Takuya Iwasaki

Choroidal thickness measurement in healthy Japanese subjects by three-dimensional high-penetration optical coherence tomography

BackgroundWe performed retinal and choroidal thickness mapping by three-dimensional high-penetration optical coherence tomography (OCT) and evaluated the choroidal thickness distribution throughout the macula in healthy eyes.MethodsForty-three eyes of 43 healthy Japanese volunteers were evaluated by 1060-nm swept-source OCT. The eyes were scanned with a three-dimensional raster scanning protocol, and the mean retinal and choroidal thicknesses of the posterior sectors were obtained. The sectors were defined by the Early Treatment Diabetic Study (ETDRS) layout. These data were compared by age (23–56xa0years), spherical equivalent refractive error (between +0.9 D and −10.3 D), and axial length (22.9–27.6xa0mm).ResultsThe mean retinal and choroidal thicknesses of the ETDRS area were 284u2009±u200914xa0μm and 348u2009±u200963xa0μm respectively. The mean regional choroidal thicknesses in the nasal inner macula and nasal outer macula were significantly smaller than those in all other sectors. The mean regional choroidal thickness in most sectors showed a significant negative correlation with axial length and a significant positive correlation with refractive error. In eyes with a long axial length (>25.0xa0mm), the mean regional choroidal thickness of five sectors showed a significant negative correlation with age. The coefficient of variation of choroidal thickness between sectors showed a significant negative correlation with axial length, and a positive correlation with refractive error. The mean retinal thickness in each sector was not significantly correlated with the mean choroidal thickness, age, axial length, or refractive error.ConclusionsThe choroidal thickness map showed a distribution entirely different from the retinal thickness map. Choroidal thickness varies significantly with location, axial length, refractive error, and age. These variations should be considered when evaluating choroidal thickness.

Visualization of sub-retinal pigment epithelium morphologies of exudative macular diseases by high-penetration optical coherence tomography.

PURPOSEnTo evaluate the clinical significance of the newly developed long-wavelength probe optical coherence tomography (LP-OCT) for the diagnosis of exudative macular diseases.nnnMETHODSnFourteen eyes of 13 participants were prospectively enrolled in the study. There were seven type I and five type II choroidal neovascularization (CNV) cases associated with age-related macular degeneration and idiopathic neovascularization and one case of polypoidal choroidal vasculopathy (PCV). A custom-built LP-OCT based on swept-source OCT (SS-OCT) technology was used. This new OCT uses a probe beam with a wavelength of 1060 nm that provides deeper penetration into the choroid and higher image contrast to the structures beneath the retinal pigment epithelium (RPE) and pathologic tissues than does conventional OCT. The depth resolution is 10.4 microm in tissue and the measurement speed is 28,000 depth scans/s. All the eyes were also examined by standard short wavelength probe OCT (SP-OCT). The image contrasts of the LP- and SP-OCT were qualitatively evaluated and analyzed by Wilcoxons paired signed rank test and Spearmans rank correlation test.nnnRESULTSnIn 10 of 14 eyes, high-contrast visualization of the diseases beneath the RPE, CNV, or fibrin was attained. These diseases were almost invisible in the SP-OCT images. The LP-OCT of the remaining eyes also revealed significant improvement in the image contrasts beneath the RPE and CNV. Qualitative evaluation of the image contrasts and subsequent statistical test indicated statistically significant improvement in the image penetration to the choroid of LP-OCT to that of SP-OCT.nnnCONCLUSIONSnLP-OCT provided significant improvement in the image contrast of exudative macular diseases.

Imaging Polarimetry in Age-Related Macular Degeneration

PURPOSEnTo evaluate the birefringence properties of eyes with age-related macular degeneration (AMD). To compare the information from two techniques--scanning laser polarimetry (GDx) and polarization-sensitive spectral-domain optical coherence tomography (OCT)--and investigate how they complement each other.nnnMETHODSnThe authors prospectively examined the eyes of two healthy subjects and 13 patients with exudative AMD. Using scanning laser polarimetry, they computed phase-retardation maps, average reflectance images, and depolarized light images. To obtain polarimetry information with improved axial resolution, they developed a fiber-based, polarization-sensitive, spectral-domain OCT system and measured the phase retardation associated with birefringence in the same eyes.nnnRESULTSnBoth GDx and polarization-sensitive spectral-domain optical coherence tomography detected abnormal birefringence at the locus of exudative lesions. Polarization-sensitive, spectral-domain OCT showed that in the old lesions with fibrosis, phase-retardation values were significantly larger than in the new lesions (P = 0.020). Increased scattered light and altered polarization scramble were associated with portions of the lesions.nnnCONCLUSIONSnGDx and polarization-sensitive spectral-domain OCT are complementary in probing birefringence properties in exudative AMD. Polarimetry findings in exudative AMD emphasized different features and were related to the progression of the disease, potentially providing a noninvasive tool for microstructure in exudative AMD.

Three-Dimensional Visualization of Ocular Vascular Pathology by Optical Coherence Angiography In Vivo

PURPOSEnTo demonstrate the clinical application of a noninvasive, three-dimensional, vascular imaging technique called Doppler optical coherence angiography (OCA). To evaluate the vascular architecture of polypoidal choroidal vasculopathy (PCV) using Doppler OCA.nnnMETHODSnThe authors prospectively examined the eyes of four healthy subjects and 15 PCV patients. Three-dimensional vascular flow imaging was performed using high-speed, high-resolution, and high-penetration spectral-domain Doppler optical coherence tomography. Two-dimensional images of the retina, choroid, and vascular lesions were obtained simultaneously.nnnRESULTSnDistribution of blood flow detected by Doppler OCA imaging corresponded well with that by indocyanine angiographic imaging. PCV lesions were localized in the space between the retinal pigment epithelium and the Bruchs membrane.nnnCONCLUSIONSnThe authors found using Doppler OCA that PCV lesions are similar in architecture to choroidal neovascularization in age-related macular degeneration. Doppler OCA facilitates rapid and noninvasive examination of exudative macular diseases.

Noninvasive Investigation of Deep Vascular Pathologies of Exudative Macular Diseases by High-Penetration Optical Coherence Angiography

PURPOSEnA newly developed high-penetration Doppler optical coherence angiography (HP-OCA) with a 1-μm probe beam for noninvasive investigation of vascular pathology of exudative macular diseases is introduced. A descriptive case series is presented to discuss the clinical utility of HP-OCA.nnnMETHODSnEleven eyes of 10 subjects with exudative macular disease, including two eyes with myopic choroidal neovascularization (mCNV); four eyes with AMD; and five eyes with polypoidal choroidal vasculopathy (PCV) were investigated. Two Doppler scanning modes (bidirectional and high-sensitive) of HP-OCA were used for the investigation. HP-OCA provides depth-resolved and en face angiograms and a structural OCT noninvasively. The HP-OCA images were compared with fluorescein angiography (FA); indocyanine green angiography (ICGA); and color fundus images.nnnRESULTSnThe abnormal vasculature patterns observed with high-sensitive HP-OCA presented high similarity to the midphase of ICGA. Several abnormal Doppler signals were observed in the en face high-sensitive HP-OCA and were colocated with FA leakage. This colocation was found in one eye with mCNV, four eyes with AMD, and one eye with PCV. Doppler tomogram of the bidirectional mode showed abnormal Doppler signals in three of five PCV cases beneath the pigment epithelium detachment. With the high-sensitive mode, Doppler signals were found beneath the elevated retinal pigment epithelium in all untreated cases.nnnCONCLUSIONSnHP-OCA revealed depth-resolved abnormal vasculatures in exudative macular diseases. The en face HP-OCA images showed high similarity with FA and ICGA images. These results suggest HP-OCA can be used for noninvasive and three-dimensional angiography in a clinical routine.

A case of hypertensive keratouveitis with endotheliitis associated with cytomegalovirus.

Aim: While cytomegalovirus is well known as a pathogenic organism of retinitis, especially associated with human immunodeficiency virus infection, there are few reports of anterior uveitis associated with cytomegalovirus. Methods: The authors present a case of keratouveitis associated with cytomegalovirus. Results: A 70-year-old Japanese man was referred to the authors because of poorly controlled hypertensive keratouveitis in the left eye. The patient had a history of recurrent hypertensive anterior uveitis. At presentation, the corneal stroma was edematous, with Descemets folds and pigmented keratic precipitates. The anterior chamber angle was depigmented compared to the fellow eye. Even though pupil dilation and posterior synechiae were absent, iris atrophy was not evident. His right eye appeared normal except for moderate cataract. Funduscopy of the left eye was hazy, with the optic disc showing a normal color but poorly defined details, and no apparent exdative retinitis. The best-corrected decimal visual acuity of the right and left eyes was 0.4 and 0.02, respectively. Intraocular pressure was 11 mmHg in the right eye and 35 mmHg in the left, despite maximum medical therapy. Systemic acyclovir and prednisolone for a month did not improve the hypertensive keratouveitis. The aqueous humor was investigated for herpes simplex virus, varicella-zoster virus and cytomegalovirus. Cytomegalovius genome was detected by polymerase chain reaction analysis. Oral valganciclovir rapidly reduced ocular hypertension within a week. CMV DNA disappeared 3 months after the initiation of valganciclovir. Conclusion: The authors reported a case of hypertensive keratouveitis with endotheliitis associated with cytomegalovirus.

Three-dimensional Vascular Imaging of Proliferative Diabetic Retinopathy by Doppler Optical Coherence Tomography

PURPOSEnTo evaluate the 3-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT).nnnDESIGNnProspective, nonrandomized clinical trial.nnnMETHODSnSeventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the 3-dimensional vascular architecture at vitreoretinal adhesions.nnnRESULTSnProliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the 3-dimensional extent of new vessels at various stages of neovascularization, and the extent of new vessels could be clearly confirmed at vitreoretinal adhesions.nnnCONCLUSIONSnDoppler OCT is useful for the detection and evaluation of the 3-dimensional vascular structure of neovascularization, and can assist in the noninvasive assessment of proliferative diabetic retinopathy.

Simultaneous investigation of vascular and retinal pigment epithelial pathologies of exudative macular diseases by multifunctional optical coherence tomography.

PURPOSEnTo investigate exudative macular disease, multifunctional optical coherence tomography (MF-OCT) using a 1-μm probe band was developed. The clinical utility of MF-OCT was examined in a descriptive case series.nnnMETHODSnTen eyes of nine subjects with exudative macular disease, including one eye with age-related macular degeneration (AMD), one eye with idiopathic neovascular maculopathy, and eight eyes with polypoidal choroidal vasculopathy (PCV), were investigated. Areas of 6 × 6 mm(2) around the pathologic region were scanned with 512 × 1024 depth scans in 6.6 seconds. Structural OCT, Doppler optical coherence angiography (OCA), and cumulative phase retardation images were obtained with a single measurement. Each MF-OCT image visualized the structure, vasculature, and birefringence. Degree of polarization uniformity values were also obtained for selective visualization of the retinal pigment epithelium (RPE). The MF-OCT images were compared with conventional ophthalmic images.nnnRESULTSnAbnormal vasculatures were observed with Doppler OCA in all eyes, which presented high similarity to indocyanine green angiography in the midphase. The RPE and exudation in the pathologic regions were discriminated in one eye with AMD and five of eight eyes with PCV. Cumulative phase retardation visualized fibrosis scars in two of the PCV cases.nnnCONCLUSIONSnMultifunctional OCT revealed depth-resolved abnormal vasculatures, the integrity of the RPE and choroid, discrimination of the RPE and exudation, and existence of fibrosis scars in exudative macular diseases. Interpretation of MF-OCT examination is well matched with conventional ophthalmic examination. These results suggest that MF-OCT can be used as a noninvasive ophthalmic examination tool prior to conventional examinations in clinical routines.

Imaging polarimetry and retinal blood vessel quantification at the epiretinal membrane

We evaluated a polarimetry method to enhance retinal blood vessels masked by the epiretinal membrane. Depolarized light images were computed by removing the polarization retaining light reaching the instrument and were compared with parallel polarized light images, average reflectance images, and the corresponding images at 514 nm. Contrasts were computed for retinal vessel profiles for arteries and veins. Contrasts were higher in the 514 nm images in normal eyes but higher in the depolarized light image in the eyes with epiretinal membranes. Depolarized light images were useful for examining the retinal vasculature in the presence of retinal disease.

Functional and morphological changes in the eyes of Behçet's patients with uveitis.

Purpose:u2002 Behçet’s disease (BD) is a chronic, recurrent, multisystem disorder, and serious ocular involvement may lead to blindness. In some BD patients, latent tissue damage caused by recurrent ocular inflammation is not reflected by visual acuity or ophthalmoscopic findings. In this study, we evaluated the morphological and functional changes of ocular features related to duration of uveitis from onset in BD patients, and analysed their association with visual acuity.