Asia Arvo 2007, 508 (322) B149

Cortical enhancement of Habitual VA of subjects using Neural Vision Correction Technology

MethodsA total of 43 subjects (21.7 ± 7) with a habitual VA of between 0.00 (6/6) and 0.30 (6/12) logMAR units in either eye participated in this study. Visual functions including Photopic High (PHVA) and Low Contrast VA (PLVA), Mesopic High Contrast VA (MHVA) and contrast sensitivity were assessed using ETDRS charts and Sine Wave Contrast Test (SWCT). All subjects were given a pre-treatment NVC conditioning before embarking on a 30 treatment sessions. Persistence evaluation was done 3 months post-treatment.

IntroductionNeural Vision Correction (NVC) technology has been shown to enhance the blurry image interpretations by amblyopes1 and low myopes2,3, early presbyope4 and patients who had refractive surgery5,6.The purpose of this study is to determine whether NVC will refine visual interpretation for subjects who had habitual VA close to but not better than 6/6.

ConclusionThe NVC technology enhanced the habitual VA and contrast sensitivity of young subjects. Highly motivated subjects with demand of greater clarity of vision could benefit from this treatment.

References1. Polat U, Ma-Naim T, Belkin M, Sagi D. Improving vision in adult amblyopia by perceptual

learning. Proc Natl Acad Sci U S A. 2004; 101(17):6992-72. Donald Tan, Bill Chan, Frederick Tey, Lionel Lee, Pilot Study To Evaluate The Efficacy of

Neural Vision Correction™ (NVC™) Technology For Vision Improvement in Low Myopia, ARVO 2004

3. Donald Tan, Enhancement of Visual Acuity and Contrast Sensitivity in Low Myopes Through the Use of Neural Vision Correction (NVC) Technology Is Maintained Over One Year, APAO 2005

4. Donald Tan, Improving VA and CSF in Subjects with Low Degrees of Myopia and Early Presbyopia using Neural Vision Correction (NVC) Technology, APAO 2006

5. Donald Tan, What Is Still Lacking in Refractive Surgery Is the Role of Neuroprocessing, AAO 2005

6. Lim KL, Fam HB. NeuroVision treatment for low myopia following LASIK regression. J Refract Surg. 2006:406-8

Results

Spatial FrequencySpatial Frequency

Post-Treatment

3mths Persistence

Baseline

n = 20 Treatment Group

Mean PHVA, PLVA, MHVA before treatment 0.06, 0.21, 0.19(±0.02, ±0.02, ±0.02)

Mean PHVA, PLVA, MHVA after treatment -0.05, 0.14, 0.08(±0.02, ±0.02, ±0.02)

PHVA, PLVA, MHVA improvement post treatment

0.11, 0.07, 0.11(±0.03, ±0.02, ±0.02)

Mean PHVA, PLVA, MHVA 3 mth after treatment

-0.05, 0.19, 0.09(±0.03, ±0.05, ±0.04)

Mean cycloplegic spherical equivalence refraction before treatment

-2.70D(±0.49)

Mean cycloplegic spherical equivalence refraction after treatment

-2.16D(±0.58)

Percentage with better than 0.00 logMAR VA (6/6) post treatment

70%

ResultsTwenty eyes of the 11 subjects who completed the study were analysed. There were statistical significant improvements in VA and contrast sensitivity at post-treatment.

A total of 32 subjects did not complete the study; whereby 25 subjects (78%) were unmotivated after the initial treatments, and the other 7 subjects (22%) had to drop out of the study due to time constraints.

The mean habitual PHVA improved from 0.06 (0 to 0.28) to -0.05 (-0.22 to 0) logMAR units, while 70% of the eyes had better than 6/6 PHVA at post-treatment. Mean PLVA and MHVA improved from 0.21 (±0.02) and 0.19 (±0.02) to 0.14 (±0.02) and 0.08 (±0.02) logMAR units respectively. Post-treatment VA improvements were +0.11 (±0.025), +0.07 (±0.016) and +0.10 (±0.022) logMAR units for PHVA, PLVA and MHVA respectively (Table 1).

Statistical significant improvements were found in contrast sensitivity. Improvements of 75%, 46%, 33%, 60% and 32% was found in 1.5cpd, 3cpd, 6cpd and 18cpd respectively (Figure 1).

There were no significant differences in persistence VA and persistence contrast sensitivity. No significant difference was found in cycloplegic spherical equivalence refraction before and after treatment.

Asia Arvo 2007, 508 (322) B149

Chris NG 1, Wilfred TANG 1, Donald TAN 2, Nir ELLENBOGAN 3

1 Singapore Polytechnic Optometry Centre 2 Singapore Eye Research Institute 3 Neuro-Vision

Table 1 Summary of Visual Functions of subjects

Figure 1 Summary of Contrast Sensitivity Functions