis study provides a promise for basis for future research directed toward the development of an image-based, noncontact method to screen for angle closure.

Cornea Findings of Spectral Domain Anterior Segment Optical Coherence Tomography in Uveitic Eyes of Various Etiologies.

To evaluate the morphologic appearance of keratic precipitates (KPs) with spectral domain anterior segment optical coherence tomography (AS-OCT) for the diagnosis of uveitic eyes of various etiologies. In all, 153 eyes of 153 patients with different types of uveitis were examined to investigate the morphologic appearance of KPs. The study included 63 eyes with herpetic iridocyclitis/endotheliitis, 58 eyes with ocular sarcoidosis, 5 eyes with Fuchs heterochromic iridocyclitis, and 27 eyes with masquerade syndrome with primary intraocular lymphoma (PIOL). AS-OCT was used to analyze the different KP types among various uveitic groups. KPs were observed in 30 eyes (51.7%) from the ocular sarcoidosis group and in 15 eyes (55.6%) from the PIOL group. In the herpetic iridocyclitis/endotheliitis group, all cases showed KPs (16 cases were positive for herpes simplex virus, 22 cases for varicella zoster virus, and 27 cases for cytomegalovirus). The reflectivity and morphology of the KPs in the AS-OCT images demonstrated different patterns depending on the causative virus. Hemispheric and relatively large KPs were observed in ocular sarcoidosis cases. KPs with Fuchs heterochromic iridocyclitis appeared as small dots. By contrast, relatively high-intensity and dense KPs were observed in PIOL cases. The morphologic features of the KPs in different types of uveitis also showed other patterns such as hemispheric and rectangular-shaped KPs protruding from the retrocornea. AS-OCT images showed characteristic and specific morphological patterns. AS-OCT examination is a noninvasive and repeatable method for the diagnosis of uveitis by evaluating the morphologies of KPs and treatment effectiveness.

Evaluation of the Effects of Biohcly in an In Vivo Model of Mechanical Wounds in the Rabbit Cornea.

Biohcly is a type of acidic nanoclustered water shown to exert an antimicrobial effect and play a role in the tissue-healing process in previous experiments. This study was performed to evaluate the in vivo effects of Biohcly treatment on mechanical corneal wound healing. Rabbit cornea "acute" mechanical wounds were created with an 8-mm hydraulic pressure trephine. The corneal wounds were treated with either Biohcly (left eye) or sterile saline (right eye) 4 times per day. To determine the state of the wounds, the wound healing rate (WHR), inflammatory index (IF), neovascularization, and anterior segment optical coherence tomography (AS-OCT) were evaluated. The expression of inflammatory factors was examined by quantitative real-time reverse transcriptional polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical staining. Biohcly was more effective than saline in healing corneal ulcers as demonstrated by the WHR calculated on the 9th and 14th days after surgery (P < 0.05). The histological and AS-OCT examinations revealed better regeneration and reduced corneal scars in the Biohcly-treated corneas. No neovascularization formed in the corneas treated with Biohcly, whereas 25% of the saline-treated wounds developed this complication. In addition, the IF scores of the Biohcly-treated wounds were significantly lower than those of the saline-treated wounds. Compared with the right-eye corneas, the left-eye corneas had much lower protein and mRNA levels of matrix metalloproteinase-9 (MMP-9) after the injury. Biohcly plays a role in wound healing and anti-inflammation in the treatment of corneal wounds. The downregulation of MMP-9 in the Biohcly-treated corneas might have been responsible for this effect.

Comparison of anterior segment optical coherence tomography findings in acanthamoeba keratitis and herpetic epithelial keratitis.

This study is to investigate the characteristic features of Acanthamoeba keratitis (AK) that differentiating it from herpetic epithelial keratitis (HEK) using anterior segment optical coherence tomography (AS-OCT). Medical records of three eyes of each AK and herpetic keratitis who had AS-OCT examination were reviewed in this study. Slit-lamp biomicroscopy and AS-OCT was performed on the initial visit and on every follow-up visits in all patients. In all three AK cases, reflective bands in the corneal stroma that correspond to the area of radial keratoneuritis were observed. The depth of the reflective bands varied in each case. After AK treatment, slit-lamp biomicroscopy confirmed that radial keratoneuritis had resolved and AS-OCT confirmed that reflective bands in the corneal stroma had also disappeared in all patients. Unlike the AS-OCT results found in AK, highly reflective HEK lesions were observed only in the subepithelial area, not in the stroma. AS-OCT seems to be helpful analyzing the specific depth of the lesion which enables to distinguish AK from HEK.

Evaluation of the anterior chamber angle and filtering bleb morphology after phacotrabeculectomy by using anterior segment optical coherence tomography

Purpose Evaluating the anterior chamber angle (ACA) and filtering bleb following phacotrabeculectomy by using anterior segment optical coherence tomography (AS-OCT). Patients and methods This is a retrospective study that included 30 eyes of 30 patients with cataract and glaucoma of both sexes and aged from 42 to 72 years. Patients attended the Ophthalmology Department of Minia University Hospital between June 2016 and November 2017. The duration of follow-up was 6 months. The patient’s underwent preoperative clinical and AS-OCT examination, followed by phacotrabeculectomy, and then postoperative AS-OCT to evaluate the angle and the filtering bleb. Results A total of eight patients were diagnosed with primary open-angle glaucoma and 22 with primary closed-angle glaucoma. Overall, eight (26.7%) eyes had closed angle in two quadrants: six (20%) eyes with closed superior and inferior quadrants and two (6.7%) eyes with closed nasal and temporal quadrants. Closed ACAs in three quadrants of the eye, the superior, nasal, and temporal quadrants, were found in six (20%) eyes. Closed ACAs in the four quadrants of the eyes were observed in eight (26.7%) eyes. Cystic blebs are highly elevated and hyporeflective (30% of cases). Diffuse blebs are moderately elevated with moderate reflectivity (50% of cases). Flat blebs are low with hyperreflectivity (20% of cases). Conclusion AS-OCT is an optimistic tool to investigate the filtering blebs. It was able to detect angle changes preoperatively and postoperatively and show the features of the bleb that are not properly detected by the slit lamp examination. It has the advantage over ultrasound biomicroscopy in being a noncontact, noninvasive procedure, allowing early postoperative examination.

Short-term in vivo morphological changes of amniotic membrane after fibrin glue-assisted pterygium surgery on anterior segment optical coherence tomography: a case presentation

BackgroundThe evaluations of morphological changes of amniotic membrane (AM), even after successful AM transplantation surgery without complications, may be difficult. Moreover, there was no report regarding morphological changes after fibrin glue-assisted AM transplantation with pterygium excision. Here, we highlight and describe the use of spectral domain optical coherence tomography (OCT) for the evaluation of the morphological features of amniotic membrane (AM) and of associated in vivo structural changes after fibrin glue-assisted pterygium surgery.Case presentationAll three patients underwent cryo-preserved AM transplantation using the permanent inlay technique (epithelial side up) with fibrin glue. In vivo morphological changes of AMs were evaluated using a spectral domain OCT equipped with an anterior segment imaging module (RTVue-100, Optovue, Inc., Fremont, CA, USA). Anterior segment OCT examinations demonstrated morphological changes, that is, re-absorption of fibrin glue or subconjunctival hemorrhage, migration of epithelium, and integration of AM into sclera, of AMs over first postoperative months.ConclusionsAnterior segment OCT might provide additional structural information, including quantitative and qualitative data, on AMs after pterygium surgery as compared with conventional slit-lamp examination.

Evaluation of the Narrow Anterior Chamber Angle by Anterior Segment Optical Coherence Tomography

Background: The aim of this work was to evaluate the narrow anterior chamber angle (ACA) in Chinese patients by anterior segment optical coherence tomography (As-OCT). Methods: Eighty right eyes of 80 consecutive patients with a shallow peripheral anterior chamber but no peripheral anterior synechia were enrolled in this study. The ACA was observed by noncompression gonioscopy and classified according to the Shaffer grading system. The iridotrabecular contact (ITC) and trabecular-iris angle (T-I angle) were assessed by As-OCT examination. Results: Gonioscopic grade 0 and ITC were observed more frequently in the superior quadrant than the other quadrants (p < 0.02). The T-I angle was significantly smaller superiorly and inferiorly than nasally and temporally (p < 0.01). The frequency of the ITC and T-I angle significantly declined when the gonioscopic grade was from 0 to 2 (p < 0.01). Logistic analysis showed that the axial length and refraction were related to the presence of ITC in more than two quadrants (p < 0.03). Conclusions: ITC was common in eyes with a shallow peripheral anterior chamber (superiorly, gonioscopic grade 0). Sites with wider gonioscopic grading tended to have a larger T-I angle. Axial length and refraction significantly impacted on the frequency of ITC.

Morphologic study of the cornea by in vivo confocal microscopy and optical coherence tomography after bifocal refractive corneal inlay implantation

To evaluate the biocompatibility of the Flexivue Microlens intracorneal inlay based on healing of corneal wounds and analysis of corneal structural features using invivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT). Ophthalmology Department, Misericordia e Dolce Hospital, Prato, Italy. Case series. The intracorneal inlay was inserted in a stromal pocket created in the nondominant eye of emmetropic presbyopic patients using a femtosecond laser. Invivo confocal microscopy and AS-OCT examinations were performed preoperatively and 1, 6, and 12 months postoperatively. The mean follow-up was 7.6 months. In the early postoperative period, IVCM showed intense cellular activity in the stroma around the inlay, edema, inflammation, and degenerative material deposition but normal regularity after 12 months. Anterior segment OCT showed a regular planar shape of the corneal pocket in all eyes. The mean of the side-cut angles was 30.7 degrees. The mean difference between the measured and planned pocket depth was 9.77 μm. At 1 month, hyperreflective areas beneath the inlay and microfolds were observed in 21 of the 52 eyes. After 12 months, the anterior segment profile was regular and interface pocket reflectivity decreased over time. Six patients had inlay removal postoperatively (3 before 6 months; 3 before 12 months); after removal, IVCM and AS-OCT showed clear corneas without signs of irregularity. Invivo confocal microscopy and AS-OCT analysis showed that the inlay elicited a low-level wound-healing response in its immediate vicinity with no alteration in the corneal structures. Dr. M. Fantozzi is a member of the Presbia medical advisory board. No other author has a financial or proprietary interest in any material or method mentioned.

Visante Anterior Segment Optical Coherence Tomography Analysis of Morphologic Changes After Deep Sclerectomy With Intraoperative Mitomycin-C and No Implant Use

To assess long-term intrascleral space maintenance after nonpenetrating deep sclerectomy (NPDS) without implant placement and with application of intraoperative mitomycin-C, using Visante anterior segment optical coherence tomography (AS-OCT). This cross-sectional, observational, case series study examined 47 eyes from 47 consecutive patients who had undergone NPDS 58.34±23.77 months earlier. All participants underwent a complete ophthalmologic examination. The presence of intrascleral space and its maximum anteroposterior and transverse lengths, maximum height, and volume were evaluated. The thickness of the trabeculo-Descemet membrane, presence and type of any subconjunctival filtering bleb, as well as scleral and suprachoroidal hyporeflectivity were analyzed. Relationships between intraocular pressure (IOP) levels and AS-OCT parameters were established. AS-OCT examinations revealed an open intrascleral space in all cases. The IOP was negatively correlated with the maximum anteroposterior length, maximum height, and volume of intrascleral space. Significant differences in IOP were found between eyes with low-reflective blebs and eyes with other subconjunctival bleb types. The overall surgical success rate was 89.4%. NPDS without implant placement and with intraoperative mitomycin C application seems to be an effective and well-tolerated method to reduce IOP with long-term effectiveness, casting doubt on the mandatory use of intrascleral implants in nonpenetrating glaucoma surgery.

Mean central corneal thickness and corneal power measurements in pigmented and white rabbits using Visante optical coherence tomography and ATLAS corneal topography

To document central corneal thickness (CCT) and power measurements in pigmented and white rabbits using Visante anterior segment optical coherence tomography (AS-OCT) and the Humphrey ATLAS Corneal Topography System (HACTS). Fourteen female rabbits (seven pigmented and seven white rabbits) were involved in this study. Twenty-eight eyes underwent AS-OCT and HACTS examination. Central corneal thickness, corneal power in the steepest and flattest meridians, astigmatism, pupil diameter (PD), and white-to-white (WTW) were calculated. The CCT was 390 ± 14.2 and 373 ± 7.2 μm for pigmented and white rabbits, respectively. The CCT values showed statistical difference between the two breeds (P = 0.017). The corneal power in the steepest meridian was 44.6 ± 1.9 Diopter (D) in pigmented rabbits and 47.8 ± 1.5 D in white rabbits. The corneal power in the flattest meridian was 44.0 ± 2.1 D in pigmented rabbits and 47.4 ± 1.5 D in white rabbits. The astigmatism, PD, and WTW values were 0.6 ± 0.22 D, 7.9 ± 0.9, and 14.5 ± 0.1 mm in pigmented rabbits, respectively. The corresponding values in white rabbits were 0.4 ± 0.23 D, 7.5 ± 0.5, and 13.5 ± 0.2 mm. There was a statistically significant difference in corneal power in the steepest and flattest meridians and for WTW. No such difference was observed for astigmatism or PD between them. Differences exist in the CCT, corneal power, and WTW between 5-month-old pigmented and white rabbits. Such difference should be considered when designing cornea-related experiments in rabbits.

Detection of the anterior segment configuration of primary angle-closure glaucoma by anterior segment optical coherence tomography

To quantitatively measure and evaluate the ocular anterior segment parameters in different subtypes of primary angle-closure glaucoma (PACG) using anterior segment optical coherence tomography (AS-OCT). This retrospective study collected Fifty-five subjects (55 eyes) with APACG, 63 (63 eyes) with chronic primary angle-closure glaucoma (CPACG) and 90 (90 eyes) normal controls from December 2009 to December 2010 in Zhongshan Ophthalmic Center. AS-OCT examination was performed on all patients and the anterior segment parameters were recorded including: central anterior chamber depth (ACD), anterior chamber width (ACW), anterior chamber volume (ACV), angle opening distance (AOD), trabecular iris area (TISA), angle recess area (ARA), lens thickness (LT) and crystalline lens rise (CLR). The differences of parameters between APACG, CPACG and normal controls were compared. The anterior segment parameters of APACG and CPACG were significantly (P ≤ 0.001) smaller, respectively, than those of normal controls (PACG: ACD 1.81 ± 0.25 mm, ACW 11.30 ± 0.43 mm, AOD 0.039 mm, ARA 0.038 mm(2), ACV 72.8 ± 16.04 mm(3), TISA 0.017 mm(2), Mean ± SD, and CPACG: ACD 2.02 ± 0.25, ACW 11.49 ± 0.45, AOD 0.042, ARA 0.053, ACV 83.60 ± 19.49, TISA 0.022 vs. normal: ACD 2.70 ± 0.35, ACW 11.81 ± 0.47, AOD 0.260, ARA 0.197, ACV 148.52 ± 31.89, TISA 0.100). The LT and CLR of PACG were significantly (P < 0.001) larger, respectively, than that of normal controls (LT: APACG 5.22 ± 0.38, CPACG 5.06 ± 0.36 mm, CLR: APACG 1.07 ± 0.26, CPACG 0.94 ± 0.21 mm vs. normal: LT 4.57 ± 0.42, CLR 0.39 ± 0.33 mm). Compared with CPACG, the anterior segment parameters of APACG were significantly (P < 0.001 - 0.015) decreased, but the LT (P = 0.003) and CLR were significantly (P < 0.001) increased. Compared with APACG-fellow eyes, the anterior segment parameters of APACG-attacked eyes were significantly (P < 0.001 - 0.041) decreased (Fellow-eye: ACD 1.90 ± 0.23 mm, AOD 0.045 mm, TISA 0.037 mm(2), ARA 0.047 mm(2) vs. attached-eye: ACD 1.81 ± 0.25, AOD 0.039, TISA 0.017 and ARA 0.038), while CLR was significantly (t = 1.349, P = 0.043) increased (fellow-eye: 1.01 ± 0.23 mm vs. Attached-eye: 1.07 ± 0.26). There was no significant difference in the other AS-OCT parameters between APACG-attacked eyes and fellow eyes (t = 0.574 - 1.147, P = 0.257 - 0.567). Our results indicated a more crowding anterior segment configuration in PACG than that in normal controls and a more anterior located and thicker lensing APACG than that in CPACG, which constitute a morphological basis of acute attack.

In Vivo Quantification of Bacterial Keratitis with Optical Coherence Tomography

To quantify the human corneal inflammatory response in treated bacterial keratitis with long-wavelength anterior segment optical coherence tomography (AS-OCT). Patients with clinically suspected bacterial keratitis were recruited from the corneal service at Southampton Eye Unit, UK. Patients underwent AS-OCT and slit-lamp examination on presentation (day 0) and days 3, 7, and 14 of treatment. Corneal thickness (CT) in the infiltrated area, infiltrate thickness (IT), and infiltrate width (IW) were measured on high-resolution AS-OCT scans. Mean values for each day and rates of change for each interval were calculated and compared (one-way ANOVA, paired t-test). Twenty-six eyes of 26 patients were recruited. Mean CT and IT on presentation were 905 μm and 388 μm, respectively. On days 3, 7, and 14, CT and IT decreased to 753 μm and 320 μm (P < 0.01), 678 μm and 296 μm (P < 0.01), and 584 μm and 207 μm (P < 0.01), respectively. Mean IW, 1498 μm on presentation, did not change during treatment (P > 0.30). Mean daily rate of CT reduction was faster in the early (days 0-3) compared to late (days 7-14) phase (4.49% vs. 1.33%, P = 0.006). Mean daily rate of IT reduction was no different in early, middle, and late phases (5.41% vs. 1.19% vs. 3.38%, P > 0.01). In the late phase, IT decreased faster than CT (3.38% vs. 1.33%, P = 0.003). CT and IT decreased significantly by day 3 in resolving bacterial keratitis. The rapid early phase reduction in IT and CT was followed by rapid late phase IT reduction. This study demonstrates that serial AS-OCT examination can be used to monitor in vivo the clinical course of inflammatory disease.