IMPACT OF POSTERIOR STROMAL SCARRING AFTER DWEK ON VISUAL RECOVERY FOLLOWING DMEK

To report a case of limited visual recovery following Descemet Membrane Endothelial Keratoplasty (DMEK) in an eye that previously underwent Descemetorhexis without Endothelial Keratoplasty (DWEK) for Fuchs endothelial corneal dystrophy (FECD).

Opthalmology Department of a tertiary referral center, Lisbon, Portugal.

A 75-year-old female was referred due to progressive visual loss and reduced contrast sensitivity in the left eye (OS) following DWEK combined with phacoemulsification and intraocular lens implantation performed one year earlier. Best corrected visual acuity (BCVA) at presentation was 0.3 (decimal scale). Slit-lamp examination denoted pseudophakia, Descemet’s membrane folds, and a paracentral temporal deep stromal scar along the 4-mm radius of the previous descemetorhexis. Specular microscopy of OS was unmeasurable, and Pentacam HR® (OCULUS Optikgeräte GmbH) revealed a central corneal thickness of 607 mm. A DMEK was performed using 20% sulfur hexafluoride gas without any intraoperative complications. On postoperative day one, the evaluation revealed a clear cornea with the previously observed paracentral temporal stromal scar along the 4-mm of prior descemetorhexis. Subsequent evaluations revealed no complications. At one-year follow-up, BCVA (-4.50x85º) improved to 0.4 (decimal). Slit lamp showed clear graft apart from persistent temporal haze derived from stromal scarring. Anterior segment optical coherence tomography displayed an attached graft despite localized hyperreflectivity in the deep posterior stroma temporally. Corneal wavefront analysis (Pentacam HR®) demonstrated increased high-order aberrations (RMS HOA=2.024 µm), predominantly due to marked trefoil component (|Z₃|=0.426 µm, mainly horizontal Z₃³=+1.154 µm), associated with horizontal coma (Z₃¹=-1.454), slight positive spherical aberration (Z₄⁰=-0.06), and moderate secondary astigmatism (Z₄²=-0.480). The HOA pattern was consistent with a trefoil-dominant irregular optical pattern arising from a posterior stromal scar. Macular and optic disc OCT of OS denoted no abnormalities.

Posterior stromal scarring following DWEK can substantially compromise visual rehabilitation, even if subsequent DMEK is performed. Despite complete graft adherence and resolution of corneal edema following DMEK, residual stromal fibrosis may induce corneal opacity, irregular astigmatism and high-order aberrations, precluding optimal visual recovery. Recognition of this potential outcome is crucial before DWEK decision.