Three optical intervention methods for low myopia control in children: a one-year follow-up study.

OBJECTIVE: This study aimed to compare the one-year efficacy of myopia prevention and control using three optical intervention methods - single vision lens (SVL), high aspherical lenticule (HAL), and orthokeratology (OK) lens - in children with low myopia. METHODS: A cohort of 150 children aged 7-13 years with low myopia was recruited and divided into three groups: SVL (n = 50), HAL (n = 50), and OK lens group (n = 50), based on their preference for glasses. Follow-up assessments were carried out over one year, focusing on data from the right eye for statistical analysis. Baseline characteristics such as gender, age, axial length (AL), spherical equivalent refractive error (SER), flat keratometry (K1), steep keratometry (K2), anterior chamber depth (ACD), white-to-white corneal diameter (WTW), and non-contact tonometry (NCT) measurements were gathered and compared among the three groups before any intervention. Changes in AL growth after 1 year of intervention were assessed across the three groups. Subsequently, the AL growth control rates between the HAL and OK lens groups were compared, with the SVL group serving as the reference standard. RESULTS: The study found no statistically significant variances in baseline characteristics (gender, age, SER, AL, K1, K2, WTW, and NCT) among the SVL, HAL, and OK lens groups (all p > 0.05). Following a one-year intervention, AL growth rates were as follows: HAL group (0.163 ± 0.113 mm) < OK lens group (0.280 ± 0.170 mm) < SVL group (0.516 ± 0.190 mm), with statistically significant disparities (p < 0.05). The HAL group demonstrated a higher 1-year AL growth control rate (68.41%) compared to the OK lens group (45.74%) for children aged 7-13 with low myopia, with a statistically significant differences (p < 0.001). And there was significant difference in the SER change between SVL group and HAL group (p < 0.001). CONCLUSION: Compared to SVL, HAL and OK lens are more effective in controlling axial growth in mild myopia. Specifically, HAL maybe shows superior outcomes in both preventive and corrective measures, also it needs to be supported by more studies from randomized controlled experiments.

Differences in network centrality between high and low myopia: a voxel-level degree centrality study.

BACKGROUND: Previous studies have linked high myopia (HM) to brain activity, and the difference between HM and low myopia (LM) can be assessed. PURPOSE: To study the differences in functional networks of brain activity between HM and LM by the voxel-level degree centrality (DC) method. MATERIAL AND METHODS: Twenty-eight patients with HM (10 men, 18 women), 18 patients with LM (4 men, 14 women), and 59 healthy controls (27 men, 32 women) were enrolled in this study. The voxel-level DC method was used to assess spontaneous brain activity. Correlation analysis was used to explore the change of average DC value in different brain regions, in order to analyze differences in brain activity between HM and LM. RESULTS: DC values of the right cerebellum anterior lobe/brainstem, right parahippocampal gyrus, and left caudate in HM patients were significantly higher than those in LM patients (P < 0.05). In contrast, DC values of the left medial frontal gyrus, right inferior frontal gyrus, left middle frontal gyrus, and left inferior parietal lobule were significantly lower in patients with HM (P < 0.05). However, there was no correlation between behavior and average DC values in different brain regions (P < 0.05). CONCLUSION: Different changes in brain regions between HM and LM may indicate differences in neural mechanisms between HM and LM. DC values could be useful as biomarkers for differences in brain activity between patients with HM and LM. This study provides a new method to assess differences in functional networks of brain activity between patients with HM and LM.

Comparison of ReLEx SMILE and PRK in terms of visual and refractive outcomes for the correction of low myopia.

PURPOSE: To compare the objective and subjective quality of vision after femtosecond laser-assisted small incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK) for low myopia. METHODS: One hundred and twenty eyes from 60 patients (34 females, 26 males) undergoing bilateral correction of low myopia (≤-4 D SE) with either ReLEx SMILE or PRK were included. Visual acuity, contrast sensitivity and higher-order aberrations were recorded preoperatively and compared postoperatively. A quality of vision questionnaire was scored and analyzed 3 months postoperatively. RESULTS: At 3 months, the SMILE group had significantly better uncorrected and corrected distant visual acuity (CDVA), compared to PRK group (p = 0.01). Post-op spherical equivalent (SE) was comparable in both groups (SMILE = -0.15 ± 0.19 D, PRK = -0.14 ± 0.23 D, p = 0.72). However, SE predictability was better in SMILE group with 97% eyes within ±0.05 D compared to 93% eyes in the PRK group. Total higher-order aberrations (HOAs) were significantly higher in PRK compared to the SMILE group (p = 0.022). The SMILE group demonstrated slightly better contrast sensitivity, which was significant at spatial frequency of 12 cpd (p = 0.03). Four eyes in the PRK group had loss of CDVA by one line due to mild haze. CONCLUSIONS: Both SMILE and PRK were effective procedures for correction of low myopia. However, SMILE offered superior quality of vision and patient satisfaction due to better postoperative comfort and lower induction of aberrations at 3 months.

Changes in choroidal thickness in myopic children with 0.01% atropine: Evidence from a 12-month follow-up.

PURPOSE: To investigate the changes of low-dose atropine (0.01%) on the choroidal thickness (ChT) of young children with low myopia. METHODS: A total of 25 eyes of 25 low myopic children were included. All subjects were prescribed 0.01% atropine eye drops to be applied once per night before bedtime in involving eyes. The ChT and ocular biometry parameters were measured before and after 1 month, 3 months, 6 months and 12 months. The children were followed up for 12 months. RESULTS: At 3 months, the ChT under the fovea significantly increased (309.96±70.82 µm) in comparison with the baseline (297.92±66.31 µm, P<0.0001) and was continuous thickening till 12 months after treatments with 0.01% atropine. Similarly, the changes of ChT under the fovea significantly increased from baseline to 3 months in comparison with the baseline to 1 month after treatments (P<0.0001). There was a significant relationship between changes in subfoveal ChT and central cornea thickness (CCT, beta=-1.76, 95% confidence intervals: -3.49 to -0.04, P = 0.045). CONCLUSIONS: Using low dose atropine eye drops significantly increased subfoveal ChT after 3 months in eyes of myopic children. In addition, the changes in subfoveal ChT may be associated with the changes of CCT.

Two-Year Visual Outcomes of Evolution Implantable Collamer Lens and Small Incision Lenticule Extraction for the Correction of Low Myopia.

Purpose: To investigate the 2-year visual quality of Evolution Implantable Collamer Lens (EVO-ICL) and small incision lenticule extraction (SMILE) for the correction of low myopia. Methods: In this prospective study, we included 25 eyes of 25 patients (7 men) who underwent EVO-ICL and 36 eyes of 36 patients (16 men) who underwent SMILE between January 2018 and December 2018. Subjective and objective visual outcomes were compared between ICL and SMILE. All patients were followed for 2 years. Results: At the postoperative 2-year visit, the percentage of patients with uncorrected distance visual acuity (UDVA) greater than or equal to preoperative corrected distance visual acuity (CDVA) was comparable in the ICL group (80%, 20/25) and SMILE group (88.89%, 32/36). Spherical equivalent (SE) was within ± 0.50 D in 96% (24/25) of the ICL group and 94.44% (34/36) of the SMILE group. No eyes lost more than 2 lines of CDVA. Postoperative high-order aberrations (HOAs) were significantly increased in the ICL group (p < 0.01) and in the SMILE group (p < 0.01). The most common visual complaint was halo after ICL and starburst after SMILE. There was no correlation between HOAs and visual complaints (p > 0.05). Conclusion: Evolution Implantable Collamer Lens provides comparable safety, efficacy, long-term visual stability, and high patient satisfaction when compared to SMILE in correcting low myopia. EVO-ICL could be a favorable alternative for low myopia. Key messages What was known?: •Visual outcomes of Evolution Implantable Collamer Lens (EVO-ICL) versus small incision lenticule extraction (SMILE) for correction of mild myopia remain unclear. What this paper adds?: •Evolution Implantable Collamer Lens (EVO-ICL) provides comparable safety, efficacy, long-term visual stability, and high patient satisfaction when compared to small incision lenticule extraction (SMILE) in correcting low myopia.•The most common visual complaint was halo after ICL and starburst after SMILE.

Low Diopter Phakic Implantable Collamer Lens: Refractive and Visual Outcomes in Low Myopia and Myopic Astigmatism.

Purpose: Nowadays the Implantable Collamer Lens (ICL - STAAR Surgical. Monrovia. CA) is a refractive surgical technique offered not only when laser corneal correction is not possible but also when the patient requires premium quality indexes and when dry eye is a concern. The use of ICL phakic lenses in low myopic patients is an emanate factor to study and analyze in order to determine treatment predictability and stability in such patients. In this paper, we conducted a 1-year follow-up study on patients with myopia below -3.5D implanted with ICL lenses. Methods: This was a retrospective analytical study that includes patients with phakic ICL implantation from 2 independent clinics with a minimum follow-up of 12 months. Visual acuity, refractive outcomes, vault, and intraocular pressure (IOP) were assessed at 1, 6 and 12 months. Results: Eighty-two eyes from 82 patients were included in this analysis. Mean spherical equivalent was -2.34 ± 0.82 (Range -5.50 to -1.00 D). Mean spherical implanted ICL power was -3.04 ± 0.78 D. In 25 eyes (30.5%) a Toric-ICL (TICL) was implanted with a mean TICL cylinder power of +1.64±0.64. Efficacy and security index remained stable for 12 months at 1.07 and 1.09, respectively. Mean vault at 12 months was 513.78 ± 262.87 µm and IOP was 15.63 ± 2.17 mmHg. Conclusion: Phakic Implantable Collamer Lens implantation in very low myopia is a predictable, stable, safe, and effective technique with high efficacy and security indexes. Low diopter Toric ICL is also an excellent option for refractive surgery in cases of low diopter astigmatism.

A Nationwide Multicenter Study on 1-Year Outcomes of Posterior Chamber Phakic Intraocular Lens Implantation for Low Myopia.

Purpose: To assess the nationwide multicenter outcomes of posterior chamber phakic intraocular lens implantation with a central hole (EVO-ICL, STAAR Surgical) for patients with low myopia. Methods: This multicenter study comprised 172 eyes of 111 consecutive patients undergoing hole ICL implantation to correct low myopia and myopic astigmatism [manifest spherical equivalent (MSE);-3 diopters (D) or less] at seven nationwide major surgical facilities. We retrospectively determined safety, efficacy, predictability, stability, and adverse events at 1 week, 1, 3, 6, and 12 months postoperatively, and at the final visit. Results: The mean follow-up period was 1.4 ± 1.0 years. Uncorrected and corrected visual acuities at 1 year postoperatively were -0.17 ± 0.12 and -0.24 ± 0.07 logarithm of the minimal angle of resolution (logMAR), respectively. At 1 year postoperatively, 91% and 100% of eyes were within 0.5 and 1.0 D of the target correction, respectively. No significant manifest refraction changes of -0.07 ± 0.26 D occurred from 1 week to 1 year. No vision-threatening complications occurred at any time in this series. Conclusions: According to our experience, the EVO-ICL performed well without significant complications throughout the 1-year observation period, even for the correction of low myopia. It is suggested that current ICL implantation is one of the viable surgical options for correcting low myopia.

Long-Term Visual and Refractive Stability and Ocular Biometric Changes after Laser-Assisted Subepithelial Keratomileusis for Correction of Myopia: An 8-Year Follow-Up.

PURPOSE: To assess the long-term visual and refractive stability and ocular biometric changes in low to moderate myopic subjects treated by laser-assisted subepithelial keratomileusis (LASEK). METHODS: It is a prospective, interventional study. Included were 70 eyes of 35 patients who underwent LASEK for correction of ≤6 diopters (D) myopia. The uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest refractions, and ocular biometric indices (by Lenstar-LS900, Haag-Streit AG, Koeniz, Switzerland) including keratometry, anterior chamber depth (ACD), aqueous depth (AD), axial length (AL), central corneal thickness (CCT), and lens thickness (LT) were assessed preoperatively and after 6 months and 8 years. RESULTS: Mean preoperative spherical equivalent was -3.99 (standard deviation [SD] =1.38) D which improved to 0.02 (SD = 0.27, P < 0.001) D and -0.10 (SD = 0.31, P < 0.001) D at 6 months and 8 years, respectively. The preoperative AL was not different from postoperative measures at 6 months (P = 0.15) and 8 years (P = 0.47). The ACD and AD decreased during 8 years, while LT increased (all P ≤ 0.001). The changes of LT inversely correlated with changes of ACD (rs = -0.67, P = 0.001 at 6 months and rs = -0.87, P < 0.001 at 8 years) and AD (rs = -0.76, P < 0.001 at 6 months and rs = -0.86, P < 0.001 at 8 years). The CCT and keratometry values reduced at 6 months postoperatively (all P < 0.001) and then did not change up to 8 years (0.21 ≤ P ≤ 0.87). CONCLUSIONS: The post-LASEK myopic regression is 0.1 D over 8 years. Ocular biometric values like keratometry, CCT, ACD, AD, and LT have been changed for a long period after LASEK in low to moderate myopia except AL.

Posterior chamber collamer phakic intraocular lens implantation: Comparison of efficacy and safety for low and moderate-to-high myopia.

PURPOSE: To compare visual, refractive and safety outcomes of central-hole posterior chamber collamer phakic intraocular lens implantation for low and moderate-to-high myopia. SUBJECTS/METHODS: This retrospective cohort study included 338 eyes submitted to posterior chamber collamer phakic intraocular lens implantation that completed a 12-month postoperative follow-up. Two groups were defined depending on preoperative spherical equivalent: group 1 comprised 106 eyes with manifest spherical equivalent of -6.00 D or less; group 2 comprised 232 eyes with manifest spherical equivalent higher than -6.00 D. Effectiveness, predictability, stability and safety outcomes were compared preoperatively and at 1, 6 and 12 months postoperatively. RESULTS: At 1-year postoperative, uncorrected and corrected visual acuities were 0.02 ± 0.17 and -0.01 ± 0.12 logMAR (group 1) and 0.04 ± 0.20 and 0.01 ± 0.16 logMAR (group 2), with an efficacy index of 1.05 ± 0.17 and 1.17 ± 0.28. Respectively, 92 (86.8%) and 199 (85.8%) eyes were within ±0.50 D of targeted refraction, and postoperative manifest refraction changes were -0.07 ± 0.25 D and -0.07 ± 0.35 D. Intraocular pressure did not change significantly. The mean rate of endothelial cell loss was 1.12% and 1.10%, respectively. One case of anterior subcapsular cataract (group 2) was observed. ICL exchange occurred in one case (group 1) and three cases (group 2). No vision-threatening complications were reported. CONCLUSION: The posterior chamber collamer phakic intraocular lens implantation demonstrated high visual and refractive efficacy with an excellent safety profile for the correction of both low and moderate-to-high myopia, revealing equivalent 1-year outcomes regardless of the degree of preoperative myopia.

Clinical outcomes of small incision lenticule extraction versus advanced surface ablation in low myopia.

PURPOSE: To compare the visual and refractive outcomes of small incision lenticule extraction and advanced surface ablation for low myopia or myopic astigmatism. METHODS: Retrospective, observational case series of our first 50 consecutive small incision lenticule extraction patients compared to refraction-matched 50 advanced surface ablation treatments with attempted spherical equivalent correction ⩽-3.5 D, astigmatism ⩽-1.5 D, and corrected distance visual acuity of 1.0 (decimal scale) or better. Only one eye per patient was included. RESULTS: Small incision lenticule extraction: mean attempted spherical equivalent correction was -2.80 ± 0.63 D. Uncorrected distance visual acuity was 0.85 and 1.0 at days 1 and 5, respectively. At 3 months, mean spherical equivalent refraction was 0.02 ± 0.32 D (range: -0.5 to +0.75 D), mean cylinder was -0.24 ± 0.21 D (range: 0 to -0.75 D), mean uncorrected distance visual acuity was 1.27, mean efficacy index was 0.96, and mean safety index was 1.05. Uncorrected distance visual acuity was same or better than corrected distance visual acuity in 96%, astigmatism ⩽0.5 D in 98% and ⩽1 D in 100% of eyes, respectively. Advanced surface ablation: mean attempted spherical equivalent correction was -2.75 ± 0.5 D. Uncorrected distance visual acuity was 0.72 and 0.61 at days 1 and 5, respectively. At 3 months, mean spherical equivalent refraction was 0.22 ± 0.32 D, mean cylinder was -0.27 ± 0.27 D, mean uncorrected distance visual acuity was 1.21, mean efficacy index was 1.03, and mean safety index was 1.08. CONCLUSION: Small incision lenticule extraction for low myopia was found to be safe and effective with outcomes at 3 months similar to those obtained with advanced surface ablation while offering a quicker visual recovery.

Influence of cataract surgery on macular vascular density in patients with myopia using optical coherence tomography angiography.

The aim of the present study was to evaluate macular vascular density (MVD) variation after uneventful cataract surgery using optical coherence tomography angiography (OCTA) in patients with high myopia. Patients with cataracts scheduled for cataract surgery were divided into a high-myopia group [spherical equivalent (SE)≤-6.0 diopter (D) and axial length (AL)≥25 mm] and a low-myopia group (SE>-6.0 D and AL<25 mm). All patients were examined for MVD and retinal thickness (RT) with OCTA pre-operatively and post-operatively (1 day, 1 week, and 1 and 3 months after surgery). A total of 55 eyes from 44 patients were included. MVD and RT both changed after cataract surgery. The mean change in superficial vascular density (SVD) in patients with high myopia was significantly lower than that in the low-myopia group at the four post-operative time-points (all P<0.05). In addition, the RT of eyes with high myopia exhibited a different variation compared with that of the low-myopia group. Significant correlations were identified between AL, RT, intraocular pressure and SVD after surgery. In conclusion, superficial retinal perfusion in patients with high myopia was significantly lower than that in low myopia patients, which may lead to complications caused by poor perfusion.

Epithelium-on photorefractive intrastromal cross-linking (PiXL) for reduction of low myopia.

PURPOSE: To report the 9-12-month outcomes of a novel procedure for reduction of low myopia through epithelium-on photorefractive intrastromal cross-linking (PiXL) with customized control of topographic distribution of ultraviolet (UV)-fluence. METHOD: Myopic patients with normal (non-ectatic) corneas underwent the PiXL procedure for reduction of low myopia. PiXL treatments were delivered through selective application of UVA light based on the refractive error of each patient. Clinical evaluation included safety (corrected distance visual acuity, endothelial cell count, central corneal thickness, anterior ocular health) and efficacy (uncorrected distance visual acuity, manifest refraction, K-mean) examinations. In addition, a patient satisfaction survey was conducted at 9 months post-procedure to evaluate patients' subjective experience with the procedure. RESULTS: Fourteen myopic eyes (mean manifest refraction spherical equivalent -1.62±0.6D; range -0.75 to -2.65D) of 8 subjects (mean age 30 years old; range 24-51 years old) were enrolled in the study. At 12 months post-procedure, a mean manifest refraction spherical equivalent reduction of 0.72±0.43D (P<0.001) was observed, with a corresponding gain in uncorrected visual acuity of 0.25 logMAR and mean K-mean flattening of 0.47±0.46D. All patients achieved best corrected visual acuity of 20/20 or better from 1 month onward. There were no cases of ocular infection or secondary changes to the crystalline lens and retina due to UV exposure, while transient corneal haze subsided gradually. CONCLUSION: The epithelium-on PiXL procedure was safe and effective in reducing myopic refractive error in this study with up to 12 months follow-up. Early results of this novel application of collagen cross-linking are encouraging but longer-term data in larger studies are required. PRECIS: This paper serves to introduce and report the early clinical results of epithelium-on PiXL, a novel application of cornea cross-linking, in reducing low myopia in Asian eyes, which are under-represented in studies of similar design.

Refractive outcomes and safety of the implantable collamer lens in young low-to-moderate myopes.

PURPOSE: To evaluate visual and refractive outcomes and safety of implantable collamer lens (ICL) implantation in low-to-moderate myopia. SETTING: Private Practice - Dougherty Laser Vision, Westlake Village, CA, USA. METHODS: A chart review was performed in 56 (104 eyes) consecutive patients who underwent implantation of the Visian ICL V4 model. Inclusion criteria were age between 21 and 40 years, spherical equivalent between -3.00 D and -10.00 D, and cylinder up to -5 D. Data on visual acuity, refraction, and complications were collected. RESULTS: The mean time to the last postoperative visit was 13.1±14.0 months (range, 2 to 50 months). The mean preoperative spherical equivalent was -6.96±1.60 D and the mean preoperative cylinder was -1.03±0.88 D. The mean preoperative corrected distance visual acuity (CDVA) was 20/20 (range, 20/15 to 20/80) that remained unchanged at last postoperative visit. At the last postoperative visit, the spherical equivalent was -0.08±0.01 D and the cylinder was 0.29±0.71 D. Comparison of postoperative uncorrected distance visual acuity (UCDVA) to preoperative CDVA indicated that 27 eyes (26%) had better postoperative UCDVA and 61 eyes (59%) had UDVA equivalent to the preoperative CDVA. Postoperatively, 4 eyes lost 1 line of CDVA and no eyes lost >1 line of CDVA. There were 32 eyes that gained at least ≥1 of CDVA. There were no intraoperative complications. Postoperatively, 3 patients (6 eyes) had dry eye, and 1 patient complained of nighttime halos in 1 eye. At the last postoperative visit, there were no eyes with lens opacity or glaucoma. CONCLUSION: ICL implantation for low and moderate myopia up to -10 D in patients up to 40 years of age was safe, accurate, and efficacious. ICL implantation may be a good alternative to laser in situ keratomileusis for young myopes less than -10.00 D.

Specificity and generalization of perceptual learning in low myopia.

PURPOSE: In this study we investigated in observers with low myopia: (i) the pattern of lateral interactions between stimuli activating early cortical analyzers and its modulation by perceptual learning (PL), and (ii) whether PL transferred to untrained stimuli and tasks and whether it exhibits interocular transfer. METHOD: Participants (seven adults with low myopia) performed 12 training sessions. Participants were trained on a contrast detection task of a central Gabor target flanked by two co-oriented and co-aligned high contrast Gabor patches. Target-to-flankers separation along the vertical axis was varied from 2 wavelengths (λ) to 8λ. RESULTS: The results showed that before PL facilitatory lateral interactions in the myopic eye were reduced in strength, but PL increased contrast sensitivity and improved facilitatory lateral interactions. However, PL did not transfer to different local/global orientations and lower spatial frequencies. On the other hand, PL resulted in an enhancement of the contrast sensitivity function (CSF) and of the uncorrected visual acuity (UCVA) both in the trained and untrained eye. CONCLUSIONS: Such improvements seem to be associated to a modulation of lateral interactions between target and flankers and it is likely to take place at a level in which the inputs from the two eyes converge.