Purpose: To report a case of spontaneous bleb formation in a presumed pellucid marginal corneal degeneration with acute hydrops.
Methods: A 51-year-old man reported sudden ocular pain with a lower conjunctival mass in his left eye. A clinical examination was performed to investigate this lesion.
Results: The intraocular pressure in the left eye was markedly lower compared with that in the opposite eye. Slit-lamp examination of the left eye showed a conjunctival mass inferior to the corneoscleral limbus adjacent to corneal epithelial and stromal edema without perforation. Corneal topography showed the typical bow tie appearance of corneal steepening rotated 120 degrees clockwise. The right eye was totally normal. Fourier-domain optical coherence tomography with a corneal anterior module adaptor clearly showed a break in Descemet membrane and a ruptured corneal stromal cleft under the conjunctiva near the corneal limbus that resulted in spontaneous bleb formation. The cornea gradually healed after bandage treatment; the spontaneous bleb became smaller and the corneal stromal cleft and edema regressed at 3 months with corneal scarring. The intraocular pressure in the left eye recovered to the same level as that in the opposite eye in association with the decreased bleb size.
Conclusions: This case indicated that spontaneous bleb formation in a pellucid marginal corneal degeneration should be included in the differential diagnosis of a conjunctival mass of unknown origin.