Refraction and visual acuity in a national Danish cohort of 4‐year‐old children of extremely preterm delivery

Abstract

ABSTRACT.Purpose: A recent threefold increase in laser treatment for advanced retinopathy of prematurity (ROP) triggered a nationwide preschool ophthalmic and developmental status among extremely preterm survivors. Here, we discuss refraction and visual acuity. Methods: Survivors (n = 178) from a national birth cohort (February 2004 to March 2006) of gestational age <28 weeks (PT) and 56 full-term (FT) controls attended for evaluation at age 4 years. Cycloplegic refraction and keratometry were achieved by Retinomax autokeratorefractor and visual acuities by symbol recognition (HOTV, logMAR). Results: The refractive distribution presented a myopic tail (4.5%) and a hyperopic tail (11.9% ≥+2.5 D) as special preterm features, and corneas were more curved. Astigmatism and anisometropia were only marginally increased, and visual acuities were generally good. Best-corrected binocular median logMAR visual acuity was 0.1 in FT and 0.2 in PT, in Snellen equivalents 0.8 and 0.63. Snellen acuity ≤0.5 occurred across the ROP subgroups, but mainly in those with at least ROP stage 3. Two children had low vision. Conclusions: The overall fair outcome for refraction and function is in accordance with other recent northern Europe experience. The results differ in particular from the poorer ophthalmic outcomes reported in the pioneer US treatment studies (cryotherapy for ROP and ETROP). The diode laser ablations (n = 32) appeared effective in our series; except one child, all treated subjects had good or fair social vision at the age of 4 years.

The neural retina in retinopathy of prematurity

“…Consistent with the results of others (Chen et al, 2010; Fledelius et al, 2015; Hellgren et al, 2016; Holmstrom and Larsson, 2005; Larsson et al, 2015; Quinn et al, 2008; Quinn et al, 2013), refractions performed on 284 ROP subjects (Fig. 18) who have been participants in our studies of retinal function and structure indicate that their frequency of ametropia increases with the severity of their antecedent ROP.…”

Ophthalmological data on 4.5‐ to 7‐year‐old Danish children

“…(), the mean spherical equivalent was approximately +1.3 D in the age group of 4‐ to 6‐year‐old children, and Fledelius et al. () found a mean spherical equivalent in full term 4‐year‐olds of +1.29 D. We found the mean refractive error to be even higher (+1.75 D in right eyes), with a weak negative correlation to age, confirming the continuing emmetropization process.…”

“…There are several Scandinavian population-based studies on ophthalmologic data of normally developed children (Table 4), but only few data describing the age group were analysed in the present study (Gr€ onlund et al 2006: 77 children in the age 4-9 years, Fledelius et al 2015: 56 children aged 4 years).…”

The usefulness of the Retinomax autorefractor for childhood screening validated against a Danish preterm cohort examined at the age of 4 years

“…The results are discussed in a separate publication, along with a literature review of refraction in preterm children. 21 The Retinomax examination was performed in 95.3% of the 234 participants.…”

“…No ROP had been recorded in 105 children, reversible ROP (stages 1-3) was found in 41 and 32 had diode laser treatment for threshold ROP. [19][20][21] Refractive data were assessed with a hand-held Retinomax K-plus3 auto-keratorefractometer (Nikon Inc) before application of cyclopentholate 1% eye drops and 30-50 min after instillation. The equipment was used in normal mode, with automated fogging of the fixation target to minimise accommodation.…”