Characteristic analysis of ocular biological parameters in newborns with highly myopic parents

Objective  To analyze the characteristic of ocular biological parameters of full-term newborns with highly myopic parents.

Methods  A cross-sectional study was conducted.A total of 120 newborns (120 eyes) who underwent fundus screening at Chongqing Aier Children’s Eye Hospital between September 2021 and December 2023 were enrolled.Data from the right eye were included for analysis.The newborns were divided into two groups based on parental history of high myopia: parental high myopia group (at least one parent with high myopia) of 60 cases (60 eyes) and non-parental high myopia group of 60 cases (60 eyes).The parental high myopia group was further subdivided into two groups: both parents with high myopia group of 20 cases (20 eyes) and one parent with high myopia group of 40 cases (40 eyes).Additionally, the parents of newborns were divided into 3 groups based on parental spherical equivalent (SE): high myopia group of 80 cases (80 eyes), low-to-moderate myopia group of 68 cases (68 eyes) and emmetropia group of 92 cases (92 eyes).All newborns were examined within 28 days after birth.SE was calculated by cycloplegic retinoscopy to calculate.Keratometry was measured with a handheld autorefractor.Axial length (AL) was measured by A-scan ultrasonography.Intraocular pressure (IOP) was measured with a handheld tonometer.For parents, refractive error was measured with a handheld autorefractor and IOP was measured with a handheld tonometer.Parental history of high myopia was recorded.SE, AL, mean keratometry, and IOP of newborns were compared between parental high myopia group and non-parental high myopia group, both parents with high myopia group and one parent with high myopia group.Correlation of the parameters were analyzed the and the differences in IOP between parents with different diopters were analyzed.Guardians were aware of the specific operating methods and significance of the examinations, and signed the informed consent form.This study complies with the Declaration of Helsinki, and the study protocol was approved by the Medical Ethics Committee of Chongqing Aier Children’s Eye Hospital.(No.2024-001-02)

Results  The SE of newborns in the parental high myopia group was (+ 2.89±0.81)D, which was significantly lower than that (+ 3.86±0.85)D in the non-parental high myopia group ( t=4.347, P<0.001).The AL of newborns in the parental high myopia group was (17.17±0.41)mm, which was significantly longer than (16.78±0.42)mm in the non-parental high myopia group ( t=3.491, P=0.001).There was no significant difference in mean keratometry or IOP between the parental high myopia and non-parental high myopia groups ( t=0.404, 0.688; both P>0.05).For the parental high myopia group, newborns with both parents having high myopia had lower hyperopic refractive error and longer AL compared to those with only one parent having high myopia, showing statistically significant differences ( t=7.386, 6.203; both P<0.001).Pearson correlation analysis revealed that SE was negatively correlated with AL ( r=-0.868, P<0.001), and AL was positively correlated with gestational age, birth weight, and birth length ( r=0.864, 0.820, 0.874; all P<0.05).The mean IOP of parents in the high myopia, low-to-moderate myopia, and emmetropia groups were (16.45±0.67), (15.21±0.53), and (14.86±0.49)mmHg, respectively (1 mmHg =0.133 kPa), with a statistically significant overall difference ( F=2.764, P=0.021), and the high myopia group had higher IOP than the low-to-moderate myopia and emmetropia groups (both P<0.05).

Conclusions  Compared with newborns having non-high myopia parents, term newborns with highly myopic parents have a lower hyperopia reserve and a longer ocular axis.

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