To evaluate the improvement in vision and Contrast sensitivity using a computer based software Revital Vision therapy in patients with Corneal thinning (Keratoconus) after Collagen cross linking procedure ,after Post laser power correction and after cataract surgery with multifocal IOLs

Not yet recruiting

Conditions: Vision sensitivity deficiencies,

Registration Number: CTRI/2022/05/042734

Lead Sponsor: Medical Research Foundation Sankara Nethralya

Brief Summary: **Background:**

A Study by Durrie D et al showed that the NeuroVision technology is effective in improving UCVA and unaided CSF in low myopia and early presbyopia1. Another study showed the induced longer-range facilitation is a result of internal response transmission. This results in cascade of neural reactions which induce plasticity in the cortex. The existence of neural plasticity in an adult brain is proven, i.e., Visual improvement in adults can be achieved by perceptual learning3. It was shown that significant neural activity can be achieved by applying "lateral masking technique" using Gabor Patches. But there seems to be no data on the stability of the improved visual acuity and contrast sensitivity for a longer duration. Also clinical trials have not yet been done on subjects after collagen cross linking.

**Aims and objectives:**

To assess the efficacy of Gabor patch based treatment in improving best corrected visual acuity and contrast sensitivity function in patients after collagen cross linking, refractive surgery and phacoemulsification with extended depth of focus or multifocal IOLs. To evaluate percentage of patients improving distance and near BCVA by at least 1 line at study end (8-12 weeks) and after one year (follow up) in comparison to baseline Percentage of patients improving CSF by at least 50% in VectorVision CSV-1000 at study end (8-12weeks) and after one year (follow up) in comparison to baseline. Percentage of patients improving Non-Strabismic Binocular Vision Anomalies at the study end (8-12 weeks) and after one year (follow up) in comparison to baseline Percentage of patients improving self-reported QoV questionnaire at study end (8-12 weeks) and after one year (follow up) in comparison to baseline.

**Expected results:**

In treatment group, we expect an improvement in distance and near BCVA by at least 4 line, CSF by at least 50%, self-reported Quality of vision questionnaire by the end of 34weeks. In Placebo group, we expect no improvement

**Reference**:

1.    Durrie, D., & McMinn, P. S. (2007). Computer-based primary visual cortex training for treatment of low myopia and early presbyopia. Transactions of the American Ophthalmological Society, 105, 132.

2.    Polat, U., & Sagi, D. (1994). Spatial interactions in human vision: from near to far via experience-dependent cascades of connections. Proceedings of the National Academy of Sciences, 91(4), 1206-1209.

3.    Polat U., Mizobe, K., Kasamatsu, T., Norcia A.M. (1998). Collinear stimuli regulate visual responses depending on Cellâ€™s contrast threshold. Nature, 391, 580-584.

Detailed Description: Not available

Recruitment & Eligibility

Status: Not Yet Recruiting

Sex: All

Target Recruitment: 180

Inclusion Criteria

Post Lasik Surgery(Cohort 1) Age for Post Refractive surgery 18-35 years Recruitment after 1 month of after Refractive surgery (LASIK/ EPI LASIK) All subjects with best-corrected visual acuity of 6/12 or better Subjects with subnormal contrast sensitivity Minimum requirement- laptop with a 15-inch screen with mouse and an internet connection at home Post Collagen Cross-Linking(Cohort 2) Age for Post Collagen Cross-Linking Surgery 10 years onwards Recruitment: Patients with stable keratoconus for over 12 months, and patients after 3 months of Collagen Cross-Linking surgery All subjects with best-corrected visual acuity of 6/12 or better Subjects with subnormal contrast sensitivity Minimum requirement- laptop with a 15-inch screen with mouse and an internet connection at home.
Post Cataract Surgery EDOF or multifocal IOLs(Cohort 3) Age for Post Cataract surgery 40-75 yrs Recruitment 4 weeks after multifocal IOL implantation.
All subjects with best-corrected visual acuity of 6/12 or better Subjects with subnormal contrast sensitivity Minimum requirement- laptop with a 15-inch screen with mouse and an internet connection at home.

Exclusion Criteria

Post Lasik Surgery(Cohort 1) Presence of ocular co morbidities Subject with severe untreated attention disorder Subject who suffers from chronic migraine Epilepsy Post Collagen Cross-Linking(Cohort 2) Presence of ocular co morbidities Subject with severe untreated attention disorder Subject who suffers from chronic migraine Epilepsy Post Cataract Surgery EDOF or multifocal IOLs (Cohort 3) Presence of ocular co morbidities Subject with severe untreated attention disorder Subject who suffers from chronic migraine Epilepsy.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Outcome measure: Improvement in Best Corrected Visual Acuity and Contrast Sensitivity Function.	Evaluated at 12 weeks , 6 months and at the end of one year
Change in Best Corrected Visual Acuity and Contrast Sensitivity Function in patients after Refractive surgery, Collagen cross linking and Phacoemulsification with extended depth of focus or multifocal IOLs	Evaluated at 12 weeks , 6 months and at the end of one year

Secondary Outcome Measures

Name	Time	Method
To improve self-reported Quality of Vision, and overall binocular vision.	12 weeks

Trial Locations

Locations (1): Medical Research Foundation Sankara Nethralaya
🇮🇳
Chennai, TAMIL NADU, India
Medical Research Foundation Sankara Nethralaya
🇮🇳Chennai, TAMIL NADU, India
Dr Rachapalle Reddi Sudhir
Principal investigator
044-28156172
drrrs@snmail.org