Zone I retinopathy of prematurity - Clinical characteristics and treatment outcomes

Purpose: To study the clinical characteristics and treatment outcomes after laser and surgical treatment in a series of infants with zone I retinopathy of prematurity (ROP). Methods: Preterm infants less than 1,500 g at birth diagnosed with zone I ROP were studied. Fifty-seven consecutive eyes in 29 infants with zone I ROP were treated with indirect diode laser. Within zone 1, two anatomic subgroups (anterior and posterior) were defined. Additionally, 27 eyes (15 patients) with retinal detachment secondary to zone I ROP were surgically treated. Structural outcomes were evaluated 3 months after surgery. Results: Atypical morphologic characteristics were observed. Thirty-one out of 48 eyes (64.6%) with anterior zone I ROP and none of the 9 eyes with posterior zone I ROP had a favorable outcome (P < 0.001) after photocoagulation. In the surgery group, 14 out of 19 (74%) eyes with stage 4 and 1 out of 8 (13%) eyes with stage 5 had favorable outcomes. Conclusions: Atypical clinical features can be observed in zone I ROP. A posterior localization of the disease carries a worse prognosis after laser photocoagulation. Surgical intervention can effectively reattach the retina in a significant number of zone I ROP-related retinal detachments.