Natural History of Subclinical Neovascularization in Nonexudative Age-Related Macular Degeneration Using Swept-Source OCT Angiography.

PURPOSE: Swept-source (SS) OCT angiography (OCTA) was used to determine the prevalence, incidence, and natural history of subclinical macular neovascularization (MNV) in eyes with nonexudative age-related macular degeneration (AMD). DESIGN: Prospective, observational, consecutive case series. PARTICIPANTS: Patients with intermediate AMD (iAMD) or geographic atrophy (GA) secondary to nonexudative AMD in 1 eye and exudative AMD in the fellow eye. METHODS: All patients were imaged using both the 3×3 mm and 6×6 mm SS OCTA fields of view (PLEX Elite 9000; Carl Zeiss Meditec, Inc, Dublin, CA). The en face slab used to detect the MNV extended from the outer retina to the choriocapillaris, and projection artifacts were removed using a proprietary algorithm. MAIN OUTCOME MEASURES: Prevalence of subclinical MNV and time to exudation with Kaplan-Meier cumulative estimates of exudation at 1 year. RESULTS: From August 2014 through March 2017, 160 patients underwent SS OCTA (110 eyes with iAMD and 50 eyes with GA). Swept-source OCTA identified subclinical MNV at the time of first imaging in 23 of 160 eyes, for a prevalence of 14.4%. Six eyes demonstrated subclinical MNV during the follow-up. Of 134 eyes with follow-up visits, a total of 13 eyes demonstrated exudation, and of these 13 eyes, 10 eyes were found to have pre-existing subclinical MNV. By 12 months, the Kaplan-Meier cumulative incidence of exudation for all 134 eyes was 6.8%. For eyes with subclinical MNV at the time of first SS OCTA imaging, the incidence was 21.1%, and for eyes without subclinical MNV, the incidence was 3.6%. There was no difference in the cumulative incidence of exudation from pre-existing MNV in eyes with iAMD or GA (P = 0.847, log-rank test). After the detection of subclinical MNV, the risk of exudation was 15.2 times (95% confidence interval, 4.2-55.4) greater compared with eyes without subclinical MNV. CONCLUSIONS: By 12 months, the risk of exudation was greater for eyes with documented subclinical MNV compared with eyes without detectable MNV. For eyes with subclinical MNV, recommendations include more frequent follow-up and home monitoring. Intravitreal therapy is not recommended until prospective studies are performed.

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.

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.

Does microperimetry have a prognostic value in central serous chorioretinopathy?

PURPOSE: To investigate the relationship between retinal sensitivity and persistence of subretinal fluid and then to analyze microperimetry as a prognostic predictor of acute central serous chorioretinopathy. METHODS: A prospective observational study. Fourteen eyes of 14 patients presenting with first episode acute central serous chorioretinopathy were enrolled and underwent ocular examination, spectral domain optical coherence tomography, and MAIA microperimetry were performed. After three months of follow-up, without any treatment, visual acuity and spectral domain optical coherence tomography macular thickness assessments and microperimetry were repeated. The main outcome was to find a relation between initial macular sensitivity and persistence of subretinal fluid. A receiver operating characteristic curve was plotted to indicate the best macular sensitivity cutoff point that would be able to predict whether a patient with acute central serous chorioretinopathy would progress to the chronic form. According to the cutoff, we calculated the sensitivity, specificity, and positive and negative predictive values for macular sensitivity as a method to predict persistence of subretinal fluid. RESULTS: On the basis of the receiver operating characteristic curve, a cutoff of 20 dB macular sensitivity was obtained, as the best balance between sensitivity and specificity to predict chronicity. Using this cutoff, the method had a sensitivity of 71% and specificity of 100% with a positive predictive value of 100% and negative predictive value of 78%. Furthermore, it was found that eyes with acute central serous chorioretinopathy and microperimetry of less than 20 dB had a relative risk of 4.5 to develop subretinal fluid persistence. CONCLUSION: Microperimetry with a cutoff of 20 dB may be a useful test to predict the persistence of subretinal fluid, allowing the ophthalmologist to use treatment tools earlier, preventing extracellular damage and visual impairment.

Choroidal nevus through a broader vision: Retinal imaging acquisition captured with Broad Line Fundus Imaging technology.

OBJECTIVE: To describe the peculiarities in imaging acquisition of fourteen patients with choroidal nevus using the Broad Line Fundus Imaging (BLFI) technology. METHODS: Single-center, retrospective, cross-sectional analysis. RESULTS: All images were acquired using the BLFI technology. We have found that choroidal nevus is undetectable in the blue channel (BC) (435-500 nm) and the green channel (GC) (500-585 nm). The only visible changes are related to the drusen, which appeared in BC and GC as light focal dots, correlated to the yellowish foci in the true-color image. On the red channel (RC) (585-640 nm), all lesions revealed the same pattern: a well-defined dark spot, with enhanced contrast, allowing the better visualization, measuring, and characterization of the nevus when compared with the other color channels, including the true-color imaging. CONCLUSION: BLFI application in choroidal nevus might be helpful at presentation, refining the diagnostic reliability, and monitoring, as it allows for better detection of alterations in the lesions. The peculiarities of the choroidal nevus are better assessed when using the RC due to its longer wavelength and deeper penetration in the retina and choroid.

Current practices and profiles of ophthalmologists involved in retinopathy of prematurity care in Brazil.

Retinopathy of prematurity (ROP) care in Brazil varies in availability of resources and infrastructure. A cross-sectional survey was conducted among ophthalmologists of the Brazilian ROP Group (BRA-ROP) to assess the profiles and practices of ophthalmologists involved in ROP care. A total of 78 responses of BRA-ROP participants (79%) were included. Participants were mostly retina experts (64.1%), female (65.4%), and over 40 years of age (60.2%). Eighty-six percent reported following Brazil's ROP screening criteria. Retinal imaging is available to 16.9% of respondents; fluorescein angiography, to 1.4%. For ROP stage 3 zone II (with plus disease), laser treatment was the preferred treatment (78.9%); for aggressive ROP, anti-VEGF was favored (66.2%). There were significant regional differences in treatment choice. Not all respondents continued to follow treated patients after discharge from the neonatal intensive care unit, highlighting an aspect of ROP care in need of improvement.

Autoimmune Retinopathy, Testing, and Its Controversies.

Purpose of review: The purpose of this revision is to sumarize the most important clinical features of the autoimune retinopathies (AIRs). Recent findings: AIRs are a group of inflammatory conditions affecting the retina characterized by progressive unexplained visual loss, abnormalities and contraction in visual fields, photoreceptor and electroretinographic dysfunction, and the presence of circulating anti-retinal antibodies. The pathogenesis of AIR remains unclear and various antiretinal antibodies have been associated to the disease. The diagnosis of AIR is based on a particular clinical presentation along with the detection of serum antiretinal antibodies. Numerous anti-inflammatory therapeutic alternatives have been described for the treatment of AIR, nevertheless there is no consensus on treatment protocol. Summary: Because of its association with different types of malignant tumors, the early diagnosis, multi-disciplinary approach and prompt treatment should be warranted.

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 microm. 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.

Impact of manual correction over automated segmentation of spectral domain optical coherence tomography.

OBJECTIVE: To study the automated segmentation of retinal layers using spectral domain optical coherence tomography (OCT) and the impact of manual correction over segmentation mistakes. METHODS: This was a retrospective, cross-sectional, comparative study that compared the automated segmentation of macular thickness using Spectralis™ OCT technology (Heidelberg Engineering, Heidelberg, Germany) versus manual segmentation in eyes with no macular changes, macular cystoid edema (CME), and choroidal neovascularization (CNV). Automated segmentation of macular thickness was manually corrected by two independent examiners and reanalyzed by them together in case of disagreement. RESULTS: In total, 306 eyes of 254 consecutive patients were evaluated. No statistically significant differences were noted between automated and manual macular thickness measurements in patients with normal maculas, while a statistically significant difference was found in central thickness in patients with CNV and with CME. Segmentation mistakes in macular OCTs were present in 5.3% (5 of 95) in the normal macula group, 16.4% (23 of 140) in the CME group, and 66.2% (47 of 71) in CNV group. The difference between automated and manual macular thickness was higher than 10% in 1.4% (2 of 140) in the CME group and in 28.17% (20 of 71) in the CNV group. Only one case in the normal group had a higher than 10% segmentation error (1 of 95). CONCLUSION: The evaluation of automated segmented OCT images revealed appropriate delimitation of macular thickness in patients with no macular changes or with CME, since the frequency and magnitude of the segmentation mistakes had low impact over clinical evaluation of the images. Conversely, automated macular thickness segmentation in patients with CNV showed a high frequency and magnitude of mistakes, with potential impact on clinical analysis.

Choroidal granuloma caused by Mycobacterium Fortuitum.

BACKGROUND: To report a case of a chronic steroid user male patient who developed local abscesses caused by M. fortuitum and concomitant asymptomatic choroidal granuloma. CASE PRESENTATION: A 37-year-old african-american male with history of use of anabolic drugs and intramuscular mineral oil injections in the upper and lower limbs for 15 years for muscular hypertrophy. He developed intramuscular abscesses with systemic infection, sub-retinal lesions in both eyes and alterations in cerebrospinal fluid suggestive of mycobacteria. Considering these findings, empirical treatment for tuberculosis was started, without success. After several negative cultures of the material drained from the abscesses, finally one of the cultures isolated the agent Mycobacterium Fortuitum. Proper treatment for atypical mycobacteria was initiated with clinical and laboratory improvement. After 6 months the sub-retinal lesions regressed. CONCLUSIONS: A typical choroidal granuloma caused by M. Fortuitum is a rare presentation of the infection and our report showed a good outcome with proper treatment.

Choriocapillaris Hypoperfusion Artifact in OCT Angiography.

BACKGROUND AND OBJECTIVE: To illustrate how optical coherence tomography (OCT) angiography (OCTA) can be misinterpreted if not evaluated along with structural en face OCT to analyze the signal intensity. PATIENTS AND METHODS: Patients with different macular diseases associated with suspicious flow impairment in the choriocapillaris were recruited to be imaged on the RTVue XR Avanti device (Optovue, Fremont, CA) with the Angio Retina mode. En face OCT angiograms, structural en face OCT, and corresponding OCT B-scans with flow signal overlaid were compared to evaluate the correspondence of signal strength to areas of flow reduction in the choriocapillaris. RESULTS: Six eyes from six patients were enrolled. Macular lesions evaluated in this study included acute central serous chorioretinopathy, paracentral acute middle maculopathy, age-related macular degeneration, adult-onset foveomacular vitelliform dystrophy, and branch retinal vein occlusion. In all cases, areas of suspicious flow decrement in the choriocapillaris corresponded to hyporeflective areas in the intensity en face OCT. Thus, a precise confirmation of choriocapillaris flow impairment was not possible. CONCLUSION: It is essential to be aware of the importance of analyzing the structural image alongside with the flow image to interpret flow impairment. This is more important in subretinal pigment epithelial structures such as choriocapillaris and choroid. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:603-610.].

OCT Angiography: An Upcoming Non-invasive Tool for Diagnosis of Age-related Macular Degeneration.

PURPOSE: To review the most recent findings, characteristics, faults and future perspectives of optical coherence tomography angiography (OCTA) in age-related macular degeneration (AMD). RECENT FINDINGS: In dry AMD, OCTA is useful on the evaluation of choriocapillaris perfusion and detection of naïve quiescent non-exudative choroidal neovascularization (CNV). In wet AMD, OCTA can provide detailed anatomic and morphologic information of CNVs, which may help to understand why and how they develop and become active. In other hand, the many artifacts present in OCTA images may lead to misinterpretation and misdiagnosis. SUMMARY: OCTA is a still developing technology that is able to provide a large amount of anatomic, functional and morphologic information in macular diseases and, particularly, AMD. As the technology evolves, the need of dye-based modalities tends to decrease.

Anatomical and functional correlation in Susac syndrome: multimodal imaging assessment.

BACKGROUND: Susac's syndrome (SuS) is an uncommon disease characterized by retinal microangiopathy that may be assessed more accurately with optical coherence tomography angiography (OCTA), a new imaging technique which provides a retinal microvasculature map. The purpose of this case report is to describe the multimodal imaging findings of SuS correlating OCTA with functional tests. CASE PRESENTATION: Retrospective review of one case with clinical and imaging evidence of SuS. Color fundus photograph, fluorescein angiography (FA), OCTA, microperimetry (MP) and visual field (VF) tests were analyzed at the time of presentation and at 1- and 6-month visit following initiation of treatment. The study patient underwent standard treatment for SuS. The patient age was 31 year-old and the baseline visual acuity was 20/60 and 20/20 in the right and left eyes, respectively. At presentation, FA showed branch retinal arterial occlusion within the macular area of the right eye and vascular leakage in the periphery of the left eye. OCTA demonstrated areas of superficial and deep retinal vascular plexuses hypoperfusion in both eyes. The OCTA segmentations in the outer retina and choriocapillaris were normal. The low VF and MP sensitivity signals precisely corresponded to the topography of decreased vascular perfusion seen on the OCTA density map in both eyes. Six months after specific SuS therapy, retinal vascular perfusion showed partial improvement in both eyes. CONCLUSION: OCTA may demonstrate superficial and deep retinal vascular non-perfusion without choriocapillary vasculature changes in SuS. This anatomical information given by OCTA corresponded to points of low sensitivity on functional tests represented by VF and MP.

Retinal Microvascular Network and Microcirculation Assessments in High Myopia.

PURPOSE: To investigate the changes of the retinal microvascular network and microcirculation in high myopia. DESIGN: A cross-sectional, matched, comparative clinical study. PARTICIPANTS: Twenty eyes of 20 subjects with nonpathological high myopia (28 ± 5 years of age) with a refractive error of -6.31 ± 1.23 D (mean ± SD) and 20 eyes of 20 age- and sex-matched control subjects (30 ± 6 years of age) with a refractive error of -1.40 ± 1.00 D were recruited. METHODS: Optical coherence tomography angiography (OCTA) was used to image the retinal microvascular network, which was later quantified by fractal analysis (box counting [Dbox], representing vessel density) in both superficial and deep vascular plexuses. The Retinal Function Imager was used to image the retinal microvessel blood flow velocity (BFV). The BFV and microvascular density in the myopia group were corrected for ocular magnification using Bennett's formula. RESULTS: The density of both superficial and deep microvascular plexuses was significantly decreased in the myopia group in comparison to the controls (P < .05). The decrease of the microvessel density of the annular zone (0.6-2.5 mm), measured as Dbox, was 2.1% and 2.9% in the superficial and deep vascular plexuses, respectively. Microvessel density reached a plateau from 0.5 mm to 1.25 mm from the fovea in both groups, but that in the myopic group was about 3% lower than the control group. No significant differences were detected between the groups in retinal microvascular BFV in either arterioles or venules (P > .05). Microvascular densities in both superficial (r = -0.45, P = .047) and deep (r = -0.54, P = .01) vascular plexuses were negatively correlated with the axial lengths in the myopic eye. No correlations were observed between BFV and vessel density (P > .05). CONCLUSIONS: Retinal microvascular decrease was observed in the high myopia subjects, whereas the retinal microvessel BFV remained unchanged. The retinal microvascular network alteration may be attributed to ocular elongation that occurs with the progression of myopia. The novel quantitative analyses of the retinal microvasculature may help to characterize the underlying pathophysiology of myopia and enable early detection and prevention of myopic retinopathy.

Fluorescein Angiography Versus Optical Coherence Tomography Angiography in Macular Telangiectasia Type I Treated With Bevacizumab Therapy.

This is a report of microvascular changes seen on fluorescein angiography (FA) and optical coherence tomography angiography (OCTA) in a 47-year-old man with macular telangiectasia Type 1 (MacTel1) after a 7-year bevacizumab (Avastin; Genentech, South San Francisco, CA) treatment course. OCTA allowed for clear visualization of most telangiectasias and aneurysms in the deep capillary plexus, with only few microvascular dilatations in the superficial plexus. In addition, areas of capillary dropout in the superficial and deep vascular plexa located near telangiectasias were documented on OCTA. Serial FA demonstrated reduced number of aneurysms and telangiectasias at the 7-year mark compared to baseline. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:263-266.].

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.

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.

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 Bruch's 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.