Busin Guide vs Forceps for the Insertion of the Donor Lenticule in Descemet Stripping Automated Endothelial Keratoplasty

PURPOSE

To compare two insertion methods in Descemet stripping automated endothelial keratoplasty (DSAEK): Busin guide-assisted vs Forceps-assisted insertion of the corneal lenticule graft.

DESIGN

Prospective, consecutive, comparative, nonrandomized study.

METHODS

setting: Cornea clinic at the Toronto Western Hospital. study population: Sixty-three eyes of 63 consecutive patients were included. All patients underwent DSAEK for Fuchs endothelial dystrophy, pseudophakic bullous keratopathy, aphakic bullous keratopathy, failed graft, or iridocorneo endothelial syndrome. Twenty-six consecutive donor discs were inserted with the Busin guide and 37 consecutive eyes underwent forceps assisted insertion of the donor. main outcome measures: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, corneal endothelial cell loss, and postoperative complications.

RESULTS

Busin guide-assisted DSAEK group had significantly worse UCVA and lower donor endothelial cell counts preoperatively. No significant differences were noted in the intraoperative or postoperative complications. Six months following surgery, BCVA was not significantly different between groups: 20/37 in the Busin guide-assisted DASEK group vs 20/42 in the Forceps-assisted group (P = .39). Mean spherical equivalent was -0.02 diopters (D) and 0.82 D (P = .06), and mean refractive cylinder was 2.2 D and 1.31 D (P = .0006), respectively. Endothelial cell loss was significantly lower in the Busin guide-assisted DASEK group: 25% loss vs 34.3% loss in the Forceps-assisted DSAEK group. (P = .04).

CONCLUSIONS

Although visual outcomes were not different between the groups studied, Busin guide-assisted DSAEK resulted in lower percentage of endothelial cell loss compared with forceps insertion, six months following surgery.

[Descemet stripping endothelial keratoplasty using Busin technique to minimize endothelial cell loss]

PURPOSE

To present the results of endothelial keratoplasty (DSEK) using "Busin" technique performed from September 2008 to December 2008 in Ophthalmology Department, District Railway Hospital in Katowice.

MATERIAL AND METHODS

7 patients (7 eyes) underwent DSEK using "Busin glide" technique, due to the corneal edema after cataract phacoemulsification. Best corrected visual acuity, central corneal thickness, endothelium cell density were assessed three and six month postoperatively.

RESULTS

Mean time period between cataract surgery to DSEK was 15.8 month (from 11 to 37 months). The mean central corneal thickness before surgery was 750 microm (from 690 microm to 850 microm), mean best corrected visual acuity 0.001 (from light perception to 0.01). The average best corrected visual acuity three months after surgery was 0.4 (0.1 to 0.6), and 0.5 (from 0.1 to 0.7), six months. Mean central corneal thickness 3 months postoperatively equaled 790 microm (from 714 microm to 850 microm), and a sixth month was 659 microm (from 800 microm to 604 microm). Three months after DSEK, mean endothelium cell density was 2640/mm2 (from 2301/mm2 to 2904/mm2), six months after DSEK the average endothelial cell density equaled 2430/mm2 (from 2210/mm2 to 2780/mm2). Disc dislocation was not observed in studied group.

CONCLUSIONS

The use of BG as a donor lenticule insertion technique in DSEK technique seems to be a safe support of this lamellar surgery.

Use of trypan blue stain in endothelial keratoplasty

We used the selective staining properties of trypan blue to demonstrate the efficacy and safety of the stain during endothelial keratoplasty (EK) surgery in 55 eyes of 51 patients. No long-term effects were seen due to the trypan blue staining up to two years postoperatively. Trypan blue facilitates the viewing and placement of the donor corneal disc into the recipient anterior chamber through a patient's cloudy cornea.

New surgical technique: upside-down phacoemulsification with posterior chamber intraocular lens and Descemet's stripping automated endothelial keratoplasty (DSAEK)

We describe a new surgical technique, namely, upside-down phacoemulsification and posterior chamber intraocular lens implantation combined with Descemet's stripping automated endothelial keratoplasty (DSAEK). This technique is aimed at decreasing potential complications associated with conventional phacoemulsification, including posterior lens capsular tear and vitreous loss during DSAEK and cataract surgery performed through a cloudy cornea.

Preparation and properties of a chitosan-based carrier of corneal endothelial cells

A novel chitosan-based membrane that was made of hydroxypropyl chitosan, gelatin and chondroitin sulfate was used as a carrier of corneal endothelial cells. The characteristics of the blend membrane, such as transparency, equilibrium water content, permeability, mechanical properties, protein absorption ability, hydrophilicity and surface morphology, were determined. To study the effects of the membrane on cell attachment and growth, rabbit corneal endothelial cells were cultured on this artificial membrane. The biodegradability and biocompatibility of the blend membrane were in vivo evaluated by its implantation into the muscle of the rats. Glucose permeation results demonstrated that the blend membrane had higher glucose permeability than natural human cornea. Scanning electron microscopy (SEM) analysis of the membranes demonstrated that no fibrils were observed. As a result, the optical transparency of the membrane was as good as the natural human cornea. The average value of tensile strength of the membrane was 13.71 MPa for dry membrane and 1.48 MPa for wet membrane. The value of elongation at break of the wet was 45.64%. The cultured rabbit corneal endothelial cells formed a monolayer on the blend membrane which demonstrated that the membrane was suitable for corneal endothelial cells to attach and grow. In addition, the membranes in vivo showed a good bioabsorption property. The mild symptoms of inflammation at sites of treatment could be resolved as the implant was absorbed by the host. The results of this study demonstrated that the hydroxypropyl chitosan-chondroitin sulfate-gelatin blend membrane can potentially be used as a carrier for corneal endothelial cell transplantation.

[Endothelial keratoplasty]

Endothelial keratoplasty (EK) is a new surgical method in treatment of corneal endothelial keratopathy, which retains healthy portions of a patient's cornea while replacing diseased endothelium with healthy donor tissue. In the past decade EK has been used increasingly and has shown better results over standard penetrating keratoplasty. The emergence and improvement of EK demonstrate the convert of corneal transplantation to refined and refractive surgery. EK, which has favorable refractive outcomes and potential low rejection rate, opens a new era for the treatment of endothelial dysfunction. However, there are still some aspects requiring to be studied, such as the methods of implantation to decrease graft dislocation rate and endothelial cell loss, use of femtosecond laser in EK to improve refractive errors, and the long-term result of immune rejection rate.

External refinement of the donor lenticule position during descemet's stripping and automated endothelial keratoplasty

The authors describe a technique to facilitate the centration of the donor lenticule during Descemet's stripping and automated endothelial keratoplasty. The donor corneal lenticule is unfolded and grossly centered in the anterior chamber using a barbed 30-gauge needle on a 3-cc air syringe or a reverse Sinsky hook. Fine adjustments to center the lenticule can be achieved by applying external pressure to the cornea with a laser in-situ keratomileusis flap roller. This simple technique provides a mechanism for simultaneously removing interface fluid and allows the surgeon to center the donor corneal lenticule without further risk of direct mechanical trauma to the donor endothelium.

[Preliminary outcome of large-diameter lamellar keratoplasty combined with deep lamellar endothelial keratoplasty for whole cornea destruction]

OBJECTIVE

To understand the indication, surgical principle, outcome and complications of large-diameter lamellar keratoplasty combined with deep lamellar endothelial keratoplasty for whole cornea destruction.

METHODS

Eleven hospitalized patients with whole cornea destruction in Zhongshan Ophthalmic Center, Sun Yat-Sen University from May, 2005 to March, 2006 were involved in this study. Five left eyes and six right eyes underwent large-diameter lamellar keratoplasty combined with deep lamellar endothelial keratoplasty. The patients were followed up for 12 to 18 months and their pinhole postoperative visual acuity, intraocular pressure, pachymetry of the central cornea and corneal endothelial cell density was recorded.

RESULTS

The pinhole postoperative visual acuity of all patients improved and averaged separately 4.4 +/- 0.3, 4.5 +/- 0.3 and 4.5 +/- 0.3 at the 3rd, 6th and 12th postoperative month. There was a temporary increase of the postoperative intraocular pressure within one postoperative week which can be controlled by medication and released soon. And the postoperative intraocular pressure averaged (19.8 +/- 2.7), (19.2 +/- 1.7) and (19.5 +/- 2.0) mm Hg respectively at the 3rd, 6th and 12th month postoperatively. At the same following up times, the pachymetry of the central cornea averaged (538.9 +/- 8.9), (536.3 +/- 6.3) and (537.2 +/- 6.9) microm respectively and the corneal endothelial cell density averaged (2519.8 +/- 110.7), (2244.4 +/- 137.9) and (2093.3 +/- 141.9) cells/mm2 respectively. The main complication was the interspace between the two lamellar grafts and it would disappear automatically within one postoperative month.

CONCLUSIONS

Large-diameter lamellar keratoplasty combined with deep lamellar endothelial keratoplasty can avoid postoperative glaucoma. It may offer further advantages over traditional surgery to treat whole cornea destruction.

Non-Descemet stripping automated endothelial keratoplasty for endothelial dysfunction secondary to argon laser iridotomy

PURPOSE

To report clinical outcomes of non-Descemet stripping automated endothelial keratoplasty (nDSAEK) as treatment of endothelial dysfunction secondary to argon laser iridotomy (ALI).

DESIGN

Single-center, prospective, noncomparative, interventional case series.

METHODS

Six eyes of six patients (two men, four women; mean age, 74.5 years) with bullous keratopathies secondary to ALI were treated with endothelial keratoplasty without recipient Descemet stripping. The donor endothelial lamella was inserted using a pull-through technique using a Busin glide with intraocular lens glide (i.e., Kobayashi double-glide technique). Best-corrected visual acuity (BCVA), astigmatism, and donor central endothelial cell density (ECD) were recorded before surgery and at six months after surgery. Intraoperative and postoperative complications also were recorded. Main outcome measures were preoperative and postoperative central ECD, with calculation of cell loss rate. BCVA, induced astigmatism, and complications also were evaluated.

RESULTS

All patients reached more than 20/32 BCVA, with two (33.3%) reaching 20/20. Mean induced astigmatism in measurable cases was 0.85 +/- 0.49 diopters. The average and standard deviation ECD at six months were 2390.5 +/- 522.4 cells/mm(2) (range, 1589 to 2898 cells/mm(2)), representing a mean cell loss from preoperative donor cell measurements of 25.8% +/- 14.7%. Complications included one case of donor dislocation requiring rebubbling (16.7%) and one case of subclinical endothelial rejection (16.7%).

CONCLUSIONS

This modified endothelial keratoplasty technique (nDSAEK and double-glide technique) for treatment of endothelial dysfunction secondary to ALI produced excellent clinical outcomes such as reduced endothelial cell loss, good visual acuity, and minimal induced astigmatism.

[Deep lamellar endothelial keratoplasty for bullous keratopathy]

OBJECTIVE

To investigate the efficacy, postoperative complications and management of deep lamellar endothelial keratoplasty (DLEK) in complex cases of severe bullous keratopathy.

METHODS

In the nonrandomized retrospective consecutive case series, fifteen cases (15 eyes) of severe and complex bullous keratopathy at Zhongshan Ophthalmic Center underwent DLEK in combination with other intraocular surgeries between October 2005 and March 2006. DLEK was combined with vitrectomy and ciliary sulcus sutured intraocular lens implantation in two patients, with vitrectomy and intraocular lens extraction in two patients and with vitrectomy and intraocular lens exchange in one patient Four patients with aphakic eyes underwent subsequent ciliary sulcus sutured intraocular lens implantation within 4 to 6 months after the DLEK donor tissue had been placed. The best spectacle corrected visual acuity (BSCVA), corneal astigmatism, curvature and endothelial cell density (ECD) were examined preoperatively and postoperatively. The graft-host interface was photographed by anterior segment optic coherent tomography (OCT). Repeated Measures Anova was applied for management of the data.

RESULTS

On postoperative day 1, 13 grafts were well attached to the host except for one dislocation (re-located immediately and well attached). Fluid leakage between the graft-host interface occurred in one eye (absorbed on day 5). All the grafts remained clear during the follow-up. Five cases (33.3%) showed narrow gaps between the borders of graft and host. Bullous epithelial lesion reoccurred above the gap in two cases (13.3%), and disappeared during follow-up. BSCVA in 4 eyes (26.7%) was 0.4, in 3 eyes (20.0%) was 0.3, in 4 eyes (26.7%) was 0.2, and in 1 eye (6.7%) was 0.1 after DLEK. At 6, 9 and 12 months, the average corneal astigmatism were (2.80 +/- 0.70) D, (2.60 +/- 0.70) D and (2.20 +/- 0.60) D (F = 5.591, P = 0.090), average corneal curvature were (43.60 +/- 1.90) D, (44.10 +/- 1.30)D and (44.10 +/- 1.00) D (F =1.515, P = 0.237). The average central corneal thickness were (666.1 +/- 70.6) microm, (544.5 +/- 30.9) microm, (538.2 +/- 34.7) microm and (532.4 +/- 41.6) microm (F = 32.692, P = 0.000) at preoperatively, 6, 9 and 12 months postoperatively, respectively. The mean ECD was (1915.7 +/- 90.8) cells/mm2 postoperatively.

CONCLUSIONS

DLEK surgery is an effective and safe procedure in severe and complex cases of bullous keratopathy,but it has to be successfully combined with other anterior segment surgeries. DLEK graft without sutures can tolerate subsequent other anterior segment surgeries at 4 to 6 months after placement of the donor tissue.

In vivo laser confocal microscopy after descemet stripping with automated endothelial keratoplasty

PURPOSE

To investigate in vivo corneal changes in patients with bullous keratopathies before and after Descemet stripping with automated endothelial keratoplasty (DSAEK) using laser confocal microscopy.

DESIGN

Single-center, prospective, comparative clinical study.

METHODS

Seven patients (two men, five women; mean age, 68.9 years; range, 59 to 78) with bullous keratopathies who underwent DSAEK enrolled in this study. Laser confocal microscopy was performed before and one, three, and six months after DSAEK. Selected images were evaluated qualitatively and quantitatively for degree of haze and density of deposits.

RESULTS

Preoperatively, corneal epithelial edema, subepithelial haze, keratocytes in a honeycomb pattern, and tiny needle-shaped materials in the stroma were observed in all patients. After DSAEK, subepithelial haze, donor-recipient interface haze, and interface particles were observed in all five measurable cases; postoperative haze and particles decreased statistically significantly (P < .05) over follow-up.

CONCLUSIONS

In vivo laser confocal microscopy is capable of identifying subclinical corneal abnormality after DSAEK with high resolution. Further studies in a large number of patients and long-term follow-up after DSAEK using this device are needed to fully understand long-term corneal stromal changes after DSAEK and whether the preexisting corneal stromal pathologies are reversible.

Descemet stripping automated endothelial keratoplasty in a 2-year-old child

Endothelial transplantation in the form of Descemet stripping endothelial keratoplasty (DSEK) or Descemet stripping automated endothelial keratoplasty (DSAEK) has rapidly become a popular, if not the preferred, method of treating endothelial failure. Although the need to perform corneal transplantation in children with endothelial dysfunction is relatively rare, this situation does arise, and in children still in the amblyogenic age group, rapid recovery from an essentially refractive-neutral corneal procedure carries significant advantages. We describe the use of DSAEK in a 2-year-old child who exhibited irreversible corneal edema from endothelial damage secondary to complicated cataract surgery. The rapid recovery and lack of induced astigmatism from DSAEK allowed for prompt institution of amblyopia therapy.

Causes of primary donor failure in descemet membrane endothelial keratoplasty

PURPOSE

To determine the causes of primary failure of donor Descemet membrane transplants in Descemet membrane endothelial keratoplasty (DMEK).

DESIGN

Laboratory and clinical study.

METHODS

From a larger series of eyes that underwent DMEK for Fuchs endothelial dystrophy or bullous keratopathy, 11 transplanted corneas did not clear within the first week after surgery. During a secondary 'Descemet stripping endothelial keratoplasty' procedure, the first graft was carefully removed and analyzed with light microscopy. For each patient, the surgical video of the initial DMEK procedure was analyzed to determine the cause of transplant failure.

RESULTS

With light microscopy, all but two explanted transplants had a endothelial cell density of 1700 cells/mm2 or higher. Three Descemet grafts may have been positioned upside down and three may have failed due to manipulation. One transplant could not be properly attached onto the recipient posterior stroma because of insufficient air-support in a post-vitrectomy eye. For four eyes, no obvious cause of failure could be determined.

CONCLUSION

Unexpectedly, graft failure after DMEK may not primarily result from tissue damage during implantation and associated endothelial cell loss. Detached grafts may therefore be managed by early reposition. When the graft is attached after surgery but fails to clear, secondary surgical intervention may be postponed, because these corneas may clear spontaneously after several weeks.

Multivariate model of refractive shift in Descemet-stripping automated endothelial keratoplasty

PURPOSE

To relate in situ graft shape in Descemet-stripping automated endothelial keratoplasty (DSAEK) to surgically induced refractive error.

SETTING

Academic eye institute.

METHODS

High frequency arc-scanning ultrasound was performed in 7 patients enrolled in a prospective study of microkeratome-assisted endothelial keratoplasty approved by the Investigative Review Board. A region of interest spanning the horizontal meridian was defined for analysis of epithelial, host, graft, and total corneal thicknesses. Graft thickness profiles were fit by quadratic polynomials where the 2nd-order coefficients represent the posterior corneal curvature contributed by the graft. The curvature coefficient and central graft thickness were analyzed as predictors of induced refractive error.

RESULTS

At final follow-up (mean 5.9 months +/- 3.2 [SD]), 3 patients had a hyperopic shift (+2.50 diopters [D] each), 3 had insignificant (< 0.50 D) refractive shifts, and 1 had a myopic shift. In the group with hyperopic shift, a negative lens effect was predicted by positive curvature coefficients, representing grafts that were thinner centrally than peripherally (mean +22.72 microm/mm(2); range +4.95 to +45.17 microm/mm(2)). In the group with minimal refractive shift, coefficients were less positive (mean +7.28 microm/mm(2); range +2.01 to +13.82 microm/mm(2)). The patient with a myopic shift (-1.00 D) had the only negative curvature coefficient (-0.64 microm/mm(2)). In a 2-predictor model of refractive shift, central graft thickness and the curvature coefficient together accounted for 86% of the variance in the refractive response to DSAEK (P = .025).

CONCLUSION

Nonuniform thickness profiles and variable central graft thicknesses both contribute to refractive shift after DSAEK.

[Treatment strategy for rejection-free corneal transplantation--transition from full-thickness corneal transplantation to corneal endothelium transplantation]

The avoidance of allograft rejection is the most critical factor for favorable surgical outcome after corneal transplantation. We report experimental data including distribution of white blood cells in human corneas for rejection-free corneal transplantation. We focused on leukocyte trafficking based on the immunological mechanism leading to allograft rejection in a mouse full-thickness corneal transplantation model. We identified two chemokine-receptors, CCR1 and CCR7 which are functionally relevant to the occurrence of allograft rejection. These chemokine receptors can be new targets for the suppression of allograft rejection after full-thickness corneal transplantation. In the human corneas, bone marrow-derived dendritic cells and monocyte-lineage cells reside constitutively in the normal epithelium and stroma, and may be associated with direct recognition of allo-antigen after corneal transplantation. We established a mouse model in which cultured allocorneal endothelium was transplanted onto a bullous keratopathy recipient cornea. During the follow-up period, the transplanted cultured allo-corneal endothelium did not show any sign of allograft rejection. Our findings demonstrated that a rejection-free mechanism is due not to suppression of immunity or to lack of response, but to failure to recognize the existence of resistance. Realization of the clinical application of cultured allo-corneal endothelium transplantation may be a shortcut to ideal rejection-free corneal transplantation.

Longterm results of deep lamellar keratoplasty using grafts with endothelium

PURPOSE

To report the longterm results of deep lamellar keratoplasty (DLK) using grafts with their own endothelia.

METHODS

Fourteen eyes of 14 patients underwent DLK using grafts with endothelium. The average follow-up was approximately 80.0 months. Preoperative diagnoses included: corneal leukoma (five eyes); gelatinous drop-like corneal dystrophy (three eyes); Avellino corneal dystrophy (two eyes); corneal perforation (two eyes); corneal mucopolysaccharidosis (one eye), and keratoconus (one eye).

RESULTS

Corrected visual acuity was improved in 13 eyes (93%), but ruptures of Descemet's membrane occurred in six eyes (43%) and a double anterior chamber was found in five eyes (36%) postoperatively. Despite this, all grafts remained clear as a result of their functioning endothelia.

CONCLUSIONS

Deep lamellar keratoplasty using a graft with its own endothelium is a safe and valuable procedure with flexibility and feasibility that should suit corneal surgeons of all levels.

[Experimental research of small-incision Descemet's stripping endothelial keratoplasty]

OBJECTIVE

To investigate the surgical procedure, clinical efficacy, complications, density of endothelial cells and histological changes after Descemet's stripping endothelial keratoplasty (DSEK) surgery.

METHODS

It was a experimental study. Twenty four New Zealand rabbits were divided into 3 groups, 8 rabbits per group. Donor grafts were dissected from 16 New Zealand rabbit eyes. Group A was experimental group, a 5 mm limbal tunnel incision was made. Descemet's membrane was striped off at 10 mm diameter, then the same diameter donor cornea (including Descemet's membrane and endothelium with a little of posterior stroma) was inserted into the recipient's anterior chamber. Air was injected into the anterior chamber to press the graft up against the recipient cornea. Group B was the control group, only striped the Descemet's membrane at the recipient cornea. Group C was the experiment control group, the procedure was similar to the group A, but the donor graft was without endothelial cells.

RESULTS

All corneas of group A were transparent, and the mean density of the endothelial cells was (2195 +/- 77)/mm2 (t = 12.455, P < 0.001). Endothelial grafts attached to the recipients well and no scar formation between them under histological observation. The corneas were severe edema in groups B and C one month after surgery.

CONCLUSIONS

DSEK is a safe surgery, can be recovered rapidly with little damages, and without interface scar formation after surgery. DSEK may be the first choice for the treatment of bullous keratopathy.

[Pay attention to specialization of pediatric penetrating keratoplasty]

Pediatric corneal transplantation is one of most important means to avoid corneal blind and promote infant vision development, but low scleral rigidity increases the forward displacement of the lens-iris diaphragm and significant refractive errors after corneal transplantation. The underlying disease process will also influence the timing of surgery. For high risk of grafts failure in pediatric penetrating keratoplasty, it is potential for excellent long term outcome to determine operative opportunity cautiously and prevent and treat appropriately grafts rejection, glaucoma, infection and corneal erosions.

Late repeat Descemet-stripping automated endothelial keratoplasty

PURPOSE

To report the outcomes of 2 patients who underwent repeat Descemet-stripping automated endothelial keratoplasty (DSAEK) 13 and 23 months after their primary surgeries.

METHODS

Two patients underwent repeat DSAEK for late graft failure at approximately 1 and 2 years, respectively. The operative procedure involved removing the failed graft and replacing it with new donor tissue.

RESULTS

The postoperative visual recovery was similar to the visual outcomes of primary DSAEK surgery, with both patients achieving 20/30 or better best spectacle-corrected visual acuity within 3 months. There were no signs of interface scarring after surgical removal of the failed donor disc.

CONCLUSIONS

Late repeat DSAEK can result in rapid visual recovery without interface scarring.

Assessment of Eye Bank–Prepared Posterior Lamellar Corneal Tissue for Endothelial Keratoplasty

OBJECTIVE

To evaluate eye bank-prepared tissue for Descemet's stripping automated endothelial keratoplasty (DSAEK).

DESIGN

Experimental study and retrospective case series.

PARTICIPANTS

Seventeen human donor corneas and 4 recipient patients undergoing DSAEK surgery.

METHODS

Corneal-scleral discs were obtained. Specular microscopy and pachymetry were performed. A designated Tissue Banks International technician used a microkeratome to prepare a flap. Posterior bed thickness was measured. The sectioned tissue was stored, and at 24 and 48 hours, pachymetry was repeated. At 48 hours, specular microscopy was repeated, and endothelial cell viability was assessed with trypan blue. Descemet's stripping automated endothelial keratoplasty was performed in 4 patients using eye bank-prepared posterior lamellar tissue.

MAIN OUTCOME MEASURES

Corneal tissue was assessed with the following parameters: corneal thickness measured with ultrasonic pachymetry, cell density counts measured with a keratoanalyzer, and cell viability as observed with trypan blue exclusion. Patient outcomes were measured by changes in visual acuity (VA) and the presence of a clear graft.

RESULTS

Donor corneal pachymetry before sectioning averaged 599+/-52 microm. Immediately after sectioning with a microkeratome set at a depth of 300 microm, mean posterior bed thickness was 328+/-95 microm. Thus, the mean cutting depth achieved by the microkeratome when set at 300 micrometers averaged 271+/-83 microm. After storage for 24 hours, the posterior beds measured 352 microm, an average swelling of 24 (7%) microm (P = 0.14). After 48 hours, the posterior beds measured 382 microm, an average swelling of 54 (16%) microm (P = 0.02). Cell counts 48 hours after sectioning decreased by an average of 11% (P = 0.10). Endothelial cell staining confirmed improvement in postsectioning morphology and survival with increased technician experience. All 4 patients receiving eye bank-prepared DSAEK tissue showed uncomplicated postoperative results, with improvement in VA.

CONCLUSIONS

The microkeratome cutting depth was moderately accurate. Pachymetry, cell density, and cell viability of sectioned tissue after 48 hours in storage were encouraging overall. Initial clinical results of eye bank-prepared DSAEK tissue showed uncomplicated postoperative courses and improved VA. Additional studies are needed to follow the long-term outcomes in the recipients of these tissues.

Scattered light and visual function in a randomized trial of deep lamellar endothelial keratoplasty and penetrating keratoplasty

PURPOSE

To compare vision, intraocular forward light scatter and corneal backscatter between deep lamellar endothelial keratoplasty (DLEK) and penetrating keratoplasty (PK) for endothelial dysfunction.

DESIGN

A randomized clinical trial.

METHODS

Thirteen eyes (12 patients) were randomized to DLEK with a 9 mm scleral incision, and 15 eyes (14 patients) were randomized to PK. The primary outcome was high-contrast best spectacle-corrected visual acuity (BSCVA) at 12 months after surgery; intraocular forward light scatter and corneal backscatter were measured at one, three, six, and 12 months after surgery.

RESULTS

BSCVA at 12 months was 0.34 +/- 0.16 logMAR (logarithm of the minimum angle of resolution) for DLEK and 0.25 +/- 0.21 logMAR for PK (P = .23; minimum detectable difference at 12 months was 0.23 logMAR). The change in postoperative forward light scatter after DLEK correlated with the change in BSCVA (r = -0.66; P < .001; n = 11). Corneal backscatter was higher after DLEK than after PK at three and six months in the anterior third (P < or = .005), at one through 12 months in the middle third (P < .001), and at one through six months in the posterior third (P < or = .02) of the cornea. Backscatter after DLEK did not return to normal through 12 months (P < .001).

CONCLUSIONS

BSCVA was similar at one year after DLEK and PK. Improvement in BSCVA after DLEK correlated with decreasing forward light scatter. Increased backscatter after DLEK originated not only from the posterior cornea (interface) but also from the host cornea, which might limit visual outcomes after posterior lamellar keratoplasty.

Novel delivery method to reduce endothelial injury in descemet stripping automated endothelial keratoplasty

PURPOSE

To present a novel technique to deliver the endothelial graft in small incision Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) and to compare graft trauma between forceps delivery and the novel technique.

DESIGN

Laboratory investigation with an interventional case report.

METHODS

Ten pairs of human donor corneas were sectioned using an automated microkeratome system (Moria ALTK System, Antony, France). The recipient model was prepared by creating a 3 mm clear corneal wound in another human donor cornea. For each pair of corneas, one endothelial graft underwent single-fold delivery with forceps, while the other was delivered with the novel cartridge based technique. Each graft was stained with 0.25% trypan blue and 0.2% alizarin red, and digital photomicrographs were taken. A proportion of graft injury was calculated and differences were analyzed. Subsequently, a patient requiring DSAEK underwent the modified novel insertion technique.

RESULTS

After insertion, the mean proportion of graft endothelial injury from forceps delivery through the ex vivo model was 26.02% (n = 10, standard deviation [SD] +/- 14.85%). The mean proportion of graft endothelial injury from cartridge delivery was 9.85% (n = 10, SD +/- 4.33%). The median difference between the two methods was -13%, representing less endothelial injury with the cartridge. This difference was statistically significant (P = .006). The patient who underwent DSAEK with this technique had improved visual acuity and a clear graft at five months.

CONCLUSIONS

In our surgical model, inserting an endothelial graft through a small corneal wound using a novel cartridge-based technique created significantly less endothelial damage than with forceps insertion. Clinically, this technique was performed without complication.

Evaluation of Deep Lamellar Endothelial Keratoplasty Surgery Using Scatterometry and Wavefront Analyses

OBJECTIVE

To determine if postsurgical corneal interface abnormalities after deep lamellar endothelial keratoplasty (DLEK) cause increased light scattering or wavefront aberrations that may help to explain decreased best-corrected visual acuity in DLEK patients compared with penetrating keratoplasty (PK) patients.

DESIGN

Prospective comparative case series.

PARTICIPANTS

Clinically clear corneas of 4 eyes that had undergone DLEK surgery and 4 eyes that had PK were studied. Normal control data for light scattering was collected from 12 right eyes and 11 left eyes with normal corneas.

METHODS

Corneal light scattering was measured with a scatterometer designed at the Johns Hopkins Applied Physics Laboratory, and wavefront analysis was performed using standard methods with a Hartmann-Shack wavefront sensor.

MAIN OUTCOME MEASURES

Corneal scattering measurements were normalized by taking the ratio of the subject's corneal light scattering to a reference material. A scattering index was calculated as the ratio of the normalized scattering for a given patient's cornea to the average scattering of normal corneas. Astigmatism and higher-order aberrations were analyzed using standard data output from wavefront analysis and Zernike polynomial decomposition.

RESULTS

The mean scattering index was significantly higher after DLEK (1.78+/-0.29, mean+/-standard deviation [SD]) than after PK (1.03+/-0.27; P = 0.043). The higher-order root mean square (RMS) wavefront error was significantly higher after PK (0.71+/-0.11 microm, mean+/-SD) than after DLEK (0.44+/-0.12 microm; P = 0.029). Zernike polynomial decomposition of the wavefront aberrations revealed that regular corneal astigmatism was the most important aberration component for both PK and DLEK, but the PK patients had significantly more regular astigmatism (1.7+/-0.45 diopters [D], mean+/-SD) than did the DLEK patients (0.84+/-0.27 D; P = 0.029).

CONCLUSIONS

Our data quantitatively support subclinical corneal haze as an explanation for the limited visual acuity after DLEK as compared with PK. Intraoperative or postoperative modifications to reduce stromal haze after DLEK may result in better visual acuity outcomes.

Descemet-Stripping Automated Endothelial Keratoplasty

PURPOSE

To qualitatively assess the extent and pattern of endothelial trauma on corneal donor Descemet-stripping automated endothelial keratoplasty (DSAEK) buttons resulting from DSAEK insertion forceps.

METHODS

An in vitro model was used with corneoscleral rims, DSAEK quality corneal donor tissue, and DSAEK insertion forceps. After insertion of the donor button through the corneoscleral rim, a vital dye assay was used to identify devitalized and necrotic endothelial cells (with alizarin red S and typan blue).

RESULTS

Corneal buttons evaluated with the forceps delivery model showed that, for each arm of the forceps, there were 2 parallel bands of purple/red staining. In addition, orthogonal wrinkles of scattered blue devitalized nuclei were seen in a parallel arrangement.

CONCLUSIONS

The DSAEK insertion forceps resulted in a reproducible pattern of endothelial damage. A thorough understanding of iatrogenic endothelial trauma could result in improved forceps design and perhaps help mitigate the high rate of donor dislocation and graft failure in the future.

Corneal Endothelial Viability After Femtosecond Laser Preparation of Posterior Lamellar Discs for Descemet-Stripping Endothelial Keratoplasty

PURPOSE

To evaluate the feasibility of the femtosecond (FS) laser in preparation of posterior lamellar discs (PLDs) and to study the effect on endothelial cell (EC) viability for Descemet-stripping endothelial keratoplasty.

METHODS

Fourteen human donor bulbi unsuitable for transplantation were used. A horizontal lamellar cut was prepared in the donor cornea with an FS laser by using a raster and/or a spiral spot pattern. The control group consisted of the paired cornea of the same donor. EC density was evaluated before and after preservation in organ culture. The PLD was stripped from the anterior part by using either a forceps or a blunt dissection technique. The damage to the endothelium was evaluated.

RESULTS

EC loss after organ storage was not statistically significant between the FS cornea group and the control group in the 15- (7.7% +/- 6.9% and 8.9% +/- 8.1%, respectively; P = 0.78) and 30-kHz (4.3% +/- 4.0% and 3.7% +/- 3.6%, respectively; P = 0.75) group. There was no significant effect of laser frequency (15 vs. 30 kHz) on EC loss (7.7% vs. 4.3%, P = 0.25). Dissection by using a forceps stripping technique resulted in higher EC loss than that with a blunt dissection technique (13.0% vs. 6.5%, P = 0.03).

CONCLUSIONS

EC loss after FS laser lamellar cutting is not dependent on the frequency (ie, energy level) of the laser. A blunt dissection technique of PLDs resulted in acceptable EC loss and supports the clinical use of the FS laser for the preparation of PLDs.

Suture Technique for Descemet Stripping and Endothelial Keratoplasty

PURPOSE

To describe a suture technique for Descemet stripping and endothelial keratoplasty (DSEK).

METHODS

The technique was performed in 2 eyes of 2 patients with Fuchs endothelial corneal dystrophy. A double-armed 10-0 prolene suture on a CIF-4 needle was used to pull the donor corneal button into the recipient's anterior chamber without the use of forceps to hold the button. The suture was also used to unfold the lenticule in the eye without marking the stroma with gentian violet, to center the lenticule and to secure that in place.

RESULTS

No intraoperative problems occurred in either case. The suture technique was successfully used to pull the donor button into the host's eye and to unfold and center the button. Both lenticules were well centered and had minimal corneal edema. At 6 months, the central endothelial loss was 8% in the first case and 10% in the second.

CONCLUSION

This suture technique for DSEK avoids the use of forceps and allows less traumatic donor button manipulation. It may be an effective alternative with low endothelial damage; further follow-up will determine the long-term effect on the central endothelial cell count.

Cultivated Corneal Endothelial Cell Sheet Transplantation in a Primate Model

PURPOSE

To examine the feasibility of cultivated corneal endothelial cell transplantation in a primate model.

METHODS

Monkey corneal endothelial cells (MCECs) obtained from three cynomolgus monkeys were cultivated, with subcultures grown on collagen type I carriers for 4 weeks. The corneal endothelium of the right eye of six monkeys was mechanically scraped, after which a cultivated MCEC sheet was brought into the anterior chamber of four eyes and fixed to Descemet's membrane by air. As the control, a collagen sheet without MCECs was transplanted into one eye of one monkey, and a suspension of cultivated MCECs was injected into the anterior chamber in one eye.

RESULTS

Cultivated MCECs produced a confluent monolayer of closely attached hexagonal cells that showed both ZO-1 and Na(+)-K(+) ATPase expression. In the early postoperative period MCEC sheets were attached to Descemet's membrane and corneal clarity was recovered. The recovered clarity was accompanied by a decrease in corneal thickness. Fluorescein DiI labeled donor corneal endothelial cells were detected on the host cornea on postoperative day 7. Six months after transplantation MCEC-transplanted corneas remained clear, and hexagonal cells were observed by in vivo specular microscopy with a density of 1992 to 2475 cells/mm(2). Control eyes showed irreversible bullous keratopathy that precluded pachymetry and specular microscopy.

CONCLUSIONS

A model of cultivated corneal endothelial transplantation for corneal endothelial dysfunction was established in primates whose corneal endothelial cells have less proliferative capacity in vivo. Our results suggest that this is a useful model for long-term observation in advance of the future clinical application of cultivated corneal endothelial transplantation.

Future Directions in Lamellar Corneal Transplantation

The concept of lamellar keratoplasty (LK) is that of targeted lamellar replacement of corneal tissue while retaining normal cornea. It involves replacing either anterior stroma [anterior lamellar keratoplasty (ALK)] or posterior replacement of deep stromal and endothelial layers [posterior lamellar keratoplasty (PLK) or endothelial keratoplasty]. Despite the distinct advantages of ALK surgery, penetrating keratoplasty (PK) remains the most common procedure-largely because lamellar surgery is more technically demanding and time consuming, and interface irregularity arising from manual lamellar dissection often results in suboptimal visual outcomes. Recent improvements of surgical technique and advances in instrumentation such as microkeratome-assisted lamellar transplantation have contributed to improved visual quality with LK surgery. Long-term graft survival rates and endothelial cell counts after PK continue to drop for many years after surgery, clearly showing the disadvantage of unnecessary replacement of healthy endothelium in anterior-stromal disorders. The aim of this review is to evaluate the shifting emphasis from penetrating to lamellar forms of corneal transplantation and to highlight some future directions in lamellar surgery including new techniques in both ALK and PLK and the use of microkeratomes and femtosecond lasers to enhance outcomes.

Corneal Transplant Rejection Rate and Severity After Endothelial Keratoplasty

PURPOSE

To examine the corneal transplant rejection rate and the rate of graft failure subsequent to rejection in the first 2 years after endothelial keratoplasty (EK) and to compare this to background data for similar cases of penetrating keratoplasty (PK).

METHODS

Anonymized data from consecutive cases of EK [deep lamellar (DLEK) or Descemet stripping (DSEK)] for Fuchs corneal endothelial dystrophy or pseudophakic bullous keratopathy operated on before August 2004 were collected in 4 participating centers. The number and timing of rejection episodes and cases of subsequent graft failure were recorded, together with the time to cessation of topical steroid medication. Two-year postoperative findings were compared with background data for similar patients undergoing PK recorded in the Swedish Corneal Transplant Registry.

RESULTS

Rejection episodes were less frequent after EK than PK (P = 0.035). Fifteen (7.5%) of 199 EK cases had a rejection episode in the first 2 years after surgery versus 92 (13%) of 708 PK cases. Graft failure after rejection in EK may have been less frequent than in PK (P = 0.063), with only 1 (6.7%) case of rejection after EK versus 26 (28.3%) cases of rejection after PK proceeding to graft failure. A strong trend toward continued use of low-dose topical steroid medication was observed in the EK group. Eighty percent of EK patients were still taking topical steroid medication 2 years after surgery, whereas topical steroid medication had been ceased within a year of surgery in almost all PK patients in the comparator group.

CONCLUSIONS

Corneal transplant rejection is less frequent and may be less severe after EK than after PK. It is not yet clear whether these apparent differences are simply a product of relatively prolonged postoperative topical steroid cover in EK patients.

Surgical alternatives to penetrating keratoplasty II: endothelial keratoplasty

Penetrating keratoplasty (PK) became the standard of care for optical and tectonic rehabilitation of corneal blindness and visual impairment in the second half of the twentieth century. Posterior corneal disorders or endotheliopathies are the reason for one-third to one-half of all corneal transplants today in the US. Any procedure that replaces the endothelium ideally should accomplish the following results: (1) a smooth surface topography without significant change in astigmatism, (2) a highly predictable corneal power, (3) a healthy donor endothelium that resolves all edema, (4) a tectonically stable globe, safe from injury and infection, and (5) an optically pure cornea. Although PK consistently can achieve results 3 and 5 above, the other goals of stable topography, predictable corneal power and tectonic stability, have remained elusive despite our best efforts at ingenious suturing and trephination techniques. Endothelial keratoplasty (EK) is a new surgical procedure designed to replace diseased corneal endothelium with healthy donor endothelium through either a lamellar corneal flap approach or through limbal scleral incision, leaving the surface of the recipient cornea untouched by surface corneal sutures. This manuscript evaluates the impact and future of EK in ophthalmology.

Endothelial cell loss after descemet stripping with endothelial keratoplasty influencing factors and 2-year trend

PURPOSE

To identify factors correlated with early endothelial cell loss after Descemet stripping with endothelial keratoplasty (DSEK) and to document cell loss over a 2-year period.

DESIGN

Cross-sectional and longitudinal retrospective analyses.

PARTICIPANTS

A series of 263 eyes in 216 patients who were treated with DSEK and were examined at the same center after surgery.

METHODS

Six-month endothelial cell density (ECD) measurements were analyzed by multivariate analysis of variance to identify preoperative, operative, and postoperative factors that significantly influenced early cell loss. In addition, ECD measurements were compared longitudinally at 6, 12, and 24 months after grafting.

MAIN OUTCOME MEASURES

Central ECD after transplantation.

RESULTS

Mean ECD was 2000+/-550 cells/mm(2) 6 months after DSEK, representing cell loss of 34+/-18%. Factors associated with lower 6-month cell loss were use of single-point fixation forceps that compressed the donor tissue only at the tip during graft insertion (P = 0.025) and absence of any secondary donor reattachment procedure (P = 0.035). Six-month cell loss also was significantly less when DSEK was performed as a combined procedure; in combined cases, the graft was inserted through a clear corneal incision, whereas in standard cases, it was inserted through a scleral tunnel incision, which likely exerted more compression. Cell loss was comparable with manual and microkeratome donor dissection techniques (P = 0.91). Postoperative ECD was correlated positively with donor ECD (P<0.0001) and was correlated inversely with donor age (P<0.0001), although these donor characteristics explained only 10% of the total variance in 6-month ECD. Factors not significantly correlated with 6-month ECD or cell loss included donor death-to-preservation time (range, 1-22 hours; P = 0.45), donor death-to-use time (range, 2-8 days; P = 0.86), and recipient demographics. In 34 DSEK eyes analyzed longitudinally, mean ECD was 3100+/-250 cells/mm(2) before surgery, 2000+/-540 cells/mm(2) at 6 months, 1900+/-480 cells/mm(2) at 1 year, and 1800+/-490 cells/mm(2) at 2 years.

CONCLUSIONS

Cell loss 6 months and 1 year after DSEK was higher than in a recent penetrating keratoplasty series performed at the same center, consistent with more donor tissue manipulation in DSEK. Cell loss was reduced with certain variations in surgical technique.

Endothelial Keratoplasty: First Report of a Ruptured Globe After Deep Lamellar Endothelial Keratoplasty

PURPOSE

To report a case of ruptured globe after endothelial keratoplasty.

METHODS

Review of clinical findings in an 80-year-old man who presented with globe rupture after blunt trauma 3 years after deep lamellar endothelial keratoplasty.

RESULTS

The rupture occurred through the temporal scleral tunnel incision with expulsion of endothelial graft and intraocular lens. Primary repair was successful, but the postoperative course has remained complicated.

CONCLUSIONS

A ruptured globe caused by blunt trauma can occur after endothelial keratoplasty as it can after other intraocular procedures. In this case, the endothelial graft was extruded with separation of the donor-graft interface. The incidence has yet to be determined and whether it is less than that after standard penetrating keratoplasty surgery will require further long-term studies.

Candida albicans Interface Infection After Deep Anterior Lamellar Keratoplasty

PURPOSE

To report a case of interface infection by Candida albicans after deep anterior lamellar keratoplasty (DALK).

METHODS

A 30-year-old man with keratoconus underwent DALK. Four weeks after surgery, the patient developed multiple infiltrates in the graft-host interface with absence of intraocular infection. Donor rim cultures grew C. albicans. Penetrating keratoplasty (PK) was performed because of worsening of the infection despite topical, local, and systemic antifungal therapy.

RESULTS

Cultures carried out on the excised donor cornea confirmed donor-to-host transmission of C. albicans. An aqueous tap taken before PK was negative. Six months after PK, the corneal graft was clear with no recurrence of infection.

CONCLUSIONS

After DALK, in cases of donor graft microbial contamination, infection may develop at the graft-host interface. This may delay or prevent direct intraocular penetration of microorganisms, reducing the risk of development of endophthalmitis. PK may be needed to eradicate the infection in cases where conservative treatment fails.

Histologic and Ultrastructural Findings in a Case of Traumatic Graft Failure in Deep Lamellar Endothelial Keratoplasty

PURPOSE

Few complications have been reported for deep lamellar endothelial keratoplasty (DLEK). Endothelial graft failure has rarely been disclosed as a complication. Although the histopathologic and ultrastructural analysis of a failed DLEK graft has been previously described, we are not aware of any reports of these features in a case of traumatic endothelial graft failure.

METHODS

We report a case of an 85-year-old man with Fuchs endothelial dystrophy who underwent DLEK for corneal decompensation after cataract extraction and intraocular lens implantation. The graft had dislocated by the fourth postoperative day and was repositioned the following day. Penetrating keratoplasty was performed 3 months later for gradually progressive intractable corneal edema. The excised cornea underwent histochemical, immunohistochemical, and ultrastructural analysis.

RESULTS

Marked endothelial loss resulting in corneal decompensation was diagnosed histopathologically. The graft-host interface line showed no substantial findings for the following histochemical and immunohistochemical stains: colloidal iron, alcian blue (pH 2.5), vimentin, epithelial membrane antigen (EMA), smooth muscle actin (SMA), anti-cytokeratin CAM 5.2, high-molecular-weight keratin, anti-cytokeratin AE1/AE3, and collagen 3. The cornea showed ultrastructural changes similar to, but more pronounced than, those observed in corneas after laser in situ keratomileusis.

CONCLUSIONS

This is the second described case of endothelial graft failure after DLEK. Histochemical and ultrastructural analysis revealed that the DLEK-operated cornea contained irregularities that may interfere with optical performance.

Early Postoperative Complications of Deep Lamellar Endothelial Keratoplasty

PURPOSE

To report and discuss the early postoperative complications of deep lamellar endothelial keratoplasty (DLEK).

METHODS

The records of the first 44 patients who underwent DLEK by 1 surgeon were reviewed. Complications occurring between the first day and eighth week after surgery were recorded.

RESULTS

In 6 patients (13.6%), the donor disc was floating in the anterior chamber on the first postoperative day and was repositioned with a 30-gauge needle. Fluid was present between the cornea and the disc in 8 patients (18.2%); in 6 of them, the fluid absorbed spontaneously. In 2 patients, the fluid was aspirated 1 month after surgery, but fibrosis developed in the interface. Two patients (4.5%) had persistent corneal edema. In 1 of them, the edema resolved after 2 months, but the other needed penetrating keratoplasty. One patient (2.3%) developed endothelial graft rejection when steroid treatment was discontinued because of exacerbation of preexisting glaucoma. Ten patients (22.7%) had elevated intraocular pressure (IOP) before surgery. The pressure was controlled with topical medication after surgery in 7 patients, 1 patient (mentioned above) suffered graft rejection, 1 patient underwent repeat trabeculectomy, and 1 patient needed insertion of a glaucoma valve. Three patients (6.8%) who did not have glaucoma before surgery developed elevated IOP postoperatively, which was controlled with topical medication.

CONCLUSION

Non-adhesion of the disc and elevated IOP were the most common complications after DLEK. The mechanical preparation of a thinner donor disc and more experience may lead to fewer postoperative complications and their more efficient management.

Descemet's stripping endothelial keratoplasty

PURPOSE OF REVIEW

Descemet's stripping endothelial keratoplasty (DSEK) is rapidly becoming the preferred treatment for corneal endothelial dysfunction. Familiarity with recent advances in techniques and instrumentation can help reduce the initially steep learning curve and incidence of complications.

RECENT FINDINGS

DSEK produces excellent visual outcomes with minimal change in corneal surface topography or refraction. It can successfully treat corneal dysfunction associated with Fuchs' endothelial dystrophy, bullous keratopathy, iridocorneal endothelial syndrome or a failed penetrating graft. Donor dissection has become automated, and new techniques have been devised to facilitate graft insertion and unfolding. Some surgeons now routinely perform DSEK with topical anesthesia. Graft detachment is the most frequent early postoperative complication, but new methods can help promote donor adherence. The incidence of graft-rejection episodes is lower after DSEK compared with standard penetrating keratoplasty, possibly because wound healing is a lesser concern, and many DSEK patients are maintained on low-dose topical steroids indefinitely. Early efforts to transplant just the endothelial cell layer show promise.

SUMMARY

DSEK provides quicker visual rehabilitation and an improved safety profile compared with standard penetrating keratoplasty. Continued evolution of this relatively new technique is helping to reduce complications and further improve outcomes.

Visual acuity, refractive error, and endothelial cell density six months after Descemet stripping and automated endothelial keratoplasty (DSAEK)

PURPOSE

To evaluate visual acuity, refractive outcomes, and endothelial cell density 6 months after Descemet stripping and automated endothelial keratoplasty (DSAEK).

METHODS

We performed an institutional review board-approved prospective study of a surgical case series of 34 patients at 2 institutions undergoing DSAEK for Fuchs endothelial dystrophy, pseudophakic bullous keratopathy, or aphakic bullous keratopathy with or without simultaneous phacoemulsification and intraocular lens implantation. Clinical outcomes, including best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, and refractive astigmatism and topographic or keratometric astigmatism, were assessed at the 6-month postoperative examination and compared with preoperative values with paired Student t tests. The change in endothelial cell density from the eye bank examination to 6 months after transplantation was similarly evaluated.

RESULTS

BSCVA averaged 20/99 preoperatively and 20/42 postoperatively (P < 0.0001). After DSAEK, 30 (88.2%) of 34 patients showed improved BSCVA, and 21 (61.8%) of the 34 patients achieved a BSCVA of 20/40 or better. For patients not undergoing simultaneous phacoemulsification and intraocular lens implantation, a hyperopic shift in refraction of 1.19 +/- 1.32 D was noted. Refractive astigmatism, topographic astigmatism, and keratometry showed no statistically significant change. Endothelial cell density of donor corneas averaged 2826 +/- 370 cells/mm, whereas the mean postoperative density was 1396 +/- 440 cells/mm. This finding corresponded to an average loss of 1426 cells/mm (50% loss; P = 0.0001). The first half of cases experienced an average cell loss of 1674 cells/mm (59% loss) compared with 1181 (41% loss) in the second half of cases (P = 0.005). Three (9%) of 34 grafts experienced iatrogenic graft failure and required reoperation with new donor tissue. Also, 9 (27%) of 34 grafts experienced dislocation in the early postoperative period and required repositioning.

CONCLUSIONS

In this prospective study of DSAEK for bullous keratopathy and Fuchs endothelial corneal dystrophy, improvement of visual acuity was achieved with only a mild tendency toward hyperopic shift and without significant induced astigmatism. Endothelial cell loss was significant, however, and may be related to surgical experience.

Diagnosis of residual Descemet's membrane after Descemet's stripping endothelial keratoplasty with anterior segment optical coherence tomography

We present a patient with residual Descemet's membrane diagnosed by anterior segment optical coherence tomography (AS-OCT) after Descemet's stripping endothelial keratoplasty (DSEK). Postoperatively, persistent partial corneal edema and interface fluid without dislocation of the donor button were observed. No improvement of interface fluid was found during the follow-up period. A primary donor graft failure was diagnosed within 4 months, and the patient was regrafted with penetrating keratoplasty. Pathology examination of the specimen revealed the presence of residual Descemet's membrane in the recipient corneal button, confirmed using AS-OCT imaging. This case report demonstrates that inadequate Descemet's stripping in the recipient button could be a potential cause of DSEK failure; AS-OCT is a useful and noninvasive instrument for diagnosing and monitoring this post-DSEK complication.

Descemet Stripping and Automated Endothelial Keratoplasty (DSAEK) in Eyes With Failed Penetrating Keratoplasty

PURPOSE

To report our results of using Descemet stripping and automated endothelial keratoplasty (DSAEK) in eyes with failed penetrating keratoplasty (PK).

METHODS

An institutional review board-approved, prospective, surgical case series of 7 eyes of 7 consecutive patients undergoing DSAEK for graft failure after 1 or more PKs at 1 academic eye center.

RESULTS

The mean follow-up period was 13.3 months (range, 9-18 months). One eye suffered recurrent donor graft dislocation and elected to undergo repeat PK instead of repeat DSAEK. Of the remaining 6 patients, the average preoperative visual acuity (VA) was 20/851 compared with a best-corrected visual acuity (BCVA) of 20/65 postoperatively (P = 0.008). After DSAEK, 6 (100%) eyes showed improved BCVA, and 4 of 6 eyes (67%) achieved a BCVA of 20/40 or better. All 6 grafts remained clear at the last follow-up visit. Two eyes showed graft dislocation on the first postoperative day and underwent repositioning of the lenticule with good results. Two other eyes were diagnosed with primary iatrogenic graft failure within 1 week of DSAEK and underwent repeat DSAEK with new donor tissue with good results. One eye experienced acute graft rejection that was successfully treated with topical steroids.

CONCLUSIONS

This pilot series of DSAEK in eyes with graft failure from previous PK shows favorable VA and graft clarity outcomes. The complications observed were similar to those observed for DSAEK for Fuchs dystrophy and pseudophakic bullous keratopathy and include graft dislocation, iatrogenic graft failure, and homograft rejection.

Descemet's stripping automated endothelial keratoplasty in intraoperative floppy-iris syndrome: Suture-drag technique

Descemet's stripping automated endothelial keratoplasty avoids a full-thickness corneal procedure and provides rapid visual rehabilitation. Success depends on positioning the graft successfully while minimizing intraoperative donor endothelial trauma. Previously described techniques for graft insertion may be problematic in patients with intraoperative floppy-iris syndrome, anatomically shallow or unstable anterior chambers, or increased intraoperative posterior vitreous pressure. We describe an alternative called the suture-drag technique that may facilitate lamellar endothelial graft insertion in these special circumstances.