Inadvertent Retention of Descemet Membrane in Penetrating Keratoplasty

Successful management of a retained host Descemet's membrane after penetrating keratoplasty (PKP) - A case report

INTRODUCTION AND IMPORTANCE

To report the 21st case showing the rare occurrence of retained Descemet's membrane (DM) following penetrating keratoplasty (PKP). We intend to investigate possible etiologies, expected sequelae, and outcome of neodymium-dpoed yttrium alumnium garnet (Nd: YAG) laser membranectomy.

CASE PRESENTATION

Our case is a 74-year-old male who underwent PKP surgery in the right eye secondary to corneal decompensation following cataract surgery in addition to corneal thinning secondary to superficial keratectomy related to the pre-existing climatic droplet keratopathy (CDK). Postoperative assessment revealed a retro-corneal membrane within the anterior chamber, which was affecting his vision.

CLINICAL DISCUSSION

Based on the post-operative course and the decreased vision as an indication for intervention, it was decided to excise the retained DM. Membranectomy with Nd: YAG laser was performed, and the patient's visual acuity measurement improved from 20/400 to 20/25. However, the endothelial cell count decreased from 1479 to 520 cells/mm2 (35 % loss) at 15 months post YAG membranectomy with clear graft. Histopathological examination confirmed the clinical suspicion of a retained DM, since it was absent in the submitted host corneal tissue in addition to the pre-existing CDK.

CONCLUSION

Retention of DM following PKP is a rare but possible complication and high index of suspicion is required for proper diagnosis and management to obtain better visual outcome. Nd: YAG laser membranectomy was effective in excising the retained DM and improving vision. Endothelial cell loss following Nd: YAG laser membranectomy as a complication was observed and should be addressed during the treatment plan.

Ultrastructural Alterations of Grafted Corneal Buttons: The Anatomic Basis for Stromal Peeling Along a Natural Plane of Separation

PURPOSE

To examine the ultrastructure of the natural plane of separation in grafted corneas and evaluate the outcomes of stromal peeling.

DESIGN

Interventional case series.

METHODS

In this multicenter study, stromal peeling was attempted in 96 consecutive eyes with unsatisfactory vision following penetrating keratoplasty (PK) for keratoconus (n = 79), herpetic keratitis (n = 11), and granular dystrophy (n = 6). Stromal exchange was performed by (1) 9 mm partial-thickness trephination; (2) creation of a corneal flap across the PK wound; (3) opening of the stromal component of the PK wound until a smooth, translucent natural plane was identified; (4) severing the attachment of the PK scar; (5) stromal peeling along the identified plane; and (6) suturing of donor lamella. Grafted corneas from cases that mandated conversion to PK were processed for transmission electron microscopy.

RESULTS

The natural plane of separation was identified in all cases. Stromal exchange was successfully completed in 84 cases (87.5%). Snellen visual acuity ≥20/40 and ≥20/25 was reached in 93% and 72% of cases at 3 years (n = 49) and 86% and 62% at 4 years (n = 21) postoperatively. Mean endothelial cell loss at 1 year was 6.6% ± 9.5%. Stromal peeling occurred along a plane lined with a continuous layer of keratocytes separating pre-Descemet membrane (DM) stroma, DM, and endothelium from the anterior stroma. Pre-DM stroma was made of poorly organized lamellae containing widely spaced, randomly arranged collagen fibrils.

CONCLUSIONS

Ultrastructural alterations in the stromal microarchitecture of grafted corneas provide evidence of a natural plane of separation identified intraoperatively. Stromal peeling can be successfully performed in post-PK eyes with various stromal pathology.

Triamcinolone Acetonide-Assisted Descemetectomy for Retained Descemet Membrane

We present a case of decreased vision due to the presence of retained Descemet membrane (DM) following Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PKP). A 78-year-old male presented postoperatively from PKP after previous failed DSAEK with retained DM. We present a unique technique for combined surgical resection using bimanual vitrectomy and forceps excision assisted by triamcinolone acetonide for membrane visualization. Histopathological evaluation confirmed incomplete DM removal during the PKP. With surgical excision, there was an improvement in best spectacle-corrected visual acuity from 20/80 to 20/30.

Retained Descemet's membrane following penetrating keratoplasty for Fuchs' endothelial dystrophy: a case report of a post-operative complication

PURPOSE

To report a case of retained Descemet's membrane following penetrating keratoplasty in a patient suffering from Fuchs' endothelial corneal dystrophy. The use of confocal microscopy, histopathological tissue analysis, and treatment options are discussed.

METHODS

Case report of an 85-year-old man with a past ophthalmic history of atrophic macular degeneration, underwent a penetrating keratoplasty for Fuchs' endothelial corneal dystrophy. Postoperative review revealed a retained retrocorneal membrane within the anterior chamber. Further surgery was performed to excise the membrane, with a subjective and objective postoperative improvement in visual acuity and without subsequent complications of the corneal graft.

RESULTS

Histopathological assessment confirmed the clinical suspicion of a retained Descemet's membrane, marrying with the initial histology from the corneal button excised during the penetrating keratoplasty, which showed only a very thin Descemet's layer.

CONCLUSION

Retention of the Descemet's membrane following penetrating keratoplasty is a rare but potential complication of this surgery, particularly in cases of Fuchs' endothelial corneal dystrophy due to the thickened and abnormal histological nature of the endothelium and high index of suspicion is required.

Corneal graft failure following Nd:YAG laser membranotomy for inadvertent retained descemet's membrane after penetrating keratoplasty

Retained Descemet's membrane (DM) following penetrating keratoplasty (PKP) is a rare finding that may reduce visual acuity following opacification or endanger the graft endothelium. The association between Nd:YAG laser membranotomy and corneal graft failure is reported. Five of 1,350 patients (0.37%) undergoing PKP for pseudophakic bullous keratopathy or graft failure between 1986 and 2008 presented with inadvertent retained DM located close to the graft endothelium. The membrane opacified within 3 to 4 months, reducing the patients' vision. Nd:YAG laser membranotomy was performed using low energy and few pulses. Patients' visual acuity improved from 6/40 to 6/90 before treatment to 6/15(-) to 6/20 at 2 weeks following membranotomy. However, the corneal graft decompensated within 6 to 8 weeks following this procedure, necessitating repeat PKP, with removal of the retained DM. Nd:YAG laser membranotomy may lead to corneal graft failure due to shockwave damage created by the laser pulses, focused near the endothelial surface.

Use of trypan blue dye during conversion of deep anterior lamellar keratoplasty to penetrating keratoplasty

We describe a technique that uses trypan blue dye to identify residual recipient corneal stroma and Descemet membrane (DM) during conversion of deep anterior lamellar keratoplasty (DALK) to penetrating keratoplasty (PKP). After the host cornea is dissected, trypan blue dye (0.06%) is used to highlight the remaining host corneal stroma and DM, if any. In 8 DALK procedures that had to be converted to PKP because of DM perforation, trypan blue staining identified remnants of DM and parts of the posterior corneal stroma in 7 eyes. Improved visualization of the residual host tissue enabled complete excision and an overall optimal recipient wound profile.