Difference In Distance Visual Acuity Research Articles

Analysis of higher-order aberrations in relation to the clinical outcome of an enhanced monofocal IOL.

To analyse higher-order aberrations of an enhanced monofocal aspheric intraocular lens (IOL) in relation to the clinical outcome compared to a monofocal aspheric IOL. Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Germany. Prospective, monocentric, controlled, non-randomized, two-armed study. After phacoemulsification, a total of 30 patients (60 eyes) were bilaterally implanted with either TECNIS Eyhance IOL model ICB00 (Johnson & Johnson Surgical Vision, Inc.) or TECNIS Monofocal 1-Piece IOL model ZCB00 (Johnson & Johnson Surgical Vision, Inc.) in 30 eyes each. Assessments were performed 1 and 3 months after surgery including refraction, uncorrected and best-corrected distance, intermediate and near visual acuity, defocus curves, contrast sensitivities under photopic, mesopic and mesopic conditions with glare, higher-order aberrations (HOAs) at pupil sizes of 5, 4, 3 and 2 mm and patient satisfaction. At 3-month follow-up, measurements of HOAs revealed significant higher negative internal and ocular primary spherical aberrations in the ICB00 group at pupil sizes of 5, 4, 3 and 2 mm. The ICB00 showed significant better results in intermediate and near visual acuity, but no difference in distance visual acuity. No significant difference was found in contrast sensitivities at any condition or spatial frequency. Spectacle independence was significant better without significant higher rates of dysphotopsia in the ICB00 group. Higher negative spherical aberrations in the ICB00 group at all measured pupil sizes appear to lead to a superior clinical outcome in intermediate and near vision compared to the ZCB00 group without compromising contrast sensitivity or distance visual acuity.

Patient Satisfaction and Visual Performance in Patients with Ocular Pathology after Bilateral Implantation of a New Extended Depth of Focus Intraocular Lens.

Aim To evaluate visual results and patient-perceived outcomes in patients with ocular pathologies implanted with a new extended depth-of-focus intraocular lens (IOL). Methods Patients with ocular pathology undergoing cataract surgery and bilaterally implanted with Vivity® IOLs were evaluated three months after surgery. The control group included patients with no ocular pathologies. Binocular defocus curves, corrected and uncorrected mono- and binocular distance visual acuity (DVA), and binocular contrast sensitivity were measured. Patients completed the Catquest-9SF questionnaire and reported on dysphotopsia and their need for spectacle-correction. Results Twenty-five patients were included in each group. Monocular uncorrected DVA was better in the control group (−0.01 ± 0.07) compared with the study group (0.03 ± 0.08), p=0.027. There were no other statistically significant differences in DVA, with an uncorrected binocular acuity of −0.06 ± 0.06 for the control group and −0.05 ± 0.06 for the study group. Binocular defocus curves were similar for both groups and there were no differences in contrast sensitivity values. Pooling the refractive results, 96% of eyes were within ±0.50 D of target refraction. Seventy percent of patients in the control group reported no halos, compared with 40% in the study group, p=0.047. In both groups, 40% of patients reported being completely spectacle-independent, with the other 60% requiring glasses for near vision always or often. All patients reported being fairly or very satisfied with their vision. Conclusion Initial results of visual function after Vivity implantation in patients with ocular pathologies are encouraging, with high patient satisfaction and few difficulties for daily activities.

Development and Validation of a Mobile Visual Acuity Examination App for Universal Use, Including Remote and Rural Regions

Background: Visual refractive errors are projected to rise in the coming decades worldwide, especially in remote and rural regions. To combat this, smartphone visual acuity testing apps may allow for the early detection of refractive errors thanks to their low cost and wide availability. Hence, we developed the OcularCheck app as a free mobile vision screening tool for public health use. Objective: We sought to determine whether OcularCheck accurately measures distance visual acuity (DVA) in comparison to a standard Snellen chart (Space Saving Chart SSC-350). Methods and Results: In January 2021, we measured DVA in n=56 eyes using the OcularCheck app and a standard Snellen chart. To minimize bias, we used two separate examiners who were blinded to each other’s measurements. To assess the similarity of measurement methods, we performed a two-tailed, paired t-test and Bland-Altman analysis using the R-Project software. The t-test showed that differences in DVA between testing methods were not significant (P=0.698). Bland-Altman analysis showed that the mean difference between measurement methods was 0.01 LogMAR (95% CI -0.03 to 0.04), and the standard deviation of differences (0.139 LogMAR) was below the test-retest variability of the Snellen chart. The main limitation of the study was that we were not able to measure DVA with non-English optotypes. Conclusion: OcularCheck provides accurate DVA measurements, and it harbors the potential to expand the accessibility of DVA screening to resource-scarce regions.

Development and Validation of a Mobile Visual Acuity Examination App for Universal Use, Including Remote and Rural Regions

Background: Visual refractive errors are projected to rise in the coming decades worldwide, especially in remote and rural regions. To combat this, smartphone visual acuity testing apps may allow for the early detection of refractive errors thanks to their low cost and wide availability. Hence, we developed the OcularCheck app as a free mobile vision screening tool for public health use. Objective: We sought to determine whether OcularCheck accurately measures distance visual acuity (DVA) in comparison to a standard Snellen chart (Space Saving Chart SSC-350). Methods and Results: In January 2021, we measured DVA in n=56 eyes using the OcularCheck app and a standard Snellen chart. To minimize bias, we used two separate examiners who were blinded to each other’s measurements. To assess the similarity of measurement methods, we performed a two-tailed, paired t-test and Bland-Altman analysis using the R-Project software. The t-test showed that differences in DVA between testing methods were not significant (P=0.698). Bland-Altman analysis showed that the mean difference between measurement methods was 0.01 LogMAR (95% CI -0.03 to 0.04), and the standard deviation of differences (0.139 LogMAR) was below the test-retest variability of the Snellen chart. The main limitation of the study was that we were not able to measure DVA with non-English optotypes. Conclusion: OcularCheck provides accurate DVA measurements, and it harbors the potential to expand the accessibility of DVA screening to resource-scarce regions.

Visual Performance and Optical Quality after Implantation of a New Generation Monofocal Intraocular Lens.

PurposeTo evaluate the performance of two intraocular lenses (IOLs). The new monofocal IOL using a higher-order aspheric optic (Tecnis Eyhance ICB00) was compared to a standard monofocal IOL (Tecnis monofocal ZCB00) of the identical platform and material.MethodsThe medical records of the patients who had undergone cataract surgery with implantation of either the ZCB00 or the ICB00 in the dominant eye from March 2020 to August 2020 and with available data from the 3-month visit were reviewed. Subjects with ocular comorbidities or corneal astigmatism greater than 1.00 diopters were excluded. The uncorrected near, intermediate, distance visual acuity and corrected distance visual acuity were the main outcome measures. Optical quality parameters measured using an optical quality analysis system, clinical records including age, sex, laterality, ocular dominance, and information related to refractory errors was also collected. Parameters related to the refractory errors were all uniformly based on the Barrett Universal II formula.ResultsOf the 197 recruited patients, 111 and 86 were implanted with the ICB00 and ZCB00, respectively. No statistically significant differences in baseline parameters were observed between the two groups. While no statistically significant differences in distance visual acuity or optical quality were found between the two groups, compared to the ZCB00 group, the ICB00 group showed significantly higher intermediate visual acuity (p < 0.001) and near visual acuity (p < 0.05) 3 months postoperatively.ConclusionsICB00 provided superior intermediate vision and comparable distance performance and photic phenomena compared to a standard monofocal IOL.

Distance visual acuity in air force pilots and student pilots when exposed to +Gz acceleration in human centrifuge

Background/Aim. High speeds that modern aircraft develop during take-off, flight and landing place an additional strain on the organ of vision. Owing to its considerable practical implementation in air combat, the effect of +Gz acceleration on the organ of vision is considered increasingly important for research. Substantial changes in visual functions may occur during high acceleration onset rates. However, it is important for a pilot to maintain visual acuity in order to be able to monitor new functional displays for rapid orientation, scan the configuration of terrain, display of weapons systems and enemy aircraft and deal with additional issues of the complexity of spatial orientation. The aim of the investigation was to establish whether distance visual acuity in air force pilots and student pilots is affected when exposed to +Gz acceleration. ??thods. The study was performed on a defined population consisting of 95 respondents from 21 to 45 years of age divided into two groups. The first group included 65 air force pilots and the second group comprised of 30 student pilots, all of whom were exposed to an acceleration of +5.5 Gz. The testing was per-formed in a human centrifuge, which mimics conditions of real Gz acceleration, in the Department of Biodynamics in Aero Medical Institute (Zemun, Serbia). We examined the obtained differences in distance visual acuity before and after exposure to acceleration. Results. After the testing, all respondents in the group of air force pilots had distance visual acuity of 1.0, while in the group of student pilots a statistically significant difference in distance visual acuity was observed after being exposed to +Gz acceleration. Conclusion. Transient changes in distant visual acuity were more pronounced in the group of student pilots in comparison with the changes in visual acuity in the air force pilots when exposed to the same acceleration values (+5Gz acceleration). Since change in distance visual acuity is the most sensitive physiological indicator when exposed to high acceleration, individual physiological pilot training in the human centrifuge increases tolerance to accelerations, which is important for flight safety in both peacetime and combat conditions.

Rainbow halos occur less following implantation of extended range of vision one-piece intraocular lenses vs diffractive bifocal intraocular lenses.

To evaluate clinical outcomes following implantation of an extended range of vision intraocular lens (IOL), the ZXR00, and a diffractive multifocal IOL with +2.75 diopters (D) add power, the ZKB00. Totally 30 patients who underwent either bilateral implantation of the ZXR00 IOL with intended emmetropia (ZXR00 emmetropia group: 20 eyes) and intended micromonovision (ZXR00 monovision group: 20 eyes), or bilateral implantation of the ZKB00 IOL with intended emmetropia (ZKB00 group: 20 eyes) were included in this study. Visual acuity at 4 m, 80, and 40 cm; and the types of halos (misty, fine, and rainbow) were analyzed at one and three months after surgery. There were no significant differences in distance visual acuity among the three groups. The mean uncorrected intermediate visual acuity was better in the ZXR00 emmetropia and monovision groups (0.02 logMAR and 0.02 logMAR, respectively) than in the ZKB00 group (0.14 logMAR). The mean uncorrected near visual acuity was worse in the ZXR00 emmetropia group (0.26 logMAR) than in the ZXR00 monovision and ZKB00 groups (0.12 logMAR and 0.10 logMAR, respectively). There was an increased incidence of rainbow halos in the ZKB00 group vs in either ZXR00 group (P=0.033). Implantation of the ZXR00 IOL with intended micromonovision provide superior visual acuity than implantation of the ZXR00 IOL with intended emmetropia. The ZXR00 IOLs tend to show a lower incidence of rainbow halos than did the ZKB00 IOL.

Visual function is reduced in young adults formerly born prematurely: a population-based study

AimsTo assess visual function in young adults born preterm and compare with full-term individuals of the same age.MethodsYoung adults, born preterm (birth weight ≤1500 g) in 1988–1990, previously included in...

Impact de l’instillation de collyres mydriatiques sur la mesure d’acuité visuelle de loin chez des patients présentant une DMLA exsudative

To demonstrate a decrease in distance visual acuity (VA) following instillation of mydriatic eyedrops in eyes with exudative age-related macular degeneration (AMD). A prospective assessment in clinical practice was conducted in our ophthalmology department at the University Hospital of Tours from 7/19/2018 to 8/29/2018. Distance (ETDRS) and near (Parinaud) VA were assessed before and after instilling one drop each of tropicamide 0.5% and phenylephrine 10% in the 40 included eyes with exudative AMD. The mean difference in distance VA before and after pupillary dilation (PD) was 0.06 LogMAR (SD=0.14) (P<0.01), i.e. -3.05 letters read (SD=7.52) on the ETDRS chart (P=0.01). For near VA, the mean difference was 0.16 LogMAR (SD=0.16) (P<0.001), i.e. -1.58 paragraphs read (SD=1.63) on the Parinaud chart (P<0.001). The absence of a clinically significant loss in post-dilation distance VA for exudative AMD could be explained by negligible glare coming from the ETDRS chart, milder photophobia, low pre-dilation VA's and a balance between higher order optical aberrations and diffraction. The opposite result for near VA could essentially be explained by greater glare induced by the light illuminating the Parinaud chart. Our primary goal was not achieved. A study presuming the absence of a clinically significant decrease in post-dilation distance VA would be necessary to consider directly measuring post-dilation VA in eyes with exudative AMD in our daily practice.

Multifocal versus monofocal intraocular lenses after cataract extraction.

Good unaided distance visual acuity (VA) is now a realistic expectation following cataract surgery and intraocular lens (IOL) implantation. Near vision, however, still requires additional refractive power, usually in the form of reading glasses. Multiple optic (multifocal) IOLs are available which claim to allow good vision at a range of distances. It is unclear whether this benefit outweighs the optical compromises inherent in multifocal IOLs. To assess the visual effects of multifocal IOLs in comparison with the current standard treatment of monofocal lens implantation. We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2016), Embase (January 1980 to June 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 13 June 2016. All randomised controlled trials comparing a multifocal IOL of any type with a monofocal IOL as control were included. Both unilateral and bilateral implantation trials were included. We also considered trials comparing multifocal IOLs with "monovision" whereby one eye is corrected for distance vision and one eye corrected for near vision. We used standard methodological procedures expected by Cochrane. We assessed the 'certainty' of the evidence using GRADE. We found 20 eligible trials that enrolled 2230 people with data available on 2061 people (3194 eyes). These trials were conducted in Europe (13), China (three), USA (one), Middle East (one), India (one) and one multicentre study in Europe and the USA. Most of these trials compared multifocal with monofocal lenses; two trials compared multifocal lenses with monovision. There was considerable variety in the make and model of lenses implanted. Overall we considered the trials at risk of performance and detection bias because it was difficult to mask participants and outcome assessors. It was also difficult to assess the role of reporting bias.There was moderate-certainty evidence that the distance acuity achieved with multifocal lenses was not different to that achieved with monofocal lenses (unaided VA worse than 6/6: pooled RR 0.96, 95% confidence interval (CI) 0.89 to 1.03; eyes = 682; studies = 8). People receiving multifocal lenses may achieve better near vision (RR for unaided near VA worse than J3/J4 was 0.20, 95% CI 0.07 to 0.58; eyes = 782; studies = 8). We judged this to be low-certainty evidence because of risk of bias in the included studies and high heterogeneity (I2 = 93%) although all included studies favoured multifocal lenses with respect to this outcome.People receiving multifocal lenses may be less spectacle dependent (RR 0.63, 95% CI 0.55 to 0.73; eyes = 1000; studies = 10). We judged this to be low-certainty evidence because of risk of bias and evidence of publication bias (skewed funnel plot). There was also high heterogeneity (I2 = 67%) but all studies favoured multifocal lenses. We did not additionally downgrade for this.Adverse subjective visual phenomena were more prevalent and more troublesome in participants with a multifocal IOL compared with monofocals (RR for glare 1.41, 95% CI 1.03 to 1.93; eyes = 544; studies = 7, low-certainty evidence and RR for haloes 3.58, 95% CI 1.99 to 6.46; eyes = 662; studies = 7; moderate-certainty evidence).Two studies compared multifocal lenses with monovision. There was no evidence for any important differences in distance VA between the groups (mean difference (MD) 0.02 logMAR, 95% CI -0.02 to 0.06; eyes = 186; studies = 1), unaided intermediate VA (MD 0.07 logMAR, 95% CI 0.04 to 0.10; eyes = 181; studies = 1) and unaided near VA (MD -0.04, 95% CI -0.08 to 0.00; eyes = 186; studies = 1) compared with people receiving monovision. People receiving multifocal lenses were less likely to be spectacle dependent (RR 0.40, 95% CI 0.30 to 0.53; eyes = 262; studies = 2) but more likely to report problems with glare (RR 1.41, 95% CI 1.14 to 1.73; eyes = 187; studies = 1) compared with people receiving monovision. In one study, the investigators noted that more people in the multifocal group underwent IOL exchange in the first year after surgery (6 participants with multifocal vs 0 participants with monovision). Multifocal IOLs are effective at improving near vision relative to monofocal IOLs although there is uncertainty as to the size of the effect. Whether that improvement outweighs the adverse effects of multifocal IOLs, such as glare and haloes, will vary between people. Motivation to achieve spectacle independence is likely to be the deciding factor.

Visual and optical performances of multifocal intraocular lenses with three different near additions: 6-month follow-up.

Purpose : To compare the visual and optical outcomes of four multifocal intraocular lenses (IOLs) with three different near additions of +3.00 diopters (D), +3.75 D and +4.00 D.Methods : In this prospective study, 133 eyes of 88 patients were implanted with one of the following IOLs: AcrySof® ReSTOR® SN6AD1 (+3.00 D) for Group A, AcrivaUD Reviol BB MF 613 or BB MFM 611 (+3.75 D) for Group B, and AcrySof® ReSTOR® SN6AD3 (+4.00 D) for Group C. The visual acuity, refraction, intraocular pressure, tomography and corneal endothelial cell density (ECD) were compared between the three groups preoperatively and at 6 month postoperatively. Defocus curve, contrast sensitivity and higher order aberrations (HOAs) at 6 month postoperative visit were measured and compared.Results : There were no statistically significant differences in distance visual acuity, refraction, intraocular pressure or ECD among the three groups after 6 months (P > 0.05). The photopic contrast sensitivity in Group C was statistically better than in Group A (P < 0.05). The scotopic ocular aberration in Group B was statistically greater compared to that in Group A (P < 0.05). The highest near-visual peaks were -0.06 logMAR at a -2.50 D (40 cm) in Group A, -0.07 logMAR at -3.00D (33 cm) in Group B, and -0.06 logMAR at -3.50 D (29 cm) in Group C. Statistically significant differences in near and intermediate visual acuities were observed among the three groups at -2.00 D (50 cm), -2.50 D (40 cm), -3.50 D (29 cm) and -4.00 D (25 cm) (P < 0.01).Conclusion : AcrySof® ReSTOR® SN6AD1 IOLs (+3.00 D) and SN6AD3 (+4.00 D) IOLs provided the best intermediate and near vision, respectively. Both intermediate and near vision were comparatively better in the eyes with AcrivaUD Reviol BB MFM 611 IOLs or BB MF 613 IOLs (+3.75 D).

Crystalens HD Intraocular Lens Analysis Using an Adaptive Optics Visual Simulator

To compare visual and optical quality of the Crystalens HD intraocular lens (IOL) with that of a monofocal IOL. The wavefront aberration patterns of the monocular Akreos Adapt AO IOL and the single-optic accommodating Crystalens HD IOL were measured in a model eye. The Crystalens IOL was measured in its nonaccommodative state and then, after flexing the haptic to produce 1.4 mm of movement, in its accommodative state. Using an adaptive optics system, subjects' aberrations were removed and replaced with those of pseudophakes viewing with either lens. Monocular distance visual acuity (DVA) at high (100%), medium (50%), and low (10%) contrast and contrast sensitivity (CS) were measured for both IOL optics. Near VA (NVA) and CS were measured for the Crystalens HD IOL in its accommodative state. Depth of focus around the distance and near focus was also evaluated for the Crystalens HD IOL. Modulation transfer function (MTF), point spread function (PSF), and Strehl ratio were also calculated. All measures were taken for 3- and 5-mm pupils. The MTF, PSF, and Strehl ratio showed comparable values between IOLs (p > 0.05). There were no significant differences in DVA and CS between IOLs for all contrasts and pupils (p > 0.05). When spherically focused, mean DVA and NVA with the Crystalens HD IOL were ≥20/20 at 100 and 50% contrasts for both pupils. Monocular DVA, NVA, and CS were slightly better with 3- than 5-mm pupils, but without statistically significant differences. The Crystalens HD IOL showed about 0.75 and 0.50 D of depth of focus in its accommodative state and nonaccommodative state, respectively. The optical and visual quality with the nonaccommodatied Crystalens HD IOL was comparable to that of a monofocal IOL. If this lens can move 1.4 mm in the eye, it will provide high-quality optics for near vision as well.

Contrast sensitivity as a function of focus in patients with the diffractive multifocal intraocular lens

Contrast sensitivity as a function of focus and visual acuity as a function of contrast were investigated in 19 patients with a diffractive multifocal intraocular lens and compared with 19 control patients with a conventional monofocal implant. The contrast sensitivity of the multifocal patients followed a bimodal curve with a maximum sensitivity at the far focus and a second peak at the near focus, corresponding to about +3 diopters in the spectacle plane. The maximum sensitivity of the multifocal group was 0.14 log units lower than the control group (PÅ.05). In the near region, the contrast sensitivity of the multifocal patients exceeded that of the control group from + 2 diopters and inward. No difference in distance visual acuity was found with high contrast letters. With intermediate contrast letters, the visual acuity of the multifocal patients was lower than that of the control group (PÅ.05).