A longitudinal study of the biometric and refractive changes in full-term infants during the first year of life

Abstract

Changes in ocular axial dimensions and refraction were followed longitudinally, using ultrasonography and retinoscopy, during the first year of life (mean ages 4-53 weeks) of a group of 20 full-term infants (10 male, 10 female). Using a mixed-model regression analysis, axial length changes as a function of time were found to be best described by a quadratic expression (AL=17.190+0.128x-0.0013x(2), where AL is the axial length in mm and x is the age in weeks), while anterior chamber depth changed linearly (ACD=2.619+0.018x, where ACD is the anterior chamber depth in mm): lens thickness was essentially constant. Spherical equivalent refraction through most of the first year showed a steady reduction in hypermetropia (SER=2.982-0.032x, where SER is the spherical equivalent refraction in dioptres): astigmatism also tended to diminish. Mean hyperopic refractive errors through the year were negatively correlated with corresponding axial lengths (SER=12.583-0.541AL), but some individual subjects showed marked departures from this pattern. These results are discussed in relation to concepts of emmetropization.

Developmental Changes in Anterior Corneal Astigmatism in Tohono O’odham Native American Infants and Children

“…[9][10][11][12] Recent reports of data from Tohono O'odham infants show a high prevalence of astigmatism, which decreases in the second year of life. 12,13 This pattern is similar to that seen in Caucasian, Asian, and Hispanic infants: astigmatism is prevalent in infancy, [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] but longitudinal studies indicate that the amount of astigmatism decreases significantly after the first year of life. 17,18,21,23,[28][29][30][31] However, cross-sectional data has shown that the initial decrease in prevalence of astigmatism after infancy in Tohono O'odham children is followed by an increase in prevalence by age 2 years to the level we see in Tohono O'odham preschool and school-age children.…”

The Relationship between Crystalline Lens Power and Refractive Error in Older Chinese Adults: The Shanghai Eye Study

“…In children, lens power decreases with age; lens power decreases remarkably in infants who are one to two years old [2–4]. In growing children, lens power decreases due to the development of myopia [5, 6].…”

Dynamic response to initial stage blindness in visual system development

“…AL measurements and baseline VA evaluations were conducted before surgery ( Figure 1a) [22,26]. The dense and total cataracts hindered their preoperative RT measurement; consequently, the first RT measurement was conducted immediately following the cataract removal during the surgery (Figure 1b).…”

“…To determine the normal rate of AL development, the referenced curve-fitting value of the age-matched normal distribution range was used for comparison ( [22,26]. As shown in Figure 5, the presurgery AL of our population was distributed mainly in the normal curve range.…”

“…We can infer the development of retinal function via RT measurement, due to the significant correlation between retinal structure and retinal cell function [21]. Measurement of AL and refractive status can provide valuable assays for the dynamic emmetropization process after birth [22]. Moreover, grating acuity may be recorded as a valuable metric for the overall visual assessment of infants and young children [23].…”