Correlation of biomarkers thiobarbituric acid reactive substance, nitric oxide and central subfield and cube average thickness in diabetic retinopathy: a cross-sectional study.

BACKGROUND: To evaluate the role of thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) as biochemical biomarkers and central subfield (CST) and cube average thickness (CAT) as biomarkers for medical imaging in diabetic retinopathy. METHODS: Forty consecutive cases of diabetic retinopathy and 20 healthy controls were included. Cases were divided into two groups: non proliferative diabetic retinopathy (n = 20) and proliferative diabetic retinopathy (n = 20) according to ETDRS classification. LogMAR visual acuity was documented. Plasma levels of TBARS, NO and glycated hemoglobin (HbA1c) were measured using standard protocol. CST and CAT were analyzed on spectral domain optical coherence tomography. Data was analyzed statistically. RESULTS: Increased severity of diabetic retinopathy was associated with an increase in plasma levels of TBARS (F = 10.92; p < 0.001), NO (F = 21.8; p < 0.001) and HbA1c (F = 5.87; p = 0.001). Increase in CST (F = 61.51; p < 0.001) and CAT (F = 60.84; p < 0.001) was also found to be associated with increased severity of diabetic retinopathy. Pearson's correlation analysis revealed a positive correlation of TBARS with CST (r = 0.29; p = 0.038) and CAT (r = 0.31; p = 0.04). A positive correlation of NO with CST (r = 0.27; p = 0.03) and CAT (r = 0.7; p = 0.001) was also observed. On univariate analysis with logMAR visual acuity as dependent variable, a significant increase in visual acuity was observed with increase in independent variables TBARS (B = 0.22; p = 0.004), NO (B = 0.006; p < 0.001), CST (B = 0.005; p < 0.001) and CAT (B = 0.005; p < 0.001). On multivariate linear regression analysis with logMAR visual acuity as dependent variable and adjusting for other factors like duration of diabetes and HbA1c, it was observed that increase in independent variables TBARS (B = 0.07), NO (B = 0.001) and CST (B = 0.004) independently predict increase in logMAR visual acuity (p < 0.001). CONCLUSION: Thiobarbituric acid reactive substance and nitric oxide serve as potential biochemical markers whereas central subfield and cube average thickness serve as potential biomarkers for medical imaging for severity of diabetic retinopathy. In a clinical retinal setting, CAT and CST will help in early recognition of increase in severity of diabetic retinopathy.

Topographic assessment of retinal pigment epithelium detachment in central serous chorioretinopathy by three-dimensional optical coherence tomography single-layer retinal pigment epithelium map.

PURPOSE: This study aims to compare the topographic distribution of retinal pigment epithelium detachment (PED) in central serous chorioretinopathy (CSC) on spectral domain optical coherence tomography (SD-OCT) single-layer retinal pigment epithelium (SL-RPE) map and fluorescein angiography for the first time. METHODS: Twenty-seven eyes of CSC with PEDs were studied retrospectively. Topographic distribution of PEDs was documented on 50° fluorescein angiography and SD-OCT SL-RPE map on macular cube 512 × 128. RESULTS: Quantity of PEDs ranged from 1 to 5 on SD-OCT SL-RPE map macular cube 512 × 128 and corresponding macular cube area on 50° fluorescein angiography. Topographic distribution of PEDs on SL-RPE map matched with PEDs on fluorescein angiography in the corresponding macular cube area, in all the cases (interobserver correlation = 0.9). CONCLUSION: SD-OCT SL-RPE map is a noninvasive, three-dimensional advanced tool for documentation of topographic assessment of PEDs and obviates the need of fluorescein angiography for monitoring CSC.