https://doi.org/10.31288/oftalmolzh2016369

Topography of inferior oblique muscle’s insertion to the sclera

V.I. Yemchenko, Cand. of Sc. (Med)

Kremenchuk City Children Hospital

Kremenchuk (Ukraine)

E-mail: glmg19@yandex.ua

Background. Object’s localization on the surface of the eyeball is traditionally performed by measuring the distance to other objects. These measurements are made in linear values straight on the eyeball surface. However, the size of the eyeball in every individual is different depending on the age and refraction. When using only linear measurements, it is impossible to localize correctly any given object on the eyeball surface without regard to the eye’s size. As a rule, all distances are given for an average size eye of an adult, 12 mm in radius. Since the sizes of eyeballs of patients, especially of children, are varied depending on the age and refraction, corresponding tables of distances should be done for different eyeball sizes when localizing the zones of insertion of extraocular muscles.

The purpose of the present paper was to specify the localization of inferior oblique muscle’s insertion to the sclera using spherical coordinate system.

Materials and Methods. 20 eyes of 18 patients were examined. Radius of the eyeballs ranged from 9.5 to 12.5 mm. The examinations were performed during strabismus surgeries. To transform the linear values into spherical coordinates, Computed Software for Calculating the Coordinates of Objects on the Surface of the Eyeball Model was used. To map out anatomical formations on the eyeball surface, we created a map of the eyeball surface in rectangular cylindrical projection of ophthalmographical spherical coordinate system (OSCC).

Results. Inferior oblique muscles insertion sites are localized between 80° and 120° longitude and between 25° and -90° latitude. However, the major area of inferior muscle insertion is between 80° and 115° longitude and between -10° and -85° latitude. Herewith, the anterior border of insertion area is mainly located within the range between 100° and 115° longitude and posterior borders are located between 80° and 100° longitude. As for latitude, it is mainly in the area between -10° and -30° for anterior borders and -55° and -85°for posterior borders. The relative longitude of the insertion site is also widely ranged, from minimal (No 5, 14, 20) to maximal (No 8, 16, 17) values.

Conclusions. The use of ophthalmographic spherical coordinate system enables to standardize the localization of inferior oblique muscle insertion sites without regard to the size of the eyeball.

The possible localization of the inferior oblique muscle insertion to the sclera was admeasured within the range mainly between 80° and 115° longitude and -10° and -85° latitude.

Key words: localization of inferior oblique muscle insertion, Spherical coordinate system, mapping of the eyeball surface

 

References

1.Avetisov ES, Kovalevskii EI, Khvatova AV. Guidelines for Pediatric Ophthalmology. M.: Meditsina; 1987. 496 p. Russian.

2.Vit VV.  Vit VV. [The structure of the human visual system]. Odessa: Astroprint. 2003. 664 p. Russian.

3.Mahkamova H. M.[ Anatomical Topographic Features of Extraocular Muscles].  Vestn. ophthalmol. 1970;78-80. Russian.

4.Duke-Elder S. Textbook of Ophthalmology. V.1 St. Louis: Mosby;1941.1080 p. 

5.Helveston E M. Atlas of  Strabismus Surgery. St. Louis – Toronto – Princeton: The C. V. Mosby Company; 1985. 395 p.  

6.Bartels M., Birch-Hirschfeld A., Cords R. Orbita. Nebenh?hlen. Lider. Tr?nenorgane. Augenmuskeln. Auge und Ohr. Berlin: Verlag von Julius Springer; 1930. 745 p.  

7.Sachsenweger R. Augenmuskell?hmungen. Leipzig: VEB Georg Thieme; 1966. 463 p. 

8.Akimenko EV, Okunevych TA. [The relationship between eye ball size and the insertion site of extraocular muscles in 1-3-year-old children with concomitant strabismus]. [Medical and medico-pedagogical rehabilitation of children with refraction abnormalities and diseases of oculomotor system. VI scientific practical conference of pediatric ophthalmologists of Ukraine]. Lviv; 2015: 16-18. Russian. 

9.Yemchenko VI, Mospan VO, Litovchenko SO et al. [Topography of the human eye surface in spherical co-ordinates]. Oftalmol Zh. 2005;5:75-80. Russian.

10.Yemchenko VI, Kukharenko DV, Kirilakha NG et al. [A computer programme for calculation object coordinates on the surface of the human eye]. Oftalmol Zh. 2008;4:49-52. Russian. 

11.Kukharenko DV, Mospan VO, Yemchenko VI. Pat. 37269 UA, MPK A 61 B 3/00, G 09 B 23/00. [Method of calculating the coordinates of objects on the surface of the eyeball model]; owner — Kukharenko DV — 2008 06807; appl. 19.05.2008; publ. 25.11.2008, Bul. № 22. Ukrainian.