Repair of Eyelid Retraction due to a Trabeculectomy Bleb

Abstract

Superior limbal trabeculectomy remains a common surgical treatment for glaucoma. Positional effects on the overlying upper eyelid-both ptosis and retraction-have been associated with the procedure. More than 1 mechanism may explain retraction; however, the eyelid may elevate mechanically due to the underlying raised superior bulbar conjunctiva.

A Vector Force Model of Upper Eyelid Position in the Setting of a Trabeculectomy Bleb

“…3 In 3 cases, Mueller's muscle was specifically evaluated and reported as nonfibrotic. 6 The vector force model is based on physical forces acting on the eyelid to cause mechanical displacement as shown in Figure 1B. Any factor that serves to increase the amount of force directed superiorly (+y direction) and posteriorly (−x direction) or decrease the amount of force directed inferiorly (−y direction) and anteriorly (+x direction) will favor eyelid retraction.…”

“…1,3-6 Additional modalities focusing on the bleb include the placement of bleb compression sutures, posterior needling of the bleb, and cautery-induced scleral fibrosis. 1,4,6 In addition to upper eyelid retraction, ptosis is a known sequela of glaucoma filtration surgery, occurring more frequently with reported rates as high as 12%. 7,8 A myriad of etiologies for ptosis following anterior segment surgery have been proposed, including speculum-induced eyelid edema 9 or horizontal stretching, 10 duration of surgery, 11 myotoxic effect of retrobulbar or peribulbar anesthesia on the levator palpebrae superioris, 12 and ocular inflammation secondary to exposed sutures, prolonged healing time, or underlying uveitic conditions.…”

“…S ince 1975, 16 cases of upper eyelid retraction following the creation of glaucoma filtration blebs have been reported. [1][2][3][4][5][6] Trabeculectomy bleb-induced upper eyelid retraction is an accepted diagnosis, but the mechanism remains unclear. Leading pathophysiologic hypotheses center on chemical, mechanical, and myogenic factors.…”

“…Leading pathophysiologic hypotheses center on chemical, mechanical, and myogenic factors. [1][2][3][4][5][6] The chemical hypothesis theorizes that an unknown sympathomimetic chemical in the aqueous stimulates Mueller's muscle, resulting in eyelid retraction. 1 The mechanical model states that the eyelid is physically elevated by a prominent underlying bleb.…”

“…1 The mechanical model states that the eyelid is physically elevated by a prominent underlying bleb. 2,5,6 The myogenic theory postulates that inflammation leads to Mueller's muscle fibrosis and subsequent eyelid retraction. 3 An array of treatment options has been described that focus on the eyelid, such as levator recession or disinsertion, Mueller's muscle recession or Müllerectomy, fullthickness blepharotomy with placement of adjustable sutures, and hyaluronic acid gel injection for tissue expansion and weight effect.…”