Monocular Contrast Sensitivity Research Articles

The Effect of Acupuncture on Visual Function in Patients with Congenital and Acquired Nystagmus.

Background: The aim of this study is to examine the short-term effect of visual function following acupuncture treatment in patients with congenital idiopathic nystagmus and acquired nystagmus (CIN and AN). Methods: An observational pilot study on six patients with confirmed diagnosis of nystagmus (three CIN and three AN patients (2♀, 4♂; mean age 42.67; SD ± 20.57 y)), was performed. Acupuncture treatment was done following a standardized protocol applying needle-acupuncture on the body and the ears. The treatment was scheduled with 10 sessions of 30 min duration over five weeks. To assess the effect of the treatment, we performed before, between, and after acupuncture objective measurement of the BCVA (EDTRS charts), contrast vision (CSV-1000, Vector Vision), nystagmography (Compact Integrated Pupillograph), complemented by evaluation questionnaires. A placebo non-acupuncture control group (Nr: 11, 22 eyes; 8♀, 3♂; mean age: 33.34 y (SD ± 7.33 y)) was taken for comparison. Results: The results showed that, following acupuncture treatment, CIN and AN patients showed improvement (SD± mean) in their binocular BCVA (baseline: 0.45 ± 0.36; between: 0.53 ± 0.34 and post-treatment: 0.51 ± 0.28), and in their monocular contrast sensitivity (baseline: 11.29 ± 12.35; between: 11.43 ± 11.45 and post-treatment: 14.0 ± 12.22). The post-/baseline-difference showed a significant improvement in contrast vision and in BCVA for CIN and AN patients, but not for controls (p = 0.029 and p = 0.007, respectively). The effect of the eye showed also, within CIN and AN, significant values for the examined parameters in the post-/baseline difference (p = 0.004 and p ≤ 0.001). Evaluated only binocularly, the respective between-/baseline and post-/baseline difference in the CIN and AN group showed significant values (p < 0.045). Two AN patients reported reduction of oscillations. Among general subjective symptoms, our patients reported reduction of tiredness and headache attacks, improvement of vision, and shorter sleep onset time. Conclusion: The applied acupuncture protocol showed improvement in the visual function of nystagmus patients and thus, in their quality of life. Further studies are mandatory to differentiate which group of nystagmus patients would benefit more from acupuncture.

Factors Affecting Contrast Sensitivity in Healthy Individuals: A Pilot Study.

Objectives:To determine the demographic and ocular features affecting contrast sensitivity levels in healthy individuals.Materials and Methods:Seventy-four eyes of 37 subjects (7-65 years old) with refractive errors less than 1.0 diopter, no history of ocular surgery, and 20/20 visual acuity were included in the study. The participants were divided by age into three groups: group 1, 7-19 years, n=11; group 2, 20-49 years, n=15; and group 3, 50-65 years, n=11. All subjects underwent anterior and posterior segment evaluation, intraocular pressure measurements, refraction measurements, and clinical evaluation for strabismus. Contrast static test was performed using Metrovision MonPack 3 vision monitor system after measuring pupil diameter. Photopic and mesopic measurements were taken sequentially from right eyes, left eyes, and both eyes together.Results:Contrast sensitivity at intermediate and high spatial frequencies was lower with increasing age. Binocular measurements were better than monocular, and mesopic measurements were better than photopic measurements at all spatial frequencies. Contrast sensitivity at higher spatial frequency was lower with hyperopic refraction values.Conclusion:Increasing age, small pupil diameter, hyperopia, and photopic conditions were associated with lower contrast sensitivity in healthy individuals. Binocular contrast sensitivity measurements were better than monocular contrast sensitivity measurements in all conditions and spatial frequencies.

Effects of Monocular Blur on Clinical Measurements of Stereopsis and Binocular Contrast Sensitivity

Visual conditions such as anisometropia, monovision and monocular undercorrection affect the combination of visual input from both eyes. This study investigated the effects of monocular blur, in binocularly normal participants, on stereoacuity and binocular contrast sensitivity. Fifteen young adults (age range between 19 and 23 years old) with normal visual acuity and binocular vision participated in this study. Stereopsis was measured using the TNO test with a series of positive spherical lenses placed before the dominant eye. The procedure was repeated using the Titmus Stereotest on five participants as a control experiment. Monocular and binocular contrast sensitivities were also measured using the Pelli-Robson Contrast Sensitivity Chart. Blur was induced monocularly with a series of positive spherical lenses placed before the dominant eye and binocular contrast sensitivity was re-measured. Stereopsis scores decreased significantly when monocular blur was imposed. Across blur levels, absolute stereopsis scores measured with TNO test were worse than those measured with Titmus stereotest (all p < 0.05). However, the ratio of scores obtained without blur and under monocular blur appeared to be similar for both tests. Stereopsis without blur was between 6.82× to 8× better than that obtained with the highest level of imposed monocular blur. Binocular contrast sensitivity score decreased significantly with increasing level of monocular blur (p < 0.01). Binocular contrast sensitivity score without blur was 1.62× better than that obtained under binocular viewing with highest level of imposed blur. Stereopsis tests are more sensitive than measurements of binocular contrast sensitivity as an indicator of interocular acuity discrepancies which could occur in anisometropic or monovision patients. However, the choice of stereopsis test is crucial, as the TNO test appears to be more sensitive to monocular blur than the Titmus stereostest. DOI: http://dx.doi.org./10.17576/JSKM-2017-1501-03

Effect of Rigid Gas Permeable Contact Lenses on Nystagmus and Visual Function in Hyperopic Patients with Infantile Nystagmus Syndrome

ABSTRACTPurpose: To determine the effect of rigid gas permeable contact lenses (RGPCL) on involuntary eye movements and visual function in hyperopic patients with infantile nystagmus syndrome. Methods: This prospective interventional case series was conducted on 16 patients with infantile nystagmus and hyperopia equal or more than +0.5 D and astigmatism more than -1 D over a 2-year period. A complete ophthalmological examination including determination of best corrected visual acuity (BCVA), contrast sensitivity, and videonystagmography was performed for all patients before and after at least 3 months of RGPCL use, and the outcomes were compared. Results: Thirty-two eyes of 16 patients with mean age of 18.6±4.9 years were enrolled. Mean spherical equivalent refractive error was +1.5±2.35 (range +1 to +6.25) diopters (D); corresponding values were +2.45±2.44 D (range +0.5 to +7.5) for spherical error and +1.90±0.83 D (range +1 to +4) for astigmatism. Monocular BCVA improved from 0.56±0.23 to 0.51±0.23 Log MAR (P=0.007), and binocular BCVA improved from 0.54±0.25 to 0.48±0.24 Log MAR (P=0.01) after fitting RGPCL. Following the use of RGPCL, contrast sensitivity was significantly improved at low (P=0.02) and intermediate (P< 0.001) frequencies but not at high frequencies (P=0.6). The frequency, amplitude, and intensity of nystagmus were decreased significantly after RGPCL use (P<0.001). Conclusion: RGPCL improved monocular and binocular BCVA and contrast sensitivity in hyperopic patients with infantile nystagmus syndrome. Motor indices of nystagmus (frequency, amplitude, and intensity) were also significantly improved after RGPCL use.

Photopic and Mesopic Performance of 2 Different Trifocal Diffractive Intraocular Lenses.

Purpose To assess photopic and mesopic vision in patients implanted with 2 different trifocal intraocular lenses (IOLs). Methods Fifty patients with cataract in both eyes had surgery with bilateral implantation of a trifocal FineVision (FV, n = 25) or AT LISA tri 839MP (LisaTri, n = 25) IOL. Three months after surgery, high-contrast photopic uncorrected distance visual acuity and corrected distance visual acuity (CDVA) were determined using the Early Treatment Diabetic Retinopathy Study test. Intermediate (65 cm) and near (40 cm) visual acuity were also measured, both with best distance correction (DCIVA and DCNVA, respectively). The CSV1000 test chart was used for binocular and monocular contrast sensitivity. Defocus curves were constructed under photopic and mesopic conditions. Results Mean patient age was 68.4 ± 5.5 years (FV) and 67.3 ± 5.6 years (LisaTri) (p = 0.540). No differences were found in terms of visual acuity between the groups. The CDVA, DCIVA, and DCNVA were 0.05 ± 0.06, 0.25 ± 0.10, and 0.13 ± 0.10 logMAR for FV and -0.04 ± 0.11, 0.32 ± 0.09, and 0.12 ± 0.11 logMAR for LisaTri, respectively (p = 0.09, p = 0.08, and p = 0.12). Photopic and mesopic defocus curves were comparable between the 2 IOL groups (p>0.05). Mesopic values were significantly worse than photopic in both groups for all the measured values (p<0.001). No differences in contrast sensitivity were observed between the 2 IOL groups (p>0.05). Conclusions Both trifocal diffractive IOLs provided good visual quality with a statistically significant decrease in mesopic conditions.

Multifocal corneal ablation (Supracor) in hyperopic presbyopia: 1-year results in a cross-sectional study.

To evaluate the efficacy and safety of the multifocal excimer laser corneal ablation profile (the Supracor procedure) in hyperopic presbyopia 1 year after laser treatment. This prospective, consecutive, one-center, cross-sectional study included 20 patients with hyperopic presbyopia 1 year after treatment with the Supracor procedure. The main outcome measures were monocular uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA), photopic contrast sensitivity (Pelli-Robson charts), patient satisfaction, and functioning at 12 months. Thirty-nine eyes of 20 patients (mean age 59 ± 7.2 years) were treated. Mean UDVA improved from 0.56 ± 0.31 (mean 0.34 logMAR) preoperatively to 0.9 ± 0.15 (mean 0.06 logMAR) 12 months after surgery. Mean UNVA increased from 0.15 ± 0.07 (mean 0.84 logMAR) before surgery to 0.62 ± 0.24 (mean 0.23 logMAR) 12 months after treatment. Four eyes lost 2 lines of corrected distance visual acuity (10.3%). Monocular photopic contrast sensitivity was within age-correlated normal range (Pelli-Robson chart, mean contrast sensitivity 1.83 ± 0.18). A total of 75% of the patients would undergo Supracor again (1 not, 4 perhaps). The most frequently reported side effects were increased glare, reduced distance vision, and fluctuations in vision. Most patients used artificial tears. One year after Supracor, UDVA and UNVA improved markedly, photopic contrast sensitivity was in normal age-correlated range, and the majority of patients (75%) was satisfied with the results. Side effects like loss of distance vision, fluctuations of vision, and increased glare have a greater influence on patient satisfaction than the improvement of spectacle-free near vision.

Effect of Photorefractive Keratectomy on Nystagmus and Visual Functions in Myopic Patients With Infantile Nystagmus Syndrome

To determine the effect of photorefractive keratectomy (PRK) on involuntary eye movements, visual acuity, and contrast sensitivity in myopic patients with infantile nystagmus syndrome. Prospective interventional case series. This study was conducted on patients with infantile nystagmus syndrome and myopia equal to or more than-1 diopter (D), who were referred to our clinic over a 2-year period. Patients older than 18 years of age with a stable refraction for at least 1 year who were good candidates for PRK were included. Complete ophthalmologic examinations including assessment of best-corrected visual acuity (BCVA), contrast sensitivity, and videonystagmography were performed for all patients before and 3months after surgery. Twenty-four eyes of 12 patients with mean age of 23 ± 2 years were enrolled in this study. Spherical equivalent refractive error was-2.82 ± 1.65 D and-0.26 ± 0.25 D before and after PRK, respectively (P < .001). Monocular BCVA improved from 0.36 ± 0.21 logMAR to 0.27 ± 0.25 logMAR and binocular BCVA improved from 0.33 ± 0.2 logMAR to 0.17 ± 0.16 logMAR (P < .001). Contrast sensitivity significantly improved at low (P < .001), intermediate (P<.001), and high frequencies (P= .01). The frequency, amplitude, and intensity of nystagmus were significantly decreased after PRK (P < .001). There was no correlation between the degree of myopia correction and improvement in sensory and motor indicesof nystagmus (P > .1, Spearman correlation coefficient). PRK in patients with infantile nystagmus syndrome and myopia improved monocular and binocular BCVA and contrast sensitivity. Furthermore, motor indices of nystagmus (frequency, amplitude, and intensity) were significantly improved after surgery in these patients.

Effectiveness of Technolas torsional eye tracking system on visual outcomes after photorefractive keratectomy.

PurposeTo investigate the efficacy of Technolas 217Z eye tracking system (torsional component) in corneal surface irregularity and high order aberrations (HOAs) after photorefractive keratectomyMethodsPatients with compound myopic astigmatism among persons demanding refractive surgery in Khatam-al-Anbia Eye Hospital with the mean age of 29 years were enrolled in this double-blind randomized interventional study. The mean spherical equivalent (SE) of refractive error was −4.75 diopters(D) (range: −1.5 to −7.0), and the mean astigmatism was 3 D (range:1.0–4). Many studies were performed for each patient including: A complete eye examination, visual acuity and Monocular contrast sensitivity evaluation, and refraction. Corneal topography, Orbscan II, and wavefront aberrometry were conducted. One eye was randomly assigned for aspheric treatment and applying eye tracking system. The other eye was treated without torsional eye tracking system. The outcome measures were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), contrast sensitivity, corneal irregularity index in 3 mm and 5 mm optical zones in Orbscan II, and mean total HOAs at the 6-monthvisit.ResultsFifty eyes of 25 patients were enrolled. Mean UCVA was improved significantly in both the study and control groups in the 6-month post-operative follow-up. There was no significant difference between the 2 groups in UCVA and BCVA (P = 0.185 and P = 0.176, respectively). Total HOAs increased in both groups after PRK. However, they were lower in eyes treated with the eye tracking system (P < 0.001). Corneal irregularity index in 3 mm and 5 mm central zones in Orbscan II was significantly lower in the study group (P = 0.045 and P = 0.031 respectively). Contrast sensitivity function was not different in the 2 groups (P = 0.15).ConclusionOur study findings suggest that applying ‘Technolas 217z’ eye tracker system (Bausch and Lomb Advanced) results in a more regular anterior surface of cornea. Therefore, we recommend it for surface laser refractive surgery.

Comparative analysis of the visual performance and aberrometric outcomes with a new hybrid and two silicone hydrogel multifocal contact lenses: a pilot study

BackgroundThe aim was to evaluate the visual performance achieved with a new multifocal hybrid contact lens and to compare it with that obtained with two other currently available multifocal soft contact lenses.MethodsThis pilot prospective comparative study comprised a total of 16 presbyopic eyes of eight patients ranging in age from 43 to 58 years. All patients were fitted with three different models of multifocal contact lens: Duette multifocal (SynergEyes), Air Optix AQUA multifocal (Alcon) and Biofinity multifocal (CooperVision). Fittings were performed randomly in each patient according to a random number sequence, with a wash‐out period between fittings of seven days. At two weeks post‐fitting, visual, photopic contrast sensitivity and ocular aberrometry were evaluated.ResultsNo statistically significant differences were found in distance and near visual acuity achieved with the three different types of multifocal contact lens (p ≥ 0.05). Likewise, no significant differences between lenses were found in the monocular and binocular defocus curve (p ≥ 0.10). Concerning contrast sensitivity, better monocular contrast sensitivities for 6, 12 and 18 cycles per degree were found with the Duette and Air Optix multifocal compared to Biofinity (p = 0.02). Binocularly, differences between lenses were not significant (p ≥ 0.27). Furthermore, trefoil aberration was significantly higher with Biofinity multifocal (p < 0.01) and Air Optix (p = 0.01) multifocal compared to Duette.ConclusionsThe Duette multifocal hybrid contact lens seems to provide similar visual quality outcomes in presbyopic patients with low corneal astigmatism, when compared with other soft multifocal contact lenses. This preliminary result should be confirmed in studies with larger samples.

Dichoptic training improves contrast sensitivity in adults with amblyopia

Dichoptic training is designed to promote binocular vision in patients with amblyopia. Initial studies have found that the training effects transfer to both binocular (stereopsis) and monocular (recognition acuity) visual functions. The aim of this study was to assess whether dichoptic training effects also transfer to contrast sensitivity (CS) in adults with amblyopia. We analyzed CS data from 30 adults who had taken part in one of two previous dichoptic training studies and assessed whether the changes in CS exceeded the 95% confidence intervals for change based on test–retest data from a separate group of observers with amblyopia. CS was measured using Gabor patches (0.5, 3 and 10cpd) before and after 10days of dichoptic training. Training was delivered using a dichoptic video game viewed through video goggles (n=15) or on an iPod touch equipped with a lenticular overlay screen (n=15). In the iPod touch study, training was combined with anodal transcranial direct current stimulation of the visual cortex. We found that dichoptic training significantly improved CS across all spatial frequencies tested for both groups. These results suggest that dichoptic training modifies the sensitivity of the neural systems that underpin monocular CS.

Cost-Effectiveness Comparison Between Monofocal and Multifocal Intraocular Lens Implantation for Cataract Patients in Taiwan

PurposeOur aim was to conduct a cost-effectiveness analysis (CEA) of monofocal and multifocal intraocular lenses (IOLs) for cataract patients in Taiwan. MethodsThis prospective nonrandomized study was designed to evaluate the effectiveness of monofocal and multifocal IOLs by means of visual performance, visual quality, vision-related quality of life, and spectacle-independence rates. The direct costs were calculated using the payment points of the fee schedule for medical services multiplied by the treatment items. The concept of incremental cost effectiveness ratios was used to evaluate the costs of different types of IOLs in cataract surgery and postoperative outcomes in patients. FindingsA total of 61 patients from the monofocal IOL group (n = 21), multifocal IOL group 1 (n = 22), and multifocal IOL group 2 (n = 18) who completed the study were included in the analysis. No significant differences were observed in mean ages or patient to eye ratio. Significant differences in effectiveness after the implantations of monofocal and multifocal IOLs were observed for spectacle-free rate and monocular contrast sensitivity under glare conditions only. The incremental cost-effectiveness ratios of monofocal versus multifocal IOLs indicated that it cost an additional $57 to $58 (US dollars) to increase each 1% of the spectacle-independence rate. ImplicationsThis study’s results indicated that multifocal IOLs provided better effectiveness on vision-related indicators like the incremental cost effectiveness ratios of postoperative spectacle-independence rate and binocular best-corrected visual acuity measurements at near vision. Our findings suggest that multifocal IOLs can be highly cost effective for patients who prefer to be spectacle free, so it is important to ensure that patients have realistic expectations when making choices between monofocal and multifocal IOLs.

A Prospective Randomized Clinical Evaluation of 3 Presbyopia-Correcting Intraocular Lenses After Cataract Extraction

To compare contrast sensitivity, visual acuity (VA), and halos in subjects bilaterally implanted with 1 of 3 FDA-approved presbyopia-correcting intraocular lenses. Prospective, randomized, partially masked, multicenter clinical trial. Seventy-eight subjects were randomized sequentially for bilateral implantation with the Crystalens AO (Bausch & Lomb Surgical), AcrySof IQ ReSTOR+3.0 (Alcon Laboratories), or Tecnis Multifocal (Abbott Medical Optics) lenses. Subjects were evaluated through visit 4 (4 to 6months after surgery) with the following monocular and binocular assessments: high- and low-contrast VA, contrast sensitivity without glare, halos or starbursts, defocus curves, optical scatter, retinal point spread function, and safety. The Crystalens AO and ReSTOR+3.0 demonstrated better monocular and binocular contrast sensitivity without glare at low to mid spatial frequencies compared with the Tecnis Multifocal lens. Binocular uncorrected distance VA was not significantly different between the 3 lenses. The Crystalens AO had significantly better binocular low-contrast distance-corrected VA than the ReSTOR+3.0 and better mean monocular low-contrast DCVA than the Tecnis Multifocal lens. The Crystalens AO demonstrated significantly better monocular and binocular uncorrected and distance-corrected intermediate VA than the ReSTOR+3.0 or Tecnis Multifocal lenses. The ReSTOR+3.0 lens had significantly better monocular and binocular uncorrected and distance-corrected near VA tested at 40cm compared with the Crystalens AO and Tecnis Multifocal lens. The Crystalens AO elicited significantly less halos than the Tecnis Multifocal lens and less optical scatter than the ReSTOR+3.0 or Tecnis Multifocal lens. The Crystalens AO had statistically better uncorrected intermediate VA and distance-corrected intermediate VA than the ReSTOR+3.0 or Tecnis Multifocal lenses and fewer photic phenomenon than the Tecnis Multifocal lens. Both multifocals had better distance-corrected near VA and uncorrected near VA than the Crystalens AO. These findings may guide intraocular lens selection for individual patients seeking to optimize vision at specific vergences or lighting conditions.

Effects of Visual Noise on Binocular Summation in Patients With Strabismus Without Amblyopia

Patients with strabismus often complain of difficulty navigating through visually stimulating environments without clear explanation for this symptom. Binocular summation (BiS), defined as the superiority of binocular over monocular viewing on visual threshold tasks, is decreased in conditions that cause large interocular differences in visual acuity, but is not well studied in strabismic populations without amblyopia. The authors hypothesized that strabismus may lead to decreased BiS for tasks related to discrimination within increased background complexity. The goal of this study was to test the extent of BiS in patients with strabismus during discrimination of a luminance target disk embedded in visual noise. Participants included 10 exotropic, 10 esotropic, and 13 age-matched control patients. Performance of a task detecting a luminance-target was measured at 0, 10, and 20 μdeg(2) of visual noise for binocular and monocular conditions. BiS was calculated as the ratio of binocular contrast sensitivity to monocular contrast sensitivity for the target embedded in noise. Patients with strabismus had lower BiS values than controls, with a significant decrease on linear regression in patients with strabismus at 20 μdeg(2) of noise (P = .05), with a trend toward significance at 10 μdeg(2) of noise (P = .07). Patients with strabismus showed a mean binocular inhibition (summation ratio < 1) at both noise levels. These findings support the hypothesis that strabismus can lead to decreased BiS and even binocular inhibition. Despite literature showing enhanced BiS in visually demanding situations such as high levels of visual noise or low contrast, BiS was not significantly affected by visual noise in either group.

Visual outcomes and patient satisfaction after refractive lens exchange with a single-piece diffractive multifocal intraocular lens.

Purpose. To report visual outcomes and patient satisfaction after unilateral or bilateral refractive lens exchange (RLE) with a single-piece bifocal diffractive multifocal intraocular lens (MIOL). Methods. All patients underwent RLE with the ZMB00 MIOL (Abbott Medical Optics). Patient charts were reviewed to evaluate the distance, intermediate, and near visual acuity (VA), contrast sensitivity, extent of visual symptoms (0–5), satisfaction (1–5), and rate of spectacle independence between unilateral and bilateral RLE group. Results. Forty-seven eyes of 28 patients were included. No intraoperative complications developed. Mean monocular uncorrected VA at distance, intermediate (67 cm), and near (30 cm) were 0.01 ± 0.12 (standard deviation), 0.27 ± 0.18, and 0.15 ± 0.11, respectively. No eyes lost >1 line of corrected distance VA. Monocular contrast sensitivity remained at normal level. Median scores of halos, night glare, and starbursts for 27 patients were 2.0, 3.0, and 0.0, respectively. Median score of satisfaction was 4.0. There were no differences in visual symptom scores or satisfaction between unilateral and bilateral group (P > 0.05). Eighty percent of 25 patients reported total spectacle freedom, with similar rate between bilateral (82%) and unilateral group (75%) (P = 1.000). Conclusions. RLE with the bifocal diffractive MIOL was safe in presbyopic patients and resulted in a high rate of spectacle independence.

Visual Outcomes of a Trifocal Aspheric Diffractive Intraocular Lens With Microincision Cataract Surgery

To evaluate the visual outcomes of patients with a new diffractive trifocal intraocular lens (IOL). A trifocal diffractive Fine Vision IOL (Physiol, Liege, Belgium) was implanted after microincision cataract surgery (MICS) in 40 eyes of 20 patients with bilateral cataract. The monocular and binocular visual performance and the refractive status were assessed, as well as the defocus curve and contrast sensitivity at 1 and 6 months postoperatively. The monocular visual outcomes (logMAR) at 6 months postoperatively were uncorrected distance visual acuity 0.18 ± 0.13, uncorrected near visual acuity 0.26 ± 0.15, and uncorrected intermediate visual acuity 0.20 ± 0.11. With the best distance correction, the visual outcomes were 0.05 ± 0.06 for corrected distance visual acuity, 0.16 ± 0.13 for distance corrected near visual acuity, and 0.17 ± 0.09 for distance corrected intermediate visual acuity. Binocular defocus curve at 6 months shows a wide range of useful vision with 0.19 ± 0.08 (logMAR) at -1.50 diopter defocus. The monocular contrast sensitivity under scotopic conditions (3 cd/m(2)) was within normal range for a population older than 60 years. The trifocal Fine Vision IOL can restore vision at different distances after cataract surgery, specifically intermediate and near vision.

Intra-eye Visual Function Comparison With and Without a Central Hole Contact Lens-Based System: Potential Applications to ICL Design

To evaluate the effects of a central hole contact lens-based design on visual performance and to compare it with the standard version of that same contact lens without the hole (non-hole scenario). The visual performance of 10 myopic patients wearing either a central hole myopic contact lens or its corresponding standard version (non-hole contact lens) was assessed on the same eye. Monocular corrected distance visual acuity was measured under photopic conditions and monocular contrast sensitivity was measured under both photopic and mesopic conditions and higher-order ocular aberrations using Hartmann-Shack aberrometry. An in vitro optical analysis of both contact lenses was performed and a symptoms questionnaire was administered to the participants. No statistically significant differences in terms of corrected distance visual acuity were found: -0.091 and -0.098 logMAR for the hole and non-hole contact lenses, respectively (P > .05). Contrast sensitivity was comparable between lenses and no differences were found for specific spatial frequencies or a particular luminance level (P > .05). The hole contact lenses provided excellent outcomes, essentially equivalent to those of non-hole contact lenses, even in terms of subjective symptoms such as glare or halo. In vivo and in vitro optical quality analysis revealed no statistically significant differences between the hole and the non-hole contact lenses for either pupil size (P > .1). A contact lens having a central hole provides good visual and optical quality outcomes comparable to those yielded by the same lens without a hole. The results suggest that the impact of a central hole may be clinically negligible.

Correlation of Inner Retinal Thickness Evaluated by Spectral-Domain Optical Coherence Tomography and Contrast Sensitivity in Parkinson disease

To compare inner retinal layer (IRL) thickness measured by spectral-domain optical coherence tomography (SD-OCT) and contrast sensitivity (CS) in patients with Parkinson disease (PD) and in healthy control (HC) subjects. Consecutive patients with and without PD were prospectively analyzed using SD-OCT and Pelli-Robson CS testing. SD-OCT IRL (ganglion-cell complex) thickness, consisting of the nerve fiber layer, ganglion cell layer, and inner plexiform layer, was segmented using an RTVue Model-RT100 with an EMM5 scan parameter covering a 5.0 × 5.0 mm cube centered on the fovea. Thickness voxel measurements at 0.25-mm intervals at sequential radial distances from the foveola were acquired horizontally and vertically. SD-OCT thickness raw data files were imported and analyzed within MATLAB (version 7.10.0). A database of CS scores and IRL thickness values by foveal location was constructed and statistically evaluated using JMP 10 (SAS Institute, Inc, Cary, NC). The results were compared between 28 eyes of 14 patients with PD and 28 eyes of 14 HC subjects. Controlling for age, mean CS scores of monocular right and randomized eyes were statistically lower in PD eyes (P < 0.05). IRL was significantly thinner in PD eyes than in HC eyes at several distances from the foveola (P < 0.05). The most numerous and significant thickness differences by diagnosis were located in the superior quadrant at a distance of 1.00-1.75 mm from the foveal center (17 μm; P < 0.01, maximum significant thickness difference and P value). Correlation was demonstrated between monocular CS and IRL thickness by diagnosis at multiple foveal locations for HC eyes as follows: nasal quadrant, 0.75-1.00 mm (P < 0.02); temporal quadrant, 0.50-1.00 mm (P < 0.05); superior quadrant, 1.00 mm (P < 0.05); and inferior quadrant, 1.00 mm (P < 0.03). No significant correlation was found between monocular CS and IRL thickness within PD subjects (P > 0.05 for each foveal location measured). CS and foveal IRL thickness are decreased in patients with PD. CS and IRL thickness correlated in HC subjects; however, no such correlation was demonstrated in PD. The functional deficit of dopaminergic interneurons, including amacrine cells, may outstrip the anatomic structural changes in the inner retina of PD patients. Inner retinal atrophic changes may underlie the pathogenesis of CS deficit and IRL thinning in PD.

Modified Monovision With Spherical Aberration to Improve Presbyopic Through-Focus Visual Performance

To investigate the impact on visual performance of modifying monovision with monocularly induced spherical aberration (SA) to increase depth of focus (DoF), thereby enhancing binocular through-focus visual performance. A binocular adaptive optics (AO) vision simulator was used to correct both eyes' native aberrations and induce traditional (TMV) and modified (MMV) monovision corrections. TMV was simulated with 1.5 diopters (D) of anisometropia (dominant eye at distance, nondominant eye at near). Zernike primary SA was induced in the nondominant eye in MMV. A total of four MMV conditions were tested with various amounts of SA (± 0.2 and ± 0.4 μm) and fixed anisometropia (1.5 D). Monocular and binocular visual acuity (VA) and contrast sensitivity (CS) at 10 cyc/deg and binocular summation were measured through-focus in three cyclopledged subjects with 4-mm pupils. MMV with positive SA had a larger benefit for intermediate distances (1.5 lines at 1.0 D) than with negative SA, compared with TMV. Negative SA had a stronger benefit in VA at near. DoF of all MMV conditions was 3.5 ± 0.5 D (mean) as compared with TMV (2.7 ± 0.3 D). Through-focus CS at 10 cyc/deg was significantly reduced with MMV as compared to TMV only at intermediate object distances, however was unaffected at distance. Binocular summation was absent at all object distances except 0.5 D, where it improved in MMV by 19% over TMV. Modified monovision with SA improves through-focus VA and DoF as compared with traditional monovision. Binocular summation also increased as interocular similarity of image quality increased due to extended monocular DoF.

Contrast sensitivity after refractive lens exchange with a multifocal diffractive aspheric intraocular lens

To evaluate distance and near contrast sensitivity (CS) under photopic and mesopic conditions before and after refractive lens exchange (RLE) and implantation of the aspheric AcrySofReSTOR (SN6AD3 model) intraocular lens (IOL). Seventy-four eyes of 37 patients after RLE underwent bilateral implantation with the aspheric AcrySof ReSTOR IOL. The patient sample was divided into myopic and hyperopic groups. Monocular uncorrected visual acuity at distance and near (UCVA and UCNVA, respectively) and monocular best corrected visual acuity at distance and near (BCVA and BCNVA, respectively) were measured before and 6 months postoperatively. Monocular CS function was measured at three different luminance levels (85, 5 and 2.5 cd/m²) before and after RLE. Post-implantation results at 6 months were compared with those found before surgery. Our results revealed that patients in both groups obtained good UCVA and BCVA after RLE at distance and near vision in relation to pre-surgery values. No statistically significant differences were found between the values of CS pre and post-RLE at distance and near, at any lighting condition and spatial frequency (p>0.002). Refractive lens exchange with aspheric AcrySof ReSTOR IOL in myopic and hyperopic population provided good visual function and yield good distance and near CS under photopic and mesopic conditions.

両眼固視中の片眼におけるコントラスト感度の低下

To investigate binocular single vision, we examined monocular contrast sensitivity during binocular fixation by changing the intervals between the beginning of fixation and a probe stimulus, within 10 seconds. Monocular contrast sensitivities were quite stable within 1s of the interval delay in both eyes, but they were reduced in either eye if the interval delay was more than 1s (Experiment 1). In Experiment 2, a similar stimulus was monocularly presented. In this case, decline of contrast sensitivity was not observed in either eye. In Experiment 3, when the stimulus was interrupted briefly before the probe presentation, the contrast sensitivity was recovered. These results suggest that after prolonged viewing the binocular system does not sustain either eye sensitivity equally unless there is interruption of the binocular stimulation.