Differences In Visual Function Research Articles

Differences in Guttae Ultramorphology in Relation to Visual Function in Fuchs Endothelial Corneal Dystrophy.

The purpose of this study was to investigate the differences in guttae ultramorphology and their relation to visual function in eyes with Fuchs endothelial corneal dystrophy (FECD). Thirty FECD eyes without ocular comorbidities were included. Visual functional parameters (best-corrected visual acuity with high-contrast and low-contrast letters and contrast sensitivity/LogCS) and corneal morphology measured with Scheimpflug tomography (Pentacam) were assessed. The surgically removed Descemet membranes were examined by light and transmission electron microscopy. Preoperative mean best-corrected visual acuity (logarithm of the minimum angle of resolution) was 0.52 ± 0.18, LogCS 0.96 ± 0.21 and central corneal thickness 640 ± 55 μm. All eyes had signs of subclinical corneal edema in Scheimpflug tomography; clinically visible corneal edema was present in 40% of eyes. Histological findings included a posterior fibrillar zone (PFZ) in 10 specimens (33%) and abnormal collagen depositions in Descemet membranes in 14 specimens (47%). Guttae buried within the PFZ were present only in eyes with clinically visible edema (n = 4, 13%). There was no difference in visual function results and tomography parameters between eyes with and without PFZ or between protruding guttae and guttae embedded in a PFZ, respectively. Guttae morphology and density were not correlated with visual functional parameters. Guttae buried in a PFZ occurred only in eyes with clinically manifest edema, and thereby, they are an ultramorphological sign for advanced FECD. Subclinical edema was present in all eyes and might be more relevant for quality of vision than guttae ultramorphology.

Neurochemistry and functional connectivity in the brain of people with Charles Bonnet syndrome.

Charles Bonnet syndrome (CBS) is a condition in which people with vision loss experience complex visual hallucinations. These complex visual hallucinations may be caused by increased excitability in the visual cortex that are present in some people with vision loss but not others. We aimed to evaluate the association between γ-aminobutyric acid (GABA) in the visual cortex and CBS. We also tested the relationship among visually evoked responses, functional connectivity, and CBS. This is a prospective, case-controlled, cross-sectional observational study. We applied 3-Tesla magnetic resonance spectroscopy, as well as task-based and resting state (RS) connectivity functional magnetic resonance imaging in six participants with CBS and six controls without CBS. GABA+ was measured in the early visual cortex (EVC) and in the lateral occipital cortex (LOC). Participants also completed visual acuity and cognitive tests, and the North-East Visual Hallucinations Interview. The two groups were well-matched for age, gender, visual acuity and cognitive scores. There was no difference in GABA+ levels between groups in the visual cortex. Most participants showed the expected blood oxygenation level dependent (BOLD) activation to images of objects and the phase-scrambled control. Using a fixed effects analysis, we found that BOLD activation was greater in participants with CBS compared to controls. Analysis of RS connectivity with LOC and EVC showed little difference between groups. A fixed effects analysis showed a correlation between the extent of functional connectivity with LOC and hallucination strength. Overall, our results provide no strong evidence for an association between GABAergic inhibition in the visual cortex and CBS. We only found subtle differences in visual function and connectivity between groups. These findings suggest that the neurochemistry and visual connectivity for people with Charles Bonnet hallucinations are comparable to a sight loss population. Differences between groups may emerge when investigating subtle and transient changes that occur at the time of visual hallucinations.

Hyperopia in schoolchildren: Investigating the impact on vision and determining appropriate methods for screening.

Hyperopia is associated with reduced vision and educational outcomes in schoolchildren. This study explored the impact of clinically significant hyperopia (≥+2.00 D) on visual function in schoolchildren and compared the ability of different screening tests (alone and in combination) to detect this level of hyperopia. Vision testing including monocular logMAR visual acuity (VA) measured to threshold (distance [DVA], near [NVA] and DVA through a plus lens [+2.50 D]), stereoacuity and cycloplegic autorefraction (tropicamide 1%) were undertaken on 263 schoolchildren (mean age: 11.76 years ± 3.38) in Queensland, Australia. Vision measures were compared between children with clinically significant hyperopia in at least one meridian (≥+2.00 D) and emmetropia/low hyperopia (>0.00 and <+2.00 D). Receiver operating curve (ROC) analysis was performed to identify optimal pass/fail criteria for each test and the diagnostic accuracy of individual and combinations of tests. Thirty-two children had clinically significant hyperopia and 225 had emmetropia/low hyperopia. DVA and NVA were worse (p < 0.01), while the difference in DVA through a plus lens was less in children with clinically significant hyperopia (p < 0.01). ROC analysis for individual tests resulted in areas under the curve (AUCs) ranging from 0.65 to 0.85. Combining screening tests revealed that failing one or more of the following tests was most effective for detecting hyperopia: DVA, NVA and difference in DVA through a plus lens, resulting in a sensitivity and specificity of 72% and 81%, respectively. Significant differences in visual function existed between schoolchildren with clinically significant hyperopia and emmetropia/low hyperopia. Combining measures of DVA and NVA and the difference in DVA through a plus lens demonstrated good discriminative ability for detecting clinically significant hyperopia in this population.

Subclinical damage to the contralateral eye in unilateral optic neuritis: A longitudinal study.

Early detection of subclinical injuries can lead to a correct diagnosis and help control the advancement of the condition. This study aims to investigate the presence of subclinical damage and silent progression to the contralateral eye's visual function and structure in patients experiencing their first episode of unilateral optic neuritis (ON). Fifty patients with first-onset unilateral ON were enrolled in this study. Based on etiology, they were classified as having neuromyelitis optica spectrum disorder-related ON (NMOSD-ON), myelin oligodendrocyte glycoprotein antibody-associated ON (MOG-ON), idiopathic ON (IDON), or multiple sclerosis-related ON (MS-ON). These cases were followed up for one year to determine whether there was any silent progression of visual function and structure in the contralateral non-ON (NON) eye. A gender- and age-matched healthy control (HC) group was included to compare the differences in visual function and structure between the patients with NON eyes and the HC group. Within two weeks of onset, best-corrected visual acuity (BCVA; P=0.008), mean deviation (MD) of the visual field (VF) (P=0.001), and peripapillary retinal nerve fiber layer (pRNFL; P=0.019) thickness were significantly worse in the NMOSD-NON patients than those in the HC group, while there were no differences in the pRNFL and the ganglion cell-inner plexiform layer (GCIPL) thicknesses and quadrant thicknesses (P > 0.05) of the groups. IDON-NON only showed subclinical damage in VF (P=0.001) and temporal pRNFL (P=0.042), while the BCVA, VF, and optic nerve structure (pRNFL, GCIPL) of the MOG-NON patients showed no subclinical damage (P > 0.05). In addition, the one-year follow-up of each NON eye type showed that there was no silent progression in NMOSD-NON, MOG-NON, or IDON-NON. A pairwise comparison of the different types of NON eyes revealed no statistical differences (P > 0.05). Among the patients with unilateral ON, NMOSD-NON and IDON-NON resulted in subclinical damage to the visual function and structure of the contralateral eye within two weeks of onset, whereas MOG-NON did not show any subclinical damage to visual function or structure. Furthermore, these subclinical damages did not show any silent progression during the one-year follow-up period.

Visual satisfaction with progressive addition lenses prescribed with novel foveal fixation axis measurements

Progressive addition lens (PAL) prescription is usually conducted using the pupillary centre as a reference, which in general does not coincide with the visual axis (kappa distance), and this difference could induce undesired prismatic effects in far and near vision distances and adaptation problems. This study aimed to assess the impact on subjects’ visual satisfaction with PALs prescribed based on foveal fixation axis (FFA) measurements. Two different PALs (LifeStyle 3i, Hoya Lens Iberia) were randomly prescribed [one with a customized inset (the difference between the FFA measurements (Ergofocus®, Lentitech, Spain) at far and near distances and the second with a standard inset (2.5 mm)] to be used by 71 healthy presbyopic volunteers in a prospective double-masked crossover clinical study involving one month of use of each PAL. Patients were self-classified into four groups according to their previous experience with PALs: neophyte, PAL users, PAL drop-out, and uncomfortable PAL users. Visual function and overall satisfaction with each PAL were collected and compared. Ninety-seven percent (95% CI 93–100%) of participants successfully adapted to PALs prescribed with FFA without significant differences (P = 0.26) among the study groups (100% neophyte and uncomfortable PAL users (95% CI 100% in both groups), 89% (95% CI 67–100%) PAL users and 94% (95% CI 82–100%) PAL drop-out group). There were no statistically significant differences in visual function (P > 0.05) between customized and standard inset PALs. Customized and standard inset lenses showed similar satisfaction (P > 0.42) that increased significantly (P < 0.01 without any carry-over effect) after 30 days of wear. PALs prescribed with FFA measurements showed high visual satisfaction, suggesting that these measurements are suitable for prescribing PAL adaptation processes. Additional research is necessary to assess differences in PAL users’ performance with different prescription methods and lens designs.

Alzheimer's disease: a continuum with visual involvements.

Alzheimer's disease (AD) is the most common form of dementia affecting the central nervous system, and alteration of several visual structures has been reported. Structural retinal changes are usually accompanied by changes in visual function in this disease. The aim of this study was to analyse the differences in visual function at different stages of the pathology (family history group (FH+), mild cognitive impairment (MCI), mild AD and moderate AD) in comparison with a control group of subjects with no cognitive decline and no family history of AD. We included 53 controls, 13 subjects with FH+, 23 patients with MCI, 25 patients with mild AD and, 21 patients with moderate AD. All were ophthalmologically healthy. Visual acuity (VA), contrast sensitivity (CS), colour perception, visual integration, and fundus examination were performed. The analysis showed a statistically significant decrease in VA, CS and visual integration score between the MCI, mild AD and moderate AD groups compared to the control group. In the CS higher frequencies and in the colour perception test (total errors number), statistically significant differences were also observed in the MCI, mild AD and moderate AD groups with respect to the FH+ group and also between the control and AD groups. The FH+ group showed no statistically significant difference in visual functions compared to the control group. All the test correlated with the Mini Mental State Examination score and showed good predictive value when memory decline was present, with better values when AD was at a more advanced stage. Alterations in visual function appear in subjects with MCI and evolve when AD is established, being stable in the initial stages of the disease (mild AD and moderate AD). Therefore, visual psychophysical tests are a useful, simple and complementary tool to neuropsychological tests to facilitate diagnosis in the preclinical and early stages of AD.

A visually guided swim assay for mouse models of human retinal disease recapitulates the multi-luminance mobility test in humans.

The purpose of this study was to develop a visually guided swim assay (VGSA) for measuring vision in mouse retinal disease models comparable to the multi-luminance mobility test (MLMT) utilized in human clinical trials. Three mouse retinal disease models were studied: Bardet-Biedl syndrome type 1 (Bbs1M390R/M390R), n = 5; Bardet-Biedl syndrome type 10 (Bbs10-/-), n = 11; and X linked retinoschisis (retinoschisin knockout; Rs1-KO), n = 5. Controls were normally-sighted mice, n = 10. Eyeless Pax6Sey-Dey mice, n = 4, were used to determine the performance of animals without vision in VGSA. Eyeless Pax6Sey-Dey mice had a VGSA time-to-platform (TTP) 7X longer than normally-sighted controls (P < 0.0001). Controls demonstrated no difference in their TTP in both lighting conditions; the same was true for Pax6Sey-Dey. At 4-6 M, Rs1-KO and Bbs10-/- had longer TTP in the dark than controls (P = 0.0156 and P = 1.23 × 10-8, respectively). At 9-11 M, both BBS models had longer TTP than controls in light and dark with times similar to Pax6Sey-Dey (P < 0.0001), demonstrating progressive vision loss in BBS models, but not in controls nor in Rs1-KO. At 1 M, Bbs10-/- ERG light-adapted (cone) amplitudes were nonrecordable, resulting in a floor effect. VGSA did not reach a floor until 9-11 M. ERG combined rod/cone b-wave amplitudes were nonrecordable in all three mutant groups at 9-11 M, but VGSA still showed differences in visual function. ERG values correlate non-linearly with VGSA, and VGSA measured the continual decline of vision. ERG is no longer a useful endpoint once the nonrecordable level is reached. VGSA differentiates between different levels of vision, different ages, and different disease models even after ERG is nonrecordable, similar to the MLMT in humans.

Short-Term Vision-Related Ocular Side Effects of Treatment with Dexmethylphenidate for Attention-Deficit/Hyperactivity Disorder.

Objective: To evaluate the short-term effect of dexmethylphenidate (D-MPH) on visual acuity (VA), pupil size, anterior chamber depth, and accommodation-convergence reflex in children treated with D-MPH for attention-deficit/hyperactivity disorder (ADHD). Method: Prospective cohort study including 15 patients aged 8-16 (11.58 ± 2.39) treated with D-MPH for ADHD. Patients were questioned for subjective complaints such as blurred vision and photosensitivity. An ophthalmic evaluation was performed twice; before and 1.5 hours after D-MPH administration. The examination included evaluation of best corrected visual acuity at distance and near, accommodation range, convergence range, 3D vision test (stereopsis), and anterior segment optical coherence tomography. Results: A significant association between change in pupil diameter and D-MPH treatment dose was demonstrated (p = 0.01). In addition, a positive correlation between complaints about blurred vision and pupil's size change was found (p < 0.05). There were no significant changes in VA, convergence range, stereopsis, accommodation range, or anterior chamber measures. Conclusions: Our findings provide support for the effect of stimulants on pupil diameter in a dose-dependent manner. No clinically significant differences in visual functions were found 1.5 hours after consumption of D-MPH. Institutional review board clinical trial refference no. 0122-17-TLV.

The use of progressive addition lenses to improve the daily visual function of children receiving topical atropine treatment.

To evaluate the changes in visual function when progressive addition lenses (PAL) are added in children using topical atropine as a myopia control therapy. Daily visual complaints and the determination of their near correction were studied. Forty children aged 7-12 years were recruited. Distance and near visual acuity, accommodative lag, heterophoria, near point of convergence and stereopsis were examined, and a questionnaire of daily visual complaints was administered. Significant differences in visual functions were found after the near correction was prescribed. Significant improvements in distance and near visual acuity, lag of accommodation and binocular visual function were observed, and fewer visual complaints were reported at the Harmon distance. The use of PAL is helpful for children undergoing topical atropine treatment for myopia control, particularly those receiving medium to high doses. This combination therapy could also be applied to younger children who have a low tolerance to contact lenses, with less risk of ocular adverse effects.

Gender Differences in Visual Functioning Questionnaire Scores among Patients with Age-Related Macular Degeneration

ABSTRACT Purpose To examine gender differences in visual functioning using the National Eye Institute Visual Functioning Questionnaire-25 (VFQ-25) in a Colorado cohort of patients with age-related macular degeneration (AMD). Methods A retrospective cohort study was conducted using a registry of AMD patients who attended the Sue Anschutz-Rodgers Eye Center (2014 to 2019). Demographic, clinical, and image data were collected, and AMD was categorized as Early/Intermediate AMD, or unilateral/bilateral neovascular (NV) AMD, geographic atrophy (GA), or Both Advanced using the Beckman Classification. Each patient completed the VFQ-25, which evaluates visual functioning, generating a composite score and subscale scores for vision-specific activities. Univariate and multivariable general linear models were used to estimate the associations between gender and VFQ-25 scores with parameter estimates (PE) and standard errors (SE). Results Among 739 patients with AMD, 294 (39.8%), 115 (15.6%), 168 (22.7%), and 162 (21.9%) were diagnosed with Early/Intermediate AMD, GA, NV AMD, and Both Advanced, respectively. Adjusted for AMD classification, age and habitual visual acuity in the better-seeing and worse-seeing eyes, female gender was not significantly associated with lower composite VFQ-25 scores (PE (SE): −1.2 (0.9), p = .193), and was significantly associated with reportedly worse ocular pain and driving subscale scores (PE (SE): −4.6 (1.0), p < .0001 and −9.1 (2.1), p < .0001, respectively). Conclusion Gender plays a role in reported driving activities and ocular pain among patients with AMD. This may need to be accounted for in future research related to the use of VFQ-25 for AMD.

Contrast Sensitivity Testing in Age-Related Macular Degeneration Using Motion Diamond Stimulus.

PurposeThis study was performed to characterize changes in contrast sensitivity (CS) that occur in patients with age-related macular degeneration (AMD) using a novel test, the motion diamond stimulus (MDS).MethodsThis was a cross-sectional study in which 20 subjects with unilateral exudative AMD (eAMD) and contralateral dry AMD received 3 assessments: the Pelli-Robson (PR) CS Chart, the MDS test, and a visual function questionnaire-25 (VFQ-25). CS results from the PR, and MDS tests were compared across 3 groups: eyes with eAMD vs dry AMD, eAMD vs control, dry AMD vs control. Healthy, undilated eyes from another study served as the control group. Significance was determined using ANOVA analysis for the MDS output parameters (α: overall contrast threshold, β: adaptability of the visual system) and PR logCS. Patients were also administered the VFQ-25 to assess vision-related quality of life.ResultsThe ANOVA of the MDS data demonstrated a significant difference in visual function according to the β parameter of the 3 groups, but no significant difference in the α parameter. PR CS results for the 3 groups were significantly different, further supporting the MDS results. Post-hoc analysis showed a significant difference in β and PR log CS between the eAMD and control eyes.ConclusionThe MDS test is valuable in discerning CS impairments in patients with AMD. It can provide further insight into the visual changes experienced by patients with AMD and has potential to quantify visual function changes that are not found on visual acuity testing alone.

Measurement of drusen and their correlation with visual symptoms in patients affected by age-related macular degeneration.

Age-related macular degeneration (AMD) is a common retinal disorder, which became more and more prevalent in the last decades. AMD is now the most prevalent cause of blindness in the western world. The disorder is classified into two phenotypes named dry and wet AMD. This is based on the recruitment of novel blood vessels and inflammatory exudates in wet AMD. In both phenotypes, the pathological hallmark is the presence of proteinaceous aggregates called drusen, which mostly accumulate between the choroid and the retinal pigment. Drusen in dry AMD represent the evident pathological finding although they are present, though less defined, in wet AMD. In AMD drusen are supposed to be a pathogenic trigger of the disorder. In fact, drusen may mechanically alter retinal function. A novel hypothesis exists, suggesting that a metabolic defect (systemic or focal within the retinal pigment epithelium) may be the real determinant of visual impairment, while causing the concomitant accumulation of proteinaceous debris and lipids forming the drusen. Here we face such an issue by analyzing the retinal anatomy to correlate visual impairment with the occurrence of drusen number, size and the extent of a drusenoid area in the foveal region. A comparison is made with wet AMD where new vessels and retinal exudates prevail. The study is carried out in 120 patients affected by dry or wet AMD and 21 patients where paradoxical findings are described. The main question consists in inferring whether the occurrence of visual impairment is due, in fact, to a drusen-dependent mechanical damage or drusen just occurs as an independent consequence of an upstream metabolic alteration, which concomitantly impairs the visual process. The present data indicate that, despite a significant difference in visual function between mild and severe AMD patients in the amount of drusen exists, a strong correlation between drusen and visual impairment does not occur. This suggests that drusen and visual deterioration develop as a consequence of similar upstream biochemical alterations but it is likely that drusen do not produce visual deterioration. This is strengthened here by extreme clinical conditions, where visual impairment is severe with a slight alteration in the planar pattern of the retina or, vice versa an extended drusenoid area occurs concomitantly with fair visual acuity, contrast sensitivity and lack of metamorphopsia. A biochemical analysis of key areas in the function of specific domains in the pigment epithelium as described in the accompanying manuscript should help to better disclose the real morpho-functional deficit, which takes place in AMD.

The impact of advanced age-related macular degeneration on the National Eye Institute's Visual Function Questionnaire-25.

To assess visual function among patients diagnosed with age-related macular degeneration (AMD) by stage of disease and laterality. This is a cross-sectional cohort study of 739 AMD patients and their responses to the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) at time of study enrolment. Patients with AMD were categorized into Early/Intermediate AMD and three groups of advanced AMD: (i) neovascular AMD (NV), (ii) geographic atrophy (GA) and (iii) Both Advanced forms. These three advanced stages were further stratified into unilateral or bilateral advanced disease. Mean composite scores and subscale scores for 12 different areas were based on a 100-point scale with the lowest and highest possible scores set at 0 and 100, respectively. Scores for the advanced AMD groups were compared with Early/Intermediate AMD using general linear modelling. A total of 739 AMD patients (294 Early/Intermediate, 115 GA, 168 NVAMD and 162 Both Advanced) were included in the analysis. Mean composite scores were highest among Early/Intermediate patients (89.9), followed by patients diagnosed with unilateral disease in the Both Advanced (88.0) and NV (86.1) groups. Mean composite scores were similar for bilateral NV (82.9) and unilateral GA (81.7), and mean scores were lowest for the bilateral GA (71.3) and bilateral Both Advanced (68.5) groups. In general, this pattern persisted across the twelve subscales as well. Subscale scores ranged from a low of 35.1 for driving among bilateral Both Advanced patients to a high of 99.2 for colour vision among patients with unilateral Both Advanced. Overall, patients with unilateral advanced disease consistently had higher mean scores than their bilateral counterparts. The largest difference was 19.5 composite score points between the unilateral and bilateral Both Advanced groups, there was a difference of 10.4 points between the GA groups, and a relatively small difference of 3.2 points between the NV groups. We found large differences in visual function as reported from the VFQ-25 across the different types of advanced stage AMD groups and number of eyes affected with advanced AMD. These findings demonstrate the importance of accounting for the type and number of eyes affected by advanced stage AMD.

Effects of Vision Correction Status on Visual Functions (Vision-Specific Quality of Life) : Focusing on University Students

Purpose : This study aimed to analyze visual functions by vision correction status, by administering questionnaires about visual functions to undergraduates. Methods : The visual functions (vision-specific quality of life) of 290 undergraduates without eye diseases were evaluated by using the Korean version of National Eye Institute's Visual Functional Questionnaire(NEI-VFQ), from March to May, 2019. This study comparatively was analyzed by the differences in visual functions by the wearing purposes of glasses or contact lens. Results : The group that did not need any correction scored 94.17 on the item of visual function, while the one that needed correction scored 85.33. The former showed the highest scores on each item but the latter showed overall lower scores at the items of the general health and general vision, ocular pain and near vision and distance vision. The group that had no need for correction scored higher at VFQ-13, while the one that needed correction scored lower at all items other than near vision and role difficulties. Conclusion : The visual functions based on the status of visual correction for undergraduates showed that the group with uncorrected vision was poorer than the other group. In particular, the scores on the items general health and general vision were significantly worse for the group with uncorrected vision. The findings suggested that uncorrected vision has negative effects on the vision-specific quality of life.

Evaluation of enhanced external counterpulsation therapy for nonarteritic anterior ischemic optic neuropathy

BackgroundTo explore the effects of enhanced external counterpulsation (EECP) and its underlying influencing factors in nonarteritic anterior ischemic optic neuropathy (NAION) patients.MethodsPatients at Zhongshan Ophthalmic Center with recent-onset (< 8 weeks) NAION were retrospectively recruited. The patients had decided whether or not they would undergo EECP treatment, and the patients who declined were included in the control group. The effectiveness of EECP was evaluated by comparing the visual function and fellow eye involvement in patients with and without EECP treatment.ResultsIn total, 61 patients (76 eyes) were included. Twenty-nine patients (37 eyes) underwent EECP treatment, while 32 patients (39 eyes) were included in the control group. Mean time from NAION onset to EECP initiation was 27.59 ± 16.70 days. In the EECP group, the mean EECP duration was 31.57 ± 18.45 days. EECP was well tolerated by all patients. However, there was no significant difference in visual function between the EECP and control groups. Furthermore, there was no evidence of the effectiveness of EECP in the subgroup analysis of patients with different systemic health conditions. Among the 42 patients with monocular NAION, the sequential attack rate was comparable between the EECP (27.78%) and control (25.00%) groups.ConclusionThis study is the first nonrandomized controlled study to evaluate the effectiveness of EECP in NAION patients. Unfortunately, we failed to demonstrate the effectiveness of EECP in NAION at the 6-month follow-up. Any further application of EECP in NAION patients should be cautious.

Spatial-sweep steady-state pattern electroretinography can detect subtle differences in visual function among healthy adults

We aimed to establish a highly sensitive method for measuring visual function using spatial-sweep steady-state pattern electroretinography (swpPERG). Overall, 35 eyes of 35 healthy adults (18 men; mean age, 32.3 years) were examined using swpPERG, and the data were recorded using spatial-patterned and contrast-reversed stimuli of size 1 (thickest) to 6. Data were converted into frequency-domain using a Fourier transform and expressed by signal-to-noise ratio (SNR). The number of participants who showed SNR ≥ 1 was significantly lesser at stimulus sizes 5 and 6 compared with those at greater stimulus sizes. Among the data with SNR ≥ 1, SNRs were negatively correlated with age at stimulus size 5 (r = −0.500, P = 0.029), and positively correlated with macular volume evaluated by optical coherence tomography (OCT) within a 6-mm circle diameter from the fovea of the retinal nerve fibre layer at size 4 (r = 0.409, P = 0.025) and of the ganglion cell layer at size 5 (r = 0.567, P = 0.011). We found that SNRs of swpPERG, recorded using the EvokeDx system, were correlated with age and macular morphology in participants without diagnosed eye diseases. The system detected subtle differences in retinal function, which may help in early disease diagnosis and visual evaluation in neuroprotective interventions in the future.

What are the characteristics and progression of visual field defects in patients with Leber hereditary optic neuropathy: a prospective single-centre study in China

ObjectiveTo study the characteristics and progression of visual field defects in patients with Leber hereditary optic neuropathy.DesignProspective study.Setting3-A-class hospital in China; single-centre study.ParticipantsFrom 100 patients diagnosed with Leber hereditary optic...

Regional differences in vision health: findings from Mwanza, Tanzania.

Visual impairment in developing countries has both social and economic impact on individuals and communities. Understanding the subjective visual functioning of populations will allow for local policymakers to identify the need for optometric or ophthalmic services in their communities. The authors surveyed 644 adult patients in Mwanza, Tanzania at three clinics (Buzuruga, Mwananchi and Kisesa) using a modified Visual Functioning Questionnaire 25. Responses were categorized into General health, General vision, Ocular pain, Near activities, Distance activities, Social function, Mental health, Role difficulties, Color vision, Peripheral vision and Dependency. Patients at Buzuruga reported the lowest scores on most subscales. Of 100 employed patients, 37% claimed to have at least some difficulty in performing job duties due to their eyesight. At Kisesa, 146 (246/221) patients (66.1%) had never had an eye exam, compared with 134/227 (59.0%) at Buzuruga and 69/173 (39.9%) at Mwananchi (p<0.01). Common reasons for not seeing an eye doctor were the perceived expense and lack of vision problems. Due to regional differences in visual functioning in Mwanza, a national effort for vision health cannot be entirely successful without addressing the individualized needs of local communities. Reducing the cost of vision care appointments may expand vision health care utilization in Mwanza.

Short-term Dynamics after Single- and Three-piece Acrylic Intraocular Lens Implantation: A Swept-source Anterior Segment Optical Coherence Tomography Study

Accurate alignment of an intraocular lens (IOL) is indispensable for achieving accurate postoperative refractive outcomes. Thus, we evaluated decentration and tilt of single- and three-piece IOLs, as well as anterior chamber depth (ACD), at 3 hours, 24 hours, 2 weeks, and 4 weeks after cataract surgery, using swept-source anterior segment optical coherence tomography. There was no significant difference in postoperative visual acuity between eyes with single- or three-piece IOLs. Absolute values of IOL decentration at 24 hours and 2 weeks after surgery were significantly larger (P = 0.008 and 0.046, respectively) in eyes with the single-piece IOL than in those with the three-piece IOL. Both single- and three-piece IOLs tended to tilt toward the inferotemporal direction; however, there was no significant difference in the absolute values of IOL tilt at any postoperative time point. ACD at 24 hours after surgery was significantly deeper (P = 0.009) in eyes with the three-piece IOL, compared with eyes with the single-piece IOL. Therefore, although both single- and three-piece IOL locations varied transiently after surgery, IOL locations were similar between both IOLs at 4 weeks after surgery and were not associated with any statistical difference in visual function.

Photoreceptor-Based Biomarkers in AOSLO Retinal Imaging.

Improved understanding of the mechanisms underlying inherited retinal degenerations has created the possibility of developing much needed treatments for these relentless, blinding diseases. However, standard clinical indicators of retinal health (such as visual acuity and visual field sensitivity) are insensitive measures of photoreceptor survival. In many retinal degenerations, significant photoreceptor loss must occur before measurable differences in visual function are observed. Thus, there is a recognized need for more sensitive outcome measures to assess therapeutic efficacy as numerous clinical trials are getting underway. Adaptive optics (AO) retinal imaging techniques correct for the monochromatic aberrations of the eye and can be used to provide nearly diffraction-limited images of the retina. Many groups routinely are using AO imaging tools to obtain in vivo images of the rod and cone photoreceptor mosaic, and it now is possible to monitor photoreceptor structure over time with single cell resolution. Highlighting recent work using AO scanning light ophthalmoscopy (AOSLO) across a range of patient populations, we review the development of photoreceptor-based metrics (e.g., density/geometry, reflectivity, and size) as candidate biomarkers. Going forward, there is a need for further development of automated tools and normative databases, with the latter facilitating the comparison of data sets across research groups and devices. Ongoing and future clinical trials for inherited retinal diseases will benefit from the improved resolution and sensitivity that multimodal AO retinal imaging affords to evaluate safety and efficacy of emerging therapies.