Incidence of ptosis may be high after trabeculectomy with mitomycin C

The incidence of ptosis can be a major complication after trabeculectomy with mitomycin C for the surgical management of glaucoma, according to a study.

Perspective from Steven J. Gedde, MD

The prospective study analyzed 36 patients who underwent trabeculectomy with MMC in one eye to investigate the incidence and clinical factors associated with postoperative ptosis, defined as a decrease in the margin reflex distance of 2 mm or more.

Preoperative median margin reflex distance was 4 mm in the operated eyes and fellow non-operated eyes. In the operated eyes, postoperative margin reflex distance was significantly reduced to 3 mm at 3 months and 2.5 mm at 6 months. Postoperative margin reflex distance did not change at 3 months or 6 months in the non-operated eyes.

Postoperative IOP of the operated eyes was significantly reduced at 3 months and 6 months.

There was a 19% incidence of ptosis at 6 months after surgery.

The change in margin reflex distance did not correlate with the clinical factors of age, spherical equivalent, preoperative margin reflex distance, 6-month postoperative IOP or IOP reduction.

“For glaucoma patients with visual field defect, the additional visual field impairment due to ptosis will further decrease the quality of vision,” the study authors said. “Attention has to be given to ptosis as a major complication following trabeculectomy with mitomycin C.” – by Kristie L. Kahl

Disclosure: The authors report no relevant financial disclosures.

Perspective

Steven J. Gedde, MD

The authors are to be congratulated for adding important information to the medical literature about a complication that is commonly seen after glaucoma filtering surgery. It is not surprising that their study found a higher incidence of ptosis than prior case series. Retrospective studies generally report lower postoperative complication rates than prospective studies such as this one. Surgical complications may be overlooked unless attention is specifically directed toward their detection. Additionally, complications may not be documented in the medical record even when observed, if they are believed to be clinically insignificant.

The study concludes, “Ptosis is a major complication following trabeculectomy with mitomycin C.” All postoperative complications are not equally serious. However, it is difficult to categorize them as “major” and “minor” because individual complications can have a broad range of severity. The number of patients in the study who underwent ptosis repair for functional or cosmetic reasons was not reported, but this information could have helped describe the significance of the complication. Many glaucoma surgeons would argue that ptosis is not a “major” complication, and this designation should be reserved for vision-threatening complications such as endophthalmitis and suprachoroidal hemorrhage.

Steven J. Gedde, MD

OSN Glaucoma Board Member

Disclosures: Gedde reports no relevant financial disclosures.

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Sources/Disclosures

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Source:

Naruo-Tsuchisaka A, et al. J Glaucoma. 2015;doi:10.1097/IJG.0000000000000174.