POSTERIOR VITREOSCHISIS - AN ECHOGRAPHIC FINDING IN PROLIFERATIVE DIABETIC-RETINOPATHY

Purpose: To describe the echographic characteristics of splitting of t he outer posterior cortical vitreous in patients with proliferative di abetic retinopathy and vitreous hemorrhage. Methods: The authors retro spectively reviewed the echographic findings in 270 patients who were evaluated at the Doheny Eye Institute between January 1983 to December 1989 for proliferative diabetic retinopathy and vitreous hemorrhage. None of the eyes had undergone pars plana vitrectomy before echographi c examination. Results: Forty-five patients (17%) had echographic evid ence of splitting of the outer posterior vitreous cortex, a finding th e authors have termed posterior vitreoschisis. In all patients, differ entiation of the posterior vitreoschisis from a true posterior hyaloid detachment was possible, either on the initial or on serial echograph ic examination, by the separate detachment of the inner wall of the vi treoschisis cavity and the true posterior hyaloid from the retinal sur face. The vitreoschisis cavities often were found to contain unclotted blood. In some eyes, the inner wall of the vitreoschisis cavity was a dherent to the apex of the most highly elevated area of traction retin al detachment, suggesting that posterior vitreoschisis may itself resu lt in clinically significant vitreoretinal traction, independent of th e presence or extent of true posterior hyaloid separation. Conclusions : The authors' findings suggest that spontaneous splitting of the oute r posterior vitreous cortex may occur in patients with proliferative d iabetic retinopathy and vitreous hemorrhage, which may mimic a true po sterior cortical vitreous detachment on echographic examination. Preop erative recognition of posterior vitreoschisis may be important in the surgical management of these patients.