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INTRODUCTION
Myopia is a worldwide public health problem, with its prevalence increasing significantly in recent decades, particularly in East Asia [1, 2]. Despite the alarming statistics, the perception persists among the general public that myopia is merely a refractive error that can be easily corrected with contact lenses or glasses, and that people with myopia do not require additional care as a result of their visual impairment [3]. However, myopia is a risk factor for many ocular pathologies, such as cataracts, glaucoma, retinal detachment and myopic maculopathy [3]. It was shown that the prevalence of myopic retinopathy in patients with less than 5 D of myopia was 0.42% compared to 25.3% for myopic patients with refractive error greater than 5 D. Above 9 D of myopia, the incidence of retinopathy exceeded 50% [4]. Marcus et al. [5] in their meta-analysis found that for low myopia (myopia up to 3 D), the odds ratio for glaucoma was 1.65, and for higher degrees of myopia (above 3 D) it was as high as 2.46. According to the Eye Disease Case-Control Study [6], myopia is a major possible risk factor for retinal detachment, with an odds ratio of 4.4 for myopia up to 3 D, increasing to 9.9 with myopia in the 3 D to 8 D range. Importantly, slowing myopia progression by 1 D has been shown to reduce the risk of developing myopic maculopathy by 40% [7]. For this reason, the scientific community is searching for more and more effective ways to slow the progression of myopia.
Myopia may be caused by genetic factors (responsible for 70% of myopia prevalence) [8-12] and environmental factors (prolonged near work) [13-16]. In terms of environmental factors, it has been hypothesized that myopia increases most rapidly in winter. This is related to reduced outdoor activity (winter weather in developed countries is not conducive to staying outdoors) and at the end of summer, when the intensity of working at near increases due to the start of the school year [17, 18]. An important factor associated with the increase of myopia is peripheral hyperopic defocus, as will be discussed later. Myopia appears to increase most between ages of 8 and 15, after which the rate of progression of this refractive error typically slows [19].
Across the world, especially in East Asian countries, the prevalence of myopia is increasing. According to the study by Matsumura et al., currently, there are around 1,950 million cases (28.3% of the global population) with myopia and 277 million cases with high myopia [19]. In a sample of 15,316 children aged 6 to 18 years in East Asia, the prevalence of myopia was 53.4% [20]. In comparison, the prevalence in France was 19.6% among children aged 0-9 and 42.7% among those aged 10-19 [21]. In Poland the prevalence was 13.3% in the age group ranging from 6 to 18 years [22]. It should be noted that the study by Czepita et al. dates from 2007, and it is very likely that these data are already outdated [22]. For adults, the differences in the prevalence of myopia in different countries are not significant, but there are still more myopic adults living in East Asia than in Western countries. Only among older adults are there no significant differences in the prevalence of myopia in different parts of the world [19].
Estimates of the prevalence of myopia and high myopia between 2000 and 2050 suggest a significant increase in the incidence of myopia worldwide. This has implications for healthcare planning, including treatment and prevention of ocular complications associated with myopia [1]. It has also been noted that progression does not end with graduation. This is thought to be related to the majority of the population working in front of computers for long periods of time [23].
The correction of refractive errors is based on central refraction values, but in the case of myopia progression, peripheral refraction is the factor modulating the increase of axial length. In most cases, refraction at the periphery of the retina differs from central one: towards the periphery, the value of astigmatism increases, and the spherical equivalent has a different value, depending on central refraction [24]. The myopic eye is characterized by an elongated shape along the visual axis, and slightly flattened areas of the periphery of the posterior pole of the eyeball. This leads to less myopia in the peripheral areas of the retina than in the center. When central refraction is corrected with single vision spectacles or contact lenses, peripheral hyperopic defocus appears at the periphery of the retina [24, 25]. Studies show that peripheral hyperopic defocus is more common in myopic children than in children without myopia [26, 27]. A study in monkeys, in which visual stimuli were selectively eliminated in the central part of the retina, showed that the process of emmetropization was not disrupted. Instead, disruptions in peripheral vision were found to have a significant impact on refractive development. This suggests that normal eyeball growth is primarily guided by visual input from the peripheral, rather than the central retina [28]. Based on these observations, it has been hypothesized that peripheral hyperopic defocus is responsible for the increase of axial length. Thus, optical methods for controlling myopia progression aim to reduce relative peripheral hyperopia.
METHODS FOR CONTROLLING MYOPIA PROGRESSION
Optical methods
One of the first attempts to control myopia growth was to undercorrect the refractive error. The reduction in accommodative effort resulting from this approach was thought to slow the progression of myopia. We now know that the blurred retinal image resulting from under-correction accelerates the elongation of the eyeball and thus the progression of the myopia [29, 30]. In other words, the previously recommended method of undercorrection for myopia is no longer considered a valid approach. Nowadays, full correction of myopia is recommended to achieve optimal visual acuity.
Progressive and bifocal spectacle lenses
Some of the earliest methods of myopia control were based on the use of multifocal (progressive – PALs) and bifocal spectacle lenses. This approach was based on the hypothesis that the accommodative lag (inadequate accommodative response) that occurs during near work leads to hyperopic defocus and the progression of myopia. The use of this type of correction was designed to eliminate accommodative lag in myopic patients. The aim of the COMET (Correction of Myopia Evaluation Trial) study was to investigate the effectiveness of PALs with +2.0 D addition in myopia progression [24]. This study showed that over a 3-year period, myopia progression in the PAL group was 1.28 ±0.06 D and in the control group wearing single vision lenses (SVL) was 1.48 ±0.06 D. The difference between the two study groups (0.2 D) was statistically significant, but without clinical significance. It was noted that PALs were most effective in patients both of whose parents were myopic and who had significant accommodative lag [24].
Berntsen et al. [31] enrolled 85 children with significant accommodative lag and divided them into two groups. The first group wore PALs in the first year of the study, while the second group wore SVLs. In the second year of the study, all children wore SVLs. In the first year of the study, the progression of myopia in the group of patients corrected with PALs was 0.35 D, and in the control group 0.52 D. In the following year, the progression of the myopia was 0.35 D and 0.41 D for the study and control group, respectively. Thus, there was no significant difference in myopia progression between the two groups [31]. In addition to the known non-significant clinical effect of PALs from prevoius study by Gwiazda et al. [24], the researchers also failed to demonstrate a relationship between the accommodative present and myopia progression.
A study published by Hasebe et al. [32] aimed to compare the clinical efficacy of newly designed positively aspheric PALs (PA-PALs) with traditional SVLs. The newly designed lenses affected accommodative lag as well as peripheral hyperopic defocus. However, the reduction in myopia progression in PA-PALs was similar to that in SVLs, and there were no statistically significant differences between groups [33]. This demonstrates the lack of association between slowing myopia progression and eliminating accommodative lag [24, 31, 32].
Spectacle lenses with defocus incorporated multiple segments technology
Currently, spectacles using lenses with defocus incorporated multiple segments (DIMS) technology are being investigated on a large scale. This design features a central optical zone the correction of the refractive error and peripheral annular area with small segments providing +3.5 D adds, forming a “honeycomb” pattern. These segments with high positive power are intended to reduce the peripheral hyperopic defocus and shift peripheral retinal image in front of the retina [33]. A study by Lam et al. [34] showed that DIMS spectacle lenses slowed the progression of myopia by 52% and axial elongation of the eyeball by 62% compared to SVLs. This study lasted 2 years and was conducted on a group of 183 children from an Asian population [34]. No significant changes in visual function were found between SVL wearers and those wearing DIMS lenses [35]. However, it should be noted that the functional assessment (measurement of contrast visual acuity, stereovision and accommodation) was performed in SVLs, but not in correction with DIMS technology. Therefore, the results may not accurately reflect the visual parameters when DIMS lenses are worn [36]. A recent study on the effectiveness of using spectacles with DIMS lenses on slowing myopia progression in Asian children showed that this approach provides promising results not only in the first two years of its use, but also in the long term [37]. The researchers noted that in children who used spectacle correction with DIMS-type lenses in the first 2 years, the progression of myopia was small and was 0.4 D, and the axial length increased by 0.22 mm (0.2 D/year and 0.11 mm/year), while over the same period of time in children wearing SVLs, myopia increased by 0.99 D and the axial length increased by 0.59 mm (0.5 D/year and 0.3 mm/year). The beneficial effects of the DIMS lenses were maintained over the following 4 years, as myopic refractive error increased by only 0.52 D (0.13 D/year) and the axial length by only 0.38 mm (0.10 mm/year). This means that the treatment with DIMS technology, which neutralize peripheral hyperopic defocus, slows the progression of myopia by 60% and the effects are long-term.
Due to the novel technology of DIMS lenses, further research is needed to confirm the safety of using this type of correction, and to evaluate its long-term effects in Caucasian children.
Spectacle lenses with highly aspherical lens technology
Another promising solution which can be used in spectacle correction is lenses with highly aspherical lenslets (HAL). HAL lenses include central area providing correction of the refractive error and 11 concentric rings at the periphery formed by the highly aspherical segments. As with DIMS technology, the central area corrects ametropia, while the segments provide myopic defocus in the peripheral parts of the retina producing volume of myopic defocus. A two-year study investigating its effectiveness on an Asian population showed that children using HAL daily for a minimum of 12 hours had a 0.99 D less increase in refractive error compared to the group using SVL, and an increase in axial length of only 0.28 mm [36].
A short-term study by Li et al. [38] determined the effect of spectacle lens technologies for myopia control on visual acuity and contrast sensitivity. Three types of lenses for myopia progression control were analyzed, which differed in the arrangement of lenslets on the lens. The first type was a lens with highly aspherical segments arranged concentrically (HAL), the second type was a lens with slightly aspherical lenslets also arranged concentrically (SAL), and the last type was a lens with a honeycomb configuration of spherical lenslets (HC). It was found that lenses with concentrically arranged segments, HAL and SAL, had a significantly lower impact on visual acuity and contrast sensitivity than those with honeycomb configuration [38].
The DIMS and HAL technologies are among the newer solutions available for controlling myopia progression, so further research is needed to determine the optimum age of therapy inclusion, the long-term efficacy also in Caucasian population, and the occurrence or absence of a rebound effect after discontinuation.
Bifocal and multifocal soft contact lenses
Some of the earliest studies using contact lenses to reduce hyperopic peripheral retinal defocus were those using soft contact lenses with addition at the lens periphery. Mostly, commercially available bifocal or multifocal soft contact lenses (BFCL, MFCL) were used slow myopia progression. A randomized clinical trial conducted in Hong Kong by Lam et al. [39] studied children aged 8 to 13 years. The value of the refractive error at baseline and at the end was measured after cycloplegia. Over 2 years, myopia progressed by an average of 0.59 ±0.49 D in BFCL group and 0.79 ±0.56 D in vision contact lenses (SVCL) group; this represents a 25% reduce of myopia progression with the use of BFCL. The axial elongation was also reduced in BFCL group (0.25 ±0.23 mm) compared to SVCL group (0.37 ±0.24 mm). This represents a 32% reduce in eyeball growth between the control and study groups [39].
A meta-analysis that included eight studies showed that both BFCL and MFCL with add power in the lens periphery are clinically effective in controlling myopia in school-aged children in different countries [40]. Studies have shown an efficacy of slowing myopia progression of 30-50% within 2 years. It can be also concluded that BFCL are more effective in controlling myopia progression than MFCL [40]. These differences may be attributed to the different lens designs – BFCL features abrupt power changes between distance and near zones, arranged circularly across the optic zone [41, 42]. In contrast, in MFCL, this power changes is gradually and the full add power is located at the lens edge, which, in case of a narrow pupil, may reduce the therapeutic effect of this correction. An exception is the MFCL-Relax (SwissLens) which, despite its multifocal design, has the add power located close to the central part of contact lenses, making it comparable more to BFCL than MFCL [43-45]. Montani and Blaser’s study showed that MFCL-Relax induces the myopic defocus in the peripheral parts of the retina, eliminating the ocular growth factor [43]. These lenses are already commercially marketed, and the first scientific studies have shown that they do not significantly affect the quality of vision, apart from a partial impairment of contrast sensitivity in the periphery [44, 45]. What is important, despite high addition power, up to +4.00 D, they do not interfere with the eye-hand coordination, eye movements or body balance [46, 47]. However, there are no studies to date evaluating the long-term effects of this type of lenses on myopia progression.
The efficacy of lenses widely available on the market, such as Acuvue BFCL (Johnson & Johnson), Proclear MFCL (CooperVision), and Biofinity MFCL (Cooper Vision), has also been investigated. In the study of Aller et al. [48], Acuvue BFCL was compared with SVCL, and the results showed that the axial length increase after one year of use was 0.05 ±0.14 mm and 0.24 ±0.17 mm for BFCL and SVCL, respectively. This shows a 70% reduction in myopia progression after the first year of BFCL use. The add power used in this study was selected based on neutralizing fixation disparity (all participants in the study had eso-fixation disparity) and ranged from +0.25 D to +3.75 D [48]. In a 2-year study by Walline et al. conducted on children aged 8-11 years, the axial elongation in the group wearing Proclear MFCL with +2.00 D add was 0.29 ±0.03 mm, while in patients wearing SVCL it was 0.41 ±0.03 mm. Thus, this represents a 29% reduction in the axial eyeball elongation with Proclear MFCL [49].
In 2020, a study comparing the efficacy of slowing myopia progression using Biofinity MFCL with mid-add (+1.5 D) and high-add (+2.5 D) was published [50]. In this 3-year study, the +2.5 add was shown to be most effective in myopia control (3-year progression of myopia: 0.60 D with +2.5 add; 0.89 D with +1.5 add; and 1.05 D with SVCL; 3-year increase of eye axial length was: 0.42 mm with +2.5 D add; 0.58 mm with +1.5 D add and 0.66 mm with SVCL) [50].
One of the most preferred solutions designed to control myopia progression is the MiSight contact lenses (Cooper Vision). A 3-year study showed an increase in myopic refraction of 0.51 ±0.64 D in the group using MiSight and 1.24 ±0.61 D in the group using SVCL. In contrast, the increase of axial length was 0.30 ±0.27 mm in the MiSight group and 0.62 ±0.30 mm in the SVCL group. This gives a 59% reduced progress of myopia and a 52% reduction of axial elongation in patients using the MiSight lens compared to the control group [51]. MiSight lenses therefore appears to be a promising method for patients who prefer contact lenses.
It should be mentioned that, to date, there have been no systematic studies that have monitored the possible progression of myopia after discontinuation of MiSight wear. At present, evidence from other optical strategies serves as the basis for this approach. It can be hypothesized that when soft contact lenses for myopia control are discontinued, progression will continue at a similar level as before their use.
Orthokeratology
Orthokeratology (OrthoK) was introduced in the 1960s as a method for correcting refractive errors. OrthoK is the use of gas-permeable contact lenses applied overnight which redistribute corneal epithelium at a thickness of approximately 50 μm, leading to central corneal flattening and mid-peripheral steepening [52, 53]. This results in the correction of the central refractive error and the reduction of peripheral hyperopic defocus, which slows the increase of the axial length. The effect of OrthoK is completely reversible [54]. The efficacy of OrthoK in controlling myopia progression has already been confirmed by many independent research centers [55, 56]. Studies showed that the highest efficacy of OrthoK in controlling myopia progression is achieved in children with moderate myopia (between –1.25 D and –4.0 D), large pupils and a history of rapid refractive error progression at the time of treatment initiation [57]. A meta-analysis, which included nine studies, found that OrthoK had better results (more significant reduction in myopia progression) in Asian than in Caucasian children [58]. Studies examining the long-term use of OrthoK have shown that OrthoK is a safe and effective method for correcting and slowing the progression of myopia [55, 56, 59-61]. Several factors contribute to the long-term success of OrthoK: proper lens fitting, strict adherence to lens care protocols, regular follow-up visits and prompt management of any complications.
The two-year LORIC (Longitudinal Orthokeratology in Children) study looked at eyeball elongation and changes in vitreous chamber depth in children aged 7-12 years. The OrthoK group showed an eyeball elongation of 0.29 ±0.27 mm, compared to 0.54 ±0.27 mm in control group providing a 50% myopia control effect [62]. Differences in vitreous chamber depth were also noted: the OrthoK group showed an increase of 0.23 ±0.25 mm, compared to 0.48 ±0.26 mm in control group. Similar results were obtained in the two-year ROMIO (Retardation of Myopia in Orthokeratology) study [57], comparing axial elongation in children aged 6 to 10 years wearing OrthoK lenses or SVLs [63]. It has shown that the axial elongation was 0.36 ±0.24 mm and 0.63 ±0.26 mm for the group wearing OrthoK and SVLs, respectively. In addition, this study showed that OrthoK was more effective in younger children (aged 7-8 years) and in those who had a faster rate of progression of myopia. A meta-analysis including seven studies found a mean difference of 0.26 mm in the increase of axial length between the OrthoK group and the control group wearing SVL, favoring OrthoK [64]. However, none of these accounted for post-treatment effects. Further randomized, large-scale studies are needed to assess the long-term effects of OrthoK.
These findings support the conclusion that OrthoK is an effective and safe method for slowing myopia progression.
Pharmacological methods – atropine
Research into myopia control has shown that not only optical methods, but also atropine effectively slows the progression of myopia and axial length. Atropine inhibits muscarinic receptors, thereby blocking the effect of acetylcholine. Despite the widespread use of atropine in controlling myopia progression, the mechanism underlying its efficacy is still not fully explained. Initial studies [65, 66] indicated that the atropine slows the progression of myopia through a cycloplegic action on the ciliary muscles and inhibiting the accommodative function of the eye. However, later studies in animal models showed that atropine acts through a non-accommodative mechanism [67-70]. Muscarinic receptors are also found in retinal, choroidal and scleral tissues; hence, other hypotheses have considered the influence of atropine on muscarinic receptors within these structures. Studies have shown the presence of muscarinic receptors within the retinal pigment epithelium (RPE). Atropine was found to increase dopamine release but also reduce electroretinography b- and d-waves what resulted in damped oscillations of RPE potentials. Based on these observations, researchers have suggested that, by suppressing retinal vital functions, atropine increases the release of dopamine from cellular stores, which then controls eye growth [71].
Regarding atropine’s effect on the choroid, it has been shown that its use results in thickening of the choroid and inhibiting ocular growth [72]. In sclera, atropine has been observed to increase the thickness of the fibrous layer, as demonstrated in studies on myopic chick eyes [73]. For a more comprehensive overview of atropine’s role in inhibiting myopia progression, see the review by Upadhyay and Beuerman [70].
Having studied the effect of atropine concentration levels on safety and efficacy of treatment, no clear consensus has been reached on the optimal concentration used. In the 2-year ATOM 1 (Atropine for the Treatment of Childhood Myopia) study, the use of 1% atropine showed a strong inhibitory effect on myopia progression [74]. The mean value of myopia progression after a 2-year period in the placebo group was 1.20 ±0.69 D and ocular elongation reached 0.38 ±0.38 mm, whereas in the 1% atropine group, the mean value of refractive error progression was only 0.28 ±0.98 D and axial elongation was negligible (0.02 ±0.35 mm). Despite its strongly inhibitory effect on axial growth, 1% atropine also results in pupil dilation and full accommodation paralysis, which significantly affects daily function [74], so attempts were made to investigate the control the myopia progression with a lower concentration of atropine [74]. In the ATOM 2 study [75], 0.5%, 0.1% and 0.01% concentrations of atropine were investigated. The outcomes of the study were as follows: in the 0.5% atropine group the refractive error increase was 0.30 ±0.69 D, in the 0.1% atropine group 0.38 ±0.60 D, and in 0.01% group it was 0.49 ±0.63 D. These results suggested that the differences in myopia progression were small and not clinically significant. It is worth mentioning that atropine 0.01% has minimal side effects compared to atropine 0.1% and 0.5% [75]. However, subsequent studies, have not shown equally promising results for very low concentration atropine. The LAMP (Low Concentration Atropine for Myopia Progression) study evaluated the efficacy of three different atropine concentrations (0.01%, 0.025%, and 0.05%) in slowing myopia progression [76]. Atropine was applied overnight for 1 year and compared with a placebo group. After this period, the mean increase in myopia was: 0.27 ±0.61 D, 0.46 ±0.45 D, 0.59 ±0.61 D, 0.81 ±0.53 D, for the 0.05%, 0.025%, 0.01%, and placebo groups, respectively. All concentrations were well tolerated by the participants. Of the three concentrations used, atropine 0.05% was the most effective in controlling myopia progression. The subsequent two years of the study confirmed the observations of the first year by showing that atropine 0.05% was most effective in controlling the increase in axial length, while there were no significant differences between of 0.025% and 0.01% atropine concentration. The LAMP study also showed that atropine 0.05% had the greatest rebound effect of the concentrations investigated, where the increase in axial length was 0.04 mm during the year after cessation of atropine. However, this increase was not considered clinically significant [76]. For concentrations of 0.025% and 0.01%, no rebound effect was observed. This suggests that prior to discontinuing atropine 0.05%, it may be beneficial to reduce the concentration used in order to minimize the risk of a rebound effect.
In summary, low concentrations of atropine are an effective method for slowing the progression of myopia. However, further research are needed to determine the best concentration that ensures efficacy, safety and comfort.
Combined methods
In recent years, studies have begun to emerge to determine the effect of combining atropine with optical interventions on the controlling myopia progression. Treatment combining OrthoK with low-concentration atropine 0.01% appears promising. Kinoshita et al. [77] suggested that the use of low-concentration atropine together with OrthoK lenses may be the optimal option to slow the process of axial elongation. Over a 2-year period, the axial length increased by 0.29 ±0.20 mm in the group treated with a combination of OrthoK and 0.01% atropine, compared to 0.40 ±0.23 mm in the group using only OrthoK alone. These findings were confirmed in a meta-analysis by Wang et al. [78], which showed that the combination of OrthoK with 0.01% atropine was more effective in slowing axial elongation than OrthoK lens monotherapy in children with myopia. In addition, no adverse effects on distance visual acuity, corneal endothelial cell density or intraocular pressure were observed during combined therapy. However, it is important to note that current literature lacks studies involving Caucasian populations [34].
Interestingly, the results of a study by Nucci et al. [79] conducted on European children aged 6-18 years, compared three treatment options for myopia control, using: 0.01% atropine, and DIMS lenses alone and a combination of DIMS lenses and 0.01% atropine. The results were compared with those of SVL group [79]. This study showed that, after 12 months, all treatments slowed the myopia progression and axial elongation by at least 50%. Comparative analysis showed that combination therapy (0.01% atropine + DIMS) the most effectively slowed the increase of the refractive error, although the difference was only 0.1 D compared to both monotherapy group. Axial elongation was 0.09 mm in the 0.01% atropine group, 0.07 mm in the DIMS group, and 0.05 mm in the combined therapy group. Although combined therapy appear to be the most optimal method to slow myopia progression, providing good results with little or no side effects, these treatments require further research.
Factors preventing the onset of myopia
In addition to optical or pharmacological methods to control myopia progression, the patient’s lifestyle e.g diet and time spent outdoors, also play an very important role. Lingham et al. [80] analyzed aspects, directly or indirectly related to spending time outdoors, that may be a protective factor against myopia: 1) brighter light, 2) reduced peripheral defocus, 3) higher vitamin D levels, 4) a varied chromatic spectrum of light, 5) higher physical activity, 6) entrained circadian rhythms, 7) less near work, and 8) greater high spatial frequency (SF) energies. Exposure to brighter light appears to be the most effective. This may be related to pupil constriction under greater light intensity, as pupil constriction reduces off-axis light beams that cause the refractive error to grow. In addition, the accommodative response is improved under intense light, resulting in higher quality retinal image [81]. Another consequence of exposure to sunlight is increased dopamine production [82]. Dopamine is the most extensively studied neurotransmitter in animal models (chickens and primates) in slowings myopia progression [82, 83]. Dopamine is thought to act as an inhibitory factor in the increase of axial length, but the exact mechanisms remains unclear. A meta-analysis of studies examining the role of time spent outdoors in relation to myopia progression showed that spending more than 13 hours per week (at least 2 hours per day) outdoors was associated with a reduce rate of myopia progression. This is a simple, effective and achievable intervention that can also positively influence other aspects of children’s health [84].
An intriguing hypothesis regarding the role of off-axis defocus in myopia progression was proposed by Flitcroft [85]. He suggested that prolonged indoor activity, such as working or studying at a desk with a computer, expose the eyes to sustain stimulation from light poorly focused on the retinal periphery, which contributes to the progression of the myopia. Precisely, when we use a computer, we fixate on the distance of the monitor for many hours a day, and light reflected from items on the desk (which are closer than the monitor), induces hyperopic defocus at the retinal periphery. Even shifting gaze to objects a few meters away to relax accommodation will not prevent the progression of the myopia, as the three dimensional structure of the environment (light reflected from desks, keyboards, monitors) generate permanent hypeopic defocus (for a better understanding of this processsee: Flitcroft [85]). According to this hypothesis, being indoors for many hours contributes to the progression of myopia. Therefore, it is important to spend as much time as possible outdoors. The use of bifocal spectacles for near work could also be beneficial, as positive power in the lower segments, shifts light reflected from objects in the lower part of the visual field in front of the retina, thus eliminating the hyperopic defocus from desk-level objects [85].
CONCLUSIONS
It is difficult to determine with certainty which method is most effective in slowing myopia progression. In general, research shows that the most effective treatment of controlling myopia progression include optical methods, i.e., orthokeratology, DIMS/HAL spectacle lenses and low-dose atropine. Other methods, such as BFCL, MFCL, progressive or bifocals spectacles, demonstrate some but much less effectiveness. Specialist should choose the treatment method based on the patient’s lifestyle and readiness to adopt the solution. In some cases contact lens application causes significant stress that prevents successful fitting, or the patient expresses aversion to wearing spectacles. Some parents also have concerns about the long-term use of pharmacological agents such as low-dose atropine, even though there are no reports of adverse health effects. It is important to remember that most of the scientific studies show that the best results in inhibiting myopia progression are obtained in patients in the early stages of the development of the myopia, so the decision to introduce any of the methods to control its progression should not be delayed, but therapy should be introduced as early as possible. Full control of myopia progression does not only mean assessing changes in refractive error; an important parameter that should be regularly controlled is eyeball length. An effective therapy is one that not only slows the progression of the refractive error, but above all reduces the rate of elongation of the eyeballs, which will reduce the risk of myopic maculopathy and other ocular pathological changes in the future.
