2020 Volume 37 Issue 2 Pages 160-164
Here, we report the case of a patient with strabismus fixus without high myopia whose eyeball and orbital volumes differed, as confirmed with the eyeball-to-orbital area ratio. The patient was treated using the SR-LR union suture.
Case: A 58-year-old woman had gradually worsening esotropia for 20 years. Her visual acuity was 1.2 ×－3.75 D OD, and 0.6 ×－3.75 D (C－1.00 D; 170°) OS. Her eye alignment was 90 prism diopters (PD) esotropia and 20 PD left hypotropia at distance and 100 PD esotropia and 25 PD left hypotropia at near. Aversion was full in the right eye, restricting all movements without adduction or depression in adduction in the left eye. The lateral rectus muscle showed an inferior shift and the superior rectus muscle showed a nasal shift. The lateral rectus–superior rectus muscle band was thin and ruptured. Orbital magnetic resonance imaging (MRI) revealed a herniated eyeball from the muscle cone in the left eye. The axis lengths were normal, but the orbital lengths were shorter than normal. The eyeball-to-orbital area ratio was below the average in both eyes. We performed the left SR-LR union suture with left medial rectus muscle recession. The eye alignment improved to 10 PD esotropia at distance and 6 PD esophoria at near.
We assumed that strabismus fixus occurred from the discordance in volume between the eyeball and orbit without high myopia. The eyeball-to-orbital area ratio was useful for the diagnosis of strabismus fixus without high myopia, and the SR-LR union suture was useful for treatment.
