El Gendy Heba A, Khalil Noha M, Eissa Iman M, Shousha Shireen Ma
Professor of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, Egypt.
Associate Professor of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, Egypt.
J Ophthalmol. 2018 Sep 16;2018:8072140. doi: 10.1155/2018/8072140. eCollection 2018.
Studying the early effect of different extraocular muscle (EOM) surgeries on corneal biomechanics.
This is a prospective, nonrandomized, interventional study, in which 42 eyes of 29 candidates for EOM surgery for strabismus correction at Cairo university hospitals, aged 14-37 years, were recruited. All participants had measuring of the visual acuity, refraction (spherical equivalent (SE)), assessment of the EOM motility and muscle balance, sensory evaluation, fundus examination, and assessing the ocular biomechanics using the Ocular response analyzer (ORA, Reichert, INC., Depew, NY) noting the corneal hysteresis (CH) and corneal resistance factor (CRF) preoperatively. Same patients were reassessed using ORA 4 weeks postoperatively following a different standard EOM surgery (recti weakening/strengthening and inferior oblique weakening either (graded recession) according to the surgical indication, and ∆CH and ∆CRF were calculated, each is the preoperative - the postoperative value.
∆CH and ∆CRF = -0.78 ± 1.56 and -0.72 ± 2.15, respectively, and a highly significant difference was found between each of the pre- and postoperative CH and CRF ( < 0.001). 18 eyes had single EOM surgery, while 24 had multiple (2 or 3) EOM surgery; ∆CH in the single group = -1.28 ± 1.5, and ∆CH in the multiple group = 0.4 ± 1.49 (=0.07). 23 eyes had EOM weakening surgery, while 18 had combined weakening and strengthening EOM surgery: ∆CH in the weakening group = -1.24 ± 1.77 and ∆CH in combined group = -0.26 ± 1.07 (=0.04). A nonsignificant difference was found for ∆CRF (=0.53).
A different EOM surgery has an early tendency for increase of the postoperative CH specially for muscle weakening procedures (recti recession/inferior oblique muscle weakening).
研究不同眼外肌（EOM）手术对角膜生物力学的早期影响。
这是一项前瞻性、非随机、干预性研究，招募了开罗大学医院29例年龄在14 - 37岁、因斜视矫正而接受EOM手术的患者的42只眼睛。所有参与者均进行了视力、屈光（等效球镜度（SE））测量，EOM运动和肌肉平衡评估、感觉评估、眼底检查，并使用眼反应分析仪（ORA，Reichert公司，纽约州迪皮尤）评估眼生物力学，记录术前角膜滞后（CH）和角膜阻力因子（CRF）。同一组患者在接受不同标准的EOM手术后4周，使用ORA进行重新评估（根据手术指征进行直肌减弱/加强和下斜肌减弱（分级后退）），并计算∆CH和∆CRF，每个值均为术前值减去术后值。
∆CH和∆CRF分别为 - 0.78 ± 1.56和 - 0.72 ± 2.15，术前和术后CH与CRF之间均存在高度显著差异（<0.001）。18只眼接受单条EOM手术，24只眼接受多条（2条或3条）EOM手术；单条手术组的∆CH = - 1.28 ± 1.5，多条手术组的∆CH = 0.4 ± 1.49（P = 0.07）。23只眼接受EOM减弱手术，18只眼接受EOM减弱与加强联合手术：减弱手术组的∆CH = - 1.24 ± 1.77，联合手术组的∆CH = - 0.26 ± 1.07（P = 0.04）。∆CRF差异无统计学意义（P = 0.53）。
不同的EOM手术有术后CH增加的早期趋势，特别是对于肌肉减弱手术（直肌后退/下斜肌减弱）。
