OCT-Based Macular Structure–Function Correlation in Dependence on Birth Weight and Gestational Age—the Giessen Long-Term ROP Study

Abstract

Increased thicknesses of the entire retina or specific layers at the fovea did not correlate with functional loss; but a thinner ONL in retinae without foveal pit did. This reduced ONL+ ratio is potentially caused by a reduced foveal cone density and may be the first morphologic functional correlate in prematurity and ROP.

Choroidal Thickness with Swept-Source Optical Coherence Tomography versus Foveal Morphology in Young Children with a History of Prematurity

“…Previous studies observed a decrease in VEGF expression in the choroid in 1-month-old rats subjected to oxygen-induced retinopathy [26]. While ROP has been shown to cause central and peripheral visual disorder, the exact cause of these deficits is not known [6, 27, 28]. In an animal ROP model, Shao et al [3] found that an involution of choroid tissue and choriocapillaris, which supplies nutrients and oxygen to the outer retina, was an important contributor to reduced cone and rod function.…”

“…We measured the following: retinal nerve fiber layer (NFL), ganglion cell layer plus inner plexiform layer (GCL + IPL), INL plus outer plexiform layer (INL + OPL), ONL plus external limiting membrane (ONL + ELM), inner segment plus inner ellipsoid segment of the photoreceptor layer plus outer segment of the photoreceptor layer (ISe + OS), and retinal pigment epithelium (RPE). The ratio of ONL + ELM to the sum of inner retinal layers (NFL + GCL + IPL + INL + OPL = IRL) overlying the foveal center was calculated, as described in our previous publication [6]. …”

“…ROP arises out of the oxygen partial pressure to which preterm infants are exposed after birth compared with that in utero and also a general loss of maternally derived factors [1, 2]. Photoreceptor deficits seem to predominate in the central retina, although central retinal vessel discrepancies are relatively small compared with that observed in the periphery [3-6]. Shao et al [3] stated that a possible explanation for deficient photoreceptor integrity and retinal vascular deficits might lie in the choroidal vascular system, particularly as the choroid is the main supplier of oxygen and nutrients to the outer retina and the photoreceptor layer.…”

“…We recently published that a lowered ratio between the thickness of the central outer nuclear layer and (the sum of overlying) inner retinal layer (ONL+/IRL) correlated directly with reduced central visual function in preterm children [6]. A ratio < 6.5 was considered to reflect macular developmental arrest (MDA) [6].…”

“…A ratio < 6.5 was considered to reflect macular developmental arrest (MDA) [6]. Other groups also showed that long-term visual outcome was compromised in patients with treated ROP (tROP) or resolved ROP [4-6].…”