1. Evaluation of a New Technique to Increase Usage of Donor Descemet’s Membrane for DMEK
World Cornea Congress VII - April 15-17, 2015
Electronic Poster
Javiera M. Compan, MD; Esteban Santiago, MD; Ronan Conlon, MD;
Kashif Baig, MD, MBA, FRCSC
University of Ottawa Eye Institute, Ottawa, Ontario, Canada

2. Financial Disclosures
Drs. Compan, Santiago, and Conlon have no financial relationships to disclose. Dr. Baig has the following relationships:
Financial Interest/ Affiliation
Name of Company(s)
Grant/Research Support
Allergan, Bausch & Lomb, Merck, Moria
Employment/Honoraria/Consulting Fees/Travel Expenses
Alcon, Allergan, Bausch & Lomb, Labtician
Major Stock Shareholder
None
Member: Advisory Panel, Standing Committee, Board of Directors
Allergan, Bausch & Lomb
Other Financial or Material Interest

3. Introduction
Donor corneal tissue is a limited resource which may affect wait times.
The migratory movement of donor endothelial cells play an important role following DMEK surgery.
Conventional use of corneal tissue: One donor per procedure
Split corneal tissue:
Hemi-Descemet membrane endothelial keratoplasty transplantation: a potential method for increasing the pool of endothelial graft tissue. Lam FC, Baydoun L, Dirisamer M, Lie J, Dapena I, Melles GR. JAMA Ophthalmol Dec;132(12):
Current Approaches to Combat the Shortage of Corneal Tissues: Split-DMEK and Double-Split Keratoplasty. Yoeruek E1,Bartz Schmidt K. Cornea Mar;34(3):e6-9.

4. Methods Retrospective chart review Inclusion criteria Technique
Pseudophakic patients with endothelial dysfunction undergoing DMEK
Technique
A trephine/SCUBA technique was first used to harvest the DMEK graft
Each graft was then split in two (2 different shapes were used)
The two halves were used in two different patients undergoing DMEK
Tissue preparation and operative use occurred on the same day
Tissue preparation challenges, intraoperative complications, and visual recovery were assessed

5. Tissue preparation Two almond-shaped grafts
Two hemi-circle shaped grafts
Original shape

6. Results
4 corneoscleral rims were used to prepare tissue for 8 DMEK procedures.
Demographics
Mean age: 76 (range 69-83)
Gender: 6 females, 2 males
Preoperative diagnoses:
7 - Fuchs Dystrophy
1 - Pseudophakic Bullous Keratopathy (PBK)
1 - Descemet’s membrane detachment (DMD) during cataract surgery
Previous Surgeries:
1 – Ahmed valve
1 - Failed DSAEK (DMD patient)

7. Vitreous loss in one patient
Surgical Experience
Almond Shape
Hemicircle
Area (mm2) 40 49
Mean donor age (years) 58 68
Peeling difficulty + ++
Intraoperative complications
Vitreous loss in one patient
Small fold in graft

8. Results Almond Shape Semi-Circle Number of patients 2 6
Mean patients age (years) 69 78
Pre-operative diagnosis
Fuchs dystrophy (2)
Fuchs dystrophy (4)
PBK (1)
DMD (1)
Post-operative complications
Graft detachment (2)
Primary graft failure (1)
% of post-operative grafts attached 0%
100%
Success rate
83% (5 patients)
Failure rate
17% (1 patient)

9. Results 4 donor tissues were used in 8 DMEK procedures
2 almond shape grafts had complete detachments 2 days after surgery and DMEK was repeated using conventional circular donor tissue
6 semi-circle shape grafts attached in post operative period
5 grafts were clear between one and six months follow-up
1 graft suffered primary failure (DMD patient) and DMEK was repeated conventional circular donor tissue
At 6-month follow-up, mean best corrected spectacle distance visual acuity improved from
Patient #2 one week post surgery
Patient #2 one month post surgery

10. Post-operative visual acuity in successful patients
Preop
1 day
1 week
1 month
2 months
4 months
Patient 1
20/40
20/150
20/50
20/30
20/30+2
Patient 2
20/70
20/60
20/20 -
Patient 3
Patient 4
20/250
Patient 5
20/100
20/80

11. Conclusions
A single donor corneal graft can be used for two DMEK procedures, and is a promising strategy to improve the efficiency of corneal transplantation.
This technique of splitting DMEK could diminish further use of donor tissue.
In this study, all saved donor tissues were used for other patients
Different factors may play a role in the functioning of the graft.
Success of Hemi-DMEK depends on graft quality, donor-recipient integration, surgeon ability for a Descemet stripping and splitting performed without incident and intraoperative graft manipulation among others.
Grafts with sharp edges are apparently more instable and tend to detach.
Five of six hemi-circle shaped grafts remain attached and clear at the end of this chart review, all of them with a visual acuity improvement trend.
A larger number of patients and a long term follow-up is necessary to compare DMEK versus hemi-DMEK in terms of procedure success and safety.

12. Cornea, Anterior Segment, and Refractive Surgery Team at the University of Ottawa Eye Institute
Attendings
Kashif Baig, MD, MBA
Bruce Jackson, MD
George Mintsioulis, MD
Setareh Ziai, MD
Clinical Fellows
Samer Abuswider, MD ( )
Setareh Ziai, MD ( )
Abdulmajeed Aljaethen, MD ( )
Season Yeung, MD ( )
Joshua Teichman, MD, MPH ( )
Javiera Compan ( )
Esteban Santiago ( )
Research Fellows
Mustafa Kapasi, MD ( )
Salina Teja, MD ( )
Ronan Conlon, MD ( )
Technologists
Sabrina Taylor, COMT
Emily Wong, COMT
Research
Melanie Lalonde, PhD
Gail Kayuk, BSc, ART
Annelise Saunders, LLB