Central corneal thickness measurements in premature infants

Effects of prematurity and retinopathy of prematurity on refractive errors and biometric optic components in school children: results of a tertiary center from Turkey

PURPOSE

To reveal refractive errors, the relationship between refractive errors and optical parameters, and the effect of prematurity and retinopathy of prematurity (ROP) on ocular development in school children with a history of prematurity.

METHODS

Premature children aged 8-12 years were divided into 3 groups as those without ROP (Group 1), with ROP that did not require treatment (Group 2), and with laser-treated ROP (Group 3). Age-matched full-term healthy children were included in the control group. Demographic features were recorded. A detailed ophthalmologic examination was performed. Anterior chamber depth (ACD), trabecular-iris angle (TIA), iris thickness (IT), lens thickness (LT), vitreous body length (VBL), axial length (AL) were measured by ultrasound biomicroscopy (UBM). The results were compared between groups.

RESULTS

Group 3 had the lowest best corrected visual acuity (0.81 ± 0.31 SL), the highest rates of myopia (55.9%) and astigmatism (50.0%). In the premature groups, ACD (p < 0.001), TIA (p < 0.001), IT (p = 0.016), VBL (p < 0.001) and AL (p < 0.001) were lower; LT (p < 0.001) was higher than in the control group. As birth weight (BW) and gestational age (GA) increased, ACD, TIA, VBL and AL increased, and LT decreased (p < 0.001). In the group 3, 35.2% anisometropia, 17.6% of esotropia and 5.9% of exotropia were detected.

CONCLUSIONS

The frequency of myopia, astigmatism, hyperopia and anisometropia is increasing in premature children, especially in cases with laser-treated ROP. Premature cases are characterized by thicker lens, shallower ACD, narrower TIA and shorter AL. Refractive errors, anisometropia, amblyopia and strabismus are important causes of visual impairment in children with laser-treated ROP.

A lower birth weight percentile is associated with central corneal thickness thinning: Results from the Gutenberg Prematurity Eye Study (GPES)

PURPOSE

Prematurity, prenatal growth restriction, and retinopathy of prematurity (ROP) are associated with altered ocular geometry, such as a steeper corneal shape in childhood, but it is unclear whether perinatal history affects corneal thickness development, so this study investigated whether corneal thickness in adulthood is affected by perinatal history.

MARTERIALS AND METHODS

The Gutenberg Prematurity Eye Study (GPES) is a retrospective cohort study with a prospective ophthalmologic examination in Germany. The corneal thickness was measured by Scheimpflug imaging (Pentacam HR, Oculus Optikgeräte GmbH, Wetzlar, Germany), and the relationship between perinatal parameters respective birth weight percentile and corneal thickness at different locations was assessed using uni- and multivariable linear regression models. Covariates included age, sex, mean corneal radius, white-to-white distance, gestational age, birth weight percentile, ROP occurrence, and treatment. The main outcome measures were corneal thickness at the apex, the pupil center, and the corneal periphery.

RESULTS

The corneal thickness was measured in 390 participants (754 eyes, mean age 29.7+/-8.7 years, 224 females). In multivariable analyses, a lower birth weight percentile was associated with a lower corneal thickness at the apex (B = 0.20, p = 0.003) and the pupil (B = 0.19, p = 0.007). These effects diminished towards the corneal periphery and were not observed beyond the 4-mm diameter circle around the thinnest corneal position. Neither gestational age, ROP occurrence, or ROP treatment affected the corneal thickness.

CONCLUSION

A lower birth weight percentile in subjects born preterm as a proxy for restricted fetal growth is associated with corneal thickness thinning in adults aged 18 to 52 years, indicating that corneal thickness development, particularly in the corneal center, may originate in the fetal stage.

Corneal Aberrations and Thickness in Adults Born Small, Appropriate, or Large for Gestational Age at Term

Background/Aims: This study investigated whether there are changes in corneal surface regularity and corneal thickness in adults born small, appropriate, or large for gestational age at term. Methods: This retrospective cohort study involved prospective Scheimpflug imaging of the cornea (Pentacam®) to compare the corneal thickness and aberrations between adults classified as small for gestational age (SGA), normal birth weight (BW), and large for gestational age (LGA). Multivariable linear regression was applied to analyze associations with gestational age, BW percentile, placental insufficiency, preeclampsia, and breastfeeding. Results: In total, 448 eyes of 261 individuals born full term (aged 29.9 ± 9.5 years, 140 females) were examined, including 29 severe SGA (BW < 3rd percentile), 32 moderate SGA (BW between 3rd and <10th percentile), 132 normal BW (BW between 10th and 90th percentile), 35 moderate LGA (BW between >90th and 97th percentile), and 33 severe LGA (BW > 97th percentile). There were no differences between groups in the corneal aberrations of the total cornea as well as of the corneal front surface, except for higher-order aberrations in the front of the cornea (p = 0.032). There was an association between the increased total root mean square of higher-order aberrations and lower birth weight percentile (p = 0.004), with increased higher-order aberrations correlating with lower visual acuity and spherical equivalent. Conclusion: Restricted prenatal growth is associated with increased higher-order aberrations in adulthood.

Association of Birth Weight with Central and Peripheral Corneal Thickness in Adulthood-Results from the Population-Based German Gutenberg Health Study

Purpose: Low birth weight (BW) is associated with altered ocular geometry such as a steeper corneal shape in adulthood. However, it is unclear whether low birth weight affects corneal thickness development in the center or periphery in adulthood which may contribute to ocular disease. The purpose of this study was to investigate corneal thickness in former low birth weight individuals in adulthood. Methods: The German Gutenberg Health Study is a prospective, population-based study in which every participant (age range 40–80 years) was measured with Scheimpflug imaging (Pentacam HR, Oculus Optikgeräte GmbH, Wetzlar, Germany). BW was collected by self-reports. The relationship between birth weight and corneal thickness at different locations were assessed. Linear regression models were carried out including uni- and multivariable analyses with adjustment for age, sex, mean corneal radius, and white-to-white distance. Main outcome measures were corneal thickness at the apex, at the pupil center, and at the corneal periphery. Results: Overall, 5657 participants were successfully measured (3019 females, aged 56.0 ± 10.3 years). In multivariable analyses a lower BW was associated with a thinner corneal thickness at the apex (B = 1.71 µm/500 g, p < 0.001) and at the pupil (B = 1.69 µm/500 g, p < 0.001). These effects diminished towards the corneal periphery resulting in no differences in the perilimbal regions. Conclusion: The present study provides evidence that lower birth weight goes along with corneal thickness alterations even into adult ages of 40 to 80 years. Thinner measurements of the cornea were particularly found in the corneal center and diminished in the periphery. This indicates that there may be fetal origins affecting corneal thickness development particularly in the corneal center.

Measurement and Analysis of Central Corneal Thickness at Different Postnatal Stages in Chinese Premature Infants

Purpose

The objective of this study was to evaluate central corneal thickness (CCT) in Chinese premature infants at different postnatal stages to study the peak point and analyze influential factors on CCT development.

Methods

This was a cross-sectional study of premature infants. Initial CCT measurement was taken at 34 weeks of gestational age (GA) and at intervals until 88 weeks of postmenstrual age (PMA) was reached. The comparison and correlation analysis were carried out to access the association of CCT with gender, birth weight (BW), GA, and retinopathy of prematurity (ROP) for each PMA. The premature infants were divided into the thick CCT group and the thin CCT group according to the average CCT at 40 w. And the difference in CCT between the two groups at subsequent 52 w and 64 w was compared.

Results

A total of 1726 premature infants (3463 measurements) with an average of 2.21 ± 1.57 measurements were included in this study. The CCT decreased from 34 w GA to 52 w PMA (R = 92.36, P < 0.0001) and then reached a plateau (R = 2.541, P=0.3567). Male (P < 0.05), low BW (P < 0.05), and low GA (P < 0.05) were associated with thicker CCT at the early stage of PMA. The premature infants who had thick CCT at 40 w would have thick CCT at 52 w and 64 w accordingly.

Conclusions

The CCT values of premature infants decreased over time and plateaued at 52 w PMA. Gender, BW, and GA were considered as the influential factors of CCT at the early stage of PMA. Moreover, CCT at 40 w could forecast its development trend at 52 w or 64 w after birth.

Central corneal thickness and corneal diameter in preterm and term newborns and preterm neonates at term

Purpose

To record central corneal thickness and corneal diameter in preterm and term newborns within first week of their birth and in preterm neonates at term age.

Methods

Babies born at ≤34 weeks of gestation period (n = 100), term babies who have a gestation period of >37 weeks (n = 100) and preterm neonates at term age (38-42 weeks) who were born at ≤34 weeks (n = 100) were included in this hospital based observational descriptive study. Corneal diameter was taken by Castroviejo Calipers. Central corneal thickness was measured using portable ultrasonic pachymeter (Pachette 3). Refractive status of the eyes was measured using streak Wellch Allyn retinoscope under cyclopentolate cycloplegia.

Results

Measure of central corneal thickness and corneal diameter in preterm newborns was found to be 633.5 ± 2.8 μm and 8.1 ± 0.6 mm, in full term newborns it was 555.1 ± 2.7 μm and 9.5 ± 0.6 mm, and in preterm neonates at term age, it was 563.5 ± 2.5 μm and 9.6 ± 0.5 mm, respectively. Mean central corneal thickness was found to be more in preterm newborns 633.5 um then term newborns 555.1 um and the difference was statistically significant (P =0.001). Mean corneal diameter was found to be maximum (9.6 mm) in preterm neonates at term age.

Conclusion

Preterm babies have thick corneas and small corneal diameters. This study is useful with respect to the analysis of glaucoma in children and using preterm corneas as donor corneas in penetrating keratoplasty.

Evaluating the change in central corneal thickness in neonates (term and preterm) in Indian population and the factors affecting it

Background and Aim:

Central corneal thickness (CCT) of term and preterm infants in Indian population is not known. We did a prospective noninterventional study to measure the CCT in term and preterm infants.

Materials and Methods:

An ultrasonic pachymeter was used. The data regarding the date of birth, expected date of delivery, birth weight were recorded. The preterm and the term infants were followed up at 8 weeks, 20 weeks and at 1-year.

Results:

A total of 85 (170 eyes) children were included in the study. The mean age was 264.6 ± 21.8 days postconception. The mean birth weight and CCT were 1834.4 ± 512.1 g and 595.8 ± 72.4 μ respectively. A comparison of CCT on the basis postgestational age showed a mean thickness of 620.7 ± 88.8 and 574.4 ± 78.3 μ in the <260 days and >260 days age groups respectively. The difference was statistically significant (Student's test, P = 0.002). The CCT of preterm infants (<260 days) decreased from a mean value of 620.7 ± 88.8 μ to 534.1 ± 57.6 μ at the end of 1-year.

Conclusion:

We present the data of CCT in term and preterm infants in Indian population. We believe that the premature babies have slightly thicker corneas than mature term babies.