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

Abstract

A vector force model systematically accounts for the multiple determinants of upper eyelid position in the setting of a trabeculectomy bleb. This model provides a framework for the evaluation of bleb-induced upper eyelid malposition and offers a logical, mathematical explanation for the occurrence of bleb-induced upper eyelid retraction and the usefulness of previously reported treatment modalities for this clinical entity.

Efficacy and safety of blepharoptosis repair after incisional glaucoma surgery

“…2,5,27 Mechanical as well as myotoxic effects have been proposed. [6][7][8][9][10] Surgical repair of ptosis in these patients carries concerns for bleb or GDD exposure, and data on efficacy and safety is limited. Our study represents the largest case series to date of patients undergoing ptosis repair after incisional glaucoma surgery.…”

Changes in eyelid position after glaucoma filtering surgery

“…[1][2][3][4][5][6][7] Many causes have been proposed to explain its etiology, including anesthesia myotoxicity, mechanical ptosis due to eyelid edema or hematoma and use of lid speculum or bridle suture causing traction of the superior rectus muscle complex. [1][2][3][4][5][6][7][8] In addition to ptosis, glaucoma filtration surgery is a noticed cause of upper eyelid retraction. Its incidence is lower than that of blepharoptosis, with approximately 19 cases reported in the literature thus far.…”

“…Its incidence is lower than that of blepharoptosis, with approximately 19 cases reported in the literature thus far. [8][9][10][11][12][13][14][15] It should only be considered a diagnosis of exclusion over more common causes of retraction such as thyroid eye disease. 15 Three pathophysiologic theories based on chemical, myogenic and mechanical factors have been postulated.…”

“…And finally, the mechanical theory, according to which a prominent bleb would mechanically lift the eyelid. [8][9][10][11][12]14,15 Although mechanical theory is the most obvious and defended, the mechanism by which blebs may cause eyelid retraction remains uncertain. [8][9][10][11]15 The purpose of the present study was to analyze the appearance of upper eyelid retraction and ptosis in patients subjected to glaucoma filtering surgery.…”

“…[8][9][10][11][12]14,15 Although mechanical theory is the most obvious and defended, the mechanism by which blebs may cause eyelid retraction remains uncertain. [8][9][10][11]15 The purpose of the present study was to analyze the appearance of upper eyelid retraction and ptosis in patients subjected to glaucoma filtering surgery. We also investigate whether type of surgery (trabeculectomy versus nonpenetrating deep sclerectomy) with or without phacoemulsification, time from surgery, age, gender, diagnosis (primary open angle glaucoma or pseudoexfoliation glaucoma), use of Mitomycin C (MMC), intraocular pressure (IOP), number of topical anti-glaucoma drugs and the use of prostaglandin analog treatment could contribute to these palpebral fissure changes.…”