ABSTRACT
Purpose
To verify the cross sectional area (CSA) of fibers positive for myosin type 1 in the global and orbital layers after bupivacaine (BUP) injection in the superior rectus of the right eye of rabbits.
Materials and Methods
A total of 40 rabbits were studied; 32 specimens received a 0.3 mL injection of BUP at 1.5% in the superior rectus of the right eye and were euthanised after 7, 28, 60 and 92 days. Another eight rabbits were used as the control group. Immunohistochemical analysis was performed using anti-slow myosin (type 1) antibodies. The ImageJ software was used to measure the CSA of the fibers. Six slides were excluded from the analysis. Finally, 7,204 fibers were counted and statistically analysed.
Results
The mean CSA was 0.040 µm2 for all the studied fibers. For the orbital layer, mean CSA was 0.038 µm2, whereas the global area measured 0.042 µm2. No statistically significant differences were observed when comparing the orbital layer groups. However, when comparing the mean CSA in the global layer of the control group with the 60-day group an increase was found (0.0339 ± 0.0062 versus 0.0503 ± 0.0114; p = .009).
Conclusion
This study revealed that 60 days after BUP injection, the extra ocular muscle of rabbits presented an increase in the CSA of myosin 1 type fibers in the global layer.
Declaration of interest
Luisa Moreira Hopker: None
Marco Aurélio Senff de Moraes: None
Rodrigo Nitsch: None
Gabriela Wahab Pasqual: None
Pamela Cavagnari: None
Solena Ziemer Kusma: None
Luciane Moreira: None
Edmar Zanoteli: None
Norma Allemann: None
Correction Statement
This article has been republished with minor changes. These changes do not impact the academic content of the article.