The treatment of advanced retinopathy of prematurity by cryotherapy and scleral buckling surgery.

Seventeen eyes of nine extremely premature infants with severe acute proliferative retinopathy of prematurity (ROP, Grades III-V) were treated. Cryotherapy alone was used in ten eyes to ablate extensive areas of avascular retina to thereby induce involution of widespread intravitreous neovascularization. No attempt was made to directly treat the arteriovenous shunt or neovascularization itself. Scleral buckling surgery was used in combination with cryotherapy in seven additional eyes to relieve diffuse vitreous traction to intravitreous neovascularization which had caused extensive traction retinal detachment. Cryotherapy was uniformly successful in causing involution of widespread intravitreous neovascularization in all patients treated. Scleral buckling surgery was initially effective in reattaching the retina in all cases but late manifestations of severe ongoing vitreoretinal traction required additional open-sky vitrectomy in two eyes and resulted in inoperable recurrent total traction retinal detachment in one eye and extensive macular scarring in another. A comparison is made between the proliferative retinopathies seen in ROP and diabetes mellitus and a rationale for effective cryotherapy in ROP is presented. In our clinical experience, the single most important prognostic factor determining the potential severity of ROP is the width and extent of the retinal avascular zone. The wider the zone, the greater the probability of rapid progression from early to advanced grades of disease.