It May Tear, Take Care

We report a case of lattice corneal dystrophy with intraoperative challenges faced during deep anterior lamellar keratoplasty (DALK) and the steps to prevent the same. A 43-year-old female presented with progressive blurring of vision in both eyes (BE) for the past 10 years. On examination, unaided corrected visual acuity was 6/36 in BE with no pinhole improvement. On slit lamp biomicroscopy, BE showed subepithelial linear deposits with underlying anterior to mid-stromal linear branching lattices in the center and mid-periphery of the cornea [Figure 1]. The rest of the anterior segment and fundus examination was within normal limits. Central corneal thickness, as measured on anterior segment optical coherence tomography, was 530 microns in right eye and 510 microns in left eye. The systemic examination was unremarkable. A diagnosis of BE type 1 lattice corneal dystrophy was made.Figure 1: Slit lamp image with retro illumination showing subepithelial deposits with stromal lattice lines in right eye (a) and left eye (b)The patient was taken for right eye DALK. Intraoperatively, perforation occurred during trephination in three clock hours temporally. As it was not possible to proceed with DALK, penetrating keratoplasty (PK) was performed. Additional sutures were placed temporally, as the wound was leaking due to a straight cut. Histopathological examination of the corneal button confirmed the diagnosis of type 1 lattice dystrophy with stromal and subepithelial deposits of amyloid [Figure 2]. At two-week postoperative period, the patient’s best corrected visual acuity was 6/12 with a well-opposed clear central corneal graft [Figure 3].Figure 2: (a) H&E staining of host corneal button showing subepithelial eosinophilic deposits, focal Bowman’s membrane damage with multiple eosinophilic deposits up to mid-stroma. (b) Congo red stain of host corneal button showing apple-green birefringence of amyloidFigure 3: Slit lamp image was taken at two-week postoperative follow-up showing a well-opposed central clear corneal graft with additional sutures placed temporally (black arrow)Lattice corneal dystrophy is a stromal corneal dystrophy caused due to mutation of the TGFB1 gene. It comprises amyloid deposition in the stroma and subepithelial layers.[1] The main modality of treatment for low visual acuity in lattice dystrophy is keratoplasty. Previously popular PK has now mostly been replaced with DALK.[2] The literature review suggests DALK is a better alternative due to the reduced risk of intraoperative expulsive hemorrhage and lesser chances of graft rejection and secondary glaucoma in the postoperative period. However, one of the major complications of DALK is intraoperative perforation of Descemet’s membrane.[3,4] Due to the altered biomechanics of the cornea, including decreased elasticity and stiffness parameters in lattice dystrophy, the chances of Descemet’s membrane (DM) perforation may be higher while performing DALK, as is evidenced in our case.[5] Thus, careful trephination is required, and guarded trephine may be a better instrument to prevent the above-said complication. Among the surgical modalities of management of lattice corneal dystrophy, DALK seems to be superior. However, considering the reduced elasticity and stiffness, the use of guarded trephine may be helpful in preventing intraoperative DM perforation. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.