Association between choriocapillaris flow deficit and choroidal neovascularization activity in eyes with myopic choroidal neovascularization.

Although choriocapillaris flow deficit (CFD) around choroidal neovascularization (CNV) is less associated with CNV activity in myopic eyes, no reports are investigating its size as an indicator of CNV activity. We investigated the relationship between CFD and high myopia-related CNV. In this retrospective, observational study, patients underwent optical coherence tomography angiography (OCTA) with split-spectrum amplitude-decorrelation angiography for diagnosing pathological myopic CNV (mCNV); CFD features around CNV margins were evaluated. Of the 33 eyes (30 patients), 11 (33.3%) had active mCNV, and 22 (66.7%) had inactive CNV. Six eyes (18.2%) were treatment-naïve, while the remainder previously underwent anti-vascular endothelial growth factor therapy. On OCTA, blood flow signals were detected in CNV in the outer retinal layer in 28 (84.8%) eyes, including all active cases (11 cases) and 17 (77.3%) of 22 inactive cases. CNV flow signal size correlated significantly with activity (P < 0.001). CFD around CNV was observed in 24 eyes (72.7%), including all active cases (11 cases) and 13 (59.1%) of 22 inactive cases. CFD size correlated significantly with CNV activity (P < 0.001). The size of both the CFD area around CNV and CNV flow signal area are useful indicators of CNV activity in eyes with mCNV, which may help determine treatment timing.

Parallel detection of Jones-matrix elements in polarization-sensitive optical coherence tomography.

The polarization properties of a sample can be characterized using a Jones matrix. To measure the Jones matrix without assumptions of the sample, two different incident states of polarization are usually used. This requirement often causes certain drawbacks in polarization-sensitive optical coherence tomography (PS-OCT), e.g., a decrease in the effective A-scan rate or axial depth range, if a multiplexing scheme is used. Because both the A-scan rate and axial depth range are important for clinical applications, including the imaging of an anterior eye segment, a new PS-OCT method that does not have these drawbacks is desired. Here, we present a parallel-detection approach that maintains the same A-scan rate and axial measurement range as conventional OCT. The interferometer consists of fiber-optic components, most of which are polarization-maintaining components with fast-axis blocking free from polarization management. When a parallel detection is implemented using swept-source OCT (SS-OCT), synchronization between the A-scans and synchronization between the detection channels have critical effects on the Jones-matrix measurement. Because it is difficult to achieve perfect synchronization using only hardware, we developed a solution using a numerical correction with signals from a static mirror. Using the developed system, we demonstrate the imaging of an anterior eye segment from the cornea to the back surface of the crystalline lens.

Effect of intravitreal injection of aflibercept or ranibizumab on chorioretinal atrophy in myopic choroidal neovascularization.

PURPOSE: To compare chorioretinal atrophy (CRA) progression in myopic choroidal neovascularization (mCNV) between intravitreal injections of ranibizumab (IVR) and aflibercept (IVA) in the eyes with mCNV. METHODS: Thirty eyes (28 patients) with treatment-naïve mCNV were included in this study. IVR or IVA was administered for up to 1 year. The best-corrected visual acuity (BCVA) was measured, and fundus photographs and fundus autofluorescence were obtained before and 1, 3, 6, and 12 months after the initial treatment. The clinical characteristics including the macular choroidal thickness in various areas and CRA progression were compared between the drugs. The clinical characteristics and macular choroidal thicknesses were compared between eyes with and without CRA progression. RESULTS: The BCVA improved significantly (p < 0.05 for all comparisons) from 0.44 to 0.26, 0.19, 0.20, and 0.17 after 1, 3, 6, and 12 months, respectively. CRA progressed in 12 (40%) eyes over 1 year. The CRA progression did not differ significantly between aflibercept and ranibizumab. The foveal choroid was significantly (p = 0.0043) thinner in aflibercept-treated eyes compared with ranibizumab-treated eyes at 1 year. Subfoveal CNV tended to cause CRA progression more frequently at 1 year, although this did not reach significance. CONCLUSIONS: IVA to treat mCNV caused more severe thinning of the foveal choroid than ranibizumab; however, no significant difference was seen in CRA progression between the drugs and the choroidal thickness should not be associated with CRA progression. The CNV location may predict CRA progression after anti-vascular endothelial growth factor therapy for mCNV.

Polarization-Sensitive Optical Coherence Tomographic Documentation of Choroidal Melanin Loss in Chronic Vogt-Koyanagi-Harada Disease.

Purpose: Vogt-Koyanagi-Harada (VKH) disease is a systemic autoimmune disorder that affects organs with melanocytes. The sunset glow fundus (SGF) in VKH disease was evaluated with polarization-sensitive optical coherence tomography (PS-OCT). Methods: The study involved 28 eyes from 14 patients with chronic VKH disease, 21 eyes from 21 age-matched controls, and 22 eyes from 22 high-myopic patients with a tessellated fundus. VKH eyes were grouped into sunset or non-sunset groups on the basis of color fundus images. The presence of melanin in the choroid was determined by using the degree of polarization uniformity (DOPU) obtained by PS-OCT. The sunset glow index (SGI) was calculated by using color fundus images. Presence of an SGF was evaluated by using DOPU, SGI, subfoveal choroidal thicknesses, near-infrared images, and autofluorescence images at 488 nm (SW-AF) and 785 nm (NIR-AF). Results: There were 16 eyes in the sunset group and 12 eyes in the non-sunset group. For all eyes in the sunset group, the disappearance of choroidal melanin was clearly detected with PS-OCT. Percentage areas of low DOPU in the choroidal interstitial stroma of the sunset group were significantly lower than those of other groups and showed no overlap with other groups. The distribution of choroidal thicknesses and SGI in the sunset group substantially overlapped with other groups. The subjective analyses of the sunset and non-sunset groups, using near infrared, SW-AF, or NIR-AF, showed substantial inconsistencies with the PS-OCT results. Conclusions: PS-OCT provides an in vivo objective evaluation of choroidal melanin loss of the SGF in chronic VKH disease.

Features of the choriocapillaris in myopic maculopathy identified by optical coherence tomography angiography.

AIM: To describe the choriocapillaris features imaged by optical coherence tomography angiography (OCTA) in eyes with myopic maculopathy. METHODS: In this retrospective, non-invasive, observational case series, 26 eyes with myopic maculopathy and 12 age-matched healthy eyes underwent fluorescein angiography, indocyanine green angiography (ICGA) (highly myopic eyes only), OCT and OCTA, and the choriocapillaris features seen on OCTA and ICGA were compared. RESULTS: In all five (19%) eyes with patchy atrophy of the 26 highly myopic eyes, OCTA showed complete loss of the choriocapillaris and large choroidal vessels in the atrophic area. In nine (35%) eyes with diffuse atrophy in the atrophic area, OCTA showed low-density choriocapillaris in all eyes and medium and large choroidal vessels in seven (78%) eyes. In 23 eyes (88%) with lacquer cracks, OCTA showed partial loss of the choriocapillaris in 22 (96%) eyes in the area of the lacquer cracks. OCTA could not visualise the full length of the lacquer cracks in any eyes compared with ICGA. CONCLUSIONS: OCTA visualised the choriocapillaris clearly. The choriocapillaris features differed depending to the category of myopic maculopathy. In eyes with lacquer cracks, choriocapillaris rupture might be less advanced than the breaks in Bruch's membrane and retinal pigment epithelium.

Birefringence imaging of posterior eye by multi-functional Jones matrix optical coherence tomography.

A clinical grade prototype of posterior multifunctional Jones matrix optical coherence tomography (JM-OCT) is presented. This JM-OCT visualized depth-localized birefringence in addition to conventional cumulative phase retardation imaging through local Jones matrix analysis. In addition, it simultaneously provides a sensitivity enhanced scattering OCT, a quantitative polarization uniformity contrast, and OCT-based angiography. The probe beam is at 1-µm wavelength band. The measurement speed and the depth-resolution were 100,000 A-lines/s, and 6.6 µm in tissue, respectively. Normal and pathologic eyes are examined and several clinical features are revealed, which includes high birefringence in the choroid and lamina cribrosa, and birefringent layered structure of the sclera. The theoretical details of the depth-localized birefringence imaging and conventional phase retardation imaging are formulated. This formulation indicates that the birefringence imaging correctly measures a depth-localized single-trip phase retardation of a tissue, while the conventional phase retardation can provide correct single-trip phase retardation only for some specific types of samples.

Changes in axial length and choroidal thickness after intraocular pressure reduction resulting from trabeculectomy.

PURPOSE: To evaluate changes in axial length and choroidal thickness after trabeculectomy. PATIENTS AND METHODS: Fourteen patients under 80 years of age with glaucoma, were enrolled. The choroid was imaged using prototypical high-penetration optic coherence tomography (OCT) and the thickness was measured. Axial length, choroidal thickness, and intraocular pressure (IOP) were measured bilaterally at 3 pm 1 day before and 6 days after trabeculectomy. The choroidal thickness was measured at the fovea and four other locations (2 mm superior, temporal, inferior, and nasal to the center of the optic nerve head). RESULTS: The IOP and axial length significantly decreased in eyes that underwent trabeculectomy (P < 0.0001 for the IOP; P < 0.001 for axial length comparisons). The mean choroidal thicknesses significantly increased in eyes that underwent trabeculectomy compared to preoperatively (P < 0.0001 for the fovea; P < 0.01 for four locations around the optic disc). The mean magnitude of change in IOP was correlated positively with the mean magnitude of change in axial length, but not correlated with the mean magnitude of change in choroidal thickness at the fovea that underwent trabeculectomy. The sum of the axial length and subfoveal choroidal thickness in eyes decreased significantly postoperatively (P < 0.05). CONCLUSION: The axial length shortened, the choroid thickened, and the sum of the axial length and subfoveal choroidal thickness decreased with IOP reduction early after trabeculectomy.