CHOROIDAL STRUCTURAL CHANGES AND VASCULARITY INDEX IN STARGARDT DISEASE ON SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To evaluate structural changes in the choroid of patients with Stargardt disease using swept source optical coherence tomography scans. METHODS: A retrospective comparison cohort study was conducted on 39 patients with Stargardt disease, and on 25 age and gender matched-healthy controls. Subfoveal choroidal thickness (SFCT) was computed from the swept source optical coherence tomography machine, and the scans were binarized into luminal area and stromal areas, which were then used to derive choroidal vascularity index (CVI). Choroidal vascularity index and SFCT were analyzed independently using linear mixed effects model. RESULTS: There was no significant difference in SFCT between the 2 groups (347.20 ± 13.61 µm in Stargardt disease vs. 333.09 ± 18.96 µm in the control group, P = 0.548). There was a significant decrease in the CVI among eyes with Stargardt disease as compared with the normal eyes (62.51 ± 0.25% vs. 65.45 ± 0.29%, P < 0.001). There was a negative association between visual acuity and CVI (correlation coefficient = -0.75, P < 0.001) and a positive association between visual acuity and SFCT (correlation coefficient = 0.21, P = 0.035). CONCLUSION: Choroidal vascularity index appears to be a more robust tool compared with SFCT for choroidal changes in Stargardt disease. Choroidal vascularity index can possibly be used as a surrogate marker for disease monitoring. A decrease in CVI was associated with a decrease in visual function in eyes with Stargardt disease.

Likelihood of spontaneous closure of cavernous sinus dural arteriovenous fistulas based on clinical and radiological findings.

BACKGROUND: Cavernous sinus dural arteriovenous fistula (CSDAVF) is a rare condition that radiologists would encounter in their careers. We aim to describe the clinical and radiological characteristics of this condition, and to provide a management workflow. METHODS: In our retrospective study, we studied 27 patients with CSDAVF from January 2007 to August 2020. Patients with direct cavernous sinus AVFs and patients with incomplete date were excluded. Clinical and radiological data were collected and analyzed. RESULTS: Fourteen patients were conservatively treated with spontaneous resolution while 13 patients had endovascular intervention performed. In the intervention group, seven patients had intra-cranial reflux seen on radiological imaging and six patients had clinical deterioration, hence requiring intervention. Clinically, among our patients, 21 had proptosis, 20 had conjunctiva hyperaemia, 18 had extraocular movement limitation, 13 had raised intraocular pressure, 11 had chemosis, ten had ocular pain, nine had ocular bruit, eight had headache and six had worsening visual acuity. Radiologically, a concurrence was seen between superior ophthalmic vein thrombosis and spontaneous resolution of the CSDAVF, as compared to those who underwent intervention. A paradoxical increase of ocular symptoms was seen despite a decrease of flow or stagnation of contrast in radiological imaging of CSDAVF. CONCLUSIONS: In our study, 52% of CSDAVF closed spontaneously. As deterioration of ocular symptoms in patients with CSDAVF might also reflect spontaneous progressive occlusion, it warrants dynamic vascular imaging to check the status of venous outflow. Patients with CSDAVF with corticovenous reflux or deterioration of visual acuity need more urgent (endovascular) treatment.

Choroidal Vascularity Index in Retinitis Pigmentosa: An OCT Study.

BACKGROUND AND OBJECTIVE: To evaluate structural changes in the choroid of patients with retinitis pigmentosa (RP) using swept-source optical coherence tomography (OCT) scans. PATIENTS AND METHODS: A prospective study was conducted comparing 35 eyes of 35 patients with RP and 26 eyes of 26 normal patients. OCT images of the choroid were binarized into luminal and stromal areas to derive choroidal vascularity index (CVI). Subfoveal choroidal thickness (CT) was also measured and compared. RESULTS: There was a significant decrease in the mean CVI among eyes with RP as compared to normal eyes (56.91 ± 1.43% vs. 59.47 ± 1.55%; P < .0001). Mean subfoveal CT was significantly greater in eyes with RP as compared to normal eyes (262.82 µm ± 69.69 µm vs. 194.65 µm ± 23.55 µm; P < .0001). CONCLUSION: Patients with RP showed a significant reduction in CVI and an increase in CT as compared to normal eyes. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:191-197.].

Choroidal structural analysis in eyes with diabetic retinopathy and diabetic macular edema-A novel OCT based imaging biomarker.

PURPOSE: To evaluate structural changes in the choroid among patients with diabetic macular edema (DME), with varying grades of diabetic retinopathy (DR), using enhance depth imaging spectral domain optical coherence tomography (EDI SD-OCT) scans. METHODS: A cross-sectional study was conducted on 82 eyes with DR and DME and 86 healthy control eyes. Eyes with DME were classified according to the severity of DR as per the international DR severity scale. Sub foveal choroidal thickness (SFCT)was obtained using EDI SD-OCT scans. These scans were binarized into luminal and stromal areas, to derive the choroidal vascularity index (CVI). CVI and SFCT were analyzed between the study and control group using paired-T test. Tukey's test was used to correlate the differences in CVI and SFCT between different grades of DR. Further analysis was done to look for the effect of DR severity and type of DME on CVI as well as SFCT using correlation coefficient and linear regression analysis. RESULTS: SFCT was significantly increased in eyes with DME as compared to the controls (334.47±51.81µm vs 284.53±56.45µm, p<0.001), and showed an ascending trend with worsening of DR, though this difference was not statistically significant [mild non-proliferative diabetic retinopathy (NPDR) = 304.33±40.39µm, moderate NPDR = 327.81±47.39µm, severe NPDR = 357.72±62.65µm, proliferative DR (PDR) = 334.59±47.4µm, p-0.09]. CVI was significantly decreased in DME with DR eyes as compared to controls (63.89±1.89 vs 67.51±2.86, p<0.001). CVI was also significantly decreased with worsening DR (mild NPDR = 66.38±0.3, moderate NPDR = 65.28±0.37, severe NPDR = 63.50±0.47, PDR = 61.27±0.9, p<0.001). CONCLUSION: SFCT and CVI are dynamic parameters that are affected by DME. Unlike CVI, SFCT is also affected by ocular and systemic factors like edema and hypertension. CVI may be a more accurate surrogate marker for DME and DR and can potentially be used to monitor the progression of DR.