Fluorophotometric analysis of the blood retinal barrier: two techniques compared

Methods of interpreting data obtained by vitreous fluorophotometry vary between institutions. One important difference in these methods is the use of total plasma fluorescein or only free fluorescein in the calculation of the plasma fluorescein curve used in the analysis of the blood retinal barrier. We examined 16 diabetic patients (32 eyes) with documented background retinopathy using vitreous fluorophotometry. We compared two methods of analysis: (1) using total plasma fluorescein, and (2) using plasma-'free' fluorescein. Both methods were equally efficient at detecting breakdown of the blood retinal barrier and were highly comparable (R = 0.84; p less than 0.001). 43.75% of eyes with documented background retinopathy had a normal blood retinal barrier as measured by these techniques.