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A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice
Published on: October 5, 2018
Morphometric changes in the rat optic nerve following short-term intermittent elevations in intraocular pressure
Karen M Joos1, Chun Li, Rebecca M Sappington
1Vanderbilt Eye Institute, Vanderbilt University, Nashville, TN 37232, USA. karen.joos@vanderbilt.edu
Investigative Ophthalmology & Visual Science
|August 7, 2010
Summary
Intermittent, controlled elevations in intraocular pressure (IOP) in rats caused nerve fiber layer thinning and axonal degeneration in the optic nerve within six weeks, mimicking early glaucoma changes.
Area of Science:
- Ophthalmology
- Neuroscience
- Animal Models
Background:
- Intraocular pressure (IOP) fluctuations are common in glaucoma patients.
- The impact of these fluctuations on optic nerve morphology is not well understood.
- Assessing these effects in vivo has been challenging.
Purpose of the Study:
- To develop a rat model for evaluating intermittent, controlled IOP elevations.
- To investigate the morphological effects of these IOP fluctuations on the rat optic nerve.
Main Methods:
- A rat model was created using an adjustable vascular loop to induce transient IOP elevation.
- Intraocular pressure was measured using a pneumatonometer.
- Optic nerve and globe tissues were analyzed using histology and morphometry.
Main Results:
- Daily 1-hour IOP elevations (mean 35.3 mmHg) returned to baseline within an hour.
- Significant nerve fiber layer thinning (22-25%) and ganglion cell soma reduction (7-10%) were observed.
- Optic nerves showed axonal degeneration (6% loss) and increased glial acidic fibrillary protein.
Conclusions:
- A reliable rat model for studying intermittent IOP elevation was established.
- Short-term (6 weeks) intermittent IOP increases induced optic nerve changes consistent with early glaucoma.
- This model provides insights into glaucoma pathogenesis driven by IOP fluctuations.
