Vitreous Contraction in Proliferative Diabetic Retinopathy

Introduction Although an extensive literature on various aspects of diabetic retinopathy has accumulated over the years, few studies of the natural course of the proliferative stage have been reported. An excellent summary of previous work is to be found in Larsen's 1960 monograph.¹More recently, Dobree²has emphasized the characteristic cycle of growth and regression of new vessels in proliferative diabetic retinopathy, and Beetham³has provided valuable long-term statistics on the rate of progression and degree of visual impairment found in these cases. The important parts that vitreous shrinkage and detachment play in the course of proliferative diabetic retinopathy apparently have not been widely recognized. Larsen¹states that he found no discussion of vitreous detachment in his extensive review of the literature on diabetic retinopathy, except for one case described by Hruby.⁴Larsen describes one characteristic picture of vitreous detachment, that in which fresh hemorrhage