Shin Yoshitake

Focal Choroidal Excavation in Eyes With Central Serous Chorioretinopathy

PURPOSE To study the prevalence and 3-dimensional (3-D) tomographic features of focal choroidal excavations in eyes with central serous chorioretinopathy (CSC) using swept-source optical coherence tomography (OCT). DESIGN Prospective, cross-sectional study. METHODS We examined 116 consecutive eyes with CSC with a prototype 3-D swept-source OCT. 3-D images of the shape of the macular area, covering 6 × 6 mm(2), were reconstructed by segmentation of the outer surface of the retinal pigment epithelium (RPE). RESULTS The 3-D swept-source OCT detected focal choroidal excavations in 9 eyes (7.8%). The 3-D scanning protocol, coupled with en face scans, allowed for clear visualization of the excavation morphology. In 5 eyes with focal excavations, unusual choroidal tissue was found beneath the excavation, bridging the bottom of the excavation and the outer choroidal boundary. Additionally, 3 of those 5 eyes showed a suprachoroidal space below the excavation, as if the outer choroidal boundary is pulled inward by this bridging tissue. The focal choroidal excavations were located within fluorescein leakage points and areas of choroidal hyperpermeability. Eyes with focal choroidal excavations were more myopic (-4.42 ± 2.92 diopters) than eyes without excavations (-0.27 ± 1.80 diopters, P = .001). Subfoveal choroidal thickness was significantly thinner (301.3 ± 60.1 μm) in eyes with focal excavations than in eyes without the excavations (376.6 ± 104.8 μm, P = .036). CONCLUSIONS Focal choroidal excavations were present in 7.8% of eyes with CSC. In these eyes, focal choroidal excavations may have formed from RPE retraction caused by focal scarring of choroidal connective tissue.

Retinal Hemorheologic Characterization of Early-Stage Diabetic Retinopathy Using Adaptive Optics Scanning Laser Ophthalmoscopy

PURPOSE Adaptive optics scanning laser ophthalmoscopy (AO-SLO) is a noninvasive technique that allows for the direct monitoring of erythrocyte aggregates in retinal capillaries. We analyzed the retinal hemorheologic characteristics in normal subjects, diabetic patients without diabetic retinopathy (NDR), and diabetic patients with nonproliferative diabetic retinopathy (NPDR), using spatiotemporal (ST) blood flow images to visualize blood corpuscle trajectory. METHODS AO-SLO images of the parafoveal capillary network were acquired for three groups: 20 healthy volunteers, 17 diabetic patients with NDR (8 type 1 and 9 type 2 patients), and 10 diabetic patients with NPDR (4 type 1 and 6 type 2). The erythrocyte aggregate velocity assigned to a relative cardiac cycle and the elongation rate of the erythrocyte aggregate were calculated. RESULTS Careful observation revealed that flow velocity fluctuations were found with higher frequency in diabetic patients than in normal subjects. The total average velocities were 1.26 ± 0.22 mm/s in the normal group, 1.31 ± 0.21 mm/s in the NDR group, and 1.63 ± 0.35 mm/s in the NPDR group. The average velocities of the NPDR group were higher than those in the normal (P = 0.001) and NDR (P = 0.009) groups. The average elongation rates of the 3 groups were 0.67 ± 0.20, 0.39 ± 0.19, and 0.33 ± 0.11, respectively. Elongation rate differed significantly between the normal and NDR (P = 0.003) groups as well as the normal and NPDR (P = 0.001) groups. CONCLUSIONS AO-SLO can be used to detect retinal hemorheologic changes in the early stages of diabetic retinopathy.

Relationship between Functional and Structural Changes in Diabetic Vessels in Optical Coherence Tomography Angiography

The decorrelation signals in optical coherence tomography angiography (OCTA) are derived from the flow of erythrocytes and concomitantly delineate the retinal vasculature. We compared the structural and functional characteristics of vascular lesions visualized in fluorescein angiography (FA), OCTA, and en-face OCT images in 53 eyes (28 patients) with diabetic retinopathy (DR). The foveal avascular zone (FAZ) areas in OCTA images in the superficial layer almost corresponded to those in FA images. The FAZ areas in the en-face OCT images in the superficial layer were smaller than those in the FA images and correlated with each other, which agreed with the finding that en-face OCT images often delineated the vascular structure in the nonperfused areas in FA images. Microaneurysms appeared as fusiform, saccular, or coiled capillaries in OCTA images and ringed, round, or oval hyperreflective lesions in en-face OCT images. OCTA and en-face OCT images detected 41.0 ± 16.1% and 40.1 ± 18.6%, respectively, of microaneurysms in FA images, although both depicted only 13.9 ± 16.4%. The number of microaneurysms in FA images was correlated with that in OCTA and en-face OCT images. Comparisons of these modalities showed the associations and dissociations between blood flow and vascular structures, which improves the understanding of the pathogenesis of DR.

Disorganized retinal lamellar structures in nonperfused areas of diabetic retinopathy.

PURPOSE To investigate morphologic changes on spectral-domain optical coherence tomography (SD-OCT) images in nonperfused areas (NPAs) in diabetic retinopathy (DR). METHODS One hundred eight consecutive eyes of 80 patients with diabetic ischemic maculopathy were retrospectively reviewed. The boundary between the nerve fiber layer (NFL) and the ganglion cell layer (GCL)/inner plexiform layer (IPL) and the status of Henles layer were characterized on the vertical sectional images of SD-OCT. These findings were compared with the NPAs on the FA images and the logMAR visual acuity (VA). RESULTS The SD-OCT images showed that most areas of capillary nonperfusion had an indistinct boundary between the NFL and GCL/IPL in DR, regardless of high or moderate OCT reflectivity. The total transverse length of the NPAs was correlated positively with that of the areas with no boundary between these layers in all 108 eyes (R = 0.860, P < 0.001). Sixty-four eyes that had center-involved diabetic macular edema (DME) also had a significant association between them (R = 0.764, P < 0.001), and the most significant correlation was seen in eyes without DME (R = 0.955, P < 0.001). The macular transverse length of the areas with no boundary between the NFL and GCL/IPL was associated modestly with the logMAR VA (R = 0.334, P < 0.001). The indistinct Henles layer on SD-OCT images often was delineated specifically in the NPAs rather than in the perfused areas. CONCLUSIONS Nonperfused areas were associated significantly with the absence of a boundary between the NFL and GCL/IPL on SD-OCT images in DR.

Single-nucleotide polymorphisms in the promoter region of matrix metalloproteinase-1, -2, and -3 in Japanese with high myopia

PURPOSE Polymorphisms in the promoter regions of matrix metalloproteinase (MMP) genes can cause variations in the expression of the MMP genes in the sclera that can lead to a greater susceptibility to axial elongation of the eye. The purpose of this study was to determine whether functional single-nucleotide polymorphisms (SNPs) in the MMP1, -2, and -3 promoter regions are associated with high myopia in the Japanese. METHODS Seven hundred twenty-five unrelated Japanese patients with high myopia (axial length of >or=26.0 mm in both eyes, or refractive error>or=-6.0 D in phakic cases) and >or=40 years of age were studied. Five hundred forty-six healthy, unrelated Japanese who were >or=40 years of age served as population-based control subjects. All the subjects were genotyped for the four functional SNPs MMP1 -1607 1G/2G, MMP2 C-1306T, MMP2 C-735T, and MMP3 -1612 5A/6A with an SNP assay. The distribution of the genotypes in the cases and control subjects was compared by the chi2 test for trend. RESULTS No significant difference was detected in the distribution of the four SNPs MMP1 -1607 1G/2G (P=0.92), MMP2 C-1306T (P=0.83), MMP2 C-735T (P=0.10), and MMP3 -1612 5A/6A (P=0.62), between the high myopia cases and the general-population controls. CONCLUSIONS The four functional SNPs in the MMP1, -2, and -3 promoter regions do not play critical roles in the development of high myopia in the Japanese population.

Association between perifoveal hyperfluorescence and serous retinal detachment in diabetic macular edema.

OBJECTIVE To study the association between the fluorescence levels on fluorescein angiography images and the characteristics on spectral-domain optical coherence tomography (SD OCT) images in diabetic macular edema (DME). DESIGN Retrospective, observational, cross-sectional study. PARTICIPANTS One hundred sixty-seven consecutive eyes of 116 patients with diabetic retinopathy for whom FA and SD OCT were performed on the same day. METHODS Fluorescein angiography using the Heidelberg Retina Angiograph 2 and OCT images using Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were obtained. The leakage of fluorescein dye in each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid was quantified and defined as fluorescence levels, which were compared with the retinal thickness and foveal pathomorphologic features evaluated by SD OCT. MAIN OUTCOME MEASURES The relationship between fluorescence levels and the foveal pathomorphologic features on SD OCT images. RESULTS One hundred twelve (67%) eyes with center-involved DME had significantly higher fluorescence levels in all subfields of the ETDRS grid than 55 (33%) eyes without DME. Fluorescence levels were correlated modestly with the retinal thickness in individual subfields in eyes with center-involved DME. Thirty-seven eyes with foveal serous retinal detachment (SRD) had greater retinal thickness in all subfields and higher levels of fluorescence in most subfields, except the superior subfield of the inner ring. After adjusting for the central retinal thickness using multivariate analyses, eyes with SRD had significantly (P = 0.0085) higher fluorescence levels in the nasal subfield of the inner ring and the superior, nasal, and inferior subfields of the outer ring (P = 0.0117, P = 0.0020, and P = 0.0017, respectively). However, the fluorescence levels in any subfields of the inner or outer ring did not differ significantly between eyes with and without foveal cystoid spaces. CONCLUSIONS The correlation between the fluorescence levels and retinal thickness suggests that the vascular hyperpermeability in the perifovea contributes to the pathogenesis of foveal SRD in DME.

Qualitative and Quantitative Characteristics of Near-Infrared Autofluorescence in Diabetic Macular Edema

OBJECTIVE To study the characteristics of near-infrared autofluorescence (NIR-AF) imaging and its association with spectral-domain optical coherence tomography (SD-OCT) findings and logarithm of the minimal angle of resolution (logMAR) visual acuity (VA) in diabetic macular edema (DME). DESIGN Retrospective, observational, cross-sectional study. PARTICIPANTS One hundred twenty-one consecutive eyes of 87 patients with center-involved DME for whom NIR-AF and SD-OCT images of sufficient quality were obtained. METHODS The NIR-AF images were acquired using Heidelberg Retina Angiograph 2 (Heidelberg Engineering, Heidelberg, Germany), and sectional retinal images were obtained using Spectralis OCT (Heidelberg Engineering). The presence of a mosaic pattern and cystoid signs were determined qualitatively. We quantified the average fluorescence intensity in the central 1-mm subfield. The characteristics of the NIR-AF images were compared with the OCT findings and logMAR VA. MAIN OUTCOME MEASURES Qualitative and quantitative characteristics of the NIR-AF images and their association with SD-OCT findings and logMAR VA. RESULTS Fifty-seven eyes with a mosaic pattern in the NIR-AF macular images had worse logMAR VA (0.355±0.239 vs. 0.212±0.235; P = 0.001), a thicker central subfield (CSF) (530±143 μm vs. 438±105 μm; P <0.001), and disrupted external limiting membrane (ELM; P <0.001) compared with 64 eyes without these findings. Forty-one eyes with a cystoid sign in the NIR-AF images had worse logMAR VA (0.393±0.233 vs. 0.221±0.234; P <0.001) and a thicker CSF (557±155 μm vs. 443±100 μm; P <0.001) than those without them; there were no significant differences in the ELM status. The relative fluorescence intensity in the central subfield in the NIR-AF images was correlated negatively with the CSF thickness and logMAR VA (R = 0.492, P <0.001 and R = 0.377, P <0.001, respectively). Eyes with foveal serous retinal detachment had lower levels of relative fluorescence intensity than those without it (0.751±0.191 vs. 0.877±0.154; P = 0.007); there was no association with the presence of foveal cystoid spaces, disrupted ELM, or hyperreflective foci in the outer retinal layers. CONCLUSIONS Novel qualitative and quantitative NIR-AF characteristics in the macula indicated the clinical relevance and suggested the pathogenesis in DME.

In Vivo Choroidal Vascular Lesions in Diabetes on Swept-Source Optical Coherence Tomography.

Diabetes induces microvascular diseases including diabetic retinopathy and choroidopathy which reciprocally promote the pathogenesis, although optical coherence tomography images of diabetic choroidopathy remains to be documented. Here we evaluated the qualitative characteristics of choroidal vascular lesions in patients with diabetes and their association with diabetic retinopathy on swept-source optical coherence tomography (SS-OCT) images. We retrospectively reviewed 110 consecutive eyes of 110 patients with diabetes and 35 eyes of 35 healthy subjects for whom SS-OCT images (6x6-mm scans centered on the fovea) of sufficient quality were acquired. The curve of chorioretinal sections was flattened using Bruch’s membrane as a reference surface, followed by generation of en-face images. We characterized choroidal vascular lesions and evaluated their association with the logarithm of the minimum angle of resolution visual acuity (logMAR VA), retinal and choroidal thicknesses, and diabetic retinopathy severity. En-face SS-OCT images showed unvisualized vessels in Sattler’s layer in 33 eyes (30.0%). Focal narrowing was seen in choroidal vessels in Haller’s layer in 56 eyes (50.9%). The choroidal vessels ended in the superficial or middle portion of Haller’s layer, referred to as vascular stumps, in 20 eyes (18.2%). Diabetic eyes had these findings more frequently than nondiabetic eyes. The subfoveal choroid was thicker in eyes with focal vascular narrowing and vascular stumps than in eyes without such lesions. Vascular stumps in Haller’s layer were significantly related to diabetic retinopathy severity, logMAR VA, and central retinal and choroidal thicknesses. These novel findings on SS-OCT images would promote the better understanding of complicated pathogenesis in diabetic retinopathy and choroidopathy.

Clinical relevance of quantified fundus autofluorescence in diabetic macular oedema

PurposeTo quantify the signal intensity of fundus autofluorescence (FAF) and evaluate its association with visual function and optical coherence tomography (OCT) findings in diabetic macular oedema (DMO).MethodsWe reviewed 103 eyes of 78 patients with DMO and 30 eyes of 22 patients without DMO. FAF images were acquired using Heidelberg Retina Angiograph 2, and the signal levels of FAF in the individual subfields of the Early Treatment Diabetic Retinopathy Study grid were measured. We evaluated the association between quantified FAF and the logMAR VA and OCT findings.ResultsOne hundred and three eyes with DMO had lower FAF signal intensity levels in the parafoveal subfields compared with 30 eyes without DMO. The autofluorescence intensity in the parafoveal subfields was associated negatively with logMAR VA and the retinal thickness in the corresponding subfields. The autofluorescence levels in the parafoveal subfield, except the nasal subfield, were lower in eyes with autofluorescent cystoid spaces in the corresponding subfield than in those without autofluorescent cystoid spaces. The autofluorescence level in the central subfield was related to foveal cystoid spaces but not logMAR VA or retinal thickness in the corresponding area.ConclusionsQuantified FAF in the parafovea has diagnostic significance and is clinically relevant in DMO.

Clinical relevance of reduced decorrelation signals in the diabetic inner choroid on optical coherence tomography angiography

Diabetes induces lesions of the retinal and choroidal capillaries, which promote the pathogenesis of diabetic retinopathy (DR). The decorrelation signals in optical coherence tomography angiography (OCTA) represent the blood flow and vascular structure, and three-dimensional OCTA images enable individual capillary layers to be evaluated separately. The current study documented that en-face OCTA images revealed spots of flow void in the choriocapillaris layer in eyes with DR. Quantitative investigation demonstrated that non-flow areas within the central subfield (CSF) increased in eyes with more severe DR grades. The non-flow areas in the choriocapillaris layer were also associated with poorer visual acuity (VA) in all 108 eyes. A modest correlation was noted between the areas of flow void and poorer VA in 69 eyes without DME, whereas the non-flow areas were not related to VA or to CSF thickness measured by OCT in 39 eyes with DME. In 12 eyes with ischemic maculopathy, the choriocapillaris layer beneath the disrupted ellipsoid zone of the photoreceptor (EZ) had greater areas of flow void than did the area beneath an intact EZ. These data suggested that disrupted choroidal circulation has clinical relevance and contributes to the pathogenesis of DR.