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).


METHODS
Experimental study and retrospective case series.


METHODS
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.


METHODS
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.
Rose
Linda
L
Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, USA.
Briceño
César A
CA
Stark
Walter J
WJ
Gloria
Dante G
DG
Jun
Albert S
AS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D002470:Cell Survival; D003315:Cornea; D003316:Corneal Diseases / Q000503:physiopathology / Q000601:surgery; D016039:Corneal Transplantation / Q000379:methods*; D003886:Descemet Membrane / Q000601:surgery; D004728:Endothelium, Corneal / Q000166:cytology / Q000637:transplantation*; D005125:Eye Banks / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D011785:Quality Assurance, Health Care; D012189:Retrospective Studies; D013048:Specimen Handling / Q000592:standards*; D014019:Tissue Donors; D014792:Visual Acuity / Q000502:physiology