Histopathology of deep anterior lamellar keratoplasty

Pawan Prasher MD¹ ², Orkun Muftuoglu MD², R N Hogan MD Ph D², V. Vinod Mootha MD²

¹Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, India;
²University of Texas Southwestern Medical Center at Dallas, Texas, USA.

Purpose: Recent advances in surgical techniques have promoted a paradigm shift in the treatment of corneal diseases from conventional full thickness penetrating keratoplasty to lamellar keratoplasty. The histopathological features of cornea in deep anterior lamellar keratoplasty (DALK) can vary with the type of technique used. We report histopathological findings in three different techniques of DALK.

Methods: Fifteen corneal buttons of patients who underwent DALK for different anterior stromal pathologies were included in the study. Eight patients underwent DALK with Melles' stromal dissection, 5 with big bubble technique and 2 underwent femtosecond laser assisted DALK. Histopathological features related to thickness variation in center versus periphery, interface and peripheral wound edges were compared between these groups.

Results: All the corneal buttons were characterized by absence of Descemet's membrane and endothelium. The anterior stromal findings varied depending upon pre-existing stromal pathology. The interface as well as peripheral edges were smoother and stromal thickness more uniform in femtosecond assisted DALK as compared to Melles' stromal dissection. The corneas having big bubble technique assisted DALK showed artifactual separation of stromal lamellae and increase in total thickness consistent with pneumatic dissection.

Summary: Histopathological findings of cornea vary with different techniques of DALK. The pathologists dealing with these specimens should be aware of advancements in the surgical techniques and changes induced by them in the cornea specimens.