Ratio of Axial Length to Corneal Radius in Japanese Patients and Accuracy of Intraocular Lens Power Calculation Based on Biometric Data

Abstract

MIKI KAMIKAWATOKO OMOTO, HIDEMASA TORII, KEN HAYASHI, MASAHIKO AYAKI, KAZUO TSUBOTA, AND KAZUNO NEGISHI PURPOSE: To evaluate the features of the axial lengthto-corneal radius (AL/CR) ratio in Japanese patients with cataracts and to determine the accuracy of intraocular lens (IOL) power calculation formulas according to the AL/CR features and the axial length (AL).DESIGN: Retrospective observational case series. METHODS: Setting was a clinical practice. Patient population was a total of 1,135 eyes (1,135 patients) with cataracts. Observation procedures included measurement of the AL and corenal radius (CR) by optical biometry and evaluation of the refractive outcomes by using the SRK/T, Holladay 1, Hoffer Q, Haigis, and Barrett Universal II formulas. Main outcome measurements were the features of the AL/CR ratio and the accuracy of IOL power calculations based on the AL/CR ratio and the AL.RESULTS: The mean AL/CR ratio was 3.15 ± 0.19. Significant weak negative correlations were observed between the spherical equivalent (SE) and AL (r [ L0.7489; P < .001) and between the SE and AL/CR ratio (r [ L0.8069; P < .001); no correlation was found between the SE and CR (r [ 0.0208, P [ .483). For medium ALs and high AL/CR ratios, the SRK/T formula performed less accurately. For long ALs and high AL/CR ratios, the Holladay 1 and Hoffer Q formulas performed less accurately. The Barrett Universal II formula performed well across a range of ALs and AL/CR ratios. CONCLUSIONS: The AL/CR ratio explained the total variation in the SE better than the AL alone. Surgeons should pay attention to the selection of IOL power calculation formulas in eyes with high AL/CR ratios. (Am J Ophthalmol 2020;-:---. Ó

Investigating the Prediction Accuracy of Recently Updated Intraocular Lens Power Formulas with Artificial Intelligence for High Myopia

“…The prevalence of myopia is growing, especially in Asia [ 3 , 4 , 5 ]. While many methods are being used to overcome this issue [ 6 , 7 , 8 , 9 , 10 , 11 ], the challenge still remains.…”

Algorithmic intraocular lens power calculation formula selection by keratometry, anterior chamber depth and axial length

“…For eyes with short AL, the accuracy between the formulas is altered depending on the anterior chamber depth (ACD) because the change in effective lens position (ELP) has an increased effect on IOL power (Eom et al 2014). A recent study reported that the IOL power calculation formula selected by the ratio of AL and K was evaluated to be more accurate than that by AL subgroup alone (Omoto et al 2020). Melles et al (2018) explored 13 301 eyes and reported the tendency of refractive prediction error in the diversity of IOL power calculation formulas according to K, ACD and AL.…”

“…A recent study reported that the IOL power calculation formula selected by the ratio of AL and K was evaluated to be more accurate than that by AL subgroup alone (Omoto et al. 2020 ).…”

Association between Refractive Errors and Ocular Biometry in an Elderly Population

“…This index is also important at older ages, as recent studies have shown that using the axial length/ corneal radius of curvature ratio can be very useful to determine the optimal intraocular power in patients with cataracts. 32 One of the interesting findings of the present study was the relationship between anterior chamber depth and refractive errors. In most previous studies, an inverse relationship was found between anterior chamber depth and spherical equivalent.…”

“…In other words, in two individuals with the same axial length/corneal radius of curvature ratio, the refraction differences can be attributed to the crystalline lens thickness as well as the contribution of the anterior chamber depth and vitreous chamber depth. This index is also important at older ages, as recent studies have shown that using the axial length/corneal radius of curvature ratio can be very useful to determine the optimal intraocular power in patients with cataracts 32 …”