scholarly journals Multi-session visual cortex transcranial random noise stimulation in adults with amblyopia

2019 ◽  
Author(s):  
Richard Donkor ◽  
Andrew E. Silva ◽  
Caroline Teske ◽  
Margaret Wallis-Duffy ◽  
Aaron Johnson ◽  
...  

PurposeWe tested the hypothesis that five daily sessions of visual cortex transcranial random noise stimulation would improve contrast sensitivity, crowded and uncrowded visual acuity in adults with amblyopia.MethodsNineteen adults with amblyopia (44.2 ± 14.9yrs, 10 female) were randomly allocated to active or sham tRNS of the visual cortex (active, n = 9; sham, n = 10). tRNS was delivered for 25 minutes across five consecutive days. Monocular contrast sensitivity, uncrowded and crowded visual acuity were measured before, during, 5 minutes and 30 minutes post stimulation on each day.ResultsActive tRNS significantly improved contrast sensitivity and uncrowded visual acuity for both amblyopic and fellow eyes whereas sham stimulation had no effect. An analysis of the day by day effects revealed large within session improvements on day 1 for the active group that waned across subsequent days. No long-lasting (multi-day) improvements were observed for contrast sensitivity, however a long-lasting improvement in amblyopic eye uncrowded visual acuity was observed for the active group. This improvement remained at 28 day follow up. However, between-group differences in baseline uncrowded visual acuity complicate the interpretation of this effect. No effect of tRNS was observed for amblyopic eye crowded visual acuity.ConclusionsIn agreement with previous non-invasive brain stimulation studies using different techniques, tRNS induced short-term contrast sensitivity improvements in adult amblyopic eyes, however, multiple sessions of tRNS did not lead to enhanced or long-lasting effects for the majority of outcome measures.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard Donkor ◽  
Andrew E. Silva ◽  
Caroline Teske ◽  
Margaret Wallis-Duffy ◽  
Aaron P. Johnson ◽  
...  

AbstractWe tested the hypothesis that five daily sessions of visual cortex transcranial random noise stimulation would improve contrast sensitivity, crowded and uncrowded visual acuity in adults with amblyopia. Nineteen adults with amblyopia (44.2 ± 14.9 years, 10 female) were randomly allocated to active or sham tRNS of the visual cortex (active, n = 9; sham, n = 10). Sixteen participants completed the study (n = 8 per group). tRNS was delivered for 25 min across five consecutive days. Monocular contrast sensitivity, uncrowded and crowded visual acuity were measured before, during, 5 min and 30 min post stimulation on each day. Active tRNS significantly improved contrast sensitivity and uncrowded visual acuity for both amblyopic and fellow eyes whereas sham stimulation had no effect. An analysis of the day by day effects revealed large within session improvements on day 1 for the active group that waned across subsequent days. No long-lasting (multi-day) improvements were observed for contrast sensitivity, however a long-lasting improvement in amblyopic eye uncrowded visual acuity was observed for the active group. This improvement remained at 28 day follow up. However, between-group differences in baseline uncrowded visual acuity complicate the interpretation of this effect. No effect of tRNS was observed for amblyopic eye crowded visual acuity. In agreement with previous non-invasive brain stimulation studies using different techniques, tRNS induced short-term contrast sensitivity improvements in adult amblyopic eyes, however, repeated sessions of tRNS did not lead to enhanced or long-lasting effects for the majority of outcome measures.


2018 ◽  
Author(s):  
Florian Herpich ◽  
Michael D Melnick ◽  
Sara Agosta ◽  
Krystel Huxlin ◽  
Duje Tadin ◽  
...  

Numerous behavioral studies have shown that visual function can improve with training, although perceptual refinements generally require weeks to months of training to attain. This, along with questions about long-term retention of learning, limits practical and clinical applications of many such paradigms. Here, we show for the first time that just 10 days of visual training coupled with transcranial random noise stimulation (tRNS) over visual areas causes dramatic improvements in visual motion perception. Relative to control conditions and anodal stimulation, tRNS-enhanced learning was at least twice as fast, and, crucially, it persisted for 6 months after the end of training and stimulation. Notably, tRNS also boosted learning in patients with chronic cortical blindness, leading to recovery of motion processing in the blind field after just 10 days of training, a period too short to elicit enhancements with training alone. In sum, our results reveal a remarkable enhancement of the capacity for long-lasting plastic and restorative changes when a neuromodulatory intervention is coupled with visual training.


2015 ◽  
Vol 8 (2) ◽  
pp. 319
Author(s):  
Rebecca Camilleri ◽  
Andrea Pavan ◽  
Antonella Veronese ◽  
Giuseppe Lo Giudice ◽  
Gianluca Campana

2001 ◽  
Vol 11 (3) ◽  
pp. 245-251 ◽  
Author(s):  
P.M. Puska ◽  
A.H.A. Tarkkanen

Purpose To examine changes in visual acuity (VA) and refraction in non-glaucomatous patients with unilateral exfoliation syndrome (EXS). Methods The best corrected values for VA (Snellen acuity cards) subjectively adjusted for refraction, and IOP were measured, and the development of lens opacities was examined in 46 non-glaucomatous patients with unilateral EXS. Results After five years the rate of conversion to bilateral exfoliation was 22% and to exfoliative glaucoma 30%. There was a significant decrease in VA in the exfoliative (E) eyes (median; QI, QIII, range: 1; 0.8, 1, 0.4-1.3 vs. 0.55; 0.4, 1, 0.05-1.4, p<0.0001) and the fellow, initially non-exfoliative (NE), eyes (1; 0.9, 1, 0.3–1.3 vs. 0.7; 0.5, 0.9, 0.1–1.4, p<0.0001) and a significant myopic change in refraction in the E eyes (+1.02 ± 2.48 vs. +0.11 ± 3.06, p=0.0001) and the NE eyes (+0.99 ± 2.25 vs. +0.43 ± 2.55 D, p<0.01). At study entry the difference in refraction between the fellow eyes (refraction in the NE eye – refraction in the E eye) was −0.27 ± 1.00D. After five years it was +0.32 ± 1.44 (p 0.016), reflecting greater myopic changes in the E eyes. The main type of lens opacification was nuclear sclerosis. Conclusions In five years, significant decreases in VA and myopic shifts in refraction occurred in the E and fellow eyes. The E eyes showed significantly greater myopic changes than the fellow eyes; the cause was clearly nuclear sclerosis, which must be taken into account in the long-term management of patients with EXS.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
F. Lopez-Lopez ◽  
F. Gomez-Ulla ◽  
M. J. Rodriguez-Cid ◽  
L. Arias

Purpose. To evaluate efficacy of intravitreal triamcinolone (IVT) and bevacizumab (IVB) as adjunctive treatments to panretinal photocoagulation (PRP) in proliferative diabetic retinopathy (PDR). Methods. In 60 eyes of 45 patients with PDR, PRP (PRP group), PRP with IVT (IVT group), or PRP with IVB (IVB group) was performed. Regression of new vessels (NV), changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), and contrast sensitivity at 1,2, and 6 months were evaluated. Results. Initial mean numbers of active NV and BCVA were 3.45 and 67.35 in the PRP group, 4.35 and 76.65 in the IVT group, and 4.79 and 75.53 in the IVB group. At the 6-month follow-up, numbers of active NV were 2.5 (P=0.064), 1.11 (P=0.000), and 1.11 (P=0.002), and there was a mean loss of 2,6 (P=0.055), 3.9 (P=0.011), and 0.9 letters (P=0.628) in the PRP, IVT, and IVB groups, respectively. Changes in CMT in the PRP and IVT groups were not significant, but significantly increased in the IVB group (P=0.032). Contrast sensitivity remained stable in PRP and IVB groups and slightly decreased in IVT group. Conclusions. Adjunctive use of both triamcinolone and bevacizumab with PRP lead to a greater reduction of active NV than PRP alone in PDR, although no differences were seen between the two of them.


Author(s):  
Kirti Singh ◽  
Mainak Bhattacharyya ◽  
Abhishek Goel ◽  
Ritu Arora ◽  
Nikhil Gotmare ◽  
...  

Purpose: Literature is relatively silent on safety profile and predictability of orthokeratology lenses in terms of myopia correction and prevention of further progression, especially in semi-tropical countries; this study was designed to fill this gap. Methods: This prospective, intervention case series enrolled 30 eyes of 30 patients with myopia up to –5.5 diopters (D). Patients were randomized into two groups of 15 each; the study group was prescribed overnight orthokeratology (OK) lenses, while the control group used daily wear conventional soft contact lenses. Follow-up examinations were performed after 1 h and 6 h, and then at 1, 7, 15, 30 days, and 4 months post lens wear. Uncorrected visual acuity (UCVA), contrast sensitivity, keratometry, central corneal thickness (CCT), and tear film break up time (TBUT) were evaluated at each follow-up examination. Results: All patients attained a visual acuity of 0.00 Logarithm of the Minimum Angle of Resolution (logMAR) after one week of lens use, which was maintained throughout the study period. While patients allotted to the study group had a gain of 8.1 Snellen lines (UCVA), those in the control group gained 8.9 lines (BCVA) at the end of follow-up period. In the OK group, cornea showed a flattening of 0.8 D (mean keratometry) after single overnight usage of OK lens and overall flattening of 1.2 D compared to baseline, at the end of four months. The change in contrast sensitivity, corneal endothelial specular count, axial length and tear film status was not significant in either group. Conclusion: Orthokeratology is an effective and safe modality to correct moderate myopia in motivated young adults. No side effects were encountered after a short-term follow-up in participants who resided in semi-tropical environments.


2021 ◽  
Vol 2 (4) ◽  
pp. 228-232
Author(s):  
Kumar Aalok ◽  

AIM: To study the effects of blunt trauma of eye on visual acuity and retinal nerve fiber layer (RNFL). METHODS: A prospective observational study was done on the patients of a road traffic accident (RTA) having blunt trauma injury of the eye from august 2018 to July 2019 at the Department of Ophthalmology, Hind Institute of Medical Sciences, Barabanki. Patients between the age group of 20 to 65 years undergoing RTA with ocular complaints were included in this study. Colour vision, contrast sensitivity, and best-corrected visual acuity (BCVA) were recorded, RNFL analysis was done through OCT. RESULTS: A total of 108 patients were enrolled in this study and were grouped as 54 cases and 54 controls. The mean age was 43±2.3 years with 11 (20.37%) females and 43 (79.6%) males in the case group. At initial visit after RTA, the difference between color vision, contrast sensitivity and BCVA between right and left eyes of cases and controls were significant. After a follow up of 3mo only significant difference was noted in contrast sensitivity between cases and control groups. Change in color vision and BCVA after 3mo was insignificant. Similarly, an initial significant difference was noted in mean RNFL thickness between cases and control groups, but after follow up of 3mo mean RNFL thickness difference was significant only in superior and temporal quadrants. CONCLUSION: RTA or blunt trauma of eye can lead to persistent RNFL thinning and decreased visual function.


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