Capillary-free vascularized retina in patients with aggressive posterior retinopathy of prematurity and late retinal capillary formation

Abstract

Purpose: To report the clinical features, clinical course, and treatment outcomes after laser photocoagulation in infants with aggressive posterior retinopathy of prematurity (APROP) and capillary-free zones in vascularized retina.

Methods: Six patients (12 eyes) with APROP and capillary-free zones in vascularized retina were retrospectively reviewed. Twelve eyes of six infants were included and were treated with laser photocoagulation for avascular retina and for capillary-free zones in vascularized retina, except for the posterior pole, and fundus findings were photographically-documented in sequence. In addition, anatomic and visual outcomes were evaluated with complications of APROP.

Results: Among all of the consecutive infants with APROP, capillary-free zones in vascularized retina were demonstrated in 24% of the infants. All of the infants were >27 weeks of gestation age and had birth weights >1,000 g. After laser treatment, 7 eyes (58.3%) had favorable outcomes, and late capillary filling in capillary-free zones of vascularized retina were noted, however 4 eyes (33.3%) progressed to retinal detachment and 1 eye (8.3%) was complicated by a retinal fold-distorting posterior pole. The visual outcomes were associated with anatomic outcomes.

Conclusions: The anatomic outcomes in infants with APROP who had capillary-free zones were comparable to previously reported infants with APROP. The late capillary filling of capillary-free zones in vascularized retina was noted, and angiogenesis was considered to be involved. This process toward normal capillary formation or neovascularization in APROP, might determine its outcome.

Keywords: Aggressive posterior retinopathy of prematurity; Angiogenesis; Capillaries.

Fig. 1

Fundus photographs of patients with aggressive posterior retinopathy of prematurity revealing capillary-free zones in vascularized retina. (A,B) The infants demonstrated multiple capillary-free zones (black arrow) surrounded by retinal vasculature or retina with capillary formation. In addition, a prominent plus sign and pre-retinal hemorrhage (white arrow) were revealed. (C,D) A more highly magnified view revealing a capillary free-zone (black arrow) within vascularized retina in contrast to the area with capillary formation denoted by an arrowhead.

Fig. 2

Short-term course of a capillary-free zone in patient 2, who had a favorable outcome. (A-D) Serial follow-up after laser treatment (A, 10 days; B, 2 weeks; C, 4 weeks; and D, 5 weeks after the laser treatment). The capillary-free zone (bordered by black arrows) and pre-retinal hemorrhage gradually decreased after the laser treatment and resolved as shown in (D) together with regression of the plus sign.

Fig. 3

Long-term clinical course of capillary-free zones demonstrated in the right eye of patient 5 (A) before laser treatment and (B) on the day of laser treatment (post-treatment). Black arrows denote capillary-free zones in vascularized retinas, in contrast to retinas with capillary formation (arrowhead). White arrows demonstrate retinal vessels, and thus the space enclosed by them indicates a vascularized zone. (C) Seven months later, capillary formation was achieved but a focal fibrous membrane was noted along the superior arcade and at the last visit, at 15 months after laser treatment, RetCam image in (D) shows a stable fibrous membrane without tractional retinal detachment, otherwise the fundus is normal.