Incidence and Risk Factors for the Ptosis after Trabeculectomy

ABSTRACT

Purpose@#To investigate the incidence and risk factors for the ptosis after trabeculectomy. @*Methods@#We retrospectively analyzed the medical records of 94 patients who underwent trabeculectomy by a single surgeon. Patients with previous eyelid surgery and ophthalmic surgery, as well as those with systemic disease affecting the eyelid, were excluded from the study. Ptosis was defined as higher eyelid crease compared with contralateral eyelid or a ≥2 mm reduction of margin reflex distance-1 after the surgery. Age, sex, bleb location, conjunctival incision site, mitomycin C concentration, range of mitomycin C contact area, and soaking time were analyzed. @*Results@#The incidence of ptosis was 19.1% (18/94) at 6 months after trabeculectomy. There were no statistically significant relationships between postoperative ptosis and the following factors age, sex, surgical site, bleb site, and conjunctival incision site. The incidence of ptosis was significantly higher in the 0.04% mitomycin C group than in the 0.02% mitomycin C group (40.0% vs 11.6%, p = 0.002). The incidence of ptosis was significantly higher in eyes with a large contact area of mitomycin C to the posterior part of the eye, compared to eyes with a smaller contact area (44.4% vs 9.0%, p < 0.001). Logistic regression analysis showed that the range of mitomycin C contact area remained statistically significant. @*Conclusions@#The large contact area of mitomycin C to the posterior part of the eye during trabeculectomy was found to be a risk factor for postoperative ptosis.