Start Submission Become a Reviewer

Reading: A comparison of the concordance of ophthalmic outcome between low birth weight singletons an...


A- A+
Alt. Display

Original article

A comparison of the concordance of ophthalmic outcome between low birth weight singletons and twins


Anna R. O’Connor ,

Division of Orthoptics, Thompson Yates Building, Brownlow Mill, Liverpool, L69 3GB, GB
About Anna R.

Dr, PhD BMedSci (Hons)

X close

Alistair R. Fielder

Department of Optometry and Visual Science, City University, London, GB
About Alistair R.


X close


Aim: To determine whether low birth weight twins have a similar outcome, and to compare the outcome of the twins with a matched comparison group of low birth weight singletons

Methods: From a low birth weight (LBW) cohort (< 1701 g) of 572 infants there were 62 twin pairs (n = 124). Of the 293 who were traced and consented to assessment at 10–12 years of age there were 14 twin pairs (n = 68). From the remaining non-twin LBW children a comparison group was created where the children were matched to each other based on birth weight, ethnicity, maternal smoking habits and whether they were small for their gestational age (neonatal group, n = 102; older group, n = 48). Ophthalmic assessment at 10-12 years included visual acuity, contrast sensitivity, evaluation of strabismus and refractive error.

Results: The twins showed a significant relationship with each other in terms of the presence or absence of retinopathy of prematurity (p = 0.001, concor­dance = 71%) but the matched singletons did not. The twins had a statistically significant relationship in terms of the level of visual acuity and refractive error. However, the relationship between the refrac­tive errors of the twins was weak (R2 = 0.14). The matched singleton group showed no statistically significant similarities on any measures of ophthalmic outcome. The level of concordance was higher between the pairs of twins for all measures of ophthalmic outcome compared with the matched singletons, but this increase did not reach statistical significance.

Conclusion: There was a higher rate of concordance in the twin children on all measures of visual outcome, which suggests that when a deficit is detected in a low birth weight child from a multiple birth the sibling(s) should also be assessed. However, in this low birth weight cohort analysis, the degree of prematurity and the resultant systemic and ocular complications, have a greater impact, compared with genetic factors, on many measures of outcome.
How to Cite: O’Connor, A.R. and Fielder, A.R., 2008. A comparison of the concordance of ophthalmic outcome between low birth weight singletons and twins. British and Irish Orthoptic Journal, 5, pp.42–46. DOI:
Published on 01 Jan 2008.
Peer Reviewed


  • PDF (EN)