Antimetabolite Application Route During Trabeculectomy Increases Risk of Postoperative Ptosis

Abstract

Purpose : To report on the incidence of ptosis following trabeculectomy and identify risk factors for developing postoperative ptosis.

Methods : Charts of patients who underwent primary fornix-based trabeculectomy (trab) or combined phacoemulsification/trabeculectomy (phaco/trab) at the Cizik Eye Clinic between 1/1/2012 and 5/31/2015 were included. Patients with at least 12 months of follow-up were included, and those with previous eyelid surgery or ptosis documented prior to trab were excluded. If both eyes of a patient were eligible, the first eye that underwent surgery was selected. Patients were followed for a maximum of 4 years. Demographics, type of surgery (trab vs. phaco/trab), intraoperative technique (mitomycin-C [MMC] use, route of MMC by pledget or injection, and use of traction suture), use of prostaglandin drops pre- and post-trab, and postoperative data (i.e. presence of ptosis noted by glaucoma specialist, date of ptosis development, and follow-up duration) were recorded. Kaplan-Meier survival curve and stepwise Cox regression analysis were performed.

Results : 102 eyes of 102 patients met the eligibility criteria with a mean age of 66 years (±12, range 24-86) and 49 (48%) males. Of 100 patients who reported race/ethnicity, there were 45 (45%) White, 36 (36%) Black, 1 (1%) Hispanic, and 18 (18%) of other race/ethnicity. 61 (60%) eyes underwent trab and 41 (40%) eyes underwent phaco/trab. Only 3 eyes did not have MMC intraoperatively. MMC was applied by pledget in 66 (65%) eyes and by subconjunctival injection in 33 (32%) eyes. A corneal traction suture was used in 78 (76%) eyes, superior rectus bridle suture in 11 (11%) eyes, and no suture in 13 (13%) eyes. 94 (92%) eyes were on prostaglandin drops pre-trab compared to 9 (9%) post-trab. Mean follow-up duration was 32 months (±12, range 12-53).

44 (43%) eyes developed ptosis at a mean of 22 months (±1.5 standard error) after trab (Figure 1). Of these, 10 (23%) eyes were referred to the Oculoplastics service. Patients with MMC applied by pledget were 2.5 times more likely to develop ptosis than by subconjunctival injection (P=0.028).

Conclusions : The incidence of ptosis after trab is significantly higher in our series than the reported rate of 6.2-19%. MMC applied by pledget during surgery increases the risk of developing ptosis.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Kaplan-Meier Survival Curve