Comparison of efficacy of storage of amniotic membrane at -20 and -80 degrees centigrade.

OBJECTIVE

To compare the efficacy of storage of amniotic membrane at -20 and -80 degrees centigrade.

STUDY DESIGN

Interventional quasi-experimental study.

PLACE AND DURATION OF STUDY

Department of Ophthalmology, Unit 1, Dow University of Health Sciences and Civil Hospital, Karachi, from January 2009 to December 2010.

METHODOLOGY

Amniotic membrane was obtained from patients undergoing elective Caesarean section screened for HIV, Hepatitis B and C and gave informed consent. It was washed with solutions containing benzyl penicillin, streptomycin and amphotericin B and frozen at -20 degrees centigrade for upto 6 weeks or at -80 degrees centigrade for upto 6 months. Fisher's exact test was used to check significance. P-value less than 0.05 was considered as significant.

RESULTS

Amniotic membrane was stored at -20 degrees centigrade on four occasions and was used in 25 (48.07%) patients. On 3 other occasions it was stored at -80 degrees centigrade and was successfully used in 27 (51.92%) patients. The association between different degrees of storage of graft and type of cases is insignificant (p = 0.99).

CONCLUSION

Compared to use of fresh amniotic membrane use of amniotic membrane stored at -20 and -80 degrees is safe and cost effective. It also excludes the chances of disease transmission. Although freezing at both temperatures is equally efficacious, freezing at -80 degrees centigrade can preserve the graft upto 6 months compared to -20 degrees centigrade which can be used only for 6 weeks.