Axial length, keratometric values and their relationship with intraocular lens power in adult cataract patients in Benin City

Purpose: Emmetropization is significantly influenced by compensatory changes between the corneal curvature and axial length. Refractive status of the eye depends on the balance between several variables, including corneal power, lens power, and axial length. The goal of this study was to determine the relationship between axial length, keratometry values and IOL power in subjects with cataract. Methods: The study participants were 100 cataract subjects scheduled for surgery at St. Teresa Specialist and Laser Eye Centre in Benin City, Nigeria. The axial length, keratometry values, and IOL power were measured using the Amplitude Scan ultrasound biometry (A-Scan), Automated keratometry, and IOL formula software respectively. Results: There was no statistically significant difference in the mean keratometric values, axial length and IOL powers among the males and the females. A strong inverse correlation was seen between axial length and keratometric values in both meridians with r = -0.569 for K1 and r = -0.508 for K2, which was statistically significant (p < 0.001 in both). Hence, axial length increases as keratometric values (k1 & k2) decrease. A statistically significant strong inverse correlation was also found between axial length and IOL power (r = -0.805, p < 0.001). This implied that as axial length increases, IOL power required decreases. A weak positive correlation between IOL powers and the keratometric values was observed (r = 0.089, p= 0.381) which was not statistically significant. Conclusion: Our findings showed that axial length has a strong inverse correlation with corneal curvature and IOL power, while the positive co-relationship of corneal curvature with IOL power was weak.