Related Experiment Video
Updated: Aug 19, 2026
A Custom Multiphoton Microscopy Platform for Live Imaging of Mouse Cornea and Conjunctiva
Published on: May 17, 2020
Histology of conjunctival vascular endothelium after filtering surgery with mitomycin C in rabbits
A Assalian1, M W Scroggs, M B Shields
1Duke University Eye Center, Durham, NC, USA.
Objective:
To examine histologic changes in conjunctival vasculature during the first 72 hours following filtering surgery with adjunctive mitomycin C in rabbits.
Design:
Thirty-six New Zealand white rabbits underwent unilateral posterior lip sclerectomy. In 18 rabbits mitomycin C (0.5 mg/mL) was applied subconjunctivally for 5 minutes. The remaining 18 animals were treated with the phosphate-buffered saline vehicle for 5 minutes. Three rabbits from either group were killed at 0, 4, 12, 24, 48 and 72 hours postoperatively.
Outcome Measures:
Degree of vascularity of filtering blebs on gross examination and appearance of conjunctival vascular specimens on light and transmission electron microscopy, as assessed by three masked observers.
Results:
On gross examination the filtering blebs in the mitomycin C group were slightly less hyperemic than those in the control group at 12, 24 and 48 hours and were markedly less hyperemic at 72 hours. Light microscopy showed tightly packed erythrocytes within the conjunctival vessels of the experimental blebs and an almost total absence of endothelium within many of the vascular channels by 72 hours. Transmission electron microscopy showed focal loss of vascular endothelial cells and thrombus formation in the experimental blebs, as early as 12 hours postoperatively.
Conclusions:
Our findings suggest that the decreased vascularity of filtering blebs observed after trabeculectomy with adjunctive mitomycin C is at least partially due to a toxic effect of the agent on the endothelial cells of the conjunctival vessels.
Insights
Mitomycin C (MMC) reduces filtering bleb vascularity after glaucoma surgery by damaging conjunctival vessel endothelial cells. This study observed these histologic changes in rabbits within 72 hours post-procedure.
Area of Science:
- Ophthalmology
- Glaucoma Surgery
- Vascular Biology
Background:
- Filtering surgery is crucial for glaucoma management.
- Mitomycin C (MMC) is commonly used as an adjunct to enhance surgical outcomes.
- Understanding MMC's effect on conjunctival vasculature is vital.
Purpose of the Study:
- To investigate the histologic changes in conjunctival vasculature following filtering surgery with MMC in a rabbit model.
- To assess the timeline of these vascular changes within the first 72 hours.
Main Methods:
- New Zealand white rabbits underwent posterior lip sclerectomy.
- Subconjunctival MMC or vehicle was applied.
- Conjunctival blebs were examined grossly and microscopically (light and transmission electron microscopy) at serial time points (0-72 hours).
Main Results:
- MMC-treated blebs showed reduced hyperemia compared to controls.
- Light microscopy revealed tightly packed erythrocytes and endothelial cell loss in MMC-treated vessels by 72 hours.
- Transmission electron microscopy demonstrated endothelial cell loss and thrombus formation as early as 12 hours postoperatively.
Conclusions:
- Mitomycin C (MMC) causes a toxic effect on conjunctival vessel endothelial cells.
- This endothelial toxicity contributes to the decreased vascularity observed in filtering blebs after glaucoma surgery.
- The findings provide mechanistic insight into MMC's efficacy in glaucoma surgery.
