Laser-Induced Chronic Ocular Hypertension Model on SD Rats
Summary
Glaucoma is one of the major causes of blindness in the world. Elevated intraocular pressure is a major risk factor. Laser photocoagulation induced ocular hypertension is one of the well established animal models. This video demonstrates how to induce ocular hypertension by Argon laser photocoagulation in rat.
Abstract
Protocol
Check and prepare the equipments
- Anaesthetize the rat by intra-peritoneal injection of ketamine (80mg/kg) and xylazine (8mg/kg) (volume ratio at 2:1).
- Apply one drop of 0.5% alcaine to the rat eyes as topical anesthetics before laser photocoagulation.
- Position the rat and expose the target veins with a curved forceps. Use the footstep to start laser photocoagulation. Apply bout 60 laser spots around the limbal vein (except the nasal area) and 15-20 laser spots on each episcleral aqueous humor drainage vein.
Laser photocoagulation
- Anaesthetize the rat by intra-peritoneal injection of ketamine (80mg/kg) and xylazine (8mg/kg) (volume ratio at 2:1).
- Apply one drop of 0.5% alcaine to the rat eyes as topical anesthetics before laser photocoagulation.
- Position the rat and expose the target veins with a curved forceps. Use the footstep to start laser photocoagulation. Apply bout 60 laser spots around the limbal vein (except the nasal area) and 15-20 laser spots on each episcleral aqueous humor drainage vein.
- After each laser treatment, apply ophthalmic Tobrex ointment on the rat eye to prevent infection.
- Switch off the laser system by turning the key anti-clockwise to point “0”.
- Switch off slit lamp by turning the switch to point “0”.
Discussion
After two laser treatments with 7 days apart, we can elevate the IOP of laser photocoagulated eye by 50% compare with control eye. The elevated IOP can sustain for at least for 3 month after first laser treatment. This rat model of elevated intraocular pressure provide valuable opportunities to study the mechanisms of pressure-induced retinal ganglion cell loss and optic nerve damage that mimic the pathological change in human glaucoma.
Divulgazioni
The authors have nothing to disclose.
Materials
| Material Name | Tipo | Company | Catalogue Number | Comment |
|---|---|---|---|---|
| ULTIMA® 2000SE Argon Laser | Tool | Coherent Inc. | ||
| Protective goggles | Altro | Coherent Inc |
Riferimenti
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- Ji, J. -. Z., Elyaman, W., Yip, H. K., Lee, V. W. H., Yick, L. -. W., Hugon, J., So, K. -. F. CNTF promotes survival of retinal ganglion cells after induction of ocular hypertension in rats: the possible involvement of STAT3 pathway. European Journal of Neuroscience. 19, 265-272 (2004).
- Li, R. S., Chen, B. -. Y., Tay, D. K., Chan, H. H. L., Pu, M. -. L., So, K. -. F. Melanopsin-Expressing Retinal Ganglion Cells Are More Injury-Resistant in a Chronic Ocular Hypertension Model. Investigative Ophthalmology & Visual Science. 47, 2951-2958 (2006).
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- WoldeMussie, E., Ruiz, G., Wijono, M., Wheeler, L. A. Neuro-protection of retinal ganglion cells by brimonidine in rats with laser-induced chronic ocular hypertension. Investigative Ophthalmology & Visual Science. 42, 2849-2855 (2001).
