Abstract

Volume.123 Number.1

Original article : Clinical science

Effect of Vertical Deviation of Contralateral Inferior Rectus Muscle Recession in Superior Oblique Palsy
Miwa Komori, Hiroko Suzuki, Akiko Hikoya, Yoshihiro Hotta, Miho Sato
Department of Ophthalmology, Hamamatsu University School of Medicine

Purpose: The aim of this study was to investigate the factors affecting vertical deviation of contralateral inferior rectus muscle (IR) recession in superior oblique palsy (SOP).
Subjects and methods: Using medical records, we enrolled 30 patients who were diagnosed with unilateral SOP and underwent contralateral IR recession at the Department of Ophthalmology, Hamamatsu University Hospital, between April 2002 and March 2017. There were 13 congenital cases and 17 acquired cases. Moreover, 17 patients had undergone nasal transposition and 15 patients had a history of strabismus surgery. We calculated changes (amount of correction) in vertical angle of deviation based on pre- and postoperative distant angle of deviation. Next, we divided these values by the amount of IR posterior disposition and used the unit amount of correction [prism diopters (PD)/mm] as an indicator of surgical effects. We compared subjects based on cause of onset, presence/absence of nasal transposition, and history of surgery. We used the Mann-Whitney U test for statistical investigations, with p<0.05 considered to indicate the presence of a significant difference.
Results: The surgical effect (mean±standard deviation) in the 30 cases was 2.9±1.9 PD/mm. For the acquired cases, surgical effects were significantly greater for the no nasal transposition group (3.7±0.9 PD/mm) than for the nasal transposition group (2.2±1.4 PD/mm) (p<0.05). For the congenital cases, surgical effects were significantly smaller for the no nasal transposition group (1.8±1.1 PD/mm) than for the nasal transposition group (4.6±3.0 PD/mm) (p<0.05). With respect to history of surgery, no significant differences were noted between the acquired cases (no history of surgery group: 2.7±1.4 PD/mm, history of surgery group: 2.8±1.8 PD/mm) and the congenital cases (no history of surgery group: 3.0±1.0 PD/mm, history of surgery group: 3.1±2.9 PD/mm).
Conclusions: The surgical effects of vertical deviation of contralateral IR recession in acquired SOP are weaker when there is nasal transposition than without. In addition, it should be kept in mind that surgical effects may vary when performing contralateral IR recession for congenital SOP.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 123: 45-50, 2019.

Key words
Contralateral inferior rectus muscle recession, Nasal transposition, Superior oblique palsy, Vertical deviation, Strabismus surgery
Reprint requests to
Miwa Komori, M.D. Department of Ophthalmology, Hamamatsu University School of Medicine. 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192, Japan