|Year : 1981 | Volume
| Issue : 3 | Page : 183-185
Assessment of gestational age by examination of anterior vascular capsule of the lens
Indra Narayanan, DK Mehta, Ashok Dutta, Sisir Paul
Kalawati Saran Children Hospital, and Deptt. of Ophthalmology, Lady Hardinge Medical College, New Delhi, India
Kalawati Saran Children Hospital, and Deptt. of Ophthalmology, Lady Hardinge Medical College, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Narayanan I, Mehta D K, Dutta A, Paul S. Assessment of gestational age by examination of anterior vascular capsule of the lens. Indian J Ophthalmol 1981;29:183-5
Gestational age of new born babies is of great importance for their management and for medicolegal purpose. Routine conventional assessment is made on maternal history, which is not well recorded in poor socioeconomic strata and physical criteria which are affected by general condition of baby, intra-uterine growth, colour of skin and maternal health. Changes in anterior vascular capsule of lens in intra-uterine and post-natal life are directly associated with development. Based on Hittner's findings of a study on new born babies in our country (where birth weight is more variable) with 27-34 weeks gestation age was undertaken.
| Materials and methods|| |
103 preterm babies with gestational age between 27-34 weeks were included, as cornea was hazy before 27 weeks and anterior vascular capsule was not visible after 34 weeks.
The gestational age of these children was determined on the basis of history and physical and neurological criteria.
Birth weight was recorded soon after birth. Ocular examination was conducted wtih the help of direct ophthalmoscope using + 10 to +20 D lenses after papillary dilation with 5% Drosyn instilled once within 36 hours after birth. Retraction of lids was necessary only in more active babies. Slit lamp examination showed these vascular loops originating from anterior surface of iris and confirmed the findings of direct ophthalmoscope [Figure 1
Grade O One or two loops just reaching beyond pupillary border.
Grade I Few loops forming arcades in one segment of whole circumference.
Grade II Arcade forming in whole circumference reaching to the middle of lens surface.
Grade III Dense loops running towards the centre but not reaching up to the centre.
Grade IV Arcades and loops covering the centre of lens capsule also.
| Observations|| |
The findings in both eyes were similar in all cases except in two babies where straight bands were more in one eye than the other. Clinical photographs with the help of fundus camera were also taken in some cases. [Figure - 1]
The vascular pattern was studied with each week [Table - 1] and it was observed that the different grades could be grouped in four categories Grade IV - 27-28; Grade III - 29-30; Grade II - 31-32; Grade I - 33-34;
The anterior vascular pattern was studied in relation to birth weight [Figure - 2]. It showed that it had no relationship with birth weight or intrauterine growth retardation.
| Discussion|| |
Pupillary membrane or anterior vascular capsule is more constant parameter of development and tends to regress after the viability of foetus is achieved. Though some of the remants of pupillary membrane may be seen in adult life but they do not contain blood and are seen as white cord. The vascular pattern showing regression had a linear relationship with gestational age as show by Hittner et al. Only few cases showed a slight over lap while majority of cases followed grading with gestational age (as shown in [Figure - 2]). This was not related to birth weight. In earlier studies it was shown that low birth weight children had ramants of pupillary memberane but the gestational age was not taken into consideration in these cases. In our study no such relationship was observed [Figure - 2].
The vascular pattern could be made out even after death. Though the vassels appeared thinner they could be visualised 4-6 hours after death beyond which they became obscure due to corneal haze.
In this preliminary study we felt that the procedure can be adopted for assessment because of following reasons :
- The technique is simple and needs an ophthalmoscope only.
- The method can be adopted by a resident doctor with little experience.
- The sick babies are not exposed much in this procedure and this method is very useful in limp babies as well.
- Gestational assessment can be made even after death (upto 4-6 hrs.). It may be of great importance in medicolegal cases where age is disputed.
| References|| |
Dubowitz, LAS, Dubowitz, V, and Goldberg C. 1970, J. of Paediatrics 77 : 1.
Hittner, H.M., Hirsch, J.J., Rudolph A.J,, 1977, J. of Paediatrics 91 : 455.
[Figure - 1], [Figure - 2]
[Table - 1]