To the Editor —The recent GRAND ROUNDS presentation entitled "Prevention and Treatment of Diabetic Complications" in the MayArchives(1980;140:691-696) is not current with (1) the literature relating to the feasibility of maintaining a euglycemic state, and (2) the reversal correlation of early diabetic retinopathy and the normalization of hemoglobin A lc level. Statements from this article are quoted below, accompanied by recent comments and references. "To date, studies using Hb A lc as a measure of diabetic control have failed to show a correlation between the presence or absence of retinopathy or nephropathy and the level of Hb A lc ." Retinopathy is now believed to be a continuum that begins with early microvascular leakage of proteins and progresses through the classic stages of exudative and hemorrhagic lesions, proliferation, etc. The modern technique of quantitative vitreous fluorophotometry is capable of measuring excessive capillary leakage in the early stages and