On the Issue of Eyeball Topography Development in the Intermediate Fetal Period of Human Ontogenesis

Abstract

The article considers the microtopography of the eyeball during the intermediate fetal period of human ontogenesis.Objective – to identify the features of qualitative and quantitative topography characteristics development of the eyeball with the orbit and its contents in the intermediate fetal period of human ontogenesisMaterial and methods. The study was conducted on 50 fetuses of both genders (25 male, 25 female) aged from the 14th to the 27th week of gestation, which make up the collection of Human Anatomy Department of the Federal State Budget Educational Institution of Higher Education Orenburg State Medical University of the Ministry of Health of the Russian Federation. All the material was divided into three age groups: group I (14–18 weeks) contained 18 fetuses, group II (19–23 weeks) contained 19 fetuses, group III (24–27 weeks) contained 13 fetuses. The work was performed by methods of macromicroscopic preparation, by modified N. I. Pirogov's oversplitting method, and by histotopographic method.Results. At an earlier stage, the eyeball occupies a central position in the orbit. By the end of the intermediate fetal period of human ontogenesis, the eyeball shifts closer to the medial wall of the orbit. In the intermediate fetal period of human ontogenesis, the entrance to the orbit has the shape of an ellipse with a height and width equal to 15.01±3.98 mm and 13.91±3.25 mm, respectively. The thickness of the medial, lateral, upper and lower walls of the orbit in the intermediate fetal period is 0.46±0.12 mm, 1.98±0.41 mm, 0.45±0.12 mm and 2.11±0.62 mm, respectively. The predominance of length and thickness of the medial rectus muscle of eye over the lateral rectus muscle of eye was noted in all observation groups.Conclusions. The eyeball topography in the intermediate fetal period of human ontogenesis is similar to the topography in the childhood and adult periods, but it has its own fetal features: the shape of the eyeball, the position in the orbit, the relation to the auxiliary apparatus. The most complex topographic and anatomical relationships are noted at the posterior pole of the eyeball in the area of the visual canal.