Influence of the anterior chamber depth on the accuracy of the intraocular lens optical power calculation in short eyes

Abstract

Aim. Determination of the relationship between the anterior chamber depth and the and accuracy of the IOL optical power calculating in the eyes with an axial length of less than 22 mm.
 Materials and methods. A total of 86 patients (133 eyes) with a short axis (from 18.54 to 21.98 (20.7 0.9) mm) were included in the study. Group I (n=40) consisted of patients with an ACD of less than 2, 5 mm. Group II (n=49) included patients with ACD from 2.5 to 2.9 mm Group III (n=44) included patients with ACD greater than 2.9 mm The calculation of the IOL optical power was carried out according to the formula SRK / T, retrospective comparison - according to the formulas Hoffer-Q, Holladay II, Olsen, Haigis and Barrett Universal II.
 Results. In group I, there were no significant differences when comparing MedAE for the six formulas (p0.05). The highest MedAE values ​​(0.51 and 0.49, respectively) and the smaller MNE range (-0.03 0.89 and -0.01 0.97, respectively) are shown for the formulas Haigis and Barrett Universal II. In group II, the MedAE for the Haigis formula was 0.45, for SRK / T and Olsen it was 0.59 and 0.66. For the Haigis formula, the lowest MNE value (0.05 0.69) is shown. In group III, no significant differences were found when comparing the average values ​​of MedAE (0.05). The lowest MedAE (0.17) and the best MNE values ​​(-0.01 0.58) are shown for the Haigis formula, while the SRK / T formula was characterized by the highest MedAE (0.37). In group II, the refractive index 0.25 and 0.50 D for the Haigis formula was significantly higher.
 Conclusion. For eyes with an ACD of less than 2.4 mm, none of the formulas showed a significant advantage, while with an ACD of 2.4-2.9 mm and higher, the use of the Haigis formula is recommended, and the SRK / T formula showed the worst result. The data obtained dictate the need to review existing standards for calculating the IOL optical power in patients with short eyes depending on ACD.