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At least 973 records · Page 54Linked to original sources

PubMed2000

Juxtapapillary capillary hemangiomas. Clinical features and visual acuity outcomes.

OBJECTIVE: To describe the clinical features, association with von Hippel-Lindau (VHL) disease and visual acuity outcomes of patients with a juxtapapillary capillary hemangioma. DESIGN: Retrospective observational case series. PARTICIPANTS: Seventy-two eyes of 68 patients identified with a juxtapapillary capillary hemangioma. Follow-up data of at least 6 months duration were available for 60 eyes. METHODS: A retrospective chart review of patients diagnosed with a juxtapapillary capillary hemangioma examined at four medical centers. MAIN OUTCOME MEASURES: Age at diagnosis, visual acuity (VA) at first examination and at last follow-up, tumor growth pattern and location, associated clinical features, type of treatment, association with VHL, and presence of peripheral hemangiomas were recorded for each patient. RESULTS: On initial examination, VA was >/=20/40 in 43 of 70 eyes (61%) and was >/=20/200 in 60 eyes (86%). At an average follow-up of 5.4 years (range, 0.5-19 years), VA of >/=20/40 was achieved in 21 eyes (35%) and >/=20/200 in 33 eyes (55%). Patients with VHL had poorer initial VA (48% vs. 70% with VA >/=20/40, and 74% vs. 93% with VA >/=20/200) and final VA (26% vs. 41% with VA >/=20/40, and 39% vs. 65% with VA >/=20/200) compared with patients without VHL. Patients with VHL more commonly were seen at an earlier age (average, 20 vs. 44 years, P: < 0.001), with bilateral (17% vs. 0%), and/or peripheral (39% vs. 0%) (P: < 0.001) tumors that more often had an endophytic growth pattern (63% vs. 22%, P: = 0.001) compared with patients without VHL. Patients selected for laser treatment generally had poorer initial (52% vs. 74% with VA >/=20/40, 79% vs. 96% with VA >/=20/200) and final VAs (18% vs. 56% with VA >/=20/40, 45% vs. 67% with VA >/=20/200) compared with patients not treated with laser. CONCLUSIONS: On long-term follow-up of patients with a juxtapapillary capillary hemangioma, the VA generally worsens. Patients with VHL and a juxtapapillary hemangioma more often present at a younger age, have tumors with an endophytic growth pattern, and have bilateral, multiple tumors. Treatment with laser photocoagulation results in variable VA outcomes.

Adolescent↗

PubMed2003

Cross-sectional study of visual acuity and electroretinogram in two types of dominant drusen.

PURPOSE: To compare the changes with increasing age of ERG parameters in relation to clinical data in two distinct phenotypes of genetically determined, dominantly inherited macular drusen: malattia leventinese (ML) and Zermatt macular dystrophy (ZMD). METHODS: Ganzfeld rod- and cone-electroretinograms (ERGs) from 15 patients affected with ML and 14 patients with ZMD and clinical data were analyzed retrospectively. The patients' ages ranged from 20 to 77 years in the ML group and from 9 to 74 years in the ZMD group. RESULTS: Both inherited macular degenerations caused a marked decrease in visual acuity, the latest after age 65. Most patients with ML retained good visual function (0.8-1.0) until the fifth decade, followed by a rapid decrease in the fifth or sixth decade. ZMD is characterized by a relatively continuous decrease in visual acuity with increasing age. Morphologically, in the juvenile stages in both entities, drusen were observed at the posterior pole. Rod-driven and cone-driven ERG b-wave amplitudes decreased nearly linearly in ML and ZMD in accord with the normal loss of amplitude with increasing age. Implicit times of cone b-waves for ML increased markedly with age, whereas in ZMD the values were always prolonged beyond the normal range with a slight increase with age. CONCLUSIONS: In terms of visual acuity, the progression of both dominantly inherited macular dystrophies is quite different. This is not reflected in the amplitudes of the b-waves in the Ganzfeld ERGs, which decrease normally for both entities. Implicit times of the cone-b waves were more markedly prolonged in ML compared with ZMD. In-depth longitudinal documentation of the natural course of those dominantly inherited macular diseases should facilitate patient counseling.

Adolescent↗

PubMed2001

Is peripheral visual acuity susceptible to perceptual learning in the adult?

While it is generally accepted that foveal visual acuity in the adult has reached an optimal value, claims for improvement of peripheral acuity with training in the adult persist in the literature. Practice effects in peripheral hyperacuity have been amply documented. A carefully controlled test is here reported to examine the influence of training on the resolution thresholds for two lines and on Landolt C acuity measurements in the retinal periphery in eight normal adults. It involved 11-30 daily sessions of 300 responses with feedback. In some observers the first day's results were somewhat poorer, but otherwise the threshold curves were essential flat. Yet in the same location vernier acuity could be improved by 50% in six training sessions. Sustained and lasting neural modifications in peripheral vision can take place in stereoscopic, orientation, vernier, bisection and time discriminations, but not in resolution and Landolt C acuities.

Adult↗

PubMed1993

Initial rapid decrease in visual acuity in siblings with Stargardt's disease.

Two siblings with Stargardt's disease who had an initial rapid decrease in visual acuity were reported. The 8-year-old boy and his 5-year-old sister experienced a bilateral visual decrease within a period of 3 months. Their parents had a consanguineous relationship. Macular changes and blocked choroidal fluorescence were noted bilaterally in both children. Normal color vision, normal or subnormal electroretinographic findings, and subnormal electro-oculographic responses were found. Stargardt's disease should be included in the list of conditions showing rapid decrease in visual acuity.

Child↗

PubMed2000

The use of binocular visual acuity in the assessment of intermittent exotropia.

BACKGROUND: It has been suggested that a decrease in distance stereoacuity in patients with intermittent exotropia is a good indicator of diminishing control. However, there has been no adequate explanation for this reported reduction in distance stereoacuity in these patients. We postulate that the decrease in stereoacuity is related to blurred visual acuity created by an increasing demand on accommodation, which these patients use in an attempt to control the exodeviation. This can best be assessed by measuring binocular visual acuity (BVA). Analysis of BVA could provide a useful clinical tool to evaluate control measures used by patients with intermittent exotropia. METHODS: A prospective study of patients with intermittent exotropia, ranging in age from 6 to 60 years, was performed. Only those patients with the presence of either basic or divergence excess (simulated or true) type exodeviation were included in the study. The data analysis included the age of these patients, age at onset of the deviation, monocular and binocular visual acuity, oculomotor and fusional status, and near and distance stereoacuity. RESULTS: Data from 36 patients show that the measurements of BVA correlated well with a corresponding loss of distance stereoacuity but not with the size of the deviation. CONCLUSION: The decrease of stereoacuity reported in patients with exotropia can be explained by increased accommodation and decreased distance BVA. This measurement can be a simple method of quantifying the fusional control of patients with intermittent exotropia.

Accommodation, Ocular↗

PubMed2001

Role of central preprogramming in dynamic visual acuity with vestibular loss.

OBJECTIVE: To determine the contribution of central preprogramming of eye movements to dynamic visual acuity (DVA) during head movement in patients with vestibular hypofunction. STUDY DESIGN: Prospective, clinical study. SETTING: Tertiary care, academic hospitals. PARTICIPANTS: Twenty-six healthy subjects and 20 patients with unilateral (UVL) and 7 with bilateral vestibular loss (BVL) (age range, 20-86 years). INTERVENTIONS: Diagnostic interventions, including caloric and rotational chair testing. MAIN OUTCOME MEASURE: Measurements of DVA during predictable (DVA-predictable) and unpredictable (DVA-unpredictable) head movements using a computerized test. RESULTS: There was a difference between DVA-predictable and DVA-unpredictable scores in all groups (P<.02). The difference between DVA-predictable and DVA-unpredictable scores for the BVL group was significantly greater than that for the other groups (P<.005). Age was a significant factor in DVA-unpredictable scores for the healthy subjects (P<.001) and UVL group (P<.02). Comparisons of DVA between groups were significant (P<.03), with the following exceptions: UVL group for head movements toward the unaffected side for DVA-predictable and DVA-unpredictable scores, compared with healthy subjects, and UVL group for head movements toward the affected side for DVA-predictable scores, compared with the BVL group. CONCLUSIONS: Unpredictable head movements cause a greater decrement in visual acuity than do predictable head movements. This suggests that central programming of eye movements and/or efference copy contributes to gaze stability during predictable head movements in healthy subjects and patients with vestibular hypofunction. Patients with BVL use central programming of eye movements to maintain gaze stability more than do healthy subjects or patients with UVL.

Adult↗

PubMed2006

[The influence of IOL implantation on visual acuity, contrast sensitivity and colour vision 2 and 4 months after cataract surgery].

PURPOSE: To assess the change in visual acuity, contrast sensitivity and colour vision in relation to the time after cataract surgery and to the type of implanted IOL, and to compare visual functions by patients with one and two pseudophakic eyes. METHODS: 45 cataract patients were examined before and then 2 and 4 month after the cataract surgery. Visual acuity (VA) was tested on logMAR optotype chart with Landolt rings, contrast sensitivity (CS) was tested on the Pelli-Robson chart and the SWCT chart. For colour vision (CV) testing, the standard Farnsworth D-15 test and the desaturated Lanthony D-15 test were used. The patients were divided into two groups--a group with one pseudophakic eye and a group with two pseudophakic eyes, and also according to the type of IOL--PMMA or hydrophobic acrylate that had been implanted. Control group was composed of phakic subjects with no ocular pathology. RESULTS: After the cataract surgery, in both groups there was a significant improvement in monocular and binocular VA (p < 0.05), in monocular and binocular CS using both types of charts--Pelli-Robson (p < 0.05) and SWCT in all the spatial frequencies (p < 0.05). Also, a significant decrease in the number of minor errors in the standard Farnsworth D-15 test (p < 0.05) as well as a substantial decrease in the number of minor and major errors in the desaturated Lanthony D-15 test (p < 0.05) and an overall improvement of CV (p < 0.05) were detected. There was no difference between the results 2 and 4 month after the surgery, except for CS in 12 c/deg (p < 0.05). The patients with two pseudophakic eyes had postoperatively better binocular VA and CS in the spatial frequencies of 12 c/deg and 18 c/deg and attained postoperative values comparable to those of control subjects. No significant difference in VA, CS or CV was found between the PMMA and hydrophobic acrylate intraocular lenses. CONCLUSION: After the cataract surgery, the visual functions tested by means of psychophysical methods of VA, CS and CV significantly improve and are stable 2 month after the surgery. The second eye surgery improves binocular visual functions the level of which doesn't differ from that of normal phakic subjects. There was no influence of the type of IOL on final state of VA, CS or CV.

Aged↗

PubMed2003

Measurement and analysis of visual acuity in multicenter randomized clinical trials in the United States: findings from a survey.

PURPOSE: To describe visual acuity (VA) testing and scoring methods used in multicenter randomized clinical trials in ophthalmology in the United States (USA) sponsored by the National Eye Institute (NEI). METHODS: A survey was conducted among multicenter studies in the US that included one or more randomized clinical trials and were sponsored by the NEI, National Institutes of Health. To be included in the survey, a study had to have VA reported in one or more publications or patient eligibility based on VA, a majority of study subjects 13 years of age or older, and a patient population primarily or exclusively from the US. A standard survey form was completed for each study based on information presented in the study manual of procedures and publications. Findings were summarized and displayed with frequency distributions. RESULTS: The survey included 24 studies, each with enrollment initiated in the period 1972 to 1999. VA was one of the study eligibility criteria for 19 (79%) studies, and VA or change in VA was the primary outcome in 12 (50%) studies. ETDRS charts have been employed in 16 of 19 studies initiated after the charts were published in 1982. All studies but one specified in the documents reviewed that VA testing was performed at multiple VA test distances. For studies that used ETDRS charts, methods of converting VA scores obtained at different test distances to a common scale fell into two categories: 11 studies used a method similar in nature to that first reported in the Macular Photocoagulation Study, and 7 studies used a method similar in nature to that first reported in the Krypton-Argon Regression of Neovascularization Study. conclusion The development of the ETDRS charts and a custom light box has led to more uniformity in VA test charts and chart illumination. However, details of VA measurement protocols vary widely from study to study. To assure comparable data across studies and ocular conditions, it would be useful to have a standard VA testing and scoring protocol with provisions for testing different levels of visual acuity that recommends a single method for converting scores from different test distances to a common scale and standard conversion of "off the chart" VA levels for calculation of means and changes in VA.

Data Collection↗

PubMed1977

The Elidice: new instrument for visual acuity self-screening.

A compact electronic device which enables the user to determine for himself whether his visual acuity reaches a chosen standard has been constructed at a cost of 25 pounds. The instrument provides a test which requires the observer to respond to the orientation of a sequence of red Landolt-Cs and which takes under five minutes to complete. 'Crowding' effects associated with conventional letter charts are avoided and the test does not discriminate against astigmatic observers. One hundred observers were tested on both the new instrument (the Elidice) and a standard Snellen chart under clinical conditions. The overall agreement between the two tests was 87.8%, with the Elidice having an over-referral level of 10-7% and an under-referral level of 1-5% as compared with the letter chart. This makes the Elidice particularly suitable for the regular screening of laser users for reduced visual acuity due to macular damage.

Humans↗

PubMed1994

Visual acuity, refractive and keratometric results of 140 consecutive radial keratotomy procedures.

We reviewed the results of the first 140 consecutive radial keratotomy procedures (83 patients) performed by one surgeon from March 1986 to April 1992. The mean follow-up time per eye was 9.9 (standard deviation [SD] 9.1) months. The mean preoperative spherical equivalent refraction of -3.74 (SD 1.70) dioptres decreased by a mean of 2.75 D (SD 1.11 D) to a postoperative mean refraction of -0.99 D (SD 1.50 D). The postoperative uncorrected visual acuity was 20/40 or better in 120 eyes (86%). All eyes had a postoperative best corrected visual acuity of 20/40 or better. Correction to within +/- 1 D of emmetropia occurred in 98 eyes (70%), and no overcorrection of more than 1 D occurred. The mean amount of corneal flattening, as determined with keratometry, was 2.68 D (SD 1.23 D). Of the 42 eyes with high myopia (-4.50 to -9.12 D) preoperatively 57% had uncorrected vision of 20/40 or better postoperatively, and 31% had correction to within +/- 1 D of emmetropia. The corresponding figures for the 39 eyes with moderate myopia (-3.25 to -4.37 D) were 100% and 82%, and for the 59 eyes with low myopia (-1.00 to -3.12 D) 98% and 90%. There were no vision-threatening complications. The only significant loss of best corrected visual acuity occurred in one eye (1%) that lost two Snellen lines.

Adolescent↗

PubMed1992

Causes of reduced visual acuity on long-term follow-up after cataract extraction in patients with uveitis and juvenile rheumatoid arthritis.

We reviewed the long-term follow-up on a consecutive series of 16 eyes from ten patients with juvenile rheumatoid arthritis-associated cataracts that were removed by using pars plana lensectomy and vitrectomy. All patients had prominent cataracts, chronic uveitis, posterior synechiae, and vitreitis preoperatively, and had at least 12 months of follow-up postoperatively. The median length of follow-up was 51 months (range, 12 months to ten years). In the early postoperative period, a visual acuity of 20/70 or better was obtained in 13 of 16 eyes (81%). With longer follow-up, the final visual acuity was 20/70 or better in only nine of 16 eyes (56%). The primary categories of delayed visual loss in these cases were glaucoma and macular disease (chronic cystoid macular edema, macular hole, hypotony maculopathy, and recurrent macular pucker). Despite these limitations in maintaining good visual acuity, a pars plana lensectomy and vitrectomy approach is effective for cataracts in these patients with uveitis.

Adolescent↗

PubMed1996

Visual acuity and fatty acid status of term infants fed human milk and formulas with and without docosahexaenoate and arachidonate from egg yolk lecithin.

Preterm infants fed formulas with docosahexaenoic acid (DHA, 22:6n-3) during the interval equivalent to the last intrauterine trimester and beyond have higher circulating DHA and transiently higher visual acuity compared with infants fed formulas containing linolenic acid. In term infants several nonrandomized studies of infants receiving DHA from human milk suggest a relationship between DHA status and acuity, but the evidence for a cause-and-effect relationship is mixed. In the present study, term infants were randomly assigned to a standard term formula (n = 20) or the same formula with egg yolk lecithin to provide DHA (0.1%) and arachidonic acid (AA, 20:4n-6, 0.43%) (n = 19) at levels reported in milk of American women. A third group of infants was breast fed for > or = 3 mo (n = 19). Grating visual acuity (Teller Acuity Card procedure) and plasma and red blood cell (RBC) phosphatidylcholine (PC) and phosphatidylethanolamine (PE) DHA and AA were determined at corrected ages of 2, 4, 6, 9 (acuity only), and 12 mo past term = 40 wk postmenstrual age (PMA). At 2 mo breast-fed infants and infants fed the supplemented formula had higher grating acuity than term infants fed standard formula. As in preterm infants, the increase was transient. Plasma PC DHA and AA and RBC PE AA increased by 2 mo in supplemented infants, but RBC PE DHA in supplemented infants was not higher than in controls until 4 mo and beyond. Despite normal intrauterine accumulation of DHA and AA, infants fed formula with 2% linolenic acid and 0.1% DHA had better 2-mo visual acuity than infants fed formula with 2% linolenic acid.

Arachidonic Acid↗

PubMed1999

[Development of visual acuity in the early phase after photorefractive keratectomy in myopia].

BACKGROUND: Photorefractive keratectomy (PRK) using the excimer laser is an accepted surgical technique for correction of myopic refraction errors in case of spectacle or contact lens incompatibility. The purpose of this study was to assess the development of uncorrected (UVA) and best-corrected visual acuity (CVA) in the early course following PRK. PATIENTS AND METHODS: 48 eyes of 29 patients that underwent myopic photorefractive keratectomy using 193 nm excimer laser (MEL 60, Aesculap-Meditec) were included in this study. The mean preoperative spherical equivalent was -5.3 +/- 2.4 diopters (D) (range -1.75 to -9.5 D). Pre-, intra- and postoperative treatment was standardized. The median time interval to complete epithelial closure was 2 days. According to their spherical equivalent, patients were divided in two groups: group 1 with myopia < or = 6 D (n = 28), group 2 with myopia more than 6 D (n = 20). Examination of UVA and CVA were performed preoperatively and on days 3, 7 as well as 1 month, 3 and 6 months postoperatively. RESULTS: On day 3 after surgery UVA was 0.43 +/- 0.21 for group 1 with myopia < or = 6 D, and 0.36 +/- 0.14 for group 2 with myopia more than 6 D. The UVA was stable after 3 months (0.92 +/- 0.29 and 0.66 +/- 0.20, respectively), the CVA was stable after 1 month (1.04 +/- 0.18 and 0.86 +/- 0.19, respectively). After surgery, the UVA increased by +0.73 +/- 0.25, whereas the CVA increased by +0.05 +/- 0.10 for the whole group. The difference comparing pre- and postoperative UVA was significantly higher in group 1 (0.81 +/- 0.22) than in group 2 (0.60 +/- 0.26) (p = 0.002). However, postoperative CVA values were not significantly different from preoperative values in both groups after 6 months (p = 0.3). CONCLUSION: Useful uncorrected visual acuity is normally achieved at day 3 after PRK in eyes with mild to moderate myopia. With higher degrees of myopia the uncorrected visual acuity does increase slower towards a lower level. One of the reasons for this phenomenon might be a significant regression of the refractive effects during the first half year after surgery.

Adult↗

PubMed2004

Criteria for improving visual acuity in ischaemic branch retinal vein occlusion using argon laser.

PURPOSE: To re-assess the value of argon laser treatment for macular oedema in ischaemic branch retinal vein occlusion (I-BRVO). METHODS: Case series consisting of three patients with macular oedema following I-BRVO. Three patients were studied including two patients where ischaemia extended to include the foveal avascular zone (FAZ), with additional retinal neovascularisation in one of these. Heavy, overlapping areas of treatment were applied to the ischaemic retina up to 500 microns from the fovea. RESULTS: All cases in the series benefited from significantly improved visual acuity. In one case laser was given several years after the initial retinal vasculopathy. CONCLUSIONS: Argon laser treatment may improve visual acuity in I-BRVO even with severe ischaemia extending into the FAZ. Treatment intensity must be sufficient to destroy ischaemic retina. Visual benefit may last for several years, and treatment can be undertaken several years after I-BRVO. The benefit to visual acuity of argon laser treatment in I-BRVO needs to be re-assessed in a prospective study.

Female↗

PubMed1986

Effects of a mu-opioid receptor agonist (codeine phosphate) on visuo-motor coordination and dynamic visual acuity in man.

Effects of codeine (30, 60 and 90 mg) on visuo-motor coordination and dynamic visual acuity, together with critical flicker fusion, digit symbol substitution, complex reaction time and subjective assessments of mood, were studied from 0.75-2.0 h after ingestion by six healthy female adults. The study was double-blind and placebo controlled, and triprolidine (10 mg) was used as the active control. The effect on visuo-motor coordination was limited and was dose related and linear, and performance was altered on visuo-motor coordination with 60 and 90 mg codeine, and on dynamic visual acuity with 90 mg codeine (P less than 0.05). No other effect of codeine was detected. Modulated neuromuscular function is likely to be the common denominator of the changes in performance with codeine, though nausea, but not sedation, may be a contributory factor. It is possible that altered performance with codeine may involve interactions with different receptors than those which lead to sedation.

Adult↗

PubMed2003

Effect of methods of myopia correction on visual acuity, contrast sensitivity, and depth of focus.

PURPOSE: To psychophysically measure spherical and irregular aberrations in patients with various types of myopia correction. SETTING: Laboratory of Experimental Ophthalmology, University of Groningen, Groningen, The Netherlands. METHODS: Three groups of patients with low myopia correction (spectacles, soft contact lens, and Intacs) and 4 groups with high myopia correction (spectacles, rigid contact lens, Artisan claw lens, and laser in situ keratomileusis [LASIK]) had through-focus contrast sensitivity measurements to establish the myopic shift and depth of focus. From these 2 parameters, spherical and irregular aberrations were determined using theoretical eye models and geometric optics. Visual acuity, stray light, and predictability were also studied. RESULTS: There were no differences in best corrected visual acuity (BCVA) or best corrected contrast sensitivity between the low myopia groups. The Intacs group had a significantly larger depth of focus (P<.05). The results in the soft contact lens group were comparable to those in a human eye model with an average amount of spherical and irregular aberrations. The LASIK group had worse uncorrected visual acuity (UCVA) and best corrected contrast sensitivity than the spectacles, rigid contact lens, and Artisan claw lens groups (P<.05) due to the amount of spherical and irregular aberrations present after LASIK. The low and high myopia spectacles groups had average amounts of spherical and irregular aberrations. CONCLUSIONS: Neither surgical techniques nor contact lenses resulted in BCVA or best corrected contrast sensitivity that surpassed the values measured in the best corrected spectacles groups. The Artisan claw lens performed better than LASIK in UCVA, predictability, and best corrected contrast sensitivity.

Adult↗

PubMed1989

Corneal topography and fluctuating visual acuity after radial keratotomy.

A high-resolution photokeratoscope using computer graphics to model corneal topography was used on patients who had undergone radial keratotomy. After radial keratotomy, central optical zones are created that can be characterized as round, oval or band-like, or dumbbell-shaped or split. The dumbbell form of optical zone was associated with larger amounts of refractive and keratometric astigmatism than the round or band-like zones. The authors correlated the shape of the optical zone with the presence or absence of diurnal variation (fluctuation) in visual acuity. Of the 26 eyes studied, 11 experienced fluctuation and 15 did not. Of those 11 eyes with fluctuating visual acuity, 10 (91%) had dumbbell-shaped or split optical zones and 1 (9%) had a round optical zone. Of the 15 eyes without fluctuation, 12 (80%) had round optical zones and 3 (20%) had band-like zones. The presence of a split or dumbbell-shaped optical zone after radial keratotomy indicates that the patient is likely to experience diurnal fluctuation of visual acuity.

Astigmatism↗

PubMed2005

Dynamic visual acuity using "far" and "near" targets.

CONCLUSIONS: DVA may be useful for assessing the functional consequences of an impaired gaze stabilization mechanism or for testing the effectiveness of a rehabilitation paradigm. Because target distance influences the relative contributions of canal and otolith inputs, the ability to measure DVA at near and far viewing distances may also lead to tests that will independently assess canal and otolith function. OBJECTIVE: To present and test a methodology that uses dynamic visual acuity (DVA) to assess the efficacy of compensatory gaze mechanisms during a functionally relevant activity that differentially measures canal and otolith function. MATERIAL AND METHODS: The effect of treadmill walking at a velocity of 1.79 m/s on subjects' visual acuity was assessed at each of two viewing distances. A custom-written threshold determination program was used to display Landolt C optotypes on a laptop computer screen during a "far" (4 m) target condition and on a micro-display for a "near" (50 cm) target condition. The walking acuity scores for each target distance were normalized by subtracting a corresponding acuity measure obtained while standing still on the treadmill belt. RESULTS: As predicted by subjective reports of relative target motion, the decrease in visual acuity was significantly greater (p < 0.00001) for the near compared to the far condition.

Adult↗