| | | | | | The Medical Algorithms Project |
|
| Chapter : | ch44. Pediatrics | Section : | Assessment of Neonatal Well-Being and Development | | Estimating Gestational Age in a Premature Infant Based on the Grading System of Hittner et al for the Anterior Vascular Capsule of the Ocular Lens | | Copyright (c) 2006-2007, Institute for Algorithmic Medicine, Houston, TX, USA. All rights reserved. |
|
Overview :
Hittner et
al developed a grading scheme for the anterior vascular capsule of the ocular
lens that correlates with gestational age. This can estimate the approximate age
for a premature infant. The authors are from Baylor College of Medicine in
Houston.
|
Appearance of the Anterior Vascular
Capsule |
Grade |
Gestational
Age |
|
vascularity extends to
center with no clear zone |
4 |
27 – 28 weeks |
|
central clearing with
vascularity extending into inner third |
3 |
29 - 30 weeks |
|
central clearing in
central half to two thirds |
2 |
31 – 32 weeks |
|
vascularity limited to
outer third of capsule |
1 |
33 – 34 weeks |
|
no
vascularity |
0 |
35+ weeks |
| | References: | |
Hittner
HM, Hirsch NJ, Randolph AJ. Assessment of gestational age by examination of the
anterior vascular capsule of the lens. J Pediatrics. 1977; 91: 455-458. (Figure
3, page 456)
|
|
| | | | | |