Optical coherence tomography and optical coherence tomography angiography in uveitis : a review

Optical coherence tomography (OCT) has dramatically changed the understanding and management of uveitis and other ocular conditions. Currently, OCT angiography (OCTA) combines structural information with the visualization of blood flow within the imaged area. The aim of this review is to present the basic principles of OCT and OCTA interpretation and to investigate the role of these imaging techniques in the diagnosis and management of uveitis. Common complications of intraocular inflammation such as macular oedema and inflammatory choroidal neovascularization are often diagnosed and followed with OCT/OCTA scans. However, uveitis specialists can obtain much more information from tomographic scans. This review provides a comprehensive description of typical OCT/OCTA findings characterizing different ocular structures in uveitis, proceeding from the cornea to the choroid. A careful interpretation of OCT/OCTA images can help in the differential diagnosis, the prediction of clinical outcomes, and the follow-up of patients with uveitis

Comparison of wide field optical coherence tomography angiography with extended field imaging and fluorescein angiography in retinal vascular disorders

Purpose To compare swept source OCTA device, with and without the extended field imaging (EFI) technique, to standard fluorescein angiography (FA) in the clinical practice. Methods Consecutive patients with vascular disorder patients underwent FA with 55-degree lens (Spectralis Heidelberg Engineering, Heidelberg, Germany) and OCTA with the prototype PlexElite (Carl Zeiss Meditec, Dublin, CA) using a 12 mm x 12 mm volume scan pattern centered on the fovea and a prototype of + 20.00-diopter designed specifically by Zeiss. The imaging methods were compared for visible field of view, extension of non-perfused areas, presence and number of neovessels, vessel density (VD) and fractal dimension (FD). Results Forty-three eyes of 27 patients were included. The mean extension ratio of EFI SS-OCTA compared to SS-OCTA without EFI and FA were 1.97 \ub1 0.02 and 0.85 \ub1 0.01. The mean extension of non-perfused areas with EFI SS-OCTA (34.22 \ub1 33.4 mm 2 ) was significantly higher than SS-OCTA without EFI (20.46 \ub1 18.70 mm 2 ), and with FA (27.55 \ub1 4.4 mm 2 ). The mean VD and FD of EFI SS-OCTA were significantly different compared to SS-OCT without EFI. Conclusions EFI SS-OCTA captured larger areas than SS-OCTA without EFI and FA. OCTA in a single shot is able to obtain more information of the retina without the use of montage techniques. Despite the determination of retinal ischemia seems to be easier and more accurate using EFI SS-OCTA, FA offers more details of the perfusion status of the retina

Measuring Dynamics of Scattering Centers in the Ocular Fundus

The study is focused on the analysis of the diffusing-wave-spectroscopy signalrecorded invivo on the ocular fundus of a rabbit eye. The motion of the scattered sites wasmeasured as a function of the pressure exerted by a Goldmann contact lens and during themoderate temperature increase induced by a therapeutic laser diode. Temporal fluctuations ofthe signal revel motion of molecules and thus changes in tissues temperature andchorioretinal blood velocity. Experimental results show the ability of the system to detectmotion of the scattering sites in the ocular fundus layers during variations of the ocularpressure and laser heating

In-vivo diffusing-wave-spectroscopy measurements of the ocular fundus

We present what is to our knowledge the first observation of a diffusing-wave-spectroscopy signal recorded in-vivo on the ocular fundus. A modified ophthalmic microscope was developed which can acquire diffusing-wave-spectroscopy signal from the eye fundus. The diffusing-wave-spectroscopy signal was recorded in-vivo on a rabbit eye during transpupillary thermotherapy. Experimental results show the ability of the system to detect motion of the scattering sites in the ocular fundus layers during laser thermal heating. (c) 2007 Optical Society of America

Optical coherence tomography features of the repair tissue following RPE tear and their correlation with visual outcomes

To assess the optical coherence tomography (OCT) features of the repair tissue after retinal pigment epithelial (RPE) tear in neovascular age-related macular degeneration. Retrospective, observational study. Medical and imaging records of patients that developed tears after starting anti-VEGF treatment and with at least 12 months of follow-up were reviewed. OCT reflectivity of the RPE-subretinal hyperreflective tissue (SHT) complex was measured at 6, 12 and 18 months (when available). Reflectivity of the adjacent unaffected RPE-Bruch’s membrane was taken as internal reference. Other variables: grade and rip occurrence (early/late); number of intravitreal injections; type of macular neovascularization; sub-macular hemorrhage (SMH) at onset. Forty-nine eyes (age: 76.1 ± 7.0 years; VA: 0.54 ± 0.27 LogMAR) were included. Thirty-eight eyes had OCT signs of healing during the follow-up, with 21 showing SMH at baseline. Final VA positively correlated with the number of injections and negatively correlated with the RPE-SHT reflectivity and the presence of SMH (p < 0.001). Reflectivity of the RPE-SHT complex was positively associated with time and SMH at baseline (p < 0.05). In our study, most eyes showed signs of tissue repair after RPE tear. The reflectivity of repair tissue, the SMH presence and the number of anti-VEGF injections appeared to be major predictors of visual outcomes

OLIMPIC : a 12-month study on the criteria driving retreatment with ranibizumab in patients with visual impairment due to myopic choroidal neovascularization

Purpose: To evaluate criteria driving retreatment with ranibizumab in Italian patients with myopic choroidal neovascularization (mCNV). Methods: OLIMPIC was a 12-month, phase IIIb, open-label study. Patients with active mCNV were treated with ranibizumab 0.5&nbsp;mg according to the European label. The study assessed local criteria in Italy driving retreatment decisions with ranibizumab; and the efficacy, safety, and tolerability of ranibizumab. Results: The mean (standard deviation [SD]) age of treated patients (N&nbsp;= 200) was 61.8 (12.7) years; range 22\u201385&nbsp;years. The multivariate regression model indicated that presence of active leakage (odds ratio [OR] 95% confidence interval [CI]: 11.30 [1.03\u2013124.14]), presence of intraretinal fluid (OR [95%CI]: 28.21 [1.55\u2013513.73]), and an improvement in best-corrected visual acuity (BCVA) from baseline &lt; 10 letters (OR [95%CI]: 17.60 [1.39\u2013222.75]) were the factors with the greatest effect on retreatment with ranibizumab. The mean (SD) BCVA gain from baseline to month 12 was 8.4 (12.8) letters (P&nbsp;&lt; 0.0001). The mean (SD) number of injections was 2.41 (1.53); range 1\u20139. Ocular and non-ocular adverse events were reported in 41 (20.5%) and 30 (15.0%) patients, respectively. Conclusions: Individualized treatment with ranibizumab was effective in improving BCVA in patients with mCNV over 12&nbsp;months. Both anatomical and functional variables had significant effects on causing retreatment. There were no new safety findings. Trial registration: www.ClinicalTrials.Gov (NCT No: NCT02034006)

Confocal Blue Reflectance Imaging in Type 2 Idiopathic Macular Telangiectasia

PURPOSE. To report the characteristics of confocal blue reflectance imaging in type 2 idiopathic macular telangiectasia (type 2 IMT). METHODS. In a prospective observational cross-sectional study, both eyes of 33 patients with type 2 IMT were examined by means of fundus biomicroscopy, fundus photography, fluorescein angiography, and optical coherence tomography (OCT). Confocal blue reflectance (CBR) imaging was performed using a confocal scanning laser ophthalmoscope (HRA2; Heidelberg Engineering, Heidelberg, Germany). To compare the results derived from different imaging modalities, an analysis was performed using image analysis software (Heidelberg Eye Explorer; Heidelberg Engineering). RESULTS. CBR imaging revealed a parafoveal area of increased reflectance that was slightly larger than the area of hyperfluorescence in late-phase fluorescein angiography. The area usually encompassed an oval parafoveal area, but sectors could be spared. A parafoveal area of increased CBR was detected in 98% of eyes that showed angiographic evidence for type 2 IMT. CONCLUSIONS. CBR imaging is a new, noninvasive, and sensitive method that may contribute to differentiate type 2 IMT from other diseases. Abnormalities of macular pigment distribution and Miiller cell pathology may contribute to the phenomenon of increased CBR and thus the pathophysiology of type 2 IMT

The Relationship Between Blue-Fundus Autofluorescence and Optical Coherence Tomography in Eyes With Lamellar Macular Holes

PURPOSE. The purpose of this study was to evaluate the relationship between blue-fundus autofluorescence (B-FAF) and optical coherence tomography (OCT) in eyes with lamellar macular holes (LMHs). METHODS. this was a multicenter, observational case series. Ninety-two eyes with LMH associated with the standard epiretinal membrane (ERM) or lamellar hole-associated epiretinal proliferation (LHEP) were evaluated. The eyes must also present an area of increased autofluorescence on B-FAF. RESULTS. The ERM-alone group and the LHEP group differed with respect to the following variables: logarithm of the minimum angle of resolution best-corrected visual acuity (0.13 +/- 0.13 vs. 0.25 +/- 0.17;P < 0.001), central foveal thickness (218.74 +/- 52.4 mu m vs. 187.28 +/- 50.29 mu m;P = 0.008), FAF diameter (400.78 +/- 189.36 mu m vs. 503.37 +/- 214.25 mu m;P = 0.014), outer plexiform layer (OPL) diameter (382.10 +/- 157.34 mu m vs. 550.79 +/- 228.05 mu m;P = 0.0001), and disruption of external limiting membrane and ellipsoid zone, which was noted in only 1 and 3 eyes with ERM alone, respectively, and in 18 and 23 eyes with LHEP, respectively (P < 0.0001 for both observations). No difference was found for diameters measured at the level of the inner limiting membrane and schisis/cavitation. In both the ERM-alone group and the LHEP group, a strong correlation was found between the diameters measured on B-FAF and diameters measured at the OPL level on OCT images (P < 0.0001 for both groups). CONCLUSIONS. In eyes with LMHs, a strong correlation exists between the diameters of the holes measured with B-FAF and those measured at the OPL level with OCT. This may indicate that the loss or displacement of retinal cells containing macular pigment at the OPL level, specifically photoreceptors and/or Muller cells, is involved in this vitreomaculopathy