Pellucid marginal degeneration and bilateral corneal perforation: case report and review of the literature.

Pellucid marginal degeneration is a relatively uncommon corneal ectatic disorder characterized by inferior peripheral corneal thinning in the absence of infiltration or inflammation. The hallmark of this disorder includes an area of corneal protrusion above the point of maximal thinning rather than within the area of maximal thinning as with keratoconus. A 1 to 2 mm zone of uninvolved normal cornea separates the region of thinning from the peripheral limbus. A characteristic pattern of inferior corneal steepening and subsequent against-the-rule astigmatism is found on corneal topography. A variant of this condition, superior pellucid marginal degeneration, causes similar findings in the superior cornea. Since Schlaeppi1 first coined the phrase in 1957, “marginale inferieure pellucide de la cornee,” a number of reports of corneal edema and hydrops seen concurrently with pellucid marginal degeneration have been documented in the literature,2-7 yet a limited number of reports presenting with coexistent spontaneous corneal perforation and pellucid marginal degeneration exist.8-14 Herein, we describe an unusual presentation of a bilateral corneal perforation in a patient with previously stable pellucid marginal degeneration in the setting of bilateral rigid gas permeable contact lens wear. To the best of our knowledge, this represents the first report of bilateral spontaneous perforation with pellucid marginal degeneration at presentation. All cases of spontaneous perforation reported in the literature are reviewed for similarities and possible predictors of this potentially devastating and rare complication of pellucid marginal degeneration. The intent of this report is to raise awareness to eye care professionals regarding the potential for severe vision-threatening complications associated with pellucid marginal degeneration despite contact lens wear and a previously documented stable examination.