Preliminary clinical validation
A total of 13 eyes of 8 patients with keratoconus (with a mean age of 41.1 years ± 19.1 and ages ranging from 20 to 69 years) were evaluated in the Department of Ophthalmology (OFTALMAR) of the Vithas Medimar International Hospital (Alicante, Spain). In all cases, IOL power was calculated using the keratometric approach (equation 1)11 and the complete Gaussian formula, including posterior cornea and pachymetric data obtained with the Sirius system (CSO; Firenze, Italy).
The agreement between both IOL power calculation methods was studied. The adjusted keratometric IOL power was calculated.
In agreement with theoretical simulations, the IOL power calculated with the adjusted keratometric approach underestimated and overestimated the IOL power calculated using the Gaussian equation in a magnitude ranging from -1.1 to 0.4 D. No statistically significant differences between both IOL power calculations were found (p > 0.05) and a very strong and statistically significant correlation between them was observed (r = 0.99, p < 0.01).å
The Bland-Altman analysis revealed the presence of a mean difference between adjusted keratometric and Gaussian corneal power of -0.31 D, with limits of agreement of -1.34 and 0.72 D (see Figure 1).