Treatment of A-pattern esotropia with marked mongoloid slanting palpebral fissures

Background: The association of oblique palpebral fissures and A- or V-patte rn has not been clarified. We report two cases of A-pattern esotropia with marked mongoloid slanting palpebral fissures associated with vertical displ acement of the horizontal rectus muscle. Cases: Case 1 was a boy with Prade r-Willi syndrome. He showed A-pattern esotropia with upward slanting palpeb ral fissures. Severe superior oblique muscle overaction was observed. Case 2 was a girl with meningocele. She also showed A-pattern esotropia with upw ard slanting palpebral fissures. Observations: In case 1. weakening surgery of the superior oblique muscles did not improve the A-pattern. Coronal ima ges of computed tomography showed one-half-muscle-width upward displacement of both lateral rectus muscles. After downward transposition surgery of th e lateral rectus muscles. the preoperative A-pattern of 25 prism diopters ( PD) was successfully corrected to 10 PD. In case 2 also, upward displacemen t of both lateral rectus Muscles was shown by computed tomography. The preo perative A-pattern of 26 PD was corrected to 4 PD postoperatively after upw ard transposition surgery of the medial rectus muscles. Conclusions: The ve rtical displacement of horizontal rectus muscles was considered the princip al cause of A-pattern in these cases associated with marked mongoloid slant ing palpebral fissures. Jpn J Ophthalmol 2001;45:482-486 (C) 2001 Japanese Ophthalmological Society.