BACKGROUNDThough there have been various methods for harvesting and preserving descemet membrane (DM) and intact endothelium, there is no literature about the morphological evaluation of endothelium after graft preparation for descemet membrane endothelial keratoplasty (DMEK). The aim of this study was to establish and improve a simple method for preparing, preserving, and morphologically evaluating the donor graft for DMEK.

METHODSTo obtain a donor graft, an air bubble was formed by injecting a 29 G needle with 1 ml sterile air into a small edge created outside the Schwalbe line. Another needle was inserted into the bubble through the stroma to aspirate the air or replace half the air with organ culture medium. Trypan blue was used to mark the location for small incision to improve the success rate. Frozen sections were stained with hematoxylin and eosin (HE). Based on the air bubble, DM grafts were divided into four groups: group A (normal control), graft without any operative technique; group B, graft with zero-pressure air bubble; group C, graft with full-pressure air bubble; group D, graft with half-pressure air bubble. The four groups of grafts were preserved for 24 hours to observe the effect of bubbles on cells. The gross and ultrastructure morphologies were evaluated using alizarin red and scanning electron microscopy (SEM), respectively.

RESULTSDonor grafts were harvested via the air bubble technique, facilitated by prior trypan blue staining. HE-stained sections revealed a pure graft without stroma. There were no significant changes under light microscope. In group A, SEM revealed a confluent layer of polygonal endothelium with distributed microvilli exhibiting characteristics of interdigitating junctions. In group B, intercellular borders became thinner. In group C, interdigitations were almost flat and microvilli were observed less frequently. In group D, other than less microvilli, there were minimal changes.

CONCLUSIONSThe donor graft preparation method appears to be effective and convenient. Properly decreasing the air pressure could protect and preserve the endothelium.

Animals ; Descemet Membrane ; cytology ; Descemet Stripping Endothelial Keratoplasty ; methods ; Endothelium, Corneal ; cytology ; Rabbits ; Tissue Donors

PURPOSE: To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. METHODS: An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. RESULTS: Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 +/- 2.17% vs. 50.48 +/- 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. CONCLUSIONS: Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.
Animals ; Corneal Endothelial Cell Loss/*prevention & control ; Descemet Stripping Endothelial Keratoplasty/*methods ; Lens Implantation, Intraocular/*instrumentation/*methods ; Lenses, Intraocular ; Models, Animal ; Postoperative Complications/*prevention & control ; Prosthesis Design ; Swine

PURPOSE: To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. METHODS: An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. RESULTS: Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 +/- 2.17% vs. 50.48 +/- 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. CONCLUSIONS: Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.
Animals ; Corneal Endothelial Cell Loss/*prevention & control ; Descemet Stripping Endothelial Keratoplasty/*methods ; Lens Implantation, Intraocular/*instrumentation/*methods ; Lenses, Intraocular ; Models, Animal ; Postoperative Complications/*prevention & control ; Prosthesis Design ; Swine

PURPOSE: To compare 2-year clinical outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) in patients with bullous keratopathy. METHODS: A retrospective chart review was performed to obtain 2 years of follow-up data of DSAEK or PK at a single center from March 2009 to September 2012. The study comprised 15 eyes of DSAEK and 11 eyes of PK. Outcome measures included best-corrected visual acuity (BCVA), spherical and keratometric changes, central corneal thickness, endothelial cell density, intraocular pressure, and postoperative complications. Graft survival rate was assessed by Kaplan-Meier survival analysis. RESULTS: There were no differences in patient baseline characteristics between the two groups. At postoperative 2 years, better BCVA of 0.69 ± 0.51 logarithm of the minimum angle of resolution (logMAR) was found after DSAEK compared to 0.88 ± 0.48 logMAR after PK. Refractive cylinder in DSAEK and PK was −2.60 ± 1.53 and −6.00 ± 1.05 diopters (D), respectively, and keratometric cylinder was 3.27 ± 3.70 and 6.34 ± 3.51 D, respectively, at postoperative 2 years. The difference of mean spherical equivalents between postoperative 1 month and 2 years was 0.84 D after DSAEK and 2.05 D after PK. A hyperopic shift of 1.17 D was present after 2 years of DSAEK. The mean endothelial cell density at postoperative 2 years was 1,548 ± 456 cells/mm² for DSAEK and 1,052 ± 567 cells/mm² for PK, with a cell loss of 19.96% vs. 52.38%, respectively when compared to postoperative 1 month. No significant difference in central corneal thickness was found between DSAEK and PK (592 ± 75 vs. 563 ± 90 µm, respectively). Finally, the 2-year survival rate did not differ significantly between DSAEK and PK (93.3% vs. 81.8%, respectively, p = 0.344). CONCLUSIONS: Compared to PK, DSAEK provided more stable refractive errors with better visual outcome, lower endothelial cell loss, and a lower rate of graft rejection at postoperative 2 years in patients with bullous keratopathy.
Cornea/diagnostic imaging/*surgery ; Corneal Diseases/diagnosis/*surgery ; Descemet Stripping Endothelial Keratoplasty/*methods ; Female ; Follow-Up Studies ; Graft Survival ; Humans ; Keratoplasty, Penetrating/*methods ; Male ; Middle Aged ; *Refraction, Ocular ; Retrospective Studies ; Time Factors ; Treatment Outcome ; Visual Acuity

PURPOSE: To compare clinical outcomes after deep lamellar endothelial keratoplasty (DLEK) with Descemet stripping endothelial keratoplasty (DSEK) performed as initial cases by a single surgeon. METHODS: Sixteen patients with corneal endothelial were enrolled. Eight patients (8 eyes) underwent DLEK and 8 patients (8 eyes) DSEK. We measured uncorrected visual acuity, best corrected visual acuity (BCVA), manifest refraction, corneal endothelial count, interface opacity via Schiempflug imaging, and contrast sensitivity, as well as tracked postoperative complications over the first postoperative year. RESULTS: Primary graft failure occurred in two DLEK cases and one DSEK case, all of which were excluded for further analysis. The average 12-month postoperative BCVA was 20/70 in the DLEK group and 20/50 in the DSEK group, with the difference not statistically significant. No significant differences were identified between the 2 groups in terms of mean spherical equivalent and refractive astigmatism, although individuals in the DSEK group tended toward hyperopia. The average endothelial cell count at postoperative month 12 was 1849+/-494 in the DLEK group and 1643+/-417 cells/mm2 in the DSEK group, representing cell losses of 26.2% and 31.9%, respectively. No significant differences in endothelial cell count or endothelial cell loss were observed between groups. Early postoperative donor disc dislocation occurred in two eyes after DLEK and one eye after DSEK. Interface opacities and contrast sensitivities were similarly not significantly different between groups. CONCLUSIONS: No significant differences in any assessed clinical outcome were observed between individuals undergoing DLEK and DSEK, when performed as initial cases by a single surgeon.
Aged ; Cell Count ; Corneal Edema/pathology/*surgery ; Descemet Stripping Endothelial Keratoplasty/*methods ; Endothelium, Corneal/pathology ; Follow-Up Studies ; Humans ; Microscopy, Acoustic ; Middle Aged ; Prospective Studies ; Treatment Outcome ; Visual Acuity