Luiz Roisman

Optical Coherence Tomography Angiography of Asymptomatic Neovascularization in Intermediate Age-Related Macular Degeneration

PURPOSE To determine whether angiography with swept-source (SS) optical coherence tomography (OCT) identifies subclinical type 1 neovascularization in asymptomatic eyes with intermediate age-related macular degeneration (iAMD). DESIGN Prospective, observational, consecutive case series. PARTICIPANTS Patients with asymptomatic iAMD in one eye and neovascular age-related macular degeneration (AMD) in their fellow eye. METHODS The patients underwent SS OCT angiography (OCTA), fluorescein angiography (FA), and indocyanine green angiography (ICGA), and the images from these 3 angiographic techniques were compared. MAIN OUTCOME MEASURES Identification of subclinical type 1 neovascularization with SS OCTA in asymptomatic eyes with iAMD. RESULTS Eleven consecutive patients with iAMD in one eye and neovascular AMD in their fellow eye were imaged with FA, ICGA, and SS OCTA between August 2014 and September 2015. Clinical examination of the 11 eyes revealed drusen and pigmentary abnormalities in the central macula and no evidence of macular fluid on routine OCT imaging. Ten of the 11 eyes had no evidence of leakage on FA and 1 eye had questionable fluorescein leakage. Indocyanine green angiography revealed the presence of central macular plaques in 3 of the 11 asymptomatic eyes with iAMD, and SS OCTA revealed unambiguous type 1 neovascularization corresponding to the plaques in all 3 eyes. Optical coherence tomography angiography did not identify neovascularization in the remaining 8 eyes. CONCLUSIONS Swept-source OCTA identified type 1 neovascularization corresponding to ICGA plaques in asymptomatic eyes with iAMD. The ability of OCTA to provide noninvasive, fast, detailed, depth-resolved identification of nonexudative neovascular lesions in eyes with iAMD suggests the need for a new classification system that distinguishes between neovascular and nonneovascular iAMD.

ZEISS Angioplex™ Spectral Domain Optical Coherence Tomography Angiography: Technical Aspects

ZEISS Angioplex™ optical coherence tomography (OCT) angiography generates high-resolution three-dimensional maps of the retinal and choroidal microvasculature while retaining all of the capabilities of the existing CIRRUS™ HD-OCT Model 5000 instrument. Angioplex™ OCT angiographic imaging on the CIRRUS™ HD-OCT platform was made possible by increasing the scanning rate to 68,000 A-scans per second and introducing improved tracking software known as FastTrac™ retinal-tracking technology. The generation of en face microvascular flow images with Angioplex™ OCT uses an algorithm known as OCT microangiography-complex, which incorporates differences in both the phase and intensity information contained within sequential B-scans performed at the same position. Current scanning patterns for en face angiographic visualization include a 3 × 3 and a 6 × 6 mm scan pattern on the retina. A volumetric dataset showing erythrocyte flow information can then be displayed as a color-coded retinal depth map in which the microvasculature of the superficial, deep, and avascular layers of the retina are displayed together with the colors red, representing the superficial microvasculature; green, representing the deep retinal vasculature; and blue, representing any vessels present in the normally avascular outer retina. Each retinal layer can be viewed separately, and the microvascular layers representing the choriocapillaris and the remaining choroid can be viewed separately as well. In addition, readjusting the contours of the slabs to target different layers of interest can generate custom en face flow images. Moreover, each en face flow image is accompanied by an en face intensity image to help with the interpretation of the flow results. Current clinical experience with this technology would suggest that OCT angiography should replace fluorescein angiography for retinovascular diseases involving any area of the retina that can be currently scanned with the CIRRUS™ HD-OCT instrument and may replace fluorescein angiography and indocyanine green angiography for some choroidal vascular diseases.

SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF NEOVASCULAR MACULAR TELANGIECTASIA TYPE 2.

Background/Purpose: To image subretinal neovascularization in proliferative macular telangiectasia Type 2 (MacTel2) using swept source optical coherence tomography based microangiography (OMAG). Methods: Patients with macular telangiectasia Type 2 were enrolled in a prospective, observational study known as the MacTel Project and evaluated using a high-speed 1,050 nm swept-source OCT prototype system. The OMAG algorithm generated en face flow images from three retinal layers, and the region bounded by the outer retina and Bruch membrane, the choriocapillaris, and the remaining choroidal vasculature. The en face OMAG images were compared with images from fluorescein angiography and indocyanine green angiography. Results: Three eyes with neovascular macular telangiectasia Type 2 were imaged. The neovascularization was best identified from the en face OMAG images that included a layer between the outer retinal boundary and Bruch membrane. Optical coherence tomography based microangiography images identified these abnormal vessels better than fluorescein angiography and were comparable to the images obtained using indocyanine green angiography. In all 3 cases, OMAG identified choroidal vessels communicating with the neovascularization, and these choroidal vessels were evident in the 2 cases with indocyanine green angiography imaging. In 1 case, monthly injections of bevacizumab reduced the microvascular complexity of the neovascularization, and the telangiectatic changes within the retinal microvasculature. In another case, less frequent bevacizumab therapy was associated with growth of the subretinal neovascular complex. Conclusion: Optical coherence tomography based microangiography imaging provided detailed, depth-resolved information about subretinal neovascularization in macular telangiectasia Type 2 eyes demonstrating superiority to fluorescein angiography imaging, and similarities to indocyanine green angiography imaging for documenting the retinal microvascular changes, the size and extent of the neovascular complex, the communications between the neovascular complex and the choroidal circulation, and the response to monthly bevacizumab therapy.

Micropulse diode laser treatment for chronic central serous chorioretinopathy: a randomized pilot trial.

BACKGROUND AND OBJECTIVE To evaluate 810-nm subthreshold diode micropulse (SDM) laser in patients with chronic central serous chorioretinopathy (CSC). PATIENTS AND METHODS Prospective, randomized, double-blind, sham-controlled pilot trial. Patients were randomized to SDM laser treatment (group 1) or sham procedure (group 2). Primary outcome measure was change in best corrected visual acuity (BCVA); secondary outcome was central macular thickness after 3 months. Laser treatment was performed along the detached area. At the 3-month visit, all patients were evaluated for re-treatment if they met re-treatment criteria. RESULTS Fifteen patients were included in this study: five patients in the sham group and 10 in the treatment group. At 3 months, BCVA was significantly enhanced in the treatment group (P = .006) compared with the sham group (P = .498). All patients from the sham group needed treatment after 3 months. An improvement in central macular thickness and leakage on fluorescein angiography was noted in all treated patients (in both groups). CONCLUSION In this limited-size, short-term exploratory study, SDM laser was effective in treating chronic CSC. There was no evidence of retinal damage induced by treatment.

Comparison Between Spectral-Domain and Swept-Source Optical Coherence Tomography Angiographic Imaging of Choroidal Neovascularization

Purpose The purpose of this study was to compare imaging of choroidal neovascularization (CNV) using swept-source (SS) and spectral-domain (SD) optical coherence tomography angiography (OCTA). Methods Optical coherence tomography angiography was performed using a 100-kHz SS-OCT instrument and a 68-kHz SD-OCTA instrument (Carl Zeiss Meditec, Inc.). Both 3 × 3- and 6 × 6-mm2 scans were obtained on both instruments. The 3 × 3-mm2 SS-OCTA scans consisted of 300 A-scans per B-scan at 300 B-scan positions, and the SD-OCTA scans consisted of 245 A-scans at 245 B-scan positions. The 6 × 6-mm2 SS-OCTA scans consisted of 420 A-scans per B-scan at 420 B-scan positions, and the SD-OCTA scans consisted of 350 A-scans and 350 B-scan positions. B-scans were repeated four times at each position in the 3 × 3-mm2 scans and twice in the 6 × 6-mm2 scans. Choroidal neovascularization was excluded if not fully contained within the 3 × 3-mm2 scans. The same algorithm was used to detect CNV on both instruments. Two graders outlined the CNV, and the lesion areas were compared between instruments. Results Twenty-seven consecutive eyes from 23 patients were analyzed. For the 3 × 3-mm2 scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.17 and 1.01 mm2, respectively (P = 0.047). For the 6 × 6-mm2 scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.24 and 0.74 mm2 (P = 0.003). Conclusions The areas of CNV tended to be larger when imaged with SS-OCTA than with SD-OCTA, and this difference was greater for the 6 × 6-mm2 scans.

Clinical factors related to visual outcome in central serous chorioretinopathy.

Purpose: The purpose of this study was to describe clinical, angiographic, and tomo-graphic prognostic factors in central serous chorioretinopathy. Methods: This is a prospective uncontrolled case series. Forty-six eyes (43 patients) with clinical and angiographic findings consistent with central serous chorioretinopathy were included. Clinical data regarding age, sex, duration of symptoms, associated conditions, and best-corrected visual acuity (BCVA) were collected at baseline. Optical coherence tomography was performed at baseline, monthly until fluid resolution occurred, and at the end of the follow-up. Results: Mean follow-up was 22.8 months. Mean baseline and final logarithm of the minimum angle of resolution BCVA were 0.3 and 0.12 (P < 0.0001), respectively. Statistically significant correlations were observed between the baseline BCVA as well as duration of symptoms and final BCVA. Angiographic patterns were not significantly correlated with the visual outcome. Shorter periods of subfoveal fluid during the follow-up were correlated with better visual acuity. Mean foveal thickness after fluid resolution was 178 ± 22 μm. Both baseline and final BCVA were strongly correlated with the foveal thickness after fluid resolution. Conclusion: Initial BCVA may be a reliable predictor of the visual outcome in central serous chorioretinopathy. Eyes with worse BCVA may have an increased risk of foveal atrophy. Fluid persistence on optical coherence tomography may be associated with worse visual prognosis.

Automated Quantitation of Choroidal Neovascularization: A Comparison Study Between Spectral-Domain and Swept-Source OCT Angiograms

Purpose To compare the lesion sizes of choroidal neovascularization (CNV) imaged with spectral-domain (SD) and swept-source (SS) optical coherence tomography angiography (OCTA) and measured using an automated detection algorithm. Methods Patients diagnosed with CNV were imaged by SD-OCTA and SS-OCTA systems using 3 × 3-mm and 6 × 6-mm scans. The complex optical microangiography (OMAGC) algorithm was used to generate the OCTA images. Optical coherence tomography A datasets for imaging CNV were derived by segmenting from the outer retina to 8 μm below Bruchs membrane. An artifact removal algorithm was used to generate angiograms free of retinal vessel projection artifacts. An automated detection algorithm was developed to quantify the size of the CNV. Automated measurements were compared with manual measurements. Measurements from SD-OCTA and SS-OCTA instruments were compared as well. Results Twenty-seven eyes from 23 subjects diagnosed with CNV were analyzed. No significant differences were detected between manual and automatic measurements: SD-OCTA 3 × 3-mm (P = 0.61, paired t-test) and 6 × 6-mm (P = 0.09, paired t-test) scans and the SS-OCTA 3 × 3-mm (P = 0.41, paired t-test) and 6 × 6-mm (P = 0.16, paired t-test) scans. Bland-Altman analyses were performed to confirm the agreement between automatic and manual measurements. Mean lesion sizes were significantly larger for the SS-OCTA images compared with the SD-OCTA images: 3 × 3-mm scans (P = 0.011, paired sample t-test) and the 6 × 6-mm scans (P = 0.021, paired t-test). Conclusions The automated algorithm measurements of CNV were in agreement with the hand-drawn measurements. On average, automated SS-OCTA measurements were larger than SD-OCTA measurements and consistent with the results from using hand-drawn measurements.

Fundus Autofluorescence and Spectral Domain OCT in Central Serous Chorioretinopathy

Background. To describe the standard autofluorescence (FAF), the near infrared autofluorescence (NIA) and optical coherence tomography (OCT) patterns in central serous chorioretinopathy, correlating them with fluorescein angiography. Methods. Cross-sectional observational study, in which patients with at least seven months of CSC underwent ophthalmologic examination, fundus photography, FAF, NIA, fluorescein angiography (FA), and spectral-domain OCT. Results. Seventeen eyes of thirteen patients were included. The presentation features were a mottled hyperFAF in the detached area and areas with pigment mottling. NIA images showed areas of hyperNIA similar to FAF and localized areas of hypoNIA, which correlated with the points of leakage in the FA. OCT showed pigment epithelium detachment at the location of these hypoNIA spots. Discussion. FAF showed increased presence of fluorophores in the area of retinal detachment, which is believed to appear secondary to lipofuscin accumulation in the RPE or the presence of debris in the subretinal fluid. NIA has been related to the choroidal melanin content and there were areas of both increased and decreased NIA, which could be explained by damage ahead the retina, basically RPE and choroid. These findings, along with the PEDs found in the areas of hypoNIA, support the notion of a primary choroidal disease in CSC.

Optical Coherence Tomography Angiography of Macular Telangiectasia Type 2

Macular telangiectasia type 2 (MacTel2) is a disease of the central macula that affects all microvascular layers of the retina and also includes neovascularization arising from both the retinal and choroidal circulations. As a result, MacTel2 is the ideal macular disease for imaging with optical coherence tomography (OCT) angiography (OCTA). In MacTel2, the earliest changes in the retinal microvasculature involve the temporal aspect of the parafoveal deep capillary plexus, and OCTA reveals these changes. Microvascular abnormalities then extend circumferentially around the fovea and into the superficial capillary plexus. As the disease progresses, dilated anastomoses form between the superficial and deep capillary plexuses, and the retina becomes more atrophic, with the formation of cysts and the loss of photoreceptor outer segments. In some patients, the anastomoses between the plexuses progress to subretinal neovascularization, with connections to the choroidal vasculature. OCTA provides clear advantages over current imaging modalities, such as traditional OCT imaging, reflectance fundus imaging, autofluorescence imaging, fluorescein angiography, and indocyanine green angiography, for MacTel2 because it is safer, cheaper, more comfortable for the patient, and more easily repeatable, it can be performed during follow-up visits, and it produces both intensity-based OCT images and flow-based images, which allow for visualization of the macular microvasculature. OCTA is the only imaging modality needed for the diagnosis and monitoring of MacTel2 at every stage of disease progression.

Projection Artifact Removal Improves Visualization and Quantitation of Macular Neovascularization Imaged by Optical Coherence Tomography Angiography

PURPOSE To visualize and quantify the size and vessel density of macular neovascularization (MNV) using optical coherence tomography angiography (OCTA) with a projection artifact removal algorithm. DESIGN Multicenter, observational study. PARTICIPANTS Subjects with MNV in at least one eye. METHODS Patients were imaged using either a swept-source OCT angiography (SS-OCTA) prototype system or a spectral-domain OCT angiography (SD-OCTA) prototype system. The optical microangiography (OMAG) algorithm was used to generate the OCTA images. Projection artifacts from the overlying retinal circulation were removed from the OMAG OCTA images using a novel algorithm. Following removal of the projection artifacts from the OCTA images, we assessed the size and vascularity of the MNV. Concurrent fluorescein angiography (FA) and indocyanine green angiography (ICGA) images were used to validate the artifact-free OMAG images whenever available. MAIN OUTCOME MEASURES Size and vascularity of MNV imaged with OCTA before and after the use of a projection-artifact removal algorithm. RESULTS A total of 30 subjects (40 eyes) diagnosed with MNV were imaged. Five patients were imaged before and after intravitreal injections of vascular endothelial growth factor (VEGF) inhibitors. Following the use of the projection artifact removal algorithm, we found improved visualization of the MNV. Lesion sizes and vascular densities were more easily measured on all the artifact-free OMAG images. In eyes treated with vascular endothelial growth factor inhibitors, vascular density was reduced in all five eyes after treatment, and in four eyes, the size of the MNV decreased. One of five patients showed a slight increase in lesion size, but a decrease in vascular density. CONCLUSIONS OCTA imaging of MNV using the OMAG algorithm combined with removal of projection artifacts resulted in improved visualization and measurements of the neovascular lesions. OMAG with projection artifact removal should be useful for assessing the response of MNV to treatment using OCTA imaging.