OCT-Angiography for monitoring and managing neovascular age-related macular degeneration.

PURPOSE: To evaluate the combined use of optical coherence tomography and angiography (OCT-A) for imaging choroidal neovascularization (CNV) secondary to neovascular age-related macular degeneration (nAMD). MATERIALS AND METHODS: This prospective observational study was conducted from May 2015 to April 2017. Included in the study were 54 patients (n = 63 eyes), all of whom had CNV secondary to nAMD and all of whom had been examined by OCT-A. Angioscans (3x3 and 6 × 6) and conventional B-scan OCT scans were obtained for all patients at baseline and at various times during the 24-month follow-up period. For diagnostic confirmation, conventional imaging methods fluorescein angiography (FA) and indocyanine green angiography (ICGA) were performed at baseline. A total of 13 patients (n = 15 eyes) underwent serial imaging during 34 follow-up visits. The main outcomes included (i) determination of OCT-A sensitivity for the detection of CNV (classic and occult) and (ii) the correlation between B-scan OCT and OCT-A vis-à-vis consecutive follow-up changes. RESULTS: At baseline, the detection rate (i.e., overall sensitivity) of OCT-A for detecting CNV was 64.4% (75.7 and 48.0% for classic and occult CNV, respectively), independent of prior treatment status. In terms of quality, 6 × 6 angioscans were superior to 3 × 3. Moreover, specific CNV morphologic patterns by B-scan OCT did not correlate with lesion composition. Correspondence between OCT-A and B-scan OCT was observed in only 53% of the cases. CONCLUSIONS: OCT-A may prove to be a valuable adjunctive diagnostic tool for the interpretation of CNV, as it not only reduces the need for invasive angiographic procedures but also facilitates the follow-up process.

Intravitreal bevacizumab (Avastin) versus triamcinolone (Volon A) for treatment of diabetic macular edema: one-year results.

PURPOSE: The objective was to compare retinal morphology and function following intravitreal injections of bevacizumab (Avastin) or triamcinolone (Volon A) in patients with early diabetic macular edema (DME). PATIENTS AND METHODS: The study was planned as a randomized, prospective, interventional clinical trial. A total of 30 diabetic patients with treatment-naïve, clinically significant macular edema were included in this study and randomized to two equal groups. One group initially received three injections of 2.5 mg bevacizumab in monthly intervals. The second group received a single injection of 8 mg triamcinolone, followed by two sham interventions. Functional and anatomic results were evaluated monthly using ETDRS vision charts and spectral-domain optical coherence tomography. According to the study protocol, retreatment after 3 months was dependent on functional and anatomic outcome in a PRN regimen. RESULTS: Baseline best corrected visual acuity (BCVA) was 0.30 logMAR and central retinal subfield thickness (CSRT) was 505 µm in the bevacizumab group and 0.32 logMAR and 490 µm CSRT in the triamcinolone group. After 3 months, BCVA improved to 0.23 logMAR (bevacizumab) and 358 µm CRST and 0.26 logMAR (triamcinolone) and 308 µm CSRT. After 12 months, BCVA further recovered in the bevacizumab group (0.18 logMAR) but slightly decreased in the triamcinolone group (0.36 logMAR). CONCLUSION: Intravitreal bevacizumab and triamcinolone are both equally effective in reducing CSRT in early DME. After 6 months, rehabilitation of vision was comparable in both treatment arms, whereas at the final follow-up at month 12, BCVA was superior in the bevacizumab than in the triamcinolone sample. This may be related to cataract development following steroid treatment, as well as to substance-specific mechanisms within the angiogenic versus the inflammatory cascade.

Comparison of retinal thickness measurements and segmentation performance of four different spectral and time domain OCT devices in neovascular age-related macular degeneration.

AIMS: To evaluate the reliability of different optical coherence tomography (OCT) devices and scanning patterns in the assessment of retinal thickness and segmentation performance in neovascular age-related macular degeneration (nAMD). METHODS: 28 eyes with nAMD and 10 healthy eyes were imaged using conventional time domain (TD) OCT as well as three spectral-domain (SD) OCT systems. Radial scans of 6 mm in size were compared between Stratus and Topcon OCT, in addition to raster scans of all three SD-OCT devices. Retinal thickness values were analysed. RESULTS: Spectralis SD-OCT demonstrated the highest values of all OCT devices in central millimetre thickness (CMMT), and Topcon OCT raster scans showed the lowest values. Significant correlations could be found between the CMMT measurements of Cirrus and Spectralis OCT (r = 0.87). Analyses showed best segmentation for Cirrus and Spectralis SD-OCTs. Cirrus 200x200x1024 scans showed 4% and Stratus OCT 38% moderate or severe segmentation errors. CONCLUSION: Retinal thickness values were generally higher in SD-OCT analysis. Different performances of automatic retinal thickness analysis indicate the potential of different software algorithms to quantify retinal morphology in nAMD. Further development of current algorithms may improve quantification of retinal thickness detection in the future even further.

[Influence of antiangiogenetic therapy on retinal thickness values in age-related macular degeneration]. / Beeinflussung von Netzhautdickenwerten durch antiangiogenetische Therapie bei altersbedingter Makuladegeneration.

BACKGROUND: This study evaluated the impact of antiangiogenetic therapy on differences in central retinal thickness (CRT) as measured with two optical coherence tomography (OCT) systems from the same manufacturer. MATERIAL AND METHODS: Data were obtained from a group of 20 patients with neovascular age-related macular degeneration before and after intravitreal treatment with ranibizumab. Imaging was performed using the Stratus and the high-definition (HD) Cirrus OCT systems. RESULTS: The mean CRT was revealed to be significantly lower as measured by OCT compared with HD-OCT before and after treatment (p<0.002). CRT differences varied more strongly before treatment than after treatment. A higher standard deviation was noted before treatment. The difference in the mean deviation of CRT measurements before and following antiangiogenetic therapy was highly significant. CONCLUSION: This study showed that differences in CRT measurements between different OCT systems were subject not only to technical differences but also to treatment effects of current antiangiogenetic strategies. These effects should be recognized because clinical studies increasingly define OCT parameters as primary or secondary outcome measures.