## 4 Discussion
However, this value depends on the near addition specification of the multifocal IOL and the optical zone diameter selected. Coma aberration in any optical system is strongly linked to three factors: (i) decentration, (ii) the power of the optical system (higher coma for higher powers, particularly with decentration), and (iii) the optic zone (higher coma for larger optic zones, especially with decentration). The primary vertical coma of the three analyzed IOLs (AN6, AN6V, and AN6 VM) did not exhibit a dependency on the IOL power; instead, it showed a correlation with the optical zone diameter and addition value in the multifocal models. Notably, higher vertical coma values were observed at the periphery, with AN6 VM values being twice as large as those of AN6V, irrespective of the lens's base power. This observation, coupled with the fact that multifocal lenses with higher power (+30.00 D) display a decrease in power at the periphery of the near zone, may indicate a laboratory strategy to avoid excessive coma increase at high powers for mesopic pupils. Consequently, if a +30.00 D AN6 VM IOL exhibits a primary vertical coma of 0.5 microns for a 5-mm optic diameter, it can be inferred that this coma might be higher without the decay in addition in the periphery of the near segment. Such an increase in coma aberration could result in a decrease in image quality for larger pupils. This could be especially important in hyperopic eyes with large pupil sizes, since those eyes require higher power IOLs and tend to have higher Kappa angles [15], so abnormally elevated coma values induced by the IOL could have a greater impact in their optical quality. Coma is highly influenced by surface centration in any optical system. As demonstrated by [PERSON] et al. [16], the human eye exhibits an inferior location of the corneal apex, which contributes to the presence of certain values of vertical coma. It is crucial to consider this information in both normal eyes with a limit value for vertical corneal coma and in keratoconic eyes. Failing to account for this could lead to the addition of corneal coma to the coma of an AN6 VM IOL, resulting in an ocular coma value similar to that of a keratoconic eye, leading to a loss of visual quality--especially in hyperopic eyes requiring high plus IOLs. One possible approach to mitigate this issue is to reduce the effective addition in the periphery of the higher plus power AN6 VM IOLs. This could help in controlling coma values to maintain visual quality and also reduce the IOL width at the periphery. By employing such measures, it may be possible to achieve better visual outcomes and minimize the potential negative impact on visual quality caused by excessive ocular coma. We have not found any evidence regarding the value of vertical coma measured on an optical bench or in implanted eyes of multifocal AN6V and AN6 VM lenses. Instead, there are studies based on the Mplus lens, which served as the precursor to AN6V and AN6 VM, but it is made of hydrophilic material rather than hydrophobic. Unfortunately, the results from these studies are not directly comparable due to the dispersion effect that the hydrophilic material produces in the wavefront analysis [17]. Some authors have reported the presence of a large primary intraocular coma in patients implanted with the Mplus lens [18,19], which has been associated with asymmetric optical geometry. However, [PERSON] et al. [20] suggested that it is not appropriate to conclude that this IOL induces such large vertical coma values when performing aberrometry analysis in patients due to inadequate analysis of wavefront sensor measurements, concluding that the actual coma induced by those IOLs is overestimated by using Hartmann-Shack sensing or laser ray tracing. The asymmetrical design of multifocal AN6V and AN6 VM allows for the placement of the near segment in various rotational positions.