An investigation was conducted to analyze the impact of peripheral add multifocal SCLs on the deceleration of myopia progression. This analysis included eight published RCTs and three cohort studies. The combined findings indicated that peripheral add multifocal SCLs were more effective in reducing refractive progression and axial growth compared to single vision SCLs or spectacles. Peripheral add multifocal SCLs did not affect high-contrast distance logMAR visual acuity but resulted in a significant decrease in low-contrast logMAR visual acuity at distance. The incidence of adverse effects related to soft contact lenses was low, and there was no significant difference in the frequency of all reported adverse events between peripheral add multifocal SCLs and single vision SCLs.

In comparison to the control group, peripheral add multifocal SCLs exhibited promising outcomes in controlling myopia among school-aged children, with effects sizes of 0.20D in decelerating myopia progression and 0.08 mm in reducing axial elongation, respectively. These values were marginally smaller than those reported in other studies involving orthokeratology and atropine. Huang et al.‘s study revealed that atropine eye drops had a significant effect in controlling myopia, while orthokeratology and SCLs with peripheral defocus design exhibited moderate effects [21]. It should be noted that Huang et al.‘s meta-analysis only included three studies that compared peripheral defocus modifying contact lenses with single vision contact lenses. Consistent with our findings, peripheral add multifocal SCLs exhibited a weaker effect in controlling myopia. For practitioners dealing with a child who requires myopia control, it is recommended to consider the use of orthokeratology lenses or low-concentration atropine. In certain cases, multifocal soft contact lenses could be recommended: (1) Individuals with low myopia: multifocal soft lenses provide a stable and significant defocus effect that fulfills the requirements for myopia control. (2) Patients with a flat cornea, a small e-value of corneal topography, and a higher degree of myopic refraction, and those who are unable to achieve optimal vision with orthokeratology lenses due to insufficient sleep time at night, can benefit from multifocal soft lenses that address both vision improvement and myopia control needs. (3) Myopia occurs at a younger age. (4) Patients with mild trichiasis: wearing SCLs during the day can protect the cornea from mechanical damage caused by trichiasis.

Significant heterogeneity was observed when comparing the efficacy of peripheral add multifocal SCLs with single-vision SCLs or spectacles. Heterogeneity persisted in the random-effects model, prompting a sensitivity analysis to identify its sources. The study conducted by Fang et al. was identified as the primary contributor to this heterogeneity [13]. Compared with other multifocal SCLs, the multifocal SCLs tested in this study differed in optimal design, defocus amount, and size of the central distance zone. In Fang et al.’s study, the defocus amount of the MFSCLs was + 6.00 D [13], compared to + 2.00D reported by Anstice et al. [22], + 1.00 D reported by Sankaridurg et al. [6], and + 2.50 D reported by Lam et al. [23], which wouldimpact the ability of multifocal SCLs to control myopia progression.

This meta-analysis also investigated the impact of peripheral add multifocal SCLs on visual performance, focusing on high- and low-contrast visual acuity. The study revealed that defocus SCLs did not affect high-contrast distance logMAR visual acuity, but caused a significant decrease in low-contrast logMAR visual acuity at distance. Visual performance with peripheral add multifocal SCLs was slightly worse at nighttime compared to daytime. Kang et al. discovered that the greater the progressive-addition power, the more noticeable the decline in low-contrast VA [24]. The peripheral add multifocal SCLs have a design with a central zone for distance correction and peripheral near addition zones that cause myopic defocus of the peripheral retina. However, this design also increases positive spherical aberration which affects central vision more in young people due to their larger natural pupils [25]. The relatively small central area of the peripheral add multifocal SCLs ensures multifocality in the pupillary region at most distances in most young subjects, but this also results in reduced visual quality compared to SV lenses. Specially designed multifocal SCLs may lead to decreased image quality and associated visual symptoms, particularly in low illumination and contrast conditions [26]. Kang et al. assumed that high-contrast VA is not a very sensitive measure of visual quality. Future clinical trials testing the efficacy of multifocal lenses for myopia control should consider low-contrast VA to better characterize the effects on vision of such lenses and allow for more informed comparison of alternative treatment options. When prescribing multifocal SCLs for myopia control, clinicians should educate patients about these effects on vision.

Another concerning aspect is ocular adverse events associated with the use of soft contact lenses. A recent review paper concluded that the occurrence of corneal infiltrative events does not seem to be higher in children than in adults [27]. Chamberlain et al. reported a total of 18 ocular adverse events (involving 11 subjects) in individuals wearing the MiSight lens, while 12 events (involving ten subjects) were observed in those using the control lens after three years of treatment. Among these, seven events (12.5%) with the test lens and seven events (13.2%) with the control lens were deemed lens-related. These complications were mostly mild in nature and did not require any therapeutic intervention [5]. Cheng et al.‘s study reported a total of 6 mild ocular AEs in three subjects (1.6%) during the course of treatment and withdrawal phase. Among these, four events were observed in four eyes of two subjects in the test cohort (allergic conjunctivitis), and the remaining event occurred in two eyes of one subject in the control cohort (contact dermatitis). All AEs were classified as nonsignificant and were considered unlikely to be associated with wearing the study contact lenses [20]. In Walline et al.‘s study, a total of thirty-five ocular adverse events (12%) that were definitely or probably related to contact lens wear were of moderate severity. None of the reported ocular adverse events were deemed serious, severe, or resulted in permanent discontinuation of contact lens wear [17]. In our study, out of the 461 individuals, 46 patients experienced lens-related complications, resulting in a combined incidence rate of 6.5%. None of these complications were severe. Allergic conjunctivitis and unspecified conjunctivitis were the most frequently observed complications, which did not require specific management. Therefore, this study highlights peripheral defocus modifying contact lenses as a comparatively safe treatment. It is important to note that the findings of the analyzed studies were obtained under controlled and optimal conditions. In real-life situations with a large number of cases and potentially reduced supervision and care, there is likely to be an increase in side effects and complications. If patients want to control myopia by wearing multifocal SCLs, it can be emphasized that SLCs are a safer option with lower and milder adverse reactions. This can help reduce the patient’s psychological burden and minimize the rate of drop out, ultimately improving the effectiveness of myopia control.

Therapy adherence is a significant concern that requires attention. In the study conducted by Walline et al. [15], the dropout rate was reported to be 33%. Lam et al. reported a dropout rate of 41% [23], Chamberlain et al. reported a rate as high as 43% [5]. Sankaridurg et al. reported a rate of 25% [11], and Paune et al. reported a rate of 37% [12]. Sankaridurg et al. reported a large number of children discontinued soon after lens dispensing (129/ 508, 25.4%) and prior to the 1 month visit. The main reasons for dropping out were: discomfort with lens wear (26/ 129, 20.2%); safety concern with contact lenses (25/129, 19.4%); no interest in contact lens wear (25/129, 19.4%); handling (15/129 or 11.6%); time conflicts and issues with attending follow up (10/129 or 7.8%); and other reasons such as red eye, rhinitis, preferred orthokeratology and unable to attend due to relocation. Of the remaining participants that continued to wear lenses, 89 participants (23.5%) were discontinued/lost to follow up over 2 years. The main reasons were: discomfort (19/89, 21%); time conflicts (12/89, 14%); lost to follow (10/89, 11%); handling (8/89, 9%); increased myopia progression (9/89, 10%); vision problems with lenses (2/89, 2%); and prefer to switch to orthokeratology (3/89, 3%) [6]. During the entire course of the treatment phase in Xu Cheng et al.’s study, a total of 14 (22%) subjects from the test SCLs cohort were discontinued from the study. Subject disinterest(3)、noncompliance to protocol(2)、 lens handling difficulties(4)、lens discomfort(3) and lost to follow-up(2) were reported as the main reasons [20]. Sankaridurg et al. also discovered discomfort was the most frequently cited reason for discontinuation from lens wear (11.7%), followed by handling issues (1.7%). Noncontact lens–related reasons such as geographic relocation (8.3%) and disinterest (6.7%) were substantial [11]. In Chamberlain et al.’s study, 12 participants (18%) from the test SCLs group discontinued the intervention program. Lens related reasons were discomfort, vision and subjects or parents/guardian decision(n = 5). Non-lens related reasons were loss of motivation, schedule, diagnosed diabetic, and protocol violation(n = 5) [5].

It can be seen that discomfort and lens handling difficulties were the most common causes of dropout. Contact lens fitters should provide patients and their parents with a comprehensive explanation regarding the possibility of discontinuing the use of multifocal SCLs prematurely, primarily due to discomfort or difficulties in handling. Another common reason for dropout was time conflicts. Initially, many participants expressed a desire to wear contact lenses as a means to slow down the progression of myopia. They were unwilling to wear lenses every day afterwards because they were too busy with school curriculum and homework, and too rushed to wear lens in early morning. Medical staff should inform patients in advance that it is advisable to avoid wearing multifocal SCLs if the patient has time pressure in the morning or is unable to consistently wear them. The study showed that only a small number of patients experienced complications, indicating that multifocal SCLs may be a safer choice. Clinicians can emphasize this finding when recommending contact lenses to patients.

Li et al. conducted a meta-analysis to evaluate the impact of concentric ring bifocal and peripheral add multifocal SCLs on the retardation of axial length growth [7]. However, certain limitations were present in their study. Firstly, the primary measure of treatment outcome was the increase in refraction and axial length in the first year, which may not accurately reflect the true status of myopia progression. Secondly, reliable conclusions cannot be drawn solely based on this meta-analysis, as it included only 8 studies, of which only 5 were RCTs. Thirdly, Li et al. did not examine the visual performance and safety of soft contact lenses. In our study, 11 high-quality studies were included and the mean annual change in refraction and axial length were chosen as the main comparative indicators. Fourthly, to reduce heterogeneity, bifocal SCLs were not included in our meta-analysis. Additionally, the visual performance and adverse effects associated with soft contact lenses were evaluated.

In this meta-analysis, three studies used single vision spectacles as the control group, while the remaining 8 studies employed soft contact lenses. The results of the subgroup analyses showed that peripheral add multifocal SCLs showed better results in delaying myopia and axis length prolongation when choosing single vision spectacles as the control group. Following the recommendation of the Food and Drug Administration Public Workshop on Controlling the Progression of Myopia [28], it is more appropriate to select the latter as a control. The lens was well-matched in all parameters, except for the peripheral add multifocal soft contact lenses, which ensures that any disparities in refraction and axial length between the two groups can be attributed to the optical design. In our meta-analysis, multifocal SCLs demonstrated superior effects in slowing refraction progression and axial growth compared to the control group. These findings remained consistent even after excluding studies that used single vision spectacles as control. It is this distinctive design that played a pivotal role in controlling myopia progression.

Among the studies included in this article, 5 articles included patients with myopia ranging from − 0.75D [6, 11, 12, 16, 18], 3 articles starting from − 1.00D [13, 15, 17], 1 article starting from − 2.00D [19], and another article starting from − 0.50D [14]. It can be observed that there is no consensus on the starting power of soft contact lenses for myopia correction. Typically, myopia of 0.75 ∼ 1.00D requires the use of glasses to improve vision. We believe that myopia of 0.75 ∼ 1.00D should be considered as a reasonable starting point for multifocal SCLs. However, one document in this study used a lower starting degree of myopia range (-0.50D), and the author explained that the inclusion criteria range for refraction(-0.50 to -8.75) was set to facilitate subject recruitment. In clinical practice, the initial correction power can be appropriately reduced (such as -0.50D) for the myopic patients with the goal of controlling myopia: Children and adolescents with myopic progression ≥ 0.50 D/year or axial elongation ≥ 0.4 mm/year; Patients with fundus pathological changes associated with axial elongation; patients with high-risk factors for myopia and/or high myopia, such as parents with a history of myopia, less time spent on outdoor activities, prolonged near work, myopia occurring in children at an early school age (7 years old and under), and myopia being higher than that of children and adolescents of the same age. One reason is that multifocal SCLs have both a stable and relatively high defocus amount, which can meet the defocus requirements for myopia control. The other reason is that their clinical side effects are relatively small and controllable.

Our study also had certain limitations and drawbacks. Firstly, the available pool of subjects included in this meta-analysis was limited, albeit being the largest reported thus far. Secondly, the studies included in this analysis had different add power for the multifocal SCLs. Thirdly, the quality of the conducted studies varied, with some lacking a double-blinded design. Fourthly both single vision SCLs and spectacle lenses were selected as control measures. Fifthly, there was an age disparity among the studies. The included articles only provided the age range and mean, which was insufficient to explore the relationship between therapeutic outcomes and age. Lastly, significant heterogeneity was observed in certain pooled analyses.

In conclusion, the findings of this meta-analysis indicate peripheral add multifocal SCLs were effective in slowing down myopia progression. However, the effect of this kind of lenses was weaker and may also lead to a significant decrease in distance low-contrast logMAR visual acuity. Despite this, the study found that SCLs were a safe treatment option with a lower incidence of adverse effects and no serious complications. Further research is needed to address several issues. For instance, the lack of a uniform add powers poses a challenge. In our meta-analysis, the included studies employed different plus power for multifocal SCLs, highlighting the need for further investigation to determine the optimal myopic defocus amount for achieving the desired myopia control effect. Specifically, more studies should be conducted to ascertain the long-term efficacy of multifocal SCLs in slowing down the progression of myopia, establish the optimal duration of SCLs wear to achieve an optimal therapeutic effect, and evaluate the impact of discontinuing long-term lens wear on the subsequent progression of myopia.