Influence of segmental supply of Cilioretinal artery on morphology of diabetic macular edema.

BACKGROUND: The supply of Cilioretinal artery (CRA) to different layers of the retina influences retinal pathologies such as diabetic retinopathy (DR). Since the supply of CRA is segmental, our aim was to analyze the location of CRA with respect to non - center involving diabetic macular edema (DME) differentiated by various segments and center involving DME based on Early Treatment of Diabetic Retinopathy Study (ETDRS) scale using optical coherence tomography (OCT). METHODS: A retrospective study was conducted in which forty-three patients with various stages of DR and the presence of CRA were identified. Presence and location of CRA was recognized using fundus fluorescein angiography. Classification of DME was based on ETDRS subfields on OCT. RESULTS: Evaluation of 26 men and 17 women with varying degrees of severity involving DR revealed the presence of unilateral CRA in 40 subjects and bilateral CRA in 3 subjects. When CRA supplied the central area, maximum retinal thickness was noted at the temporal quadrant (271.67 ± 164.02 µm) along with non - center involving DME (194.87 ± 121.06 µm); when CRA supplied the lower area, maximum retinal thickness was noted at the superior quadrant (293.64 ± 159.36 µm) along with center involving DME (395 ± 285.75 µm) and when it supplied the upper area, maximum retinal thickness was noted at the nasal quadrant (293.49 ± 176.18 µm) along with center involving DME (292 ± 192.79 µm). CONCLUSION: The presence of CRA seems to influence the morphology of the retina amongst patients diagnosed with DR by altering the segments involved in DME based on its supply location. However, further studies with a larger sample size are warranted to strenghten this association.

Wide-field choroidal vascular analysis in central serous chorioretinopathy.

PURPOSE: To report the wide-field choroidal vessel analysis in central serous chrorioretinopathy (CSCR) and their fellow eyes. METHODS: Wide-field optical coherence tomography (WF-OCT) images (55°) were obtained using Spectralis HRA + OCT (Heidelberg Engineering, Germany) in extremes of gazes in all quadrants and manual montages were created to obtain wide field images up to equator. Choroidal thickness (CT), large choroidal vessel layer thickness (LCVT), and choroidal vascularity index (CVI) were calculated in macular segment (twice the disc to fovea distance) and all four quadrants. Regression analysis was performed to identify the factors influencing CVI. RESULTS: Thirty-one patients of CSCR including 39 eyes of CSCR (32 chronic, 7 acute) and 23 fellow eyes were analyzed. CT and LCVT were significantly higher in submacular choroid than all extramacular segments in both CSCR and fellow eyes (all p values <0.01). CVI varied significantly in different segments in horizontal (p < 0.01 in both) and vertical meridian (p < 0.01 and p = 0.01 respectively) in CSCR and fellow eyes. Both CSCR and fellow eyes had highest CVI in nasal segment with minimum CVI in macular segment. Age (p = 0.85), gender (p = 0.39), chronicity of the disease (acute vs chronic, p = 0.57), axial length (p = 0.67), SBP (p = 0.81), and DBP (p = 0.94) were not significantly correlated to CVI. CONCLUSION: CVI shows significant regional variation with macular segment showing the lowest CVI whereas nasal segments have highest CVI in both CSCR and their fellow eyes. On the contrary, submacular segment has highest CT and LCVT with taper towards periphery in both CSCR and fellow eyes.

OCT-Angiography as a reliable prognostic tool in laser-treated proliferative diabetic retinopathy: The RENOCTA Study.

PURPOSE: To quantitatively assess retinal neovascularizations (RNVs) in proliferative diabetic retinopathy (PDR) before and after photocoagulative laser treatment (PLT) using Optical Coherence Tomography Angiography (OCT-A). METHODS: Consecutive patients with PDR were examined with fluorescein angiography (FA) and OCT-A before and after PLT. Baseline and after-treatment FA images were quantitatively analyzed to assess both the RNVs area and leakage area. On OCT-A RNVs area, vascular perfusion density (VPD), vessel length density (VLD) and fractal dimension were computed. VPD of the full-retina OCT-A underneath the RNV was determined to evaluate potential laser-induced changes in vascular perfusion. RESULTS: Fifteen eyes of 13 patients with PDR were enrolled. The mean area of the RNVs was 0.47 ± 0.50 mm2 in the baseline OCT-A and 0.32 ± 0.40 mm2 in the post-treatment assessment (p = 0.0002). The mean RNV VPD of RNV was 2% ± 4% in pre-treatment and 1% ± 1% for the post-treatment (p = 0.0001). The mean VLD of RNV was 7.26 ± 1.53 at baseline and 6.64 ± 1.65 in the post treatment (p = 0.0002). A significant difference in terms of mean RNVs area and VPD reduction between eyes that needed additional treatment and those that did not (~40% vs ~20%; p < 0.05), was observed. Mean VPD of full-retinal thickness OCT-angiogram was 55% ± 10% for the pre-treatment and 53% ± 8% for the post treatment scan (p = 0.02). CONCLUSION: The quantitative OCT-A assessment of laser-induced changes of RNVs can be a useful non-invasive approach for determining treatment efficacy. A reduction of RNVs area or VPD ⩾ 40% might reveal those eyes that won't require additional treatment. Retinal perfusion impairment seemed to progress independently from the treatment.