Choroidal Circulation in Severe ROP

Abstract

Purpose: : to describe choroidal circulation in severe ROP by means of FA.

Methods: : From Dec '04 until Jun '09 364 inborn preterm with gestational age (GA) 32 weeks and /or birth weight (BW) 1500 g were screened for ROP at the Catholic University of the Sacred Heart Hospital in Rome. The mean BW was 1220 g (range 350-2420 g) and the mean GA was 29.5 weeks (range 24-35 wks). 39 babies (10.7%) required laser treatment. 40 eyes (20 babies) developed type 1 ROP and underwent laser photocoagulation. 37 eyes (19 babies) classified as type 2 ROP and progressed to "classical threshold" as defined by the Cryo ROP study were also treated. Prior to photocoagulation, FA was performed on each baby under general anesthesia using Ret Cam (Clarity, Pleasanton, CA).

Results: : Extreme variability in filling, plateau and draining of choriocapillaris was observed. The arteriolar phase appeared as late up to 30 seconds in 15 eyes (10 eyes in Zone I; 5 eyes in Zone 2).The venous phase delayed up to 1 minutes was observed in 17 eyes (11 eyes in Zone I; 6 eyes in Zone 2). Neonatal physiological hypo pigmentatio allowed possible to well document areas of persistent hypo-fluorescence at the posterior pole. Huge areas of hypo-fluorescence were observed also at the periphery together with an irregular filling pattern. Altered choroidal filling was observed centrally in 41 eyes and peripherally in 20 eyes. Abnormalities in plateau and draining phase were also observed in several eyes.

Conclusions: : Although FA is not the gold standard for examining choroidal circulation, due some limitation in choriocapillaris visualization (lack of contrast, leakage of dye in the extravascular space) some consideration can be drawn. Persistent hypo-fluorescence surrounding the normal lobular hyper-fluorescence due to choroidal filling pattern can be interpreted as lack in choriocapillaris development at the posterior pole. An irregular choroidal filling at the periphery is another sign of bad perfusion of the retina. All these findings show an extreme instability of choroidal circulation in premature babies with severe ROP.

Keywords: retinopathy of prematurity • choroid