ABSTRACT
We sought to determine effect of signal strength on mean retinal nerve fibre layer (RNFL) using Spectralis optical coherence tomography (S-OCT). Thirty normal subjects (18 female, mean 37.9 years, range 24-61) were imaged with S-OCT using variably dense Bangerter foils to alter Q value (1 unit signal strength = 4 units Q). We found a statistically significant (p < 0.01) linear relationship (R = 0.8643) between Q and RNFL (1 unit decrease Q = 0.181 um mean RNFL increase). Unlike previous observations of Cirrus and Stratus OCT, we found RNFL thickness does not decrease with decreasing signal strength in S-OCT.
ABSTRACT
BACKGROUND: We evaluated the reproducibility of office-based flicker electroretinography (ERG) in patients with nonproliferative diabetic retinopathy (NPDR). METHODS: An observational study was conducted in which ultra-widefield fluorescein angiography (UWF-FA) was performed on 20 patients with mild-to-moderate NPDR; images were graded by the Fundus Photography Reading Center (Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI, USA). Fixed- and multi-luminance flicker ERG was repeated four times (greater than or equal to seven days apart). Recording consistency was assessed using intra-class correlation coefficients (ICCs), coefficients of variation, and Pearson correlations. RESULTS: 82.5% and 17.5% of eyes had mild and moderate NPDR using UWF-FA; 90% of the angiograms were given a high confidence grade. Fixed-luminance phase values were highly reproducible (ICC: 0.949; P < .001). There was a significant negative correlation between fixed-luminance phase and log-corrected ischemic index values (-0.426; P = .015). CONCLUSIONS: Office-based, fixed-luminance phase values are highly reproducible and negatively correlate with retinal ischemia in NPDR, suggesting that global retinal dysfunction may be reliably quantified early in patients with diabetes.
