Dr. Prachi Sharma ( P20078 )
INTRODUCTION
- Corneal diseases are one of the major causes of blindness.
- Donor corneas are screened in several ways in order to prevent grafts with poor viability or grafts that may transmit diseases being used in keratoplasty.
Graft viability affected by :
- Physiological and morphological characteristics of donor corneal endothelium.
- Previous eye diseases, intraocular surgery or trauma.
- Donor age
- Death-enucleation time
- Methods of corneal removal and storage.
UNFIT Grafts:
- Endothelial cell density (ECD) <1500 cells/mm2
- Severe polymegathism
- Fused cells and single cell defects
- Central corneal guttata
- Severe oedema
- Inflammatory cells and bacteria.
STUDY DESIGN
A retrospective cross sectional study on all the donor
corneas since 1st may 2016 till 31st july 2016 at eye
bank RIO PGIMS, Rohtak.
MATERIAL AND METHOD
- 33 eyes from 33 different donors. Groups were made. qAge groups (years) :
| A | B | C | ||
| =< 50 | 50-75 | >75 | ||
| Cause of death : | ||||
| A | B | C | ||
| Septicaemia, cancer, | Cardiac arrest, IC | Other causes | ||
| HIV/HBsAg | bleed, pulmonary | |||
| seropositive (other | embolism | |||
| C/I) | ||||
Death-Enucleation time (hrs) :
| A | B |
| 0-3 | 3-6 |
- Method
The fixed-frame method for endothelial cell counting using konan’scellchek D was used.
The average number of cells per square millimetre of the cornea was calculated.
Statistical analysis
Unpaired t-test.
Spearman correlation test
For all tests p<0.05 were considered statistically significant.
RESULT
| TOTAL POPULATION (n=33) | 60.09 |
| mean age (years) | |
| Standard deviation (± ) | 18.50 |
| Range | 20-88 |
| Mean time Death – enucleation time | 2.77± 1.69 |
| (n=33) (hours) | |
| Range | 0.3 –6.45 |
| Total male | 20 |
| Total female | 13 |
Age Vs ECD
| Age groups | ECD(cells/mm2) | Statistical significance | |
| Group A (n=9) | 2245.11± 665.95 | 0.148 (>0.05 NS) | A vs. B |
| Group B (n=17) | 1847.76± 555.44 | 0.02 (<0.05 | B vs. C |
| Significant) | |||
| Group C (n=7) | 1372.71± 376.51 | 0.005 (<0.01 | A vs. C |
| Significant) | |||
| Parameters | Correlation Coefficient (r | Significance | |
| value) | |||
| Age vs. ECD | -0.506 | 0.003 | (<0.05 Significant) |
| ECD eye 1 vs. ECD eye | 0.363 | 0.038 | (p <0.05 |
| 2 | Significant) | ||
CAUSE OF DEATH Vs ECD
| Groups | ECD (cells/mm2) | Statistical significance | |
| Group A (n=4) | 1750± 423.70 | A vs. B | p=0.287 (>0.05 |
| NS) | |||
| Group B (n=17) | 1780.23± 622.71 | A vs. C | p=0.06 (>0.05 NS) |
| Group C (n=12) | 1996.91± 688.20 | B vs. C | p=0.394 (>0.05 |
| NS) | |||
Death-Enucleation time Vs ECD
| Death- | Time(hours) | ECD(cells/mm2) | Statistical | |
| Enucleation time | Mean± SD | Mean± SD | significance ECD | |
| (A vs. B) | ||||
| Group A (n=18) | 1.66± 0.96 | 1803.83± 682.60 | p=0.602 | |
| (>0.05 NS) | ||||
| Group B (n=15) | 4.11± 1.38 | 1917.2± 554.67 | ||
Gender Vs ECD
| Gender | ECD(cells/mm2) | Statistical significance | |
| Mean± SD | (A vs. B) | ||
| Male | 1969.70± 625.59 | p=0.190 | |
| (>0.05 NS) | |||
| Female | 1679.46± 593.98 | ||
Discussion:
The results of the present study clearly show that corneal endothelial cell density decreases with age (r-{-}0.506; p<0.003), which is in accordance with the results from other reports (Yee et al. 1985; Musch et al.1993; Armitage & Easty 1997; Møller-Pedersen 1997).
No statistically significant differences between male (1969.70± 625.59 cells/mm2) and female (1679.46± 593.98 cells/mm2) corneas were observed.
The correlation between the endothelial cell densities of paired corneas was statistically significant (r-0.363, p < 0.038).
The mean corneal endothelial cell density compared to cause of death were 1750 ± 423.70 cells/mm2 in group A, 1780.23 ± 622.71 cells/mm2 in group B, and 1996.91 ± 688.20 cells/mm2 in group C. The differences between these three groups were not statistically significant.
Redbrake et al. (1995, 1997), Volker-Dieben et al. (1982) and Vail et al. (1994) found the cause of donor death to have no influence on the outcome of corneal grafting.
- No statistically significant differences in death-enucleation time with ECD was found.
LIMITATIONS
- Information about the general condition of the donors prior to death
- Uncertainity to what extent different treatment modalities may affect the corneal endothelium.
CONCLUSION
There was a statistically significant negative correlation between donor age and mean ECD.
The correlation between the ECD of the paired corneas was also statistically significant.
The effect of cause of death and death-enucleation time on ECD was not found statistically significant.
REFERENCES
Armitage WJ & Easty DL (1997): Factors influencing the suitability of organ-cultured corneas for transplantation. Invest Ophthalmol Vis Sci 38:6–24
Møller-Pedersen T (1997): A comparative study of human corneal keratocyte and endothelial cell density during ageing. Cornea 16:333–338
Redbrake C, Salla S, Vonderhecken M, Sieben P & Reim M (1997): Gewebezustand humaner Hornhaute vor und nach Organkultur. Einfluß der Todesursache des Spenders. Ophthalmologe 94:573–577
Vail A, Gore SM, Bradley BA, Easty DL, Rogers CA, Armitage WJ (1994): Influence of donor histocompatibility factors on corneal graft outcome. Transplantation 58:1210–1216
- Volker-Dieben HJ, Kok-Van Alphen CC, Lansbergen Q & Persijn GG (1982): Different influences on corneal graft survival in 539 transplants. Acta Ophthalmol (Copenh) 60:190–192
- Yee RW, Matsuda M, Schultz RO, Edelhauser HF (1985): Changes in the normal corneal endothelial cellular pattern as a function of age. Curr Eye Res 4: 671–678
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