A study into the effects of premature birth on retinal abnormalities in school-age children conducted by a team of researchers at NTU Hospital and the College of Medicine has been published in the prestigious American journal Investigative Ophthalmology and Visual Science. The article, titled “Long-term Evaluation of Refractive Status and Optical Components in Eyes of Children Born Prematurely,” demonstrates that children born prematurely tend to experience more serious abnormalities, including myopia (nearsightedness), hyperopia (farsightedness) and astigmatism, than children born at full term.

While total fertility rates are falling, rates of premature births are rising gradually. Retinal pathology in pre-term children is one of the leading causes of ophthalmic problems for children, whether in developing or developed nations.

The occurrence of retinal pathology in children born prematurely is related to gestational age, birth weight, oxygen supply and certain growth hormones. The current consensus calls for retinal examinations after 31 weeks or four weeks after birth for any pre-term child with a gestational age less than 30 weeks or birth weight lower than 1500 grams. Freezing, laser treatment and anti-angiogenesis therapy are available to treat these children’s retinal abnormalities.

The occurrence of retinal pathology in children born prematurely is related to gestational age, birth weight, oxygen supply and certain growth hormones. The current consensus calls for retinal examinations after 31 weeks or four weeks after birth for any pre-term child with a gestational age less than 30 weeks or birth weight lower than 1500 grams. Freezing, laser treatment and anti-angiogenesis therapy are available to treat these children’s retinal abnormalities.

The NTU researchers assembled a cohort of 108 school-aged children who had been born pre-term. They reviewed the participants’ neonatal histories and conducted detailed eye examinations of their refractive statuses as well as ultrasound examinations of their optical components, and compared the results with those of age-matched children. The study found that, compared to the control group, the children born prematurely experienced higher rates of myopia (48% vs. 29%), hyperopia (23% vs. 15%) and astigmatism (73% vs. 41%).

The study discovered that hyperopia in the test cases was caused by shorter axial length and that their myopia resulted from shallower anterior chamber depth and greater lens thickness. It also found an association between retinopathy of prematurity and significantly higher myopia and astigmatism—the more severe the retinopathy of prematurity, the more severe the subsequent refractive abnormalities.

The research team is presently conducting research into pharmacological treatments for retinal abnormalities caused by premature birth in hopes of understanding the long-term influence of these therapies on the development of vision in these children.

Government policy presently calls for eye examinations for children around the age of three. The NTU team’s research shows that children born prematurely suffer more severe refractive abnormalities and amblyopia than those born at full term. Eye screening for children born pre-term should be carried out at an earlier age, whether or not they exhibit retinal pathology. For these children, ophthalmologists should test for amblyopia at four months and one year after birth and test for refractive abnormalities when the children are two. This will permit the earlier detection of eye problems so that critical periods for treatment are not missed.