Herein, we investigated the clinical outcomes and patient satisfaction after implantation of monofocal IOLs with enhanced intermediate function in patients with moderate to high myopia, targeting mild myopia of − 2.00 D instead of emmetropia. There was no difference in CDVA between patients targeting postoperative myopia of − 2.00 D and those targeting emmetropia. However, patients targeting postoperative myopia of − 2.00 D achieved significantly better UNVA than those targeting emmetropia. The UIVA in Group 2 tended to be better than that in Group 1. Photic phenomena such as glare and halo did not differ between the two groups, with the incidence being relatively low in both groups.

The ICB00 IOL can be used to correct presbyopia when multifocal IOLs are not suitable since it can provide better intermediate and near vision compared with monofocal IOLs [9,10,11]. A study by Mencucci et al. [2] comparing the outcomes of the ZCB00 and ICB00 IOLs in 80 eyes found that the ICB00 provided relatively good intermediate visual acuity, which reduced the patient’s dependence on glasses. Koh et al. [12] also found similar results, in that the ICB00 group showed significantly better UIVA and UNVA than the ZCB00 group at 3 months postoperatively. Cinar et al. [13] found no difference in CDVA, UDVA, CNVA, and UNVA between the ICB00 IOL and another monofocal IOL (SN60WF IOL), while CIVA and UIVA were significantly better in patients with the ICB00 IOL. A study conducted by Corbelli et al. [14] comparing the clinical outcomes of the ICB00 IOL with those from the EDoF IOL (Symfony ZXR00) reported that the ICB00 IOL provided binocular UIVA similar to that of the ZXR00, with a comparable spectacle independence score between the two IOLs. While the contrast sensitivity score was similar between the two IOLs, photic phenomena such as halo and glare were more severe in eyes with ZXR00 IOL. Another recent study showed that monocular and binocular UDVA, UIVA, and CDVA were similar between the 48 eyes implanted with ICB00 IOLs bilaterally and 40 eyes with EDoF ZXR00 IOL implantation. Monocular UNVA and spectacle independence for near distance were better in the ZXR00 group, whereas binocular UNVA did not differ significantly between the two IOLs [15].

Considering these advantages, the ICB00 IOL can be a good option for patients not pursuing a multifocal or trifocal IOL who need near or intermediate vision [16,17,18]. Therefore, we assumed that the benefits of bilateral ICB00 IOL implantation in patients with moderate to high myopia, targeting mild myopia of − 2.00 D, can maintain their existing near vision and improve the UDVA after cataract surgery. A recent study comparing the results of ICB00 IOLs targeting mild monovision (nondominant eye target of − 0.75 D) with those targeting emmetropia in both eyes showed that the UIVA and UNVA was one line better in the monovision group without any difference in UDVA. Additionally, the monovision group tended to have less difficulty and higher satisfaction with near and intermediate vision [19]. In patients with myopia who previously had relatively good near vision, achieving emmetropia after cataract surgery may cause severe complaints. Jaafar et al. [20] studied 139 patients after cataract surgery, dividing them into two groups: patients with a target of emmetropia and those with a target of residual myopia (− 0.50 D to − 1.00 D), and examined the effects of postoperative near vision satisfaction and quality of life. The results showed that overall satisfaction did not differ between the two groups, but near vision satisfaction was significantly higher in the residual myopia group, especially for reading small print letters (font sizes 8 to 9). Similarly, patients with myopia who are used to near vision without glasses may have less postoperative satisfaction with surgery targeting emmetropia. In patients with myopia, targeting emmetropia inevitably renders their intermediate and near vision even worse than that before the cataract surgery. Hayashi et al. [6] previously studied the optimal target for cataract surgery in patients with myopia who were operated on by targeting − 1.00, − 1.50, − 2.00, − 2.50, or − 3.00 D. Patients targeting postoperative myopia of − 2.00 D showed visual acuity better than 20/30 at distances of 0.7, 0.5, and 0.3 m, suggesting that postoperative myopia of − 2.00 D could be an optimal target for patients with pre-existing mild myopia.

Trifocal IOLs can be another good option for patients with pre-existing myopia, allowing them to see near and far distances without glasses. Kim et al. [21] investigated postoperative near vision spectacle independence in patients with mix-and-match implantation of the EDoF (AT LARA 829MP) and trifocal IOLs (AT LISA tri839MP). Of these, 79.4% did not require reading glasses, but 20.6% did, and near vision spectacle independence was lower in patients with more preoperative myopia. Thus, they found that preoperatively, patients with myopia who underwent mix-and-match implantation tended to require glasses for near vision. They recommended that surgeons should consider this before surgery, as patients with myopia have significant difficulty achieving near vision with trifocal IOLs. However, in our study, we achieved better results than this mix-match implantation as 100% of the patients implanted with ICB00 IOLs targeting myopia did not require near glasses.

Other studies have compared trifocal IOL outcomes in patients with high and extremely high myopia to those in patients with normal AL. Meng et al. [22] compared the outcomes of a trifocal IOL (AT LISA, tri 839MP) in the control (AL < 26 mm), high myopia (AL 26 to 28 mm), and extreme myopia groups (AL ≥ 28 mm). In control and high myopia groups, approximately 60% of eyes achieved UNVA and UIVA of 0.10 logMAR or better, but significantly fewer eyes in the extreme myopia group achieved 0.10 logMAR or better. Defocus curves revealed that the visual acuity was significantly worse in the extreme myopia group than in the other groups at 0.00, − 0.50, and − 2.00 D. These results suggest that surgeons should consider poor satisfaction with trifocal IOLs in patients with high myopia and extremely high myopia.

No patient in either group indicated that they were dissatisfied or very dissatisfied, and the percentage of patients who were very satisfied or satisfied was higher in patients targeting emmetropia. The relatively lower satisfaction rate with the ICB00 IOL with a − 2.00 D target than the emmetropic target was attributed to the inability to meet the postoperative expectations of UDVA in patients with myopia. Previous studies have shown that the incidence of posterior subcapsular cataracts is significantly higher in patients with myopia, and they suffer from cataracts at earlier ages compared with patients without myopia, resulting in a severe reduction in visual acuity and quality of life [22]. Accordingly, patients with high myopia tend to have cataract surgery at a younger age than patients without myopia and have higher expectations of postoperative improvement in visual function and quality of life [24]. Therefore, bilateral implantation of monofocal IOL with enhanced intermediate function in patients with moderate to high myopia, targeting mild myopia of − 2.00 D, could result in a relatively lower satisfaction score than expected because of decreased UDVA. Hence, preoperative education in younger patients with cataracts with moderate to high myopia is crucial for avoiding disappointment.

Reduction in photic phenomena, such as glare and halos, which caused patient dissatisfaction with trifocal IOLs, is a relative advantage when using the ICB00 IOL. Several studies have shown that the ICB00 IOL has better contrast sensitivity than trifocal IOLs, and multifocal IOLs have limitations with unwanted effects such as halo and glare [18, 25,26,27]. Except for the high-order aspheric central zone, the physical structure of the ICB00 IOL closely resembles that of its monofocal counterpart; thus, contrast sensitivity is not compromised for improving the depth of focus [28]. We found similar results, in that patients with bilateral ICB00 IOL implantation experienced less discomfort, with lower percentages of glare and halos in the emmetropia and myopic targeted groups.

This study has several limitations. First, the sample size of the group with a residual myopia target of − 2.00 D with the Eyhance IOL was small. A long-term prospective study with a larger sample size is required. Second, the randomization was not perfectly performed because the patients decided, during preoperative counseling, whether they wished to use glasses or desired near vision without glasses. Third, we did not evaluate variables such as the patients’ underlying diseases; therefore, we cannot confirm their impact. Lastly, targeting bilateral myopia can be inconvenient because it might require the use of glasses during all daily tasks, and micro-monovision would therefore be a good alternative.