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.