[Magnetic resonance imaging of of the right extraocular muscle paths in healthy persons and in patients with high myopia].
OBJECTIVE
To investigate the paths of the rectus extraocular muscles (EOMs) in patients with high axial myopia, using high-resolution magnetic resonance imaging (MRI).


METHODS
Coronal MR images (T1 weighting) of the orbit were obtained with controlled gaze. Positions of recti EOMs were measured digitally in the middle of the orbit, using the NIH-image analysis software. Orbits of three different patient groups were analysed. Group 1 (n = 14 orbits): Patients with high axial myopia and restrictive eye motility. Group 2 (n = 8 orbits) subjects with high axial myopia and normal eye motility. Controls (n = 11 orbits) with normal eye motility and no refractive error.


RESULTS
In comparison to the controls, patients with high axial myopia were found to have significant misplacement of the recti EOMs. Thus in group 1 (group 2 within brackets) the lateral rectus muscle (LR) was misplaced 2.9 (1.4) mm into the lower temporal quadrant p < 0.001 (p = 0.07). The course of the superior rectus muscle (SR) was shifted 1.5 (1.5) mm medially p = 0.02 (p = 0.03) and the path of the inferior rectus muscle (IR) 1.3 (1.3) mm medially p = 0.06 (p = 0.06). The medial rectus muscle (MR) showed a 1.3 (1.2) mm downward mislocation p = 0.01 (p = 0.07).


CONCLUSIONS
In patients with high axial myopia (group 1 and group 2) misplacement of all rectus EOMs could be demonstrated by high resolution MRI with controlled gaze. All patients showed an approximately equal amount of MR, SR and IR mislocation. However, misplacement of the LR was significantly greater in patients with high myopia and restrictive eye motility (group 1) than in those without restrictive ocular motility (group 2), p = 0.03. We therefore assume that LR downward mislocation is a major determinant for restrictive eye motility in high myopia.
Schroeder
B
B
Augenklinik für Schielbehandlung und Neuroophthalmologie, Justus-Liebig-Universität Giessen. schroed2@mailer.uni-marburg.de
Krzizok
T
T
Traupe
H
H
D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005133:Eye Movements; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009216:Myopia / Q000150:complications / Q000175:diagnosis*; D009801:Oculomotor Muscles / Q000473:pathology* / Q000503:physiopathology; D013285:Strabismus / Q000150:complications / Q000175:diagnosis*
Magnetresonanztomographische Messungen des Verlaufs der geraden äusseren Augenmuskeln bei Normalpersonen und bei Patienten mit hochgradiger Kurzsichtigkeit.