Refraction and keratometry in premature infants

Abnormalities of emmetropisation, resulting most often in myopia, have long been independently associated by numerous authors from nearly every corner of the globe with increasing prematurity, increasing severity of retinopathy of prematurity (ROP), and retinal ablative therapy. This topic has also been the subject of an editorial in the BJO in 1997, the substance of which remains true today.1 These refractive error abnormalities of prematurity and of ROP have been found to present early in infancy and persist into adulthood. It is not clear whether the mechanism for the development of myopia of prematurity is the same or different from the mechanism for the development of myopia of ROP.1 It appears that an alteration in the normal growth patterns of the eye is caused by the prematurity, the retinal ablative therapy, or probably both factors, leading to the refractive error. This disruption in growth results in structural abnormalities of parts of the eye which affect refractive development. These structures might include corneal curvature, axial length, lens thickness, and anterior chamber depth.

Most authors of studies involving myopia of prematurity have had only refractive error data available, which makes it impossible to directly determine which ocular structures have had their development altered before term. …