Purpose: To investigate the changes in extraocular muscle thicknesses by variations in the thyroid stimulating antibody (TSAb) level in patients with thyroid eye disease (TED). Methods: A total of 67 TED patients were enrolled. They were divided into two groups: an experimental group with clinically significant elevated TSAb levels (≥140 IU/L) and a control group (TSAb <140 IU/L). All of the lateral, medial, superior, and inferior rectus muscle thicknesses were measured with the aid of anterior segment optical coherence tomography (OCT). The average thicknesses for both eyes were recorded for each patient based on the values measured at the ends of the muscles (which become vertically thinner from the points of tendon attachment). We measured changes in TSAb levels and extraocular muscle thicknesses after two follow-up periods and sought correlations among these parameters. Results: At the initial visits, the inferior rectus muscle thickness was positively correlated with the TSAb level in the experimental group (p = 0.045, r = 0.478). None of the medial, superior, or lateral rectus muscle thicknesses were so correlated. On follow-up, the variation in TSAb level correlated negatively with changes in lateral rectus muscle thickness (p = 0.038, r = -0.357). The superior rectus muscle thickness tended to be negatively correlated with the TSAb level, but statistical significance was not attained (p = 0.146, r = -0.669). The thicknesses of the inferior and superior rectus muscles did not change over time. Conclusions In TED patients, TSAb variations seem to reflect the extent of periorbital tissue edema, thus correlating negatively with especially lateral rectus muscle thickness changes.

Purpose: We present a case of a subconjunctival abscess formation with periorbital cellulitis following scleral buckling (SB) and pars planar vitrectomy (PPV).Case summary: A 51-year-old female patient came to our hospital with complaints of ocular pain and discharge in the right eye. The patient underwent SB and several times of PPV for multiple rhegmatogenous retinal detachment due to acute retinal necrosis. The onset of symptoms was 9 months after the last vitrectomy. A subconjunctival abscess was seen at 8 o'clock position on slit lamp, and periorbital cellulitis was observed on computed tomography image, the patient underwent an incision and drainage (I&D) surgery. Another 9 months later, a subconjunctival abscess was newly found at 4 o'clock position. Since the abscess site and the position of the stitch which sutured the buckle sponge was exactly same, the cause of infection was thought to be the sponge suture materials. Along with I&D surgery, the suture at the end of the sponge was removed. After then, conjunctival and periorbital inflammation got improved and the patient is still in the process of examination to date. Conclusions Subconjunctival abscess or periorbital cellulitis is a rare complication of SB, caused by the use of an exogenous materials such as silicon sponge or suture stitches. Therefore, when ocular pain or inflammation is observed in SB patients, early detection and active treatment is required for suspected periorbital cellulitis.