Purpose To detect and quantify choroidal neovascularization (CNV) in age-related macular degeneration (AMD) patients using optical coherence tomography (OCT) angiography. Design Observational, cross-sectional study. Participants Five normal subjects and five neovascular AMD patients were included. Methods Five eyes with neovascular AMD and five normal age-matched controls were scanned by a high-speed (100,000 A-scans/sec) 1050 nm wavelength swept-source OCT. The macular angiography scan covered a 3×3 mm area and comprised 200×200×8 A-scans acquired in 3.5 sec. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by three dimensional (3D) orthogonal registration and merging of 4 scans. The 3D angiography was segmented into 3 layers: inner retina (to show retinal vasculature), outer retina (to identify CNV), and choroid. En face maximum projection was used to obtain 2D angiograms from the 3 layers. CNV area and flow index were computed from the en face OCT angiogram of the outer retinal layer. Flow (decorrelation) and structural data were combined in composite color angiograms for both en face and cross-sectional views. Main Outcome Measurements CNV angiogram, CNV area, and CNV flow index. Results En face OCT angiograms of CNVs showed sizes and locations that were confirmed by fluorescein angiography. OCT angiography provided more distinct vascular network patterns that were less obscured by subretinal hemorrhage. The en face angiograms also showed areas of reduced choroidal flow adjacent to the CNV in all cases and significantly reduced retinal flow in one case. Cross-sectional angiograms were used to visualize CNV location relative to the retinal pigment epithelium and Bruch’s layer and classify type I and type II CNV. A feeder vessel could be identified in one case. Higher flow indexes were associated with larger CNV and type II CNV. Conclusions OCT angiography provides depth-resolved information and detailed images of CNV in neovascular AMD. Quantitative information regarding CNV flow and area can be obtained. Further studies are needed to assess the role of quantitative OCT angiography in the evaluation and treatment of neovascular AMD.

Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities.optical coherence tomography angiography | ophthalmic imaging | ocular circulation O ptical coherence tomography (OCT) has become the most commonly used imaging modality in ophthalmology. It provides cross-sectional and 3D imaging of the retina and optic nerve head with micrometer-scale depth resolution. Structural OCT enhances the clinician's ability to detect and monitor fluid exudation associated with retinal vascular diseases. Whereas anatomical alterations that impact vision are readily visible, structural OCT has a limited ability to image the retinal or choroidal vasculatures. Furthermore, it is unable to directly detect capillary dropout or pathologic new vessel growth (neovascularization) that are the major vascular changes associated with two of the leading causes of blindness, age-related macular degeneration (AMD) and diabetic retinopathy (1). To visualize these changes, traditional i.v. contrast dye-based angiography techniques are currently used.Fluorescein dye is primarily used to visualize the retinal vasculature. A separate dye, indocyanine green (ICG), is necessary to evaluate the choroidal vasculature. Both fluorescein angiography (FA) and ICG angiography require i.v. injection, which is time consuming, and which can cause nausea, vomiting, and, rarely, anaphylaxis (2). Dye leakage or staining provides information regarding vascular incompetence (e.g., from abnormal capillary growth), but it also obscures the image and blurs the boundaries of neovascularization. Additionally, conventional angiography is 2D, which makes it difficult to distinguish vascular abnormalities within different layers. Therefore, it is desirable to develop a no-injection, dye-free method...

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Objective To report 5-year results from a previously reported trial evaluating intravitreal 0.5-mg ranibizumab with prompt versus deferred (for ≥24 weeks) focal/grid laser treatment for diabetic macular edema (DME). Design Multicenter randomized clinical trial. Participants Among participants from the trial with 3 years of follow-up who subsequently consented to a 2-year extension and survived through 5 years, 124 (97%) and 111 (92%) completed the 5-year visit, in the prompt and deferred groups, respectively. Methods Random assignment to ranibizumab every 4 weeks until no longer improving (with resumption if worsening) and either prompt or deferred (>= 24 weeks) focal/grid laser treatment. Main Outcome Measures Best-corrected visual acuity at the 5-year visit. Results The mean change in visual acuity letter score from baseline through the 5-year visit was +7.2 letters in the prompt laser group compared with +9.8 letters in the deferred laser group (mean difference -2.6 letters, 95% confidence interval -5.5 to +0.4 letters, P = 0.09). At the 5-year visit in the prompt vs. deferred laser groups respectively, there was vision loss of ≥10 letters in 9% vs. 8%, an improvement of ≥10 letters in 46% vs. 58%, and an improvement of >15 letters in 27% vs. 38% of participants. From baseline through 5 years, 56% of participants in the deferred group did not receive laser. The median number of injections was 13 vs. 17 in the prompt and deferral groups, including 54% and 45% receiving no injections during year 4 and 62% and 52% receiving no injections during year 5, respectively. Conclusions Five-year results suggest focal/grid laser treatment at the initiation of intravitreal ranibizumab is no better than deferring laser treatment for ≥24 weeks in eyes with DME involving the central macula with vision impairment. While over half of eyes where laser treatment is deferred may avoid laser for at least 5 years, such eyes may require more injections to achieve these results when following this protocol. Most eyes treated with ranibizumab and either prompt or deferred laser maintain vision gains obtained by the first year through 5 years with little additional treatment after 3 years.

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