The lid fissure changes can be caused by strabismus surgery. The purpose of this study was to evaluate the effect of the strabismus surgery on lid fissure alteration in Amirolmomenin Hospital of Rasht, Iran.

In this cross-sectional study, all candidate of strabismus surgery were included in state of a variety of strabismus surgery according preoperative deviation in the 2016 to reach a sufficient sample size (n = 60 cases). All of the patients who were candidates for strabismus surgery were evaluated for the vertical palpebral fissure height, and MRD1 and MRD2, with clinical examination, one day prior to the surgery and one-month and three month after.

97 eyes (47 left eyes, 50 right eyes) under strabismus surgery, 63.8% (37 cases) were female and 36.2% (21 persons) were male. The average and standard deviation of age was 19.7 ± 13.8 years. The results of our study showed that the pre and postoperative deviation was statistically significant in all surgical methods (P <0.05). Also, changes in LFH and MRD2 were performed before-1 month and before-3 months in medial rectus and lateral rectus recess were statistically significant (P <0.05). The effect of correction of deviation per millimeter on LFH before-3 months were in medial rectus recession surgery 0/138 ± 0.031mm and in lateral rectus recession surgery 119.11 ± 0.024mm respectively, that was statistically significant (P<0.05. ?

The results of our study showed change in medial and latral rectus recession surgery in eyelid fissure, in front view of the eyes (LFH), and Marginal reflex distance from lower eyelid (MRD2). In latral rectus recession, In addition to the two above mentioned, cornea reflex from the upper eyelid (MRD2) increased significantly over time. Therefore, it seems necessary to consider these patients to be aware of possible changes in the eyelid fissure before the strabrismus surgery.