Related Experiment Video
Updated: Jan 25, 2026

A Revised Surgical Approach to Induce Endolymphatic Hydrops in the Guinea Pig
Published on: June 4, 2020
Ocular size and shape in lens-induced Myopization in young Guinea pigs
Li Dong1, Xu Han Shi1, Yi Kun Kang2
1Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Background:
Lens-induced myopization in guinea pigs has been used as model for the process of myopization in humans. It has not been explored yet whether the change in globe shape in eyes undergoing myopization is similar in experimental myopia in guinea pigs and in clinical myopia in patients.
Methods:
The study included 70 guinea pigs (age:2-3 weeks) equally divided into a study group with lens-induced myopization for 5 weeks, and a control group wearing goggles with no refractive power. The globe diameters were measured using a microcaliper after enucleation.
Results:
The horizontal globe diameter (9.19 ± 0.15 mm versus 9.15 ± 0.18 mm; P = 0.25) and vertical globe diameter (9.02 ± 0.11 mm versus 8.99 ± 0.14 mm; P = 0.29) did not differ significantly between the study group and control group. The sagittal diameter was significantly longer in the study group (8.96 ± 0.15 mm versus 8.84 ± 0.14 mm; P = 0.001). While the vertical and horizontal globe diameters were correlated with each other in a ratio of approximately 1:1 (non-standardized regression coefficient B:0.94;95% confidence interval (CI):0.73,1.15), the steepness of the regression lines of the associations of both diameters with the sagittal diameter were flatter (horizontal to sagittal diameter: B: 0.64; 95% CI: 0.44,0.83; vertical to sagittal diameter:B:0.55;95% CI:0.41,0.69). Correspondingly, the ratios of horizontal-to-sagittal globe diameter and of vertical-to-sagittal globe diameter decreased (P < 0.001) with longer sagittal diameter.
Conclusions:
For each mm axial elongation in young guinea pigs the horizontal globe diameter increased by 0.64 mm (95%CI:0.44,0.83) and the vertical diameter by 0.55 mm (95% CI:0.41,0.69), indicating that the globe enlargement occurred predominantly in the sagittal direction. Axial elongation in guinea pigs led to a similar relative change in ocular shape as in humans.
Related Concept Videos
Molecular Shape and Polarity
Cell Size
Surface Area
Cells can take in nutrients and water via diffusion through the plasma membrane itself or through specific channels in the membrane. The area of the membrane surrounding...
Molecular Shapes
Two regions of electron density in a diatomic...
VSEPR Theory and the Basic Shapes
First Derivatives and the Shape of a Graph
Second Derivatives and the Shape of a Graph

