Dr.DR. PRASHANSA YADAV

DR. PRABHAKAR S.K., DR. OSHIN MIDDHA, DR. FEBA MARY GEORGE, DR. BINDU MALINI M

Abstract

Aim: To find out predictability and influence of biometric values on power calculation

Methods: Study conducted at tertiary Institution on 110 eyes after obtaining preop biometry values and calculating IOL power by SRK-II and A-scan. Statistical analysis performed by Excels 2007.

Results: Mean age 61.8(±9.33) years with 60(54.54%) females. Obtained Mean values being Ka 44.48 D, AL 22.74 mm and MD of 0.05 D obtained for IOL power by both methods. Pearson correlation showed negative relation of Kh, Kv, and Ka (r=-0.6) with AL (r=-0.75). Positive relation (r=0.96) found for SRK-II and A-scan derived IOL powers. High positive correlation (R2=0.99) observed for Ka and IOL powers (R2=0.92). Paired t-test showed statistical significance (p=0.003) for Kh and Kv.

Conclusion: IOL power differed by 0.48 D per unit change in Keratometry values, and by 0.73 D of either value of each methods on regression. In doubtful cases, we recommend SRK II formula use to avoid post-operative hyperopic shift.