[Applications of Orbit 1.8 Computer Biomechanics Simulation for diagnosis and treatment of congenital superior oblique paresis].

OBJECTIVE

To evaluate the significance of Orbit 1.8 Computer Biomechanics Simulation in the diagnosis and treatment of congenital superior oblique paresis.

METHODS

Fifteen patients with congenital superior oblique paresis were enrolled in the present study. Hess test and other strabismus tests were performed before and after the surgery. Parameters such as contractile force, elasticity, innervation of extraocular muscles and the secondary changes in other muscles were treated by the Orbit 1.8 to simulate the preoperative situation. A biomechanical strabismus model was created. Surgical manipulations were tested on the model to predict postoperative outcomes. After surgery, simulated and actual outcomes were compared.

RESULTS

The predicted results matched with the actual results quite well. Before the surgery, the mean difference between these two data was 1.66 degrees +/- 0.44 degrees in horizontal and 1.97 degrees +/- 0.51 degrees in vertical gaze. After surgery, mean difference in horizontal and vertical gaze of these two data was 1.21 degrees +/- 0.34 degrees and 1.59 degrees +/- 0.41 degrees.

CONCLUSIONS

Orbit 1.8 Computer Biomechanics Simulation offers a biomechanical approach to understand all of the forces that combine to control eye movement and how these forces interact in normal eyes and in eyes with motility problems. It can be used to reflect the causes of strabismus, to design the surgical procedure, to verify the diagnosis and to predict the outcome of surgery. It is a helpful tool in the diagnosis and treatment of ocular motility disorders.