PurposeTo 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.MethodsA 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.ResultsSFCT 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).ConclusionSFCT 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.

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.

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.].

than 0.05 was considered significant. RESULTS: Out of 1500 questionnaires, 1000 were received (response rate 0f 66.6%). Majority of the respondents were Libyans (n ϭ 883; 88.3 %) while 117 (11.7%) were non Libyans. Fifty three percent (nϭ474) of Libyans respondents were females while seventy four percent (nϭ87) of non Libyans respondents were males. Forty eight per cents (nϭ420) of Libyans and forty four percent (nϭ 51) of non Libyans were categorized in 25-40 years age group. Majority (nϭ529; 59.9%) of Libyans respondents had high level of education while non Libyans respondents (nϭ 61; 52.1) had intermediate education. Knowledge score was significantly higher among Libyans (11.7 Ϯ 3.8) than non Libyans (9.7Ϯ 4.7, t ϭ 26.13), (P Ͻ 0.001). A significant difference was noted when Libyans and non Libyans were compared with age, gender and tertiary educations level (P Ͻ 0.001). No significant differences were seen among other demographic variables and knowledge scores. CONCLUSIONS: The present study findings showed that overall level of knowledge of Libyans and non Libyans respondents was low; however, Libyans had more knowledge than non Libyans about TB. There is a need of massive health education campaign by policy makers in order to improve the population's knowledge towards TB.