distant visual acuity
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Trials ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Yibo Li ◽  
Lili Zhu ◽  
Raoying Wang ◽  
Xingyue Yang ◽  
Xinqi Jiang ◽  
...  

Abstract Background Currently, the population with myopia climbs steadily, and is developing toward younger age, posing a great concern to the health of adolescents. Myopia in severe cases can cause irreversible consequences such as glaucoma, blindness, and other complications. At present, the solutions for myopia are glasses, medication, and surgery. This study aims to investigate the role of a physiotherapy category based on guided meditation for vision acuity training on adolescent myopia. Methods This is a prospective, randomized, multicenter clinical trial. One thousand one hundred forty primary and secondary school students aged 8–18 years old from 27 schools will be recruited and randomly divided into an experimental and a control group at a ratio of 2:1 in two phases, with a training period of 30 days in each phase and a follow-up period of 3 months. No interventions will be conducted during the follow-up period, nor will other interventions employed. Inclusion criteria will meet the diagnostic criteria for simple myopia and −6.00D ≤ spherical lenses ≤ −0.50D and cylindrical lenses ≤1.50D. The primary observation index will be to compare the statistical differences in distant visual acuity between the two groups; the secondary observation indexes will be ocular symptoms (mainly including eye fatigue, dryness, pain, double vision, neck pain, thought disorders, and lags in response), diopter, and astigmatism. Discussion The purpose of this two-phase trial is to compare the clinical effectiveness of focused vision-guided meditation with Chinese eye exercises that are also non-pharmacological, non-invasive interventions for myopia, and to maximize the benefit to the subjects. The results will indicate whether the training based on focused vision-guided meditation has the ability to improve distant visual acuity, relieve ocular symptoms, and ameliorate diopter. In addition, this trial will provide clinical efficacy of the training, which is expected to provide meaningful data for vision rehabilitation. At the same time, the vision acuity training method, which is permeated with the concept of Traditional Chinese Medicine (TCM) rehabilitation and health maintenance, will be applied to achieve the goal of preventing or alleviating myopic development and reducing myopia rate. Trial registration Chinese Clinical Trial Registry ChiCTR2000038642. Registered on 26 September 2020


2021 ◽  
Vol 15 ◽  
Author(s):  
Meng-Tian Kang ◽  
Bo Wang ◽  
An-Ran Ran ◽  
Jiahe Gan ◽  
Jialing Du ◽  
...  

Purpose: To assess neural changes in perceptual effects induced by myopic defocus and hyperopic defocus stimuli in ametropic and emmetropic subjects using functional magnetic resonance imaging (fMRI).Methods: This study included 41 subjects with a mean age of 26.0 ± 2.9 years. The mean spherical equivalence refraction was −0.54 ± 0.51D in the emmetropic group and −3.57 ± 2.27D in the ametropic group. The subjects were instructed to view through full refractive correction, with values of +2.00D to induce myopic defocus state and −2.00D to induce hyperopic defocus state. This was carried over in three random sessions. Arterial spin labeling (ASL) perfusion was measured using fMRI to obtain quantified regional cerebral blood flow (rCBF). Behavioral tests including distant visual acuity (VA) and contrast sensitivity (CS), were measured every 5 min for 30 min.Results: Myopic defocus induced significantly greater rCBF increase in four cerebral regions compared with full correction: right precentral gyrus, right superior temporal gyrus, left inferior parietal lobule, and left middle temporal gyrus (P < 0.001). The differences were less significant in low myopes than emmetropes. In the hyperopic defocus session, the increased responses of rCBF were only observed in the right and left precentral gyrus. Myopic defocused VA and CS improved significantly within 5 min and reached a plateau shortly after.Conclusion: This study revealed that myopic defocus stimuli can significantly increase blood perfusion in visual attention-related cerebral regions, which suggests a potential direction for future investigation on the relationship between retinal defocus and its neural consequences.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ruoyan Wei ◽  
Meiyan Li ◽  
Weiming Yang ◽  
Haipeng Xu ◽  
Joanne Choi ◽  
...  

Purpose: To report the clinical outcomes of phototherapeutic keratectomy (PTK) for pediatric band keratopathy after treatment for retinoblastoma.Methods: A 5-year-old boy presented with a 2-year history of poor visual acuity and a horizontal gray-white band across the central cornea in the right eye. He was diagnosed with band keratopathy after chemo-laser-cryotherapy for retinoblastoma. The band keratopathy was treated via PTK using the Mel-90 excimer laser with an optical treatment zone of 7.0 mm and ablation depth of 120 μm. The patient was followed at 1 week and 3 months postoperatively.Results: Surgery and postoperative follow-up were uneventful. At the 3-month follow-up, the uncorrected distant visual acuity of the right eye improved to 20/125, and the corrected distance visual acuity improved to 20/70 with a refraction of +10.00 D/−2.50 DC × 15. The clarity of the ablated area was evidently improved. The central corneal thickness decreases from 612 to 584 μm. The optical coherence tomography showed the thin band of hyperreflectivity in the ablated area disappeared, corneal transparency improved and the corneal surface smoothened.Conclusions: PTK is a safe and effective procedure to treat band keratopathy following treatment of retinoblastoma in children. Early intervention can reduce the risk of developing deprivation amblyopia.


2021 ◽  
Vol 14 (7) ◽  
pp. 1081-1091
Author(s):  
Li Chen ◽  
◽  
Xiao Lin ◽  
Hao-Yu Li ◽  
Yi Du ◽  
...  

AIM: To update and investigate the clinical outcomes and complications between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS). METHODS: A Meta-analysis was performed using databases, including Pubmed, Embase, and the Cochrane library. At least one of the clinical outcomes and/or complications data in each included randomized controlled trials (RCT) was reported. The quality of the RCT was assessed with the Cochrane risk assessments tool. RESULTS: Overall, 25 RCTs including 3781 eyes were included. No statistically significant difference detected between FLACS and CPCS in terms of corrected distant visual acuity (CDVA), uncorrected distant visual acuity (UDVA), and central corneal thickness (CCT) at the long-term follow up, although FLACS showed better CDVA at 1wk postoperatively, and less increase in CCT at 1d and 1wk. FLACS had better postoperative endothelial cell count (ECC) at 1 and 4-6wk, while there was no significantly difference between FLACS and CPCS at 1d, 3 and 6mo [weighted mean difference (WMD): 51.54, 95% confidence interval (CI): -5.46 to 108.54, P=0.08; WMD: 48.52, 95%CI: -17.54 to 114.58, P=0.15; WMD: 12.17, 95%CI: -48.61 to 72.94, P=0.69, respectively]. Postoperative endothelial cell loss (ECL) of the FLACS was significantly lower than that of the CPCS at 1, 4-6wk, and 3mo (P=0.02, 0.008, 0.03, respectively). However, there was no significant difference between two groups at 6mo (WMD: -30.36, 95%CI: -78.84 to 18.12, P=0.22). No significant difference was discovered with respect to the macular edema [odds ratio (OR): 0.93, 95%CI: 0.42 to 2.05, P=0.85], capsular complication excluding posterior capsular tears (OR: 0.79, 95%CI: 0.42 to 1.50, P=0.47) and intraocular pressure change (OR: 0.82, 95%CI: 0.39 to 1.72, P=0.60). However, posterior capsular tears were more common in CPCS group (OR: 0.12, 95%CI: 0.01 to 0.98, P=0.05). The effective phacoemulsification times were significantly lower in the FLACS group compared to the CPCS group (WMD: -0.78, 95%CI: -1.23 to -0.34, P=0.0006). CONCLUSION: No statistically significant difference is discovered between FLACS and CPCS in clinical outcomes at the long-term follow up. However, higher rate of posterior capsular tears is detected in patients receiving CPCS.


2021 ◽  
Author(s):  
Yibo Li ◽  
Lili Zhu ◽  
Raoying Wang ◽  
Xinqi Jiang ◽  
Tao Lu

Abstract Background: Currently, the population with myopia climbs steadily, and developing toward younger age, posing a great concern to the health of adolescents. Myopia in severe cases can cause irreversible consequences such as glaucoma, blindness and other complications. At present, the solutions for myopia are glasses, medication and surgery. This study aims to investigate the role of a physiotherapy category based on guided meditation for vision acuity training on adolescent myopia. Methods: This is a prospective, randomized, multicenter clinical trial. 1140 primary and secondary school students aged 8-18 years old from 27 schools will be recruited and randomly divided into an experimental group and a control group at a ratio of 2:1 in two phases, with a training period of 30 days in each phase and a follow-up period of 3 months. No interventions will be conducted during the follow-up period, nor will other interventions employed. Inclusion criteria will meet the diagnostic criteria for simple myopia and -6.00D ≤ spherical lenses ≤ -0.50D, cylindrical lenses ≤ 1.50D. The primary observation index will be to compare the statistical differences in distant visual acuity between the two groups; the secondary observation indexes will be ocular symptoms (mainly including eye fatigue, dryness, pain, double vision, neck pain, thought disorders, and lags in response), diopter and astigmatism. Discussion: The purpose of this two-phase trial is to compare the clinical effectiveness of focused vision-guided meditation with Chinese eye exercises that are also non-pharmacological, non-invasive interventions for myopia, and to maximize the benefit to the subjects. The results will indicate whether the training based on focused vision-guided meditation has the ability to improve distant visual acuity, relieve ocular symptoms and ameliorate diopter. In addition, this trial will provide clinical efficacy of the training, which is expected to provide meaningful data for vision rehabilitation. At the same time, the vision acuity training method, which is permeated with the concept of Traditional Chinese Medicine (TCM) rehabilitation and health maintenance, will be applied to achieve the goal of preventing or alleviating myopic development and reducing myopia rate. Trial registration: Chinese Clinical Trial Registry (identifier: ChiCTR2000038642; Registered 26 September 2020, http://www.chictr.org.cn/showproj.aspx?proj=61729).


2021 ◽  
Vol 9 (B) ◽  
pp. 244-249
Author(s):  
Abdullah Alsalhi ◽  
Nadia Northway ◽  
Glyn Walsh ◽  
Abd Elaziz Mohamed Elmadina

BACKGROUND: Reading can be described as a complex cognitive process of decrypting signs to create meaning. Eventually, it is a way of language achievement, communication, and sharing of information and ideas. Changing lighting and color are known to improve visual comfort and the perceptual difficulties that affect reading for those with poor vision. AIM: The main objectives of the current study were to investigate the effect of changing the wavelengths and color with different levels of positional noise on reading performance with non-word for subjects with best-corrected distant visual acuity (BCVA) equal or better than 6/6. METHODOLOGY: In a cross-section interventional study, 20 English speakers were asked to read non-words presented in a printed format. The stimuli were black print words in a horizontal arrangement on a matte white card. They were degraded using positional noise produced by random vertical displacements of the letter position below or above the horizontal line on three levels. RESULTS: Introducing positional noise affected real and non-words recognition differently. The detrimental effects of positional noise with non-words on reading rate were not influenced by changes in wavelengths and color. The long-wavelength reading rate resulted in the lowest performance compared with other wavelengths with all levels of noise. CONCLUSION: Reading performance is affected by changes in the levels of positional noise. However, the reading rate is not affected by changes in wavelength and color with non-words. The long-wavelength reading rate resulted in the lowest performance compared with other wavelengths and color with all levels of noise.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christine de Weger ◽  
F. Nienke Boonstra ◽  
Jeroen Goossens

AbstractIn children with Down syndrome (DS) development of visual, motor and cognitive functions is atypical. It is unknown whether the visual impairments in children with DS aggravate their lag in cognitive development. Visual impairment and developmental lags in adaptive behaviour and executive functions were assessed in 104 children with DS, 2–16 years, by comparing their adaptive behaviour, executive functions and visual acuity (distant and near) scores against published age-matched norm scores of typically developing children. Associations between these lags were explored. Mean (± SEM) differences to age-matched norms indicated reduced performance in DS: Vineland Screener questionnaire, − 63 ± 3.8 months; task-based Minnesota Executive Function Scale (MEFS), − 46.09 ± 2.07 points; BRIEF-P questionnaire, 25.29 ± 4.66 points; BRIEF parents’ and teachers’ questionnaire, 17.89 ± 3.92 points and 40.10 ± 3.81 points; distant and near visual acuity, 0.51 ± 0.03 LogMAR and 0.63 ± 0.03 LogMAR (near − 0.11 ± 0.04 LogMAR poorer than distant). Adaptive behaviour (Vineland-S) correlated with the severity of visual impairment (r = − 0.396). Children with DS are severely impaired in adaptive behaviour, executive functions and visual acuities (near visual acuity more severely impaired than distant visual acuity). Larger impairment in adaptive behaviour is found in children with larger visual impairment. This supports the idea that visual acuity plays a role in adaptive development.


2021 ◽  
Vol 9 (B) ◽  
pp. 130-135
Author(s):  
Abdullah Alsalhi ◽  
Nadia Northway ◽  
Glyn Walsh ◽  
Abd Elaziz Mohamed Elmadina

BACKGROUND: Reading can be described as a complex cognitive process of decrypting signs to create meaning. Eventually, it is a way of language achievement, communication, and sharing information and ideas. Changing lighting and color are known to improve visual comfort and the perceptual difficulties that affect reading for those with poor vision. AIM: This study aims to investigate the effect of changing the wavelengths and different levels of positional noise on reading performance for participants with best-corrected distant visual acuity (BCVA) of 6/6 or better. METHODOLOGY: Twenty English speakers with BCVA 6/6 or better were asked to read words presented in a printed format. The stimuli were black print words in a horizontal arrangement on matte white card. They were degraded using positional noise produced by random vertical displacements of the letter position below or above the horizontal line on three levels. RESULTS: Introducing positional noise affected word recognition differently with different wavelengths. The role of short wavelength in enhancing orthographic reading and word recognition is clear – they reduce the effects of positional noise. The error rate and duration time have different effects with different wavelengths, even when positional noise is introduced. CONCLUSION: The reading rate is not affected by changing the wavelength of the light. However, the mean differences in wpm were affected by changing the wavelengths. Also, introducing positional noise affects word recognition differently with different wavelengths.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shangfei Yang ◽  
Hui Jiang ◽  
Kailai Nie ◽  
Liwen Feng ◽  
Wei Fan

Abstract Background The use of capsular tension ring (CTR) implantation to treat cataract patients with weak zonules is still controversial. The aim of this study was to examine the effects of CTR implantation on capsular stability after phacoemulsification in patients with weak zonules, especially patients who have undergone pars plana vitrectomy (PPV) or those who suffer from severe myopia. Methods A total of 42 patients who underwent phacoemulsification and received an intraocular lens (IOL) were randomized to undergo CTR implantation or not. The control and CTR groups were compared in terms of uncorrected distant visual acuity (UDVA), best corrected distant visual acuity (BCDVA), refractive prediction error, the area of anterior capsulorhexis, and IOL inclination angle. Follow-up visits were conducted postoperatively at 1 day, 1 week, 1 month and 3 months. Subgroup analyses were performed based on PPV and severe myopia. Results Surgery significantly improved UDVA and BCDVA to similar extents in CTR and control patients, and refraction prediction error was similar between the two groups at all follow-up times. At 3 months after surgery, the area of anterior capsulorhexis was significantly larger in CTR patients than in controls (p = 0.0199). These differences were also significant between the subgroups of patients with severe myopia. Vertical IOL inclination was less within CTR groups at 3 months after surgery, especially in patients with severe myopia (p = 0.0286). At 1 week postoperatively, the proportion of individuals whose posterior lens capsule that had completely adhered to the posterior IOL surface was significantly higher among CTR patients (p = 0.023). No serious surgical complications were observed. Conclusion CTR implantation can benefit cataract patients with weak zonules by maintaining the shape of the capsular bag, reducing capsule shrinkage and stabilizing IOL inclination. Trial registration Chinese Clinical Trial Registry ChiCTR-INR-17011217, date of registration April 22, 2017, prospectively registered.


2020 ◽  
Author(s):  
Shangfei Yang ◽  
Hui Jiang ◽  
Kailai Nie ◽  
Liwen Feng ◽  
Wei Fan

Abstract Background: The use of capsular tension ring (CTR) implantation to treat cataract patients with weak zonules is still controversial. The aim of this study was to examine the effects of CTR implantation on capsular stability after phacoemulsification in patients with weak zonules, especially patients who have undergone pars plana vitrectomy (PPV) or those who suffer from severe myopia.Methods: A total of 42 patients who underwent phacoemulsification and received an intraocular lens (IOL) were randomized to undergo CTR implantation or not. The control and CTR groups were compared in terms of uncorrected distant visual acuity (UDVA), best corrected distant visual acuity (BCDVA), refractive prediction error, the area of anterior capsulorhexis, and IOL inclination angle. Follow-up visits were conducted postoperatively at 1 day, 1 week, 1 month and 3 months. subgroup analyses were performed based on PPV and severe myopia. Results: Surgery significantly improved UDVA and BCDVA to similar extents in CTR and control patients, and refraction prediction error was similar between the two groups at all follow-up times. At 3 months after surgery, the area of anterior capsulorhexis was significantly larger in CTR patients than in controls (p = 0.0199). These differences were also significant between the subgroups of patients with severe myopia. Vertical IOL inclination was less within CTR groups at 3 months after surgery, especially in patients with severe myopia (p = 0.0286). At 1 week postoperatively, the proportion of individuals whose posterior lens capsule that had completely adhered to the posterior IOL surface was significantly higher among CTR patients (p = 0.023). No serious surgical complications were observed.Conclusion: CTR implantation can benefit cataract patients with weak zonules by maintaining the shape of the capsular bag, reducing capsule shrinkage and stabilizing IOL inclination.Trial registration: Chinese Clinical Trial Registry ChiCTR-INR-17011217, date of registration April 22, 2017, prospectively registered.


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