Cystic Epithelial Ingrowth in a Case of Deep Anterior Lamellar Keratoplasty

In deep anterior lamellar keratoplasty (DALK), complications related to baring of the Descemet membrane such as incomplete exposure or perforations are well known.¹ Epithelial ingrowth, on the other hand, is rare following anterior lamellar keratoplasty and usually occurs as a sheet of cells across the interface.² Herein, we report the first case, to our knowledge, of a cystic pattern of epithelial downgrowth in a case of DALK and its subsequent management.

Ultrasound biomicroscopic examination revealed an echolucent, thin-walled cystic structure attached to the graft-host junction while pressing on the underlying iris tissue with resultant iris atrophy. The cyst was free from the angle, ciliary body, and intraocular lens–capsular bag complex (Figure 1C).

Epithelial ingrowth following lamellar corneal procedures occurs in a diffuse pattern across the ocular structures and through the potential space of the lamellar interface as observed in laser-assisted in situ keratomileusis, Descemet-stripping endothelial keratoplasty, or anterior lamellar keratoplasty.^3,4 A cystic pattern, on the other hand, commonly complicates penetrating trauma or intraocular surgery.⁵

We hypothesize that surface cells migrated across the graft-host junction or through the needle tract to form a nest of cells at the microperforation site that subsequently progressed to a cystic proliferation into the anterior chamber along the path of least resistance. This is evident by the attachment of the cyst to the perforation site at the graft-host junction away from the scleral tunnel and the nature of cells in histopathological sections. Together, fluid turbulence in the anterior chamber precludes a possibility of cell implantation during phacoemulsification. Thus, intraoperative Descemet membrane perforation during DALK can predispose to subsequent epithelial downgrowth, apart from the known consequences of double anterior chamber and enhanced endothelial cell loss.

Epithelial cysts have been treated with a variety of techniques. However, no particular procedure has established its superiority. The primary challenges in this case were to preserve the functioning of the graft as well as provide the advantages of a lamellar keratoplasty. A traditional aggressive approach to epithelial ingrowth may not be practical for a cystic form, where delineation of the cyst margin allows for a more complete excision. Early conservative surgery can preserve the greater integrity of ocular structures as shown in this case and prevent complications associated with progressive ingrowth. A similar observation was obtained by Haller et al⁶ in a different subset of patients. Our approach seems to have successfully prevented recurrence of downgrowth without jeopardizing the graft until the last follow-up at 12 months.

To conclude, cystic epithelial downgrowth is a rare complication of intraoperative Descemet membrane perforation in DALK, which is amenable to conservative surgical treatment.

Correspondence: Dr Sengupta, Cornea and Refractive Services, Priyamvada Birla Aravind Eye Hospital, 10 Loudon St, Kolkata 700017, West Bengal, India (jayansu@hotmail.com).