Cornea - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group - CorneaLow-energy and high-frequency femtosecond laser in theproduction of donor corneal lamellaeGustavo Victor 1 , Walton Nosé 3 , Sidney J. Sousa 2 , Milton R. Alves 1 .1 Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil;2 Ophthalmology, University of Sao Paulo - FMRP, Ribeirao Preto,Brazil; 3 Ophthalmology, Federal University of Sao Paulo, Sao Paulo,Brazil.Purpose: This study evaluated the efficacy and reliability of a lowenergyfemtosecond laser with a high repetition rate in themanufacture of deep anterior and endothelial corneal lamellaeMethods: This is a prospective and laboratory investigation. Twentyfivehuman corneal buttons were cut tangentially to provide thickanterior lamellae (diameter, 10 mm; thickness, 500 µm). The cutswere made using an LDV® femtosecond laser in a Ziemer® anteriorchamber. For a better edge, the lamellae were trephined with an 8-mm trephine (Katena®). The center thicknesses of the whole corneasand of the anterior lamellae were measured using a Mitutoyo®thickness gauge with an accuracy of 0.001 mmResults: The thicknesses of the 25 corneas ranged from 500 to 705µm (mean, 584 ± 51 µm). The thicknesses of the anterior lamellaeranged from 420 to 480 µm (mean, 455 ± 12.7 µm). The thicknessesof the posterior lamellae ranged from 30 to 250 µm (mean, 129 ±52.8 µm). There were no discrepancies between the observed andexpected diameters of the lamellae, and all cuts were perfectly round.The lamellar interfaces appeared regular by surgical microscopy.There were no cases of inter-lamellar adhesionConclusions: The LDV® femtosecond laser appears to be a safe andreliable instrument for cutting deep anterior lamellae from donorcorneoscleral buttons. Even the worst-case scenario for the expectedcut precision for the whole population of donated corneas would onlybe about ± 32 µmCommercial Relationships: Gustavo Victor, None; Walton Nosé,None; Sidney J. Sousa, None; Milton R. Alves, NoneSupport: FAPESPProgram Number: 3088 Poster Board Number: D0023Presentation Time: 8:30 AM - 10:15 AMTears of post-LASIK corneal donor tissue during surgeonperformeddonor graft preparation for DSAEKDrew Davis 1 , Peter A. Karth 1 , Christopher Croasdale 2, 3 , Steven B.Koenig 1 . 1 Medical College of Wisconsin, Wauwatosa, IN;2 Ophthalmology, Davis Duehr Dean Clinic, Madison, WI;3 University of Wisconsin School of Medicine and Public Health,Madison, WI.Purpose: To describe four cases by two different surgeons in whichtears or tissue damage occurred during surgeon-performedpreparation of the posterior lamellar corneal lenticule in post-laserassisted in situ keratomileusis (LASIK) corneal donor tissue forDescemet stripping automated endothelial keratoplasty (DSAEK).Methods: In this retrospective case series, all donor corneal tissueshad previously undergone LASIK surgery. In all cases, a Moria®artificial anterior chamber maintainer (Moria, Doyleston, PA) and aMoria® ALTK microkeratome (300-um-depth) was used by thesurgeon to separate the lamellar corneal tissue.Results: In all four cases, the post-LASIK corneal donor tissues weretorn or damaged during preparation. In two cases, large tears of theposterior lamella occurred during surgeon preparation of the donorlenticule with a microkeratome, and the tissue was deemed unusable.One case was subsequently canceled immediately prior to plannedDSAEK; in the second case, an additional donor cornea was availableand was successfully transplanted. In the third and fourth cases, thetissue was damaged but was deemed usable. A button-holeperforation occurred in the anterior lamellar cap of the third case, anda linear paracentral ridge was inadvertantly created on the posteriorlamella of the donor tissue in the fourth case.Conclusions: While published literature supports use of post-LASIKdonor corneal tissue in DSAEK, we believe that our casesdemonstrate a need for caution in surgeon preparation of post-LASIKdonor corneal tissue. To avoid tissue waste and cancelled procedures,we recommend post-LASIK donor tissue be prepared in thelaboratory prior to the planned procedure. As more potential cornealdonors undergo LASIK each year, effective preparation of post-LASIK donor corneal tissue will become an increasingly importantconsideration.Commercial Relationships: Drew Davis, None; Peter A. Karth,None; Christopher Croasdale, None; Steven B. Koenig, NoneProgram Number: 3089 Poster Board Number: D0024Presentation Time: 8:30 AM - 10:15 AMDSAEK for Corneal Decompensation After Ex-Press ShuntSurgery -A Case SeriesJayne S. Weiss 1 , Shalin Shah 1 , Hilary Thompson 2 , Christina Bovone 3 .1 Department of Ophthalmology, LSU, New Orleans, LA;2 Biostatistics Section, School of Public Health, LSUHSC, NewOrleans, LA; 3 Villa Igea Hospital, Forli, Italy.Purpose: Corneal decompensation is a known risk of anteriorchamber implantation of older glaucoma shunts (Ahmed, Baerveldt,Molteno). There is little literature discussing this association of thisrisk with Ex-press shunts. The purpose of the study was to determinewhether the Ex-Press shunt implantation could be associated withdevelopment of subsequent corneal decompensation and whetherDSAEK surgery could be successfully performed in such cases.Methods: A retrospective case review from one corneal surgeon ofall cases of DSAEK performed since 2005 that had prior Ex-Pressshunt surgery. Ocular history including number of surgicalprocedures, intraocular pressure prior to and after Ex-Press shunt,best corrected visually acuity (BCVA) before Ex-Press shunt surgery,before and after DSAEK, and surgical complications were reviewed.Results: The average age and average intraocular pressures (IOP)prior to of Ex-Press shunt placement was 63.8 years +/- 3.4 standarddeviation (SD) and 24.60 mmHg +/- .40 SD respectively. BCVAprior to Ex-Press shunt placement was log MAR 0.64 +/-.16 SD. Theaverage post-operative IOP after Ex-Press shunt was 16.80 mmHg+/- 1.0 SD. The mean number of surgeries prior to DSAEK was 2.8+/- 1.64. 4 of the 5 patients with corneal decompensation after Ex-Press shunt placement had one or more prior filtering procedures witha mean of 1.75 +/- .83. One of these patients also had 2 prior failedEx-Press shunts. Vision decreased to count fingers in all patientsbefore DSAEK. The average age at which significant cornealdecompensation was identified and DSAEK was performed was 66.0years +/- 3.2 SD. with average time of onset of corneal edema afterEx-Press shunt of 2.2 years +/- .44 SD. The average BCVA afterDSAEK was .78 +/- .18 SD with decreased vision resulting fromoptic nerve damage in all cases. All corneas remained clear. IOP wascontrolled in 4 patients, 1 patient required cyclocrytherapy for IOPcontrol.Conclusions: This is the first case series documenting cornealdecompensation after Ex-Press shunt placement. Long term follow upof patients who have had Ex-Press shunt surgery is needed todetermine if the shunt device itself increases the risk of cornealdecompensation. This case series demonstrates that DSAEK surgerycan be successful in treatment of corneal decompensation after Ex-Press valve placement.Commercial Relationships: Jayne S. Weiss, None; Shalin Shah,None; Hilary Thompson, None; Christina Bovone, NoneSupport: Lions Eye Foundation, Research to Prevent Blindness©2013, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permissionto reproduce any abstract, contact the ARVO Office at arvo@arvo.org.