failed descemet‘s membrane endothelial keratoplasty (dmek) grafts - a clinicopathologic analysis -

Failed Descemet‘s Membrane Endothelial Keratoplasty (DMEK) Grafts

- A Clinicopathologic Analysis - L. M. Heindl, MD, C. Hofmann-Rummelt, U. Schlötzer-Schrehardt, PhD,

F. E. Kruse, MD, C. Cursiefen, MD

Department of Ophthalmology and Eye Hospital, University Erlangen-Nürnberg, Germany

Chairman: Prof. F.E. Kruse, MD

We have no financial interests or relationships to disclose.

Background

Descemet‘s Membrane Endothelial

Keratoplasty (DMEK)

is a new surgical alternative to standard full-

thickness penetrating keratoplasty (PK) for the

treatment of corneal endothelial disorders

(~40% of all keratoplasties performed).

Purpose

To describe the clinicopathologic findings

in failed Descemet’s membrane endothelial

keratoplasty (DMEK) grafts.

Patients and Methods

- Retrospective interventional case series

- Three consecutive patients with three DMEK failures

undergoing secondary penetrating keratoplasty

- Light and electron microscopic analysis

Clinical Data of DMEK Failures

Case

No.

Age,

Gender

Preoperative Diagnosis

Primary Procedure

Donor

ECD

Re-

bubbling

Postoperative

Graft Position

Interval between PK and DMEK

1 70 F PBK DMEK 2909 1 Persistent

partial detachment

5 months

2 78 F Fuchs + Cataract

Triple-DMEK

2920 0 Complete detachment

1 month

3 70 F PBK DMEK 2454 1 Complete

(re-)attachment

5 months

ECD = Endothelial cell density (cells/mm²); F = Female; PBK = Pseudophakic bullous keratopathy; Fuchs = Fuchs’ endothelial dystrophy; DMEK = Descemet’s membrane endothelial keratoplasty

Histopathologic Findings / Case 3

HE, × 200HE, × 400HE, × 400

HE, × 12.5

Stromal fibroblasts above detached Descemet’s membrane

Endothelial cell showing fibroblastic transformation

Posterior collagenous layer

Histopathologic Results

- Endothelial cell count:

1.3 ± 1.5 cells / 8 HPF (range, 0 - 3 cells / 8

HPF)

- Posterior collagenous layer:

1 / 3

- Chronic stromal inflammation:

1 / 3

- Interface fibrosis:

0 / 3

- Epithelial ingrowth:

0 / 3

- Retained Descemet‘s membrane:

0 / 3

- Malpositioning of Descemet‘s membrane: 0 /

3

Ultrastructural Findings / Case 3

3 µm 5 µm

5 µm

Fibroblastic transformation of endothelial cells

Attached Descemet’s membrane

2 µm

Close connection between Descemet’s membrane and stroma

Stromal fibroblast within the layer gap of detached Descemet’s membrane

Conclusion

Descemet membrane endothelial keratoplasty

(DMEK) failures are mostly primary due to the

loss and alteration of endothelial cells.

Other contributings factors may include

retrocorneal membrane formation and

chronic stromal inflammation.