Retention of Host Embryonic Descemet Membrane in Endothelial Keratoplasty

Splitting of the Recipient's Descemet Membrane in Descemet Membrane Endothelial Keratoplasty-Ultrastructure and Clinical Relevance

PURPOSE

In Descemet membrane endothelial keratoplasty (DMEK), lamellar splitting of the Descemet membrane (DM) may occur during stripping of host DM, leaving residual DM on the recipient's DMEK interface. The purpose of this study was to determine the incidence rate of lamellar splitting of DM during DMEK and to describe the ultrastructure of DM in these eyes.

DESIGN

Retrospective consecutive case series.

METHODS

setting: Institutional, single-center.

PATIENT POPULATION

Total of 664 eyes with Fuchs endothelial corneal dystrophy (FECD) scheduled for primary DMEK.

INTERVENTION

DMEK.

MAIN OUTCOME MEASURES

The incidence rate of lamellar DM splitting in the recipients' eyes; ultrastructural alterations of stripped DM specimens (transmission electron microscopy); preoperative best-corrected visual acuity (BCVA), central corneal thickness (CCT), and prevalence of diabetes mellitus.

RESULTS

Sixty-three of 664 eyes (9.5%) with FECD showed lamellar splitting of DM resulting in the dissociation of 2 separate layers. Transmission electron microscopy revealed accumulations of banded and wide-spaced collagen between the thicker posterior banded layer and the thin anterior banded layer, which is adhesive to the corneal stroma. Lamellar splitting occurred along these abnormal collagen inclusions, demarcating the borderline between both layers of DM.

CONCLUSIONS

Lamellar DM splitting occurs during DM stripping in almost 10% of eyes with FECD. This phenomenon appears to be caused by abnormal collagenous material deposits at the borderline between anterior and posterior layers of DM.

Textural interface opacity after Descemet-stripping automated endothelial keratoplasty

PURPOSE

To describe cases of interface haze, also known as textural interface opacity, after Descemet-stripping automated endothelial keratoplasty (DSAEK).

SETTING

Department of Cornea, External Disease, and Refractive Surgery Service, Duke Eye Center, Durham, North Carolina, USA.

DESIGN

Retrospective case series.

METHODS

Patients' clinical and demographic characteristics, cornea donor information, surgical technique, histopathology, and anterior segment optical coherence tomography (OCT) were reviewed retrospectively and clinical outcomes reported.

RESULTS

The interface haze that developed after DSAEK comprised 2 types of textural interface opacity; that is, total (11 cases) and partial (3 cases). The time of onset of textural interface opacity ranged from 1 day to 7 weeks postoperatively. Although most patients with textural interface opacity showed improvement, with a corrected distance visual acuity better than 20/50, 3 had persistent decreased visual acuity and required repeat DSAEK. Seven eyes had concurrent phacoemulsification with intraocular lens implantation and DSAEK. The corneal graft was inserted with an Endoserter device in 11 eyes, an insertion forceps in 2 eyes, and a cystotome needle in 1 eye. Histopathology of the grafts of eyes that required repeat DSAEK showed no inflammation, no foreign-body deposit, and no fibrosis. Anterior segment OCT showed increased hyperreflectivity in the interface.

CONCLUSIONS

Although the etiology of textural interface opacity is unclear, it may be related to retained ophthalmic viscosurgical device (OVD) or an adhesive property of the OVD used during the surgery. Although most cases resolve with time, repeat DSAEK may be an effective treatment for refractory cases.

FINANCIAL DISCLOSURE

Dr. Kim is a consultant to Ocular Systems, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

Inadvertent placement of a glaucoma tube into the graft-host interface of an eye with previous Descemet stripping automated endothelial keratoplasty

PURPOSE

The aim of this study was to report the inadvertent insertion of a glaucoma tube into the graft-host interface in a patient with previous Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

This is a retrospective case report.

RESULTS

A 56-year-old aniridic woman with a history of multiple failed penetrating keratoplasties (PKPs) and glaucoma underwent DSAEK under failed PKP of her left eye at our institution. After undergoing a subsequent glaucoma tube placement by an outside glaucoma specialist, the tube was identified in the DSAEK-PKP interface. The tube was successfully repositioned at the time of repeat PKP with placement of a Boston type I keratoprosthesis.

CONCLUSIONS

Inadvertent insertion of a glaucoma tube into the DSAEK interface may result in ocular morbidity in patients with previous DSAEK surgery.

Reproducibility of graft preparations in Descemet's membrane endothelial keratoplasty

PURPOSE

To assess the reproducibility of manual graft preparation and evaluate the incidence rate and nature of structural anomalies of Descemet's membrane (DM) preventing successful graft preparation in DM endothelial keratoplasty (DMEK).

DESIGN

Prospective, single-center, nonrandomized, consecutive case series.

PARTICIPANTS

We analyzed 350 corneoscleral buttons from donors aged 18-95 years stored in Optisol-GS or Dulbecco's modified Eagle's medium and used for DMEK surgery in 343 consecutive patients with Fuchs' endothelial dystrophy or pseudophakic bullous keratopathy.

METHODS

Residual endothelial cell-DM complexes obtained after successful DM stripping for DMEK and whole donor corneas obtained after unsuccessful DM stripping were examined by transmission electron microscopy and immunohistochemistry.

MAIN OUTCOME MEASURES

Accuracy of the cleavage plane between DM and corneal stroma and structural abnormalities of the DM-stroma interface.

RESULTS

Uneventful manual separation without any disruption of DM was achieved in 335 of 350 donor corneas (95.7%) by use of a previously established bimanual submerged preparation technique. Correspondingly, the peeled DM specimens revealed a regular and smooth cleavage plane exposing the amorphous interfacial matrix on their anterior surface. Although 8 of 350 donor corneas (2.3%) showed focal adhesions of DM to the corneal stroma and developed isolated tears during stripping, preparation of the graft could be successfully completed. However, 7 of the 350 donor corneas (2.0%) showed extremely strong adhesion and multiple tears of DM, preventing successful preparation of the graft. These specimens revealed either ultrastructural (peg-like interlockings) or biochemical abnormalities (increased staining intensities for adhesive glycoproteins) along the DM-stroma interface.

CONCLUSIONS

Using an appropriate technique, manual preparation of grafts for DMEK with reproducible tissue qualities is possible in the vast majority (98%) of donor corneas. Although a relatively rare phenomenon, interindividual variations in DM structure and composition may be responsible for failure of graft preparation in about 2% of donor corneas.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.