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Updated: Feb 1, 2026
A Step by Step Protocol for Subretinal Surgery in Rabbits
Published on: September 13, 2016
[Anti-scarring effect of rapamycin in rabbits following glaucoma filtering surgery]
Xin Kang1, Ying Shen1, Haixia Zhao1
1Center of Myopia, Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, China.
Objective:
To study the anti- scarring effect of rapamycin in rabbits receiving glaucoma filtering surgery.
Methods:
Ninety-six Chinchilla rabbits were randomized equally into 3 rapamycin treatment groups and one control group. All the rabbits underwent trabeculectomy, after which the rabbits in the 3 rapamycin groups were treated with eye drops containing 1%, 3%, or 5% rapamycin in the operated eyes, and those in the control groups were given castor oil 4 times a day. The intraocular pressure (IOP) and inflammatory reaction in the treated eyes were observed, and the PCNA-positive cells in the filtering bleb were detected using immunohistochemistry. RTFs isolated from the Tenon's capsule of the rabbits were cultured in vitro, and the expressions of caspase-3, caspase-8, and caspase-9 in the fibroblasts were detected after treatment with different concentrations of rapamycin.
Results:
The IOP was significantly lower in rapamycin-treated group than in the control group after the surgery (P < 0.05). The counts of the PCNA-positive cells were significantly lower in rapamycin-treated rabbits than in the control group (P < 0.05). Rapamycin treatment dose-dependently increased the expressions of caspase-3 and caspase- 9 at both the mRNA (P < 0.001) and protein (P < 0.001) levels without causing significant changes in the expressions of caspase-8.
Conclusions:
Rapamycin can inhibit excessive proliferation of the fibroblasts in the filtering bleb to reduce scar formation after glaucoma filtration surgery in rabbits. Rapamycin also increases the expressions of caspase-3 and caspase-9 to induce apoptosis of the RTFs.
Insights
Rapamycin eye drops reduced scarring after glaucoma surgery in rabbits by inhibiting fibroblast proliferation and promoting apoptosis. This treatment lowered intraocular pressure and reduced cell proliferation in filtering blebs.
Area of Science:
- Ophthalmology
- Pharmacology
- Cell Biology
Background:
- Glaucoma filtration surgery can lead to scarring, which impairs its long-term efficacy.
- Fibroblast proliferation in the filtering bleb is a key factor in scar formation.
- Rapamycin, an mTOR inhibitor, has shown anti-proliferative and pro-apoptotic effects.
Purpose of the Study:
- To investigate the anti-scarring potential of rapamycin in a rabbit model of glaucoma filtration surgery.
- To evaluate the effect of rapamycin on fibroblast proliferation and apoptosis in the filtering bleb.
Main Methods:
- Trabeculectomy was performed on 96 rabbits, randomized into three rapamycin treatment groups (1%, 3%, 5%) and a control group.
- Intraocular pressure (IOP) and inflammatory reactions were monitored; PCNA-positive cells in filtering blebs were quantified via immunohistochemistry.
- Rabbit Tenon's capsule fibroblasts (RTFs) were cultured, and caspase expressions (caspase-3, -8, -9) were analyzed after rapamycin treatment.
Main Results:
- Rapamycin treatment significantly reduced IOP and PCNA-positive cell counts in filtering blebs compared to controls (P < 0.05).
- Rapamycin dose-dependently increased mRNA and protein expression of caspase-3 and caspase-9 (P < 0.001).
- No significant changes in caspase-8 expression were observed with rapamycin treatment.
Conclusions:
- Rapamycin effectively inhibits fibroblast proliferation and reduces scar formation following glaucoma filtration surgery in rabbits.
- Rapamycin induces apoptosis of rabbit Tenon's capsule fibroblasts (RTFs) by upregulating caspase-3 and caspase-9 expression.
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