RESUMO
The mouse model has been widely employed to explore the mysteries of myopia. For now, existing techniques for induction of experimental myopia in mice can be classified into three types: (1) devices directly glued to the fur; (2) devices attached using a combination of glue and sutures; (3) devices attached using a skull-mounted apparatus. These techniques each have its advantages, disadvantages when considering the devices stability, safety, complexity, effectiveness, and so forth. Thus, techniques for myopia induction in mice have yet to be further refined to popularize the applications. In this pilot study, we introduce a new head fixation device named the head-mounted spectacle frame apparatus for the study of mouse lens-induced myopia. Surgical procedures for device attachment were relatively simple and easy to learn in our study. Effective myopia induction was validated by retinoscopy refraction and axial length measurement using optical coherence tomography. In addition, it showed improved compliance and reliable safety when compared to the published methods. The head-mounted spectacle frame apparatus provides a new choice for the study of lens-induced myopia in mouse. It also allows for the use of form deprivation, making it attractive for future experimental mouse myopia trials.
RESUMO
PURPOSE: To study the influence of NaCl solution with different concentration on lens transparency in anesthetized mice. METHODS: Four kinds of NaCl solution with different concentration were prepared as eye drops to imply graded osmolarity (100, 300, 500 and 1000 mOsmol/kg). Five groups of anesthetized mice were set-up to induce lens opacity, in which four groups were treated with NaCl solution and another group naturally exposed to air. The lens opacity was graded as no opacity, mild, medium and severe opacity at 0, 10, 20, 30, 45 and 60 min after the start of the experiment. A numerical value from 0 to 3 was assigned to each grade for the cataract index (CI) calculation and data analysis. The same procedure was repeated in all groups 48 h later. The reversion process of lens opacity was explored using a hypotonic NaCl solution (100 mOsmol/kg) in another pair of groups, a 500 mOsmol/kg NaCl solution group and natural exposure group. The gross appearance and time course of development and reversion of lens opacity were assessed. RESULTS: Lens opacity primarily developed in a hypertonic NaCl solution-treated and naturally exposed eyes, and the gross anatomical appearance were similar. The speed of lens opacity development and CI changes were osmolarity-dependent, and the higher NaCl concentration solution used, the faster and more severe the formation of opacification. Both hypertonic NaCl-solution-induced lens opacity and natural exposure induced lens opacity could be resolved by hypotonic NaCl solution prior to anesthesia recovery. CONCLUSIONS: This study indicates a crucial effect of NaCl concentration on the development and reversion of lens opacity in the anesthetized mice, and support the osmolarity theory in the reversible lens opacification phenomenon. It is also of practical significance to mouse eye studies that require lens transparency.
