Evaluation of diabetic retinopathy by fluorophotometry - European concerted action on ocular fluorometry

Background: Fluorophotometric variables (permeability of the blood-retinal barrier (BRB) and blood-aqueous barrier (BAB), corneal autofluorescence, an d lenticular light transmittance) are reported to correlate with the severi ty of diabetic retinopathy. This preliminary multicenter study was performe d to measure these variables simultaneously in patients with type 2 diabete s mellitus and to assess which of these variables could be of help in evalu ating diabetic retinopathy. Methods: Eighty-two patients with type 2 diabet es and diabetic retinopathy were recruited in seven European university cli nics. Each patient was investigated three times, at intervals of about one year. The investigations included fluorophotometric determination of cornea l autofluorescence, lenticular light transmittance, and permeability of the BRB and BAB. Retinopathy was classified into four grades, using a simplifi ed evaluation system based on the Modified Airlie House retinopathy classif ication and applied to color fundus slides of standard fields 1 and 2. Resu lts: Multiregression analyses revealed that only corneal autofluorescence a nd BRB permeability were correlated with the severity of diabetic retinopat hy (P < 0.05). Corneal autofluorescence and BRB permeability as single vari ables were found to be indicative of severe nonproliferative retinopathy an d proliferative retinopathy (sensitivity 100% and 86%, respectively, and sp ecificity 65% and 85%, respectively). Combination of both variables increas ed specificity to 92%. Conclusions: This preliminary multicenter study show s that fluorophotometric variables can be measured simultaneously and relia bly in patients with diabetes and that corneal autofluorescence and BRB per meability (individually or in combination) could be of help in detecting se vere non-proliferative retinopathy and proliferative retinopathy.