Authors : Mohan Kumar H, Sangeetha T, Kanthamani , Nithiya Joe Babu
DOI : 10.18231/j.ijceo.2019.090
Volume : 5
Issue : 3
Year : 2019
Page No : 376-381
Introduction: This study aimed to measure the postoperative residual spherical error and to find the correlation between the axial length and anterior chamber depth measured preoperatively with the postoperative refractive status.
Materials and Methods: A total of 174 patients of the age group 40-70 years axial length ? 22 mm undergoing cataract surgery were included in our prospective study in which the accuracy of SRK II was compared with Haigis formula. The participants were divided into group A and B by simple randomization technique. The subjects under group A were implanted with IOL calculated using Haigis formula and those under group B with SRK II formula. They were evaluated for visual acuity and residual refractive error. The degree of emmetropia of the participants was analysed using above data.
Results: A total of 174 eyes were included in our study of which 64 (36.7%) were males and 110(63.2%) were females. The mean axial length was 21.47mm and the mean anterior chamber depth was 3.17mm. Significant differences were found between the spherical error calculated by SRK II formula and Haigis formula. The mean spherical error in group A with Haigis formula was - 0.36 (range 0 D to -1.5) meanwhile group B with SRK II formula had a mean spherical error of + 0.55 (range 0 to +2 D). The postoperative refraction of patients implanted with IOLs calculated using Haigis formula was closer to emmetropia.
Conclusion: It was found that in patients with short axial length, Haigis formula gave an accurate prediction of the IOL power compared to SRK II formula. Using Haigis formula led to a mild over correction leading to a slightly more myopic outcome while SRK II formula led to a mild under correction leading to a mild hypermetropic outcome.
Keywords: Formula, Haigis, IOL power calculations, SRK II, Short axial length.