Histopathology of Posterior Lamellar Endothelial Keratoplasty Graft Failure'

1
Histopathology of Posterior Lamellar Endothelial
Keratoplasty Graft Failure.

• James A Sbarbaro MD1
• Ralph C Eagle, Jr. MD2
• Irving M Raber MD3

• Department of Ophthalmology. Drexel University.
• Wills Eye Institute. Department of Ocular
  Pathology.
• Wills Eye Institute. Cornea Service.

The authors have no financial interest related
to the materal presented in this poster.
2
Introduction

• Endothelial Keratoplasty strives to provide a
  less invasive alternative to full thickness
  penetrating keratoplasty that alleviates corneal
  edema without inducing high astigmatism or large
  changes in corneal power, while at the same time
  providing excellent vision and rapid visual
  recovery.1,2,3,4
• Endothelial Keratoplasty techniques vary, but
  generally can be described as the placement of a
  partial thickness donor button of posterior
  stroma, Descemet membrane (DM), and endothelium
  onto the posterior surface of the host cornea
  through a small incision.1,2,3,4
• In Deep Lamellar Endothelial Keratoplasty (DLEK),
  a partial thickness lamella of posterior host
  stroma and DM is manually dissected from the host
  cornea prior to graft placement.1,2,3,4
• In Decemet Stripping Automated Endothelial
  Keratoplasty (DSAEK), only DM without posterior
  host stroma is removed prior to graft
  placement.1,2,3,4
• Sutures are not used to secure the graft in
  either technique.1,2,3,4

3

• Romaniv and Price5 described the histopathology
  of an endothelial lamellar graft onto a
  previously failed penetrating keratoplasty
  without prior removal of Descemet membrane in
  which the cornea failed to clear after partial
  detachment of Descemet membrane from the donor
  button.
• Lord and Price6 described the histopathology of
  an endothelial lamellar graft in a patient who
  underwent the original posterior lamellar
  keratoplasty described by Melles2 for Fuchs
  endothelial dystrophy and subsequent penetrating
  keratoplasty secondary to herpes keratitis.
• Terry7 described the comparative histopathology
  of DLEK and DSAEK recipient stromal beds in
  cadaver eyes.
• We describe the previously unreported
  histopathologic findings and relevant clinical
  details of three patients undergoing penetrating
  keratoplasty (PK) by one of the authors (IMR)
  after failure of posterior lamellar endothelial
  keratoplasty.

4

• Patient 1 was an 84 year old female with
  pseudophakic bullous keratopathy (PBK) who
  underwent DSAEK by an outside surgeon. No
  surgical complications were noted and the lack of
  visual improvement was felt to be secondary to
  primary graft failure.
• On initial clinical presentation (IMR), patient 1
  had finger counting vision, stromal and
  epithelial edema, slight inferior displacement of
  the graft, 8 clock hours of broad inferior
  iridocorneal adhesions, and a posterior chamber
  intraocular lens in the capsular bag.
• PK was chosen over repeat DSAEK because of the
  increased complexity of DSAEK in the presence of
  broad iridocorneal adhesions.
• The PK was performed 18 months after the original
  DSAEK.
• Patient 2 was a 73 year old male with PBK who
  underwent DSAEK by one of the authors (IMR) using
  a 8.0 mm endothelial graft.
• On initial clinical presentation (IMR), patient 2
  had counting fingers vision, a history of
  pseudoexfoliation, generalized stromal and
  epithelial edema, a superior-temporal laser
  iridotomy, and a posterior chamber intraocular
  lens in the capsular bag.
• On the first postoperative day following DSAEK,
  the patient had severe anterior chamber
  inflammation and an intraocular pressure of 50
  mmHG secondary to air-bubble pupilary seclusion.
  The pressure returned to normal and the chamber
  deepened after fifty percent of the air bubble
  was released through the paracentis.

5

• After a 5 month interval where the patient failed
  to achieve good vision secondary to persistent
  cornea edema, the patient elected PK over repeat
  DSAEK.
• Patient 3 was an 84 year old female with
  persistent corneal edema secondary to a descemet
  membrane detachment status post cataract
  extraction by phacoemulsification and intraocular
  lens implantation who underwent DLEK using a 7.5
  mm endothelial graft by one of the authors (IMR).
• On initial clinical presentation (IMR), patient 3
  had 20/400 vision, stromal and epithelial edema
  with an underlying descemet membrane detachment
  originating from a superior clear corneal
  incision used during the previous
  phacoemulsication, and a posterior chamber
  intraocular lens in the capsular bag.
• After two unsuccessful attempts to reattach
  descemet membrane using intracameral 20 sulfur
  hexafluoride (SF6) gas, a DLEK was performed.
• After a 12 month interval where the patient
  failed to achieve to achieve good vision
  secondary to persistent interface haze, a PK was
  chosen over repeat DLEK or DSAEK.

6
Methods

• Retrospective clinicopathologic case series of
  three patients undergoing penetrating
  keratoplasty after lamellar endothelial
  keratoplasty.
• The ophthalmology charts of the three patients
  were reviewed in full.
• The removed penetrating keratoplasty corneal
  buttons were submitted for routine histological
  examination.
• The three specimens were bisected, processed
  routinely and stained with hematoxylin-eosin and
  periodic acid-Schiff.
• Photomicrographs of pertinent findings were
  taken.

7
Results Case 1

• In all cases, histopathology revealed thickened
  and edematous corneas consistent with donor
  failure due to endothelial decompensation.
• Although varying degrees of posterior lamellar
  graft detachment were observed in each instance,
  significant parts of each graft remained firmly
  adherent to the host stroma, or to segments of
  residual host Descemet membrane.
• Scar tissue was present at the edge of the graft
  in case 1 (Between arrows).

Graft Detachment
8
Case 2

• In all cases, the interface between host stroma
  and donor graft in areas of adherence was
  inconspicuous resembling that seen at the flap
  stromal interface after lasik.8
• In case 1 and 2, a delicate retrocorneal fibrous
  membrane was present.
• In all cases, the donor graft endothelium was
  atrophic.

9
Case 3

• Most of the graft in case 2 remained firmly
  adherent with small areas of peripheral
  detachment.
• In contrast, the graft in case 3 adhered
  peripherally but had separated from the stroma
  centrally forming a thin cleft. It is uncertain
  whether the latter was present in vivo.
• Peripheral Adherence at host stroma/ donor
  interface.

10
Conclusions

• Histopathology in these 3 patients suggests
  endothelial decompensation and incomplete graft
  adherence as possible etiologies for posterior
  lamellar graft failure.
• The presence of residual host DM anterior to the
  graft periphery did not appear to prevent firm
  adherence suggesting that DM may not need to be
  removed from the host cornea prior to graft
  placement in non-guttate corneas such as those
  present after primary penetrating graft failure.5
• As has been previously reported, the interface
  between the host stroma and the graft is
  inconspicuous.8 This observation does not
  support the theory that the dearth of 20/20
  results1 after endothelial keratoplasty
  procedures is related to the host-graft interface.

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Conclusions continued

• Although there were no obvious differences
  between the DLEK and DSAEK host stroma/donor
  graft interfaces on routine histopathology in
  this small series, Terry has demonstrated that
  the DSAEK host stromal bed is smoother and
  without the presence of cut stromal fibrils when
  compared to that seen in DLEK using 50 times
  magnification electron microscopy imaging.7
• Future histopathological analysis is needed to
  improve our understanding of posterior lamellar
  graft failure.

12
References

• Terry MA. Endothelial keratoplasty history,
  current state, and future directions. Cornea
  2006 25(8)873-8.
• Melles GR, Eggink FA, Lander F, et al. A surgical
  technique for posteriorlamellar keratoplasty.
  Cornea. 199817618626.
• Price FW, Price MO. Descemets stripping with
  endothelial keratoplasty in 50 eyes a refractive
  neutral cornea transplant. J Refract Surg.
  200521 339345.
• Terry MA, Ousley PJ. Deep lamellar endothelial
  keratoplasty visual acuity, astigmatism, and
  endothelial survival in a large prospective
  series. Ophthalmology. 200511215411548.
• Romaniv N, Price MO, Price FW, Mamalis N. Donor
  descemet membrane detachment after endothelial
  keratoplasty. Cornea 2006 25(8)943-7.
• Lord RK, Price FW, Price MO, Werner L, Mamalis N.
  Histology of posterior lamellar keratoplasty.
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• Terry MA, Hoar KL, Wall J, Ousley P. Histology
  of dislocations in endothelial keratoplasty (DSEK
  and DLEK) a laboratory-based, surgical solution
  to dislocation in 100 consecutive DSEK cases.
  Cornea 2006 25(8)926-32.
• Dawson DG, Edelhauser HF, Grossniklaus HE.
  Long-term histopathologic findings in human
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