This work was supported by Natural Science Foundation of Beijing Municipality (7202229).

The present study enrolled consecutive myopia patients in the Department of Ophthalmology of Peking University Third Hospital. The research protocol was approved by the Peking University Third Hospital Ethics Committee, and informed consent was obtained from each participant.
1. Patient preparation
<ol>
	<li>Use the following initial inclusion criteria to enroll subjects: myopia subjects aged 17-45 years old.</li>
	<li>Use the following exclusion criteria: any history of ocular diseases, including keratitis, glaucoma, cataract, retinal and macular diseases, that significantly impact corrected distance visual acuity (CDVA). Evaluate uncorrected distance visual acuity (using the standard logarithmic VA chart), dominant eye, intraocular pressure, slit lamp, corneal topography, fundus photography, automatic computer optometry, cycloplegic subjective refraction, and CDVA. Exclude participants with keratoconus, cloudy cornea, or retinal abnormalities, including retinal breaks, retinal vascular inflammation, congenital retinal and macular diseases, or monocular CDVA worse than zero (based on the standard logarithmic VA chart).</li>
	<li>Set up the DVA test components, including test distance, environment, hardware, software, movement mode, and rules as follows:
	<ol>
		<li>For test distance and environment, set the test distance according to the size of the screen and examination requirements. 
		&#8203;NOTE: Here, DVA was assessed at 2.5 m in a quiet and bright room (luminance 15-30 lux).</li>
		<li>For hardware, present the optotype with a 24 inch in-plane switching (IPS) or twisted nematic (TN) screen (refresh rate, 60 to 144 Hz; response rate less than 5 ms).</li>
		<li>Ensure that the software is designed to display the optotype according to the preset velocity and size. Use the dynamic optotype as the letter E designed according to the standard logarithmic visual chart with four opening directions: upper, left, lower, and right. Ensure that the visual angle of the motion optotype presented at the test distance equals the optotype with the decimal size in the standard logarithmic visual chart. Set the color of the letter E to black, with a white background. Express the velocity of motion as the viewing angle changes per second.</li>
		<li>Movement mode: during the test, ensure that the optotype with a specific size and velocity appears in the middle of the screen&#39;s left side, moves horizontally to the right side, and then disappears.</li>
		<li>Test rule: Ask the subjects to identify the opening direction of the visual target. Test the minimum visual target at a certain speed that the subjects can recognize.</li>
	</ol>
	</li>
</ol>
2. Subjective refraction
NOTE: The result of subjective cycloplegic refraction is the basis for the eyeglasses prescription to correct the refractive error in myopia subjects.
<ol>
	<li>Perform automatic computer optometry as the primary data for subjective cycloplegic refraction and measure the pupil distance.</li>
	<li>Examine one eye at a time and occlude the other eye.
	<ol>
		<li>First, achieve the maximum plus to maximum visual acuity: fogging with +0.75 - +1.0 D lens, inducing a visual acuity of 0.3-0.5 (decimal visual acuity). Next, gradually decrease the positive lens in a 0.25 D step. Use a Lancaster red-green test to tune the accurate spherical diopter. Add more negative/positive lens if the patients report that the letter seen against the red/green background is clearer. 
		NOTE: The primary spherical diopter is obtained after the above step.</li>
	</ol>
	</li>
	<li>Refine the cylinder axis.
	<ol>
		<li>Place the Jackson cross cylinder device in the &#34;axis&#34; position so that the thumb-wheel&#39;s connecting line is parallel to the axis of the astigmatism. Rotate the thumb-wheel and ask the subject to compare the clearness between both sides. Turn the cylinder axis toward the red dots on the cross cylinder in the side with clearer vision. Repeat the binary comparison until the endpoint.</li>
	</ol>
	</li>
	<li>Refine cylinder power.
	<ol>
		<li>Turn the Jackson cross cylinder device so that the thumb-wheel&#39;s connecting line is at 45&#176; to the astigmatism axis. Rotating the thumb-wheel, ask the subject to compare the clearness between both sides. If the patient reports clearer placement of the cross cylinder red/white dots connecting line along the cylinder axis, add a negative/positive lens, respectively. Repeat the binary comparison until the endpoint.</li>
	</ol>
	</li>
	<li>For the second maximum plus to maximum visual acuity, repeat the Lancaster red-green test to tune the accurate spherical diopter.</li>
	<li>For binocular balance, apply a vertical prism of 6&#916; before one eye to dissociate the binocular vision. Balance the clearness of the optotypes between both eyes.</li>
</ol>
3. Dynamic visual acuity test
NOTE: DVA was measured binocularly with refractive errors fully corrected with eyeglasses in the present study.
<ol>
	<li>Test settings
	<ol>
		<li>Adjust the test distance according to the requirements. Adjust the seat to make the subject&#39;s sight at the screen&#39;s midpoint level. Ensure the subject wears the distance vision corrected eyeglasses binocularly.</li>
	</ol>
	</li>
	<li>Test parameter configurations
	<ol>
		<li>Set the optotype moving velocity and the initial optotype size.</li>
	</ol>
	</li>
	<li>For the pretest, display five optotypes with a randomized opening direction to guide the subjects to understand the test mode.</li>
	<li>Formal test
	<ol>
		<li>Start the test at the size 3-4 lines bigger than the best-corrected distance visual acuity. Display the optotype with randomized opening directions.</li>
		<li>Ask the subject to identify the opening direction of the moving optotype. Present the next optotype after the subject&#39;s response. Present eight optotypes for a certain size. If five out of eight optotypes are identified correctly, adjust the optotype to one size smaller. Repeat the above procedures until the size for which the subject can identify less than five optotypes is obtained.</li>
	</ol>
	</li>
	<li>Record the minimum size (A, decimal VA) that subjects can recognize (five out of eight optotypes are identified correctly) and the number (b) of optotypes recognized for one size smaller than A.</li>
	<li>DVA calculation
	<ol>
		<li>Present eight optotypes for each size so that each identified optotype gains 0.1/8 visual acuity. Calculate DVA according to the algorithm of logarithmic visual acuity, as shown by Eq (1); see step 3.5 for an explanation of A and b: 
		<img alt="Equation 1" src="/files/ftp_upload/63864/63864eq01v2.jpg" style="margin: auto;" /> (1) 
		NOTE: In the present study, optotypes of 40 and 80 dps were examined in order. Previous studies have reported that people could apply smooth pursuit when observing dynamic objects moving at 30-60 dps, whereas observing objects moving faster than 60 dps involves head movement and saccade16,17. Thus, two motion speeds of 40 and 80 dps were selected.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Nakatsuka, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+static+visual+acuity+on+dynamic+visual+acuity:+a+pilot+study.">Effect of static visual acuity on dynamic visual acuity: a pilot study.</a> Perceptual and Motor Skills. 103 (1), 160-164 (2006).</li><li>Ueda, T., Nawa, Y., Okamoto, M., Hara, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+pupil+size+on+dynamic+visual+acuity.">Effect of pupil size on dynamic visual acuity.</a> Perceptual and Motor Skills. 104 (1), 267-272 (2007).</li><li>Ao, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Significant+improvement+in+dynamic+visual+acuity+after+cataract+surgery:+a+promising+potential+parameter+for+functional+vision.">Significant improvement in dynamic visual acuity after cataract surgery: a promising potential parameter for functional vision.</a> PLoS One. 9 (12), 115812 (2014).</li><li>Ren, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+standardized+test+system+to+evaluate+dynamic+visual+acuity+post+trifocal+or+monofocal+intraocular+lens+implantation:+a+multicenter+study.">A novel standardized test system to evaluate dynamic visual acuity post trifocal or monofocal intraocular lens implantation: a multicenter study.</a> Eye. 34 (12), 2235-2241 (2020).</li><li>Dacey, D. M., Peterson, B. B., Robinson, F. R., Gamlin, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fireworks+in+the+primate+retina:+in+vitro+photodynamics+reveals+diverse+LGN-projecting+ganglion+cell+types.">Fireworks in the primate retina: in vitro photodynamics reveals diverse LGN-projecting ganglion cell types.</a> Neuron. 37 (1), 15-27 (2003).</li><li>Skottun, B. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+few+words+on+differentiating+magno-+and+parvocellular+contributions+to+vision+on+the+basis+of+temporal+frequency.">A few words on differentiating magno- and parvocellular contributions to vision on the basis of temporal frequency.</a> Neuroscience and Biobehavioral Reviews. 71, 756-760 (2016).</li><li>Janky, K. L., Zuniga, M. G., Ward, B., Carey, J. P., Schubert, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Canal+plane+dynamic+visual+acuity+in+superior+canal+dehiscence.">Canal plane dynamic visual acuity in superior canal dehiscence.</a> Otology &amp; Neurotology. 35 (5), 844-849 (2014).</li><li>Gimmon, Y., Schubert, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vestibular+testing-rotary+chair+and+dynamic+visual+acuity+tests.">Vestibular testing-rotary chair and dynamic visual acuity tests.</a> Advances in Oto-Rhino-Laryngology. 82, 39-46 (2019).</li><li>Verbecque, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+visual+acuity+test+while+walking+or+running+on+treadmill:+Reliability+and+normative+data.">Dynamic visual acuity test while walking or running on treadmill: Reliability and normative data.</a> Gait &amp; Posture. 65, 137-142 (2018).</li><li>Verbecque, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feasibility+of+the+clinical+dynamic+visual+acuity+test+in+typically+developing+preschoolers.">Feasibility of the clinical dynamic visual acuity test in typically developing preschoolers.</a> European Archives of Oto-Rhino-Laryngology. 275 (5), 1343-1348 (2018).</li><li>Morgan, I. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+epidemics+of+myopia:+Aetiology+and+prevention.">The epidemics of myopia: Aetiology and prevention.</a> Progress in Retinal and Eye Research. 62, 134-149 (2018).</li><li>Lewerenz, D., Blanco, D., Ratzlaff, C., Zodrow, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+prism+on+preferred+retinal+locus.">The effect of prism on preferred retinal locus.</a> Clinical and Experimental Optometry. 101 (2), 260-266 (2018).</li><li>Lin, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+defocus+with+single-vision+eyeglass+lenses+in+myopic+children.">Peripheral defocus with single-vision eyeglass lenses in myopic children.</a> Optometry and Vision Science. 87 (1), 4-9 (2010).</li><li>Backhouse, S., Fox, S., Ibrahim, B., Phillips, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+refraction+in+myopia+corrected+with+eyeglasss+versus+contact+lenses.">Peripheral refraction in myopia corrected with eyeglasss versus contact lenses.</a> Ophthalmic and Physiological Optics. 32 (4), 294-303 (2012).</li><li>Bakaraju, R. C., Ehrmann, K., Ho, A., Papas, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pantoscopic+tilt+in+eyeglass-corrected+myopia+and+its+effect+on+peripheral+refraction.">Pantoscopic tilt in eyeglass-corrected myopia and its effect on peripheral refraction.</a> Ophthalmic and Physiological Optics. 28 (6), 538-549 (2008).</li><li>Hasegawa, T., Yamashita, M., Suzuki, T., Hisa, Y., Wada, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Active+linear+head+motion+improves+dynamic+visual+acuity+in+pursuing+a+high-speed+moving+object.">Active linear head motion improves dynamic visual acuity in pursuing a high-speed moving object.</a> Experimental Brain Research. 194 (4), 505-516 (2009).</li><li>Meyer, C. H., Lasker, A. G., Robinson, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+upper+limit+of+human+smooth+pursuit+velocity.">The upper limit of human smooth pursuit velocity.</a> Vision Research. 25 (4), 561-563 (1985).</li><li>Fogt, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+negative+directional+aftereffect+associated+with+adaptation+to+the+prismatic+effects+of+eyeglass+lenses.">The negative directional aftereffect associated with adaptation to the prismatic effects of eyeglass lenses.</a> Optometry and Vision Science. 77 (2), 96-101 (2000).</li><li>Chang, S. T., Liu, Y. H., Lee, J. S., See, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparing+sports+vision+among+three+groups+of+soft+tennis+adolescent+athletes:+Normal+vision,+refractive+errors+with+and+without+correction.">Comparing sports vision among three groups of soft tennis adolescent athletes: Normal vision, refractive errors with and without correction.</a> Indian Journal of Ophthalmology. 63 (9), 716-721 (2015).</li><li>Dacey, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiology,+morphology+and+spatial+densities+of+identified+ganglion+cell+types+in+primate+retina.">Physiology, morphology and spatial densities of identified ganglion cell types in primate retina.</a> Ciba Foundation Symposium. 184, 12-34 (1994).</li><li>Lee, M. W., Nam, K. Y., Park, H. J., Lim, H. B., Kim, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Longitudinal+changes+in+the+ganglion+cell-inner+plexiform+layer+thickness+in+high+myopia:+a+prospective+observational+study.">Longitudinal changes in the ganglion cell-inner plexiform layer thickness in high myopia: a prospective observational study.</a> British Journal of Ophthalmology. 104 (5), 604-609 (2020).</li><li>Seo, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ganglion+cell-inner+plexiform+layer+and+retinal+nerve+fiber+layer+thickness+according+to+myopia+and+optic+disc+area:+a+quantitative+and+three-dimensional+analysis.">Ganglion cell-inner plexiform layer and retinal nerve fiber layer thickness according to myopia and optic disc area: a quantitative and three-dimensional analysis.</a> BMC Ophthalmology. 17 (1), 22 (2017).</li><li>Zhang, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=eyeglass+wear,+and+risk+of+bicycle+accidents+among+rural+Chinese+secondary+school+students:+the+Xichang+Pediatric+Refractive+Error+Study+report+no.+7.">eyeglass wear, and risk of bicycle accidents among rural Chinese secondary school students: the Xichang Pediatric Refractive Error Study report no. 7.</a> Archives of Ophthalmology. 127 (6), 776-783 (2009).</li></ol>

The authors declare that they have no competing interests.

DVA is a promising indicator to assess visual function, which might better reflect actual vision in daily life. Myopic patients could have corrected, normal SVA, but their DVA might be affected. This study demonstrates a method to examine the DVA in myopic subjects with eyeglass correction accurately and analyzes its correlation with optometric parameters, including refraction, accommodation, and the dominant eye. The results indicated that DVA at 40 dps was superior to that at 80 dps. The closer the refraction state is ...

Current visual assessment mainly focuses on static vision, including static visual acuity (SVA), visual field, and contrast sensitivity. In daily life, either the object or the observer is often in motion rather than being stationary. Therefore, SVA may not sufficiently reflect visual function in daily lives, especially when objects are moving at high speeds, such as during sports and driving1. DVA defines the ability to identify the details of moving optotypes1,2, which might reflect real-life situations better and be more sensitive to visual disturbance and improvement3,4. Moreover, as magnocellular (M) ganglion cells located mainly in the peripheral retina primarily transmit high temporal frequency signals, DVA might reflect visual signal transmission differently from SVA5,6. The DVA test (DVAT) can be mainly divided into two types: static- and moving-object DVATs. While the static-object DVAT demonstrates the vestibule-ocular reflex7,8,9,10, the moving-object DVAT is commonly applied in clinical ophthalmology to detect visual acuity in the identification of moving targets3,4.
The prevalence of myopia has rapidly increased in recent decades, especially in Asian countries11. Myopia has an essential impact on static uncorrected distance visual acuity, which could be corrected with various lenses. Eyeglasses are mostly used among myopia patients due to accessibility and convenience. However, eyeglasses, especially high myopia lenses, have obvious peripheral defocus and prism effects that cause unclear and skewed images to be observed through the peripheral region12,13,14,15. For a static optotype, the subject commonly uses the central area of eyeglasses that could obtain a clear vision. However, the moving target could easily move out of the eyeglasses&#39; clearest point. Thus, with eyeglass correction, myopic subjects might have normal SVA and affected DVA. However, no research has been performed to investigate the impact of myopia diopter on DVA in populations with eyeglasses.
This study demonstrates a method to examine DVA in eyeglass-corrected myopia patients and aimed to explore the impact of myopia diopter on moving-object binocular DVA in eyeglass-corrected patients. The research provides a basis for accurately interpreting DVAT in clinical ophthalmology considering the impact of eyeglasses and evidence on the influence of corrected myopia on motion-related activities.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Automatic computer optometry</td>
			<td>TOPCON</td>
			<td>KR8100</td>
			<td></td>
		</tr>
		<tr>
			<td>Corneal topography</td>
			<td>OCULUS</td>
			<td>Pentacam</td>
			<td></td>
		</tr>
		<tr>
			<td>Dynamic visual acuity test design software</td>
			<td>Mathworks</td>
			<td>matlab 2017b</td>
			<td></td>
		</tr>
		<tr>
			<td>Fundus photography</td>
			<td>Optos</td>
			<td>Daytona</td>
			<td></td>
		</tr>
		<tr>
			<td>Matlab</td>
			<td>Mathworks</td>
			<td>2017b</td>
			<td></td>
		</tr>
		<tr>
			<td>Noncontact tonometry</td>
			<td>CANON</td>
			<td>TX-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Phoropter</td>
			<td>&#160;NIDEK</td>
			<td>RT-5100</td>
			<td></td>
		</tr>
		<tr>
			<td>scientific statistical software</td>
			<td>IBM</td>
			<td>SPSS 26.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Slit lamp</td>
			<td>Koniz</td>
			<td>IM 900</td>
			<td></td>
		</tr>
	</tbody>
</table>

binocular dynamic visual acuity in eyeglass-corrected myopic patients

Current clinical visual assessment mainly focuses on static vision. However, static vision may not sufficiently reflect real-life visual function as moving optotypes are frequently observed daily. Dynamic visual acuity (DVA) might reflect real-life situations better, especially when objects are moving at high speeds. Myopia impacts static uncorrected distance visual acuity, conveniently corrected with eyeglasses. However, due to peripheral defocus and prism effects, eyeglass correction might affect DVA. The present research demonstrates a standard method to examine eyeglass-corrected DVA in myopia patients, and aimed to explore the influence of eyeglass correction on DVA. 
Initially, standard subjective refraction was performed to provide the eyeglass prescription to correct the refractive error. Then, binocular distance vision-corrected DVA was examined using the object-moving DVA protocol. Software was designed to display the moving optotypes according to the preset velocity and size on a screen. The optotype was the standard logarithmic visual chart letter E and moves from the middle of the left to the right side horizontally during the test. Moving optotypes with randomized opening direction for each size are displayed. The subjects were required to identify the opening direction of the optotype, and the DVA is defined as the minimum optotype that subjects could recognize, calculated according to the algorithm of logarithmic visual acuity.
Then, the method was applied in 181 young myopic subjects with eyeglass-corrected-to-normal static visual acuity. Dominant eye, cycloplegic subjective refraction (sphere and cylinder), accommodation function (negative and positive relative accommodation, binocular cross-cylinder), and binocular DVA at 40 and 80 degrees per second (dps) were examined. The results showed that with increasing age, DVA first increased and then decreased. When myopia was fully corrected with eyeglasses, a worse binocular DVA was associated with more significant myopic refractive error. There was no correlation between the dominant eye, accommodation function, and binocular DVA.

Subject examinations 
For the enrolled subjects, accommodation function, including negative relative accommodation (NRA), accommodation response (binocular cross-cylinder (BCC)), and positive relative accommodation (PRA), were examined in the mentioned order. Binocular DVA at 40 dps and 80 dps was tested with distance visual acuity-corrected eyeglasses based on subjective refraction.
Statistical analysis 
Statistical analysis was performed using scie...

Watch this Scientific Journal Video about Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients at JoVE.com

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

The present research demonstrates a method to accurately examine dynamic visual acuity (DVA) in myopic subjects with eyeglass correction. Further analysis indicated that the closer the refraction state to emmetropia, the better the eyeglass-corrected binocular DVA is at both 40 and 80 degrees per second.

Current clinical visual assessment mainly focuses on static vision. However, static vision may not sufficiently reflect real-life visual function as ...

binocular-dynamic-visual-acuity-in-eyeglass-corrected-myopic-patients

Research

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Medicine

2.4K Views.  Peking University Third Hospital. The present research demonstrates a method to accurately examine dynamic visual acuity (DVA) in myopic subjects with eyeglass correction. Further analysis indicated that the closer the refraction state to emmetropia, the better the eyeglass-corrected binocular DVA is at both 40 and 80 degrees per second.

Video: Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Driving Simulation in the Clinic: Testing Visual Exploratory Behavior in Daily Life Activities in Patients with Visual Field Defects

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily life, despite similar visual deficits. We assume this could be due to variable development of compensatory strategies such as altered visual scanning behavior. Scanning compensatory therapy (SCT) is studied as part of the visual training after infarction next to vision restoration therapy. SCT consists of learning to make larger eye movements into the blind field enlarging the visual field of search, which has been proven to be the most useful strategy1, not only in natural search tasks but also in mastering daily life activities2. Nevertheless, in clinical routine it is difficult to identify individual levels and training effects of compensatory behavior, since it requires measurement of eye movements in a head unrestrained condition. Studies demonstrated that unrestrained head movements alter the visual exploratory behavior compared to a head-restrained laboratory condition3. Martin et al.4 and Hayhoe et al.5 showed that behavior demonstrated in a laboratory setting cannot be assigned easily to a natural condition. Hence, our goal was to develop a study set-up which uncovers different compensatory oculomotor strategies quickly in a realistic testing situation: Patients are tested in the clinical environment in a driving simulator. SILAB software (Wuerzburg Institute for Traffic Sciences GmbH (WIVW)) was used to program driving scenarios of varying complexity and recording the driver's performance. The software was combined with a head mounted infrared video pupil tracker, recording head- and eye-movements (EyeSeeCam, University of Munich Hospital, Clinical Neurosciences).
The positioning of the patient in the driving simulator and the positioning, adjustment and calibration of the camera is demonstrated. Typical performances of a patient with and without compensatory strategy and a healthy control are illustrated in this pilot study. Different oculomotor behaviors (frequency and amplitude of eye- and head-movements) are evaluated very quickly during the drive itself by dynamic overlay pictures indicating where the subjects gaze is located on the screen, and by analyzing the data. Compensatory gaze behavior in a patient leads to a driving performance comparable to a healthy control, while the performance of a patient without compensatory behavior is significantly worse. The data of eye- and head-movement-behavior as well as driving performance are discussed with respect to different oculomotor strategies and in a broader context with respect to possible training effects throughout the testing session and implications on rehabilitation potential.

Patients with visual deficits after stroke report about different constraints in daily life most likely due to variable compensatory strategies, which are difficult to differentiate in clinical routine. We present a clinical set-up which allows measurement of different compensatory head- and eye-movement-strategies and evaluating their effects on driving performance.

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily ...

Development of an Audio-based Virtual Gaming Environment to Assist with Navigation Skills in the Blind

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio based cues and set within the context of a video game metaphor, users gather relevant spatial information regarding a building's layout. This allows the user to develop an accurate spatial cognitive map of a large-scale three-dimensional space that can be manipulated for the purposes of a real indoor navigation task. After game play, participants are then assessed on their ability to navigate within the target physical building represented in the game. Preliminary results suggest that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building as indexed by their performance on a series of navigation tasks. These tasks included path finding through the virtual and physical building, as well as a series of drop off tasks. We find that the immersive and highly interactive nature of the AbES software appears to greatly engage the blind user to actively explore the virtual environment. Applications of this approach may extend to larger populations of visually impaired individuals.

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind.

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio ...

Computerized Dynamic Posturography for Postural Control Assessment in Patients with Intermittent Claudication

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic conditions. As part of a diagnostic assessment, the early detection of postural deficits is important so that appropriate and targeted interventions can be prescribed. The Sensory Organization Test (SOT) on the EquiTest determines an individual&#39;s use of the sensory systems (somatosensory, visual, and vestibular) that are responsible for postural control. Somatosensory and visual input are altered by the calibrated sway-referenced support surface and visual surround, which move in the anterior-posterior direction in response to the individual&#39;s postural sway. This creates a conflicting sensory experience. The Motor Control Test (MCT) challenges postural control by creating unexpected postural disturbances in the form of backwards and forwards translations. The translations are graded in magnitude and the time to recover from the perturbation is computed.
Intermittent claudication, the most common symptom of peripheral arterial disease, is characterized by a cramping pain in the lower limbs and caused by muscle ischemia secondary to reduced blood flow to working muscles during physical exertion. Claudicants often display poor balance, making them susceptible to falls and activity avoidance. The Ankle Brachial Pressure Index (ABPI) is a noninvasive method for indicating the presence of peripheral arterial disease and intermittent claudication, a common symptom in the lower extremities. ABPI is measured as the highest systolic pressure from either the dorsalis pedis or posterior tibial artery divided by the highest brachial artery systolic pressure from either arm. This paper will focus on the use of computerized dynamic posturography in the assessment of balance in claudicants.

Individuals with intermittent claudication exhibit poor balance compared to healthy controls. Computerized dynamic posturography is an objective method for measuring an individual's postural responses to balance disturbances. This provides an objective reflection of the person&#x2019;s ability to respond to situations under which sensory stimuli are altered and unexpected perturbations occur.

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic ...

Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients

In order to follow optic neuritis patients and evaluate the effectiveness of their treatment, a handy, accurate and quantifiable tool is required to assess changes in myelination at the central nervous system (CNS). However, standard measurements, including routine visual tests and MRI scans, are not sensitive enough for this purpose. We present two visual tests addressing dynamic monocular and binocular functions which may closely associate with the extent of myelination along visual pathways. These include Object From Motion (OFM) extraction and Time-constrained stereo protocols. In the OFM test, an array of dots compose an object, by moving the dots within the image rightward while moving the dots outside the image leftward or vice versa. The dot pattern generates a camouflaged object that cannot be detected when the dots are stationary or moving as a whole. Importantly, object recognition is critically dependent on motion perception. In the Time-constrained Stereo protocol, spatially disparate images are presented for a limited length of time, challenging binocular 3-dimensional integration in time. Both tests are appropriate for clinical usage and provide a simple, yet powerful, way to identify and quantify processes of demyelination and remyelination along visual pathways. These protocols may be efficient to diagnose and follow optic neuritis and multiple sclerosis patients.
In the diagnostic process, these protocols may reveal visual deficits that cannot be identified via current standard visual measurements. Moreover, these protocols sensitively identify the basis of the currently unexplained continued visual complaints of patients following recovery of visual acuity. In the longitudinal follow up course, the protocols can be used as a sensitive marker of demyelinating and remyelinating processes along time. These protocols may therefore be used to evaluate the efficacy of current and evolving therapeutic strategies, targeting myelination of the CNS.

Object From Motion (OFM) and Time-constrained stereo protocols are sensitive tools to identify monocular and binocular dynamic visual function deficits, which are uniquely affected in optic neuritis patients. Furthermore, these tests may be used as quantitative noninvasive tools to assess the extent of myelination along visual pathways.

In order to follow optic neuritis patients and evaluate the effectiveness of their treatment, a handy, accurate and quantifiable tool is required to ...

In Vivo Dynamics of Retinal Microglial Activation During Neurodegeneration: Confocal Ophthalmoscopic Imaging and Cell Morphometry in Mouse Glaucoma

Microglia, which are CNS-resident neuroimmune cells, transform their morphology and size in response to CNS damage, switching to an activated state with distinct functions and gene expression profiles. The roles of microglial activation in health, injury and disease remain incompletely understood due to their dynamic and complex regulation in response to changes in their microenvironment. Thus, it is critical to non-invasively monitor and analyze changes in microglial activation over time in the intact organism. In vivo studies of microglial activation have been delayed by technical limitations to tracking microglial behavior without altering the CNS environment. This has been particularly challenging during chronic neurodegeneration, where long-term changes must be tracked. The retina, a CNS organ amenable to non-invasive live imaging, offers a powerful system to visualize and characterize the dynamics of microglia activation during chronic disorders.
This protocol outlines methods for long-term, in vivo imaging of retinal microglia, using confocal ophthalmoscopy (cSLO) and CX3CR1GFP/+ reporter mice, to visualize microglia with cellular resolution. Also, we describe methods to quantify monthly changes in cell activation and density in large cell subsets (200-300 cells per retina). We confirm the use of somal area as a useful metric for live tracking of microglial activation in the retina by applying automated threshold-based morphometric analysis of in vivo images. We use these live image acquisition and analyses strategies to monitor the dynamic changes in microglial activation and microgliosis during early stages of retinal neurodegeneration in a mouse model of chronic glaucoma. This approach should be useful to investigate the contributions of microglia to neuronal and axonal decline in chronic CNS disorders that affect the retina and optic nerve.

In Vivo Dynamics of Retinal Microglial Activation During Neurodegeneration: Confocal Ophthalmoscopic Imaging and Cell Morphometry in Mouse Glaucoma

Microglia activation and microgliosis are key responses to chronic neurodegeneration. Here, we present methods for in vivo, long-term visualization of retinal CX3CR1-GFP+ microglial cells by confocal ophthalmoscopy, and for threshold and morphometric analyses to identify and quantify their activation. We monitor microglial changes during early stages of age-related glaucoma.

Microglia, which are CNS-resident neuroimmune cells, transform their morphology and size in response to CNS damage, switching to an activated state with ...

A Simple Mechanical Procedure to Create Limbal Stem Cell Deficiency in Mouse

Limbal stem cell deficiency (LSCD) is a state of malfunction or loss of limbal epithelial stem cells, after which the corneal epithelium is replaced with conjunctiva. Patients suffer from recurrent corneal defects, pain, inflammation, and loss of vision.
Previously, a murine model of LSCD was described and compared to two other models. The goal was to produce a consistent mouse model of LSCD that both mimics the phenotype in humans and lasts long enough to make it possible to study the disease pathophysiology and to evaluate new treatments. Here, the technique is described in more detail.
A motorized tool with a rotating burr has been designed to remove the rust rings from the corneal surface or to smooth the pterygium bed in patients. It is a suitable device to create the desired LSCD model. It is a readily available, easy-to-use tool with a fine tip that makes it appropriate for working on small eyes, as in mice. Its application prevents unnecessary trauma to the eye and it does not result in unwanted injuries, as often is the case with chemical injury models. As opposed to a blunt scraper, it removes the epithelium with the basement membrane. In this protocol, the limbal area was abraded two times, and then the whole corneal epithelium was shaved from limbus to limbus. To avoid stroma injury, care was taken not to brush the corneal surface once the epithelium was already removed.

The following article provides an easy, reproducible technique to effectively create a sustainable mouse model of limbal stem cell deficiency (LSCD). This animal model is useful in testing and comparing the efficacy of treatments for limbal stem cell diseases.

Limbal stem cell deficiency (LSCD) is a state of malfunction or loss of limbal epithelial stem cells, after which the corneal epithelium is replaced with ...

Fertility Preservation in Patients with Severe Ovarian Dysfunction

Ovarian function progressively declines during aging and in some pathophysiological conditions including karyotype abnormality, autoimmune diseases, chemo- and radiation-therapies, as well as ovarian surgeries. In unmarried women with severe ovarian dysfunction, fertility preservation is important for future pregnancies. Although oocyte cryopreservation is an established method for fertility preservation, these patients could only preserve a limited number of oocytes even after ovarian hyperstimulation, leading to repeated stimulations to ensure sufficient oocytes to guarantee future pregnancy. To solve this issue, we have recently developed a drug-free in vitro activation (IVA) procedure, which enable us to stimulate early stages of ovarian follicles to develop to the preantral follicle stage. These preantral follicles can respond to the unique protocol of gonadotropin stimulation, resulting in increased number of retrieved oocytes per ovarian stimulation for cryopreservation. The drug-free IVA comprised from the surgical approach and ovarian stimulation. We removed a part of cortex from one or both ovaries from patients under laparoscopic surgery. The ovarian cortical tissues were cut into small cubes to disrupt the Hippo signaling pathway and stimulate the development of early stage follicles. These cubes were grafted orthotropically into remaining ovaries as well as beneath the serosa of both Fallopian tubes. We have already published the surgical procedure of the drug-free IVA and the protocol of subsequent ovarian stimulation, but herein we present the details of laboratory methods required for drug-free IVA.

We present details of laboratory procedures for drug-free in vitro activation (IVA) of ovarian follicles for patients with severe ovarian dysfunction. This method could increase the number of retrievable oocytes per ovarian hyperstimulation and benefit fertility preservation for those patients.

Ovarian function progressively declines during aging and in some pathophysiological conditions including karyotype abnormality, autoimmune diseases, ...

Providing Visual Biofeedback Using Brightness Mode Ultrasound During a Golf Swing

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional rehabilitation techniques in an athletic, physically active population. Brightness mode (B-mode) ultrasound can be applied using frame-by-frame analysis synchronized with video to understand muscle thickness changes during these dynamic tasks. Visual biofeedback with ultrasound has been established in static positions for the muscles of the lateral abdominal wall. However, by securing the transducer to the abdomen using an elastic belt and foam block, biofeedback can be applied during more specific tasks prevalent in lifetime sports, such as golf. To analyze muscle activity during a golf swing, muscle thickness changes can be compared. The thickness must increase throughout the task, indicating that the muscle is more active. This methodology allows clinicians to immediately replay ultrasound videos for patients as a visual tool to instruct proper activity of the muscles of interest. For example, ultrasound can be used to target the external and internal obliques, which play an important role in swinging a golf club or any other rotational sport or activity. This methodology aims to increase oblique muscle thickness during the golf swing. Additionally, the timing of muscle contraction can be targeted by instructing the patient to contract the abdominal muscles at specific time points, such as the beginning of the downswing, with the goal of improving muscle firing patterns during tasks.

Brightness mode ultrasound can be used to provide visual biofeedback of the muscles of the lateral abdominal wall during a golf swing. Post-swing visual and verbal instruction can increase the muscle activation and timing of the external and internal obliques.

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional ...

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...

Developing an Exercise Program for Rheumatoid Arthritis Patients

Evaluation of Changes in Hydration and Body Cell Mass with Bioelectrical Impedance Analysis after Exercise Program for Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is a debilitating disease that can result in complications such as rheumatoid cachexia. While physical exercise has shown benefits for RA patients, its impact on hydration and body cell mass remains uncertain. The presence of pain, inflammation, and joint changes often restrict activity and make traditional body composition assessments unreliable due to altered hydration levels. Bioelectrical impedance is a commonly used method for estimating body composition, but it has limitations since it was primarily developed for the general population and does not consider changes in body composition. On the other hand, bioelectrical impedance vectorial analysis (BIVA) offers a more comprehensive approach. BIVA involves graphically interpreting resistance (R) and reactance (Xc), adjusted for height, to provide valuable information about hydration status and the integrity of the cell mass.
Twelve women with RA were included in this study. At the beginning of the study, hydration and body cell mass measurements were obtained using the BIVA method. Subsequently, the patients participated in a six-month dynamic exercise program encompassing cardiovascular capacity, strength, and coordination training. To evaluate changes in hydration and body cell mass, the differences in the R and Xc parameters, adjusted for height, were compared using BIVA confidence software. The results showed notable changes: resistance decreased after the exercise program, while reactance increased. BIVA, as a classification method, can effectively categorize patients into dehydration, overhydration, normal, athlete, thin, cachectic, and obese categories. This makes it a valuable tool for assessing RA patients, as it provides information independent of body weight or prediction equations. Overall, the implementation of BIVA in this study shed light on the effects of the exercise program on hydration and body cell mass in RA patients. Its advantages lie in its ability to provide comprehensive information and overcome the limitations of traditional body composition assessment methods.

Author Spotlight: Implementation of BIVA for Analyzing Disease Risk Factors in Patients with Low Body Cell Mass 

This protocol assesses alterations in hydration and body cell mass status using bioelectrical impedance vectorial analysis following a dynamic exercise program designed for patients with rheumatoid arthritis. The dynamic exercise program itself is detailed, highlighting its components focused on cardiovascular capacity, strength, and coordination. The protocol details steps, instruments, and limitations.

Rheumatoid arthritis (RA) is a debilitating disease that can result in complications such as rheumatoid cachexia. While physical exercise has shown ...