1. Study of Death to Preservation Time and
Its Impact on Quality & Utilization of Donor Corneas
PBN:
SN: 225
Dhaval Patel1, Radhika Tandon1, Aarti Vij2, Sanjeev Lalwani, Adarsh Kumar
Dr R P Centre for Ophthalmic Sciences1, Organ Retrieval & Banking Organization2,
All India Institute of Medical Sciences, New Delhi, India
PURPOSE
To study the effects of death to preservation time on quality and utilization of donor corneas.
BACKGROUND
Corneal Blindness: INDIA1
3.5 million people
Need = 100,000 Keratoplasty/ year
Collection = 47,400 in 2012
Every year, supply of suitable donor corneas cannot meet the demand because donor tissue is often rejected for the reason of “long cadaveric time.”
MATERIALS & METHODS
Study Design: Prospective Observational Study
Study Site: National Eye Bank, AIIMS
Study Period: November 2011 to January 2013.
We evaluated Donor Corneas by Standard Grading System adapted & modified from Cornea Donor Study (NEI ) Tissue Eligibility Criteria. 2
Parameters evaluated included donor age, gender, history of diabetes, lens status, type of retrieval and type of donation, corneal grading, endothelial cell density, and primary graft failure & graft infection in first 4 weeks after transplantation.
Corneal parameters like epithelial defect, haze, exposure, stromal edema, descemet’s folds, grade, and ECD were compared in five intervals of DPT i.e. 0-6, 6-9, 9-12, 12-18, and >18 hours.
Effect of donor refrigeration prior to tissue retrieval was evaluated.
RESULTS
Death to Preservation Time
Mean DPT:
6:50 ± 5:50 hours
(Range: 20 minutes to
28 hours)
DPT and Corneal Grading
DPT
Total
0-5:59
6:00-8:59
9:00-11:59
12:00-17:59
≥ 18:00
P value (Pearson Chi-Square)
n=1092
n=616
n=160
n=111
n=155
n=50
Optical
38%
34%
43%
39%
45%
54%
0.05
 Grading
Therapeutic
57%
61%
52%
40%
NSFS 5% 4% 3% 6%
0-1499
10%
0.51
ECD
29%
27%
30%
33%
32%
24%
>=2000
66%
69%
60%
62%
65%
71%
Donor Characteristics
DPT and Refrigeration
Donor Characteristics
N (%)
HCRP VD
Total
Age (years)
0-29
94 (16.3)
7 (1.2)
101 (17.5)
30-59
106 (18.4)
29 (5.1)
135 (23.5)
>=60
57 (9.9)
282 (49.1)
339 (59)
Median
65 years
Mean ± SD
58.72 ± 23.12
Gender
Male
176 (30.6)
175 (30.4)
351 (61)
Female
81 (14.1)
143 (24.9)
224 (39)
History of Diabetes
Yes
24 (4.2)
31 (5.4) No
250 (43.5)
294 (51.1)
544 (94.6)
Lens Status
Phakic
955 (83.8)
Pseudophakic
155 (16)
Aphakic
2 (0.2)
DPT & DONOR REFRIGERATION
0-5:59
6:00-11:59
≥ 12:00
Refrigeration No
Yes
P value
n=590
n=26
n=217
n=54
n=109
n=96
Grading
Optical
198 11
0.372 73 38
<0.001 33 63
Therapeutic
361 15
130 16 71 30
NSFS 31 14 5 3
DPT & DONOR REFRIGERATION
0-5:59
6:00-11:59
≥ 12:00 No
Yes
P value
n=241
n=16
n=107
n=25
n=59
n=58
ECD
0-1499 11
0.245 9 1
0.412 4
<0.001 67 2 36 6 26 8
>=2000
166 14 62 18 29 50
Donor Characteristics
P value
Grade
ECD
Culture
Primary Graft Failure
Graft Infection
Age
<0.001
0.001
0.2268
0.611
0.715
Gender
0.326
0.086
0.239
0.16
Diabetes
<0.01
0.138
0.451
0.527
0.346
Lens Status
0.003
0.725
0.694
Enucleation/In-situ
0.007
0.097
0.373
0.8
HCRP/VD
0.09
0.328
0.703
Other Parameters
Death to Utilization Time
Mean death to utilization time (DUT) was 2.3 days.
Utilization rate was similar in all intervals of DPT.
DUT was not related to primary graft failure (p=0.54)
but was related to graft infection (p=0.001).
 Donor Characteristics
Corneal Grading/ ECD
Age
Age has Inverse relationship with Grading & ECD.(p<0.001,p=0.001)
Gender
Male Corneas have better grading than that of Females (p<0.001)
Diabetes
Non-diabetic Donors have better Grading than Diabetic (p<0.01)
Lens Status
Phakic Eye has better grading and ECD that Pseudophakic. (p<0.001,p=0.003)
Enucleation/
In-situ
In-situ technique has better grading & ECD than Enucleation. (p=0.005,p=0.007)
HCRP/VD
HCRP donors have better grading & ECD than Voluntary Donors. (p<0.001,p=0.001)
Prolonged DPT had significant effect on Donor Culture Positivity (p=0.001).
Primary graft failure and graft infection rate was 1.9% & 4.9% in optical grade corneas and 1.3% & 10.4% in therapeutic grade corneas respectively. Up to duration of 28 hours, DPT was not related to Primary Graft Failure (p=0.131) and Graft Infection (p=0.137) in first 4 weeks of Transplantation.
CONCLUSIONS
There is no correlation between death preservation time (DPT) and donor cornea quality in our study range 20 minutes to 28 hours provided donor is refrigerated in case of DPT more than 6 hours .
Donor Characteristics having impact on Cornea Quality are Age, Gender, Diabetes, Lens Status, Type of Retrieval and HCRP-Voluntary Donation.
DPT has no significant effect on rate of utilization of donor cornea.
REFERENCE
NPCB Statistics Report
Baseline Donor Characteristics in the Cornea Donor Study, Cornea 2005;24:389–396
ABBREVIATIONS
DPT: Death Preservation Time
ECD: Endothelial Cell Density
HCRP: Hospital Cornea Retrieval Program
NSFS: Not Suitable For Surgery
VD: Voluntary Donation
Asia ARVO New Delhi, October 28-31, 2013