Pre‐term delivery and the growth of the eye An oculometric study of eye size around term‐time

Abstract

Refraction and axial eye dimensions, evaluated by ultrasound measurements, were investigated in 101 pre-term infants and 25 full-term controls. Gestational ages in the pre-term group ranged from 25 to 34 weeks, birth weights from 728 to 2480 g. All were seen in the eye clinic due to risk of developing retinopathy of prematurity. Age at examination was 36-54 weeks (gestationalkonceptional) in the pre-terms and 37.3-50 weeks in the term infants. Adjusted to a 40 weeks axial length value (based on an assumed avarage eye elongation of 0.14 mm per week) the term-values were similar, 17.02 and 17.03 mm in the two groups. Within the premature group, however, the 40-week ajusted axial lengths were shorter, the shorter the gestational age. The study demonstrated more foetal anterior segment proportions, with flatter anterior chambers and thicker, more spheroid lenses in the preterm infants. Probably this explains the early preponderance of myopia in that group, at feature eventually to disappear, and not to be confused with myopia of prematurity. As compared to the full-terms a correlational disturbance by pre-term delivery was further indicated by the absence of the usual correlation between axial length and refractive value.

Eye size in healthy Swedish children and in children with fetal alcohol syndrome

“…3). A similar finding was reported by Fledelius (1992) who demonstrated, in very preterm infants, features like shallow anterior chambers, slightly thicker lenses and shorter axial lengths. There was no evidence that the vitreous chamber was affected in the preterm children.…”

“…One of the main difficulties in recruiting healthy controls in the lowest age groups for ultrasound examination of the eye is that the measurements have to be performed under general anaesthesia, and parents are often reluctant to expose their children to such an examination (Fledelius 1992). Therefore, previous reference values have usually not included those from the youngest age groups, i.e.…”

“…In the last decades the technique of ophthalmic ultrasonography was refined with the introduction of higher frequency transducers, soft ultrasound probes (Snead et al 1990) and semiautomatic and computerized measuring procedures. Most recent studies on ocular dimensions have been limited to newborns, premature neonates and children with congenital cataracts (Yankov 1982;Fledelius 1992;Tucker et al 1992;von Noorden & Lewis 1987). Recent reports on the growth of ocular structures in older children have, with one exception (Zadnik et al 1993), been restricted to non-Caucasian children (Tane & Kohno 1983;Youn et al 1990; van Rens & Arkell 1991).…”

Anterior Chamber Angle and Anterior Segment Structure of Eyes in Children With Early Stages of Retinopathy of Prematurity

“…4 Premature infants exhibit more highly curved corneas, shallower anterior chambers, and shorter axial lengths (AL) than full-term infants. 5,6 These differences become more significant as the severity of ROP increases. 7 The lens thickness (LT) is also greater in children with treated ROP than in children with spontaneously regressed ROP or children with normal full-term birth.…”

Distribution and Determinants of Eye Size and Shape in Newborn Children: A Magnetic Resonance Imaging Analysis

“…The mean AL was 17.3 mm, comparable with that reported in other studies on newborn eyes. 34,[36][37][38] Axer-Seigel reported mean values of 16.6 6 0.4 mm for right eyes and 16.5 6 0.4 mm for left eyes in term infants, while Isenberg reported a mean value of 16.2 mm. 37,38 The mean value at term reported by Fledelius in preterm infants, adjusted for an assumed average eye elongation of 0.14 mm per week, was 17.02 mm.…”