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Corneal diameter, axial length, and intraocular pressure in premature infants
S M Tucker1, R W Enzenauer, A V Levin
1Department of Ophthalmology, University of Toronto, Ontario, Canada.
Insights
Ophthalmologists can now use established normative values for corneal diameter and axial length in premature infants. These measurements correlate with gestational age and birth weight, aiding in ocular assessments.
Area of Science:
- Ophthalmology
- Neonatology
- Pediatric Ophthalmology
Background:
- Premature infants require precise ocular assessments.
- Establishing normative ocular dimensions is crucial for early detection of potential issues.
Purpose of the Study:
- To determine the correlation between corneal diameter, axial length, and intraocular pressure with gestational age and birth weight in premature infants.
- To establish normative values for these ocular parameters in the neonatal period.
Main Methods:
- Corneal diameter was measured using corneal templates.
- Total axial length was determined via standardized A-scan ultrasound.
- Intraocular pressure was measured using a Tonopen II tonometer in 70 premature infants.
Main Results:
- Corneal diameter and axial length demonstrated parallel linear increases with gestational age and birth weight.
- Mean intraocular pressure was 10.3 mmHg (SD, 3.5), with no significant correlation found with gestational age or birth weight.
Conclusions:
- Normative values for corneal diameter and axial length in premature newborns are now established.
- A mean and standard deviation for intraocular pressure in premature infants were determined.
- These established values will assist ophthalmologists in evaluating ocular dimensions in premature infants.
Purpose:
Seventy premature infants 25 to 37 weeks' postconceptional age were examined during their first week of life to determine the correlation of corneal diameter, axial length, and intraocular pressure with gestational age and birth weight.
Methods:
Corneal diameter measurement was determined with corneal templates, total axial length with standardized A-scan ultrasound, and intraocular pressure with a Tonopen II tonometer.
Results:
Corneal diameter and total axial length showed parallel linear increases from 6.2 mm to 9.0 mm and 12.6 mm to 16.2 mm, respectively; however, no significant correlation was found between intraocular pressure and gestational age or birth weight. The mean intraocular pressure was 10.3 mmHg (standard deviation, 3.5).
Conclusion:
Normative values are established for corneal diameter and total axial length as they relate to birth weight and gestational age, and a mean and standard deviation for intraocular pressure in the premature newborn. These values will aid the ophthalmologist in assessing ocular dimensions in premature infants.