Ophthalmic and Physiological Optics最新文献

Purpose: This study was designed to compare the effects of mental load, caused by concurrent auditory tasks, on attended and non-attended visual stimuli in older and younger adults.

Methods: Participants performed a visual orientation discrimination task involving two spatially separated Gabor patches of 4 cycles/degree and 55% contrast. Participants received either a valid-cue, invalid-cue or a neutral-cue for the patch whose orientation they were required to determine. An auditory n-back task was performed simultaneously to impose mental load. Repeated-measures ANOVA was used for investigation of main effects and interactions of ageing, mental load and attention condition on orientation discrimination.

Results: A total of 27 younger (mean age ± SD, 22.6 ± 1.3 years) and 23 older adults (54.7 ± 4.3 years) participated in the study. There was a significant effect of age (p = 0.01) and mental load (p < 0.001) on the proportion of correct orientation discrimination responses. Attentional condition significantly affected the proportion of correct responses (p = 0.02), but there was no significant interaction between attention, mental load and age group (p = 0.85). There was no overall difference in the proportion of no responses (the proportion of trials in which the participants failed to respond) between the two age groups (p = 0.53) nor on the overall effect of attention on the proportion of no responses (p = 0.25). There was, however, a significant effect of mental load on the proportion of no responses (p = 0.002).

Conclusion: Although mental load reduced performance equally for both age groups and for all attentional conditions, older adults had poorer overall performance. Therefore, a given mental load is more likely to drive older observers to unacceptable levels of task performance.

Purpose: Given the potential role of light and its wavelength on ocular growth, this study investigated the effect of short-term exposure to red, cyan and blue light on ocular biometry in humans.

Methods: Forty-four young adults and 20 children, comprising emmetropes and myopes, underwent 2-h sessions of cyan (507 nm), red (638 nm) and broadband white light on three separate days via light-emitting glasses. Additionally, young adults were exposed to blue light (454 nm) on an additional day. Axial length (AL) and choroidal thickness (CT) were measured in the right eye before the light exposure (0 min), after 60 and 120 min of exposure and 30 min after light offset using an optical biometer and optical coherence tomographer, respectively.

Results: Compared to broadband light, exposure to red light resulted in a significant increase in AL (mean difference between white and red light at 120 min, +0.007 mm [0.002]), but no significant change in CT, while cyan light caused a significant AL reduction (-0.010 mm [0.003]) and choroidal thickening (+0.008 mm [0.002]) in young adults (p < 0.05). Blue light caused a significant decrease of -0.007 mm (0.002) in young adult eyes at 60 min (p < 0.05). In children, cyan light led to a significant reduction in AL (-0.016 mm [0.004]) and strong sustained choroidal thickening (+0.014 mm [0.004]) compared to broadband light at 120 min (p < 0.05). The effects of cyan light on AL and CT were found to be stronger in myopic young adults and emmetropic children. The opposing effects of red and cyan light on ocular biometry were similar between the two age groups (p > 0.05).

Conclusions: Exposure to cyan light resulted in AL reduction and choroidal thickening in both young adults and children. Further research is needed to determine the application of these results in developing interventions for myopia control.

Purpose: It is common to hear talk of 'responders' and 'non-responders' with respect to myopia control interventions. We consider the reality of distinguishing these sub-groups using data from the first year of the Low-concentration Atropine for Myopia Progression (LAMP) study.

Methods: The first year of the LAMP study was a robustly designed, placebo-controlled trial of three different low concentrations of atropine using a large sample size (N > 100 randomised to each group). The authors subsequently published mean axial elongation and myopia progression rates by age group. We used these data to calculate efficacy in terms of both absolute reduction in myopic progression and absolute reduction in axial elongation for each of the different atropine concentrations at each age group. We then compared these efficacy data to the overall progression for each of the two progression metrics.

Results: Plotting efficacy as a function of overall myopia progression and axial elongation for each of the different atropine concentrations demonstrates the invariant nature of efficacy, in terms of clinically meaningful reduction in progression, despite a substantial range of underlying overall progression. That is, faster progressors-the so-called non-responders-achieved similar reduction in axial elongation and myopia progression as the slower progressors-the so-called responders-within the various atropine treatment groups.

Conclusion: The use of the terms, responders and non-responders, during myopia progression interventions is not supported by evidence. Those designated as such may simply be slower or faster progressors, who, on average achieve the same benefit from treatment.

Background: The certificate of vision impairment has an important role in enabling access to support for people with vision impairment (VI) and the provision of epidemiological data regarding sight loss. However, the rates of certification may not accurately reflect the number of people living with certifiable VI.

Methods: Observational data from a national primary care low vision rehabilitation service between 1 April 2021 and 31 March 2022 were analysed. Descriptive statistics were used to describe the certification status of patients with certifiable VI. For patients with age-related macular degeneration (AMD) and best-corrected visual acuity of 6/60 or worse, logistic regression was undertaken to assess the effects of patient characteristics on certification status.

Results: For patients with AMD and certifiable levels of visual acuity, 41.00% (n = 426) were not certified. The reported certification was 60.09% (n = 256) and 58.24% (n = 357) for neovascular AMD and atrophic AMD, respectively. Existing patients of the service were 3.87 times more likely to be certified than new patients (OR 3.87, 95% CI 2.7-5.4). Increasing age (OR 1.02, 95% CI 1.004-1.038) and decreasing visual acuity (OR 0.62, 95% CI 0.50-0.78) were associated with an increased likelihood of certification.

Conclusion: A significant number of patients live with certifiable vision impairment but do not access certification. Policy changes in Wales now enable patients with bilateral atrophic AMD to access certification within the primary care setting. Given the unmet need, consideration should be given to primary care certification in the rest of the UK, and in Wales, the potential to expand the scope of conditions.

Introduction: Low-level light therapy (LLLT) or photobiomodulation, the application of red light to the eye, is used for the treatment of dry eye. Limited studies have investigated the efficacy of LLLT as a stand-alone treatment. The investigation aimed to evaluate the effect of LLLT on signs and symptoms of dry eye.

Methods: Participants with mild to moderate dry eye were recruited for this three-visit study. Visits were 7 (±3) days apart and all participants received 633 nm LLLT (eye-light®) for 15 min at each visit. Clinical measures including first and average non-invasive keratograph tear break-up time (NIKBUT), tear meniscus height (TMH), meibomian gland (MG) loss for upper and lower eyelids, ocular surface disease index (OSDI) score, tear film lipid layer thickness, meibum quality score, Schirmer's test, corneal fluorescein staining and eyelid temperature for external upper (EUL) and external lower (ELL) eyelids were measured from the right eye of participants before and after treatment.

Results: Thirty participants (mean [SD] age: 31.1 [9.5] years) completed the study. Treatment with LLLT resulted in significant differences in first and average NIKBUT, TMH, tear film lipid layer thickness, OSDI score, Schirmer's test, meibum quality score and eyelid temperature over time (all p < 0.05). Compared to baseline, TMH, tear film lipid layer thickness and eyelid temperature significantly increased by 0.06 mm (95% CI: 0.01-0.11), 12.9 nm (95% CI: 1.18-24.55), and 7.0°C, respectively, for both EUL (95% CI: 6.17-7.84) and ELL (95% CI: 6.17-7.73). The respective decrease in the OSDI score and Schirmer's test was 10.2 (95% CI: -15.15 to -5.26) and 4.4 mm (95% CI: -7.31 to -1.42; all p < 0.05). There was no significant difference in corneal fluorescein staining and MG loss after LLLT.

Conclusion: Low-level light therapy treatment significantly improved signs and symptoms of dry eye in the early phases of treatment, suggesting its efficacy for dry eye management.

Introduction: Fusional reserves differ with the method of measurement. The goal of this study was to compare the subjective and objective responses during the measurement of positive and negative fusional reserves using both step and ramp methods.

Methods: A haploscopic system was used to measure fusional reserves. Eye movements were recorded using an EyeLink 1000 Plus eye tracker (SR Research). The stimulus disparity was changed to either mimic a prism bar (steps) or a Risley prism (ramp). Subjective responses were obtained by pressing a key on the keyboard, whereas objective break and recovery points were determined offline using a custom algorithm coded in Matlab.

Results: Thirty-three adults participated in this study. For the ramp method, the subjective and objective responses were similar for the negative (break and recovery points (t(32) = -0.82, p = 0.42) and (t(32) = 0.42, p = 0.67), respectively) and positive fusional reserves (break and recovery points (U = -1.34, p = 0.18) and t(19) = -0.25, p = 0.81), respectively). For the step method, no significant differences in positive fusional reserves were observed when measured subjectively and objectively for the break (t(32) = 1.27, p = 0.21) or the recovery point (U = -2.02, Bonferroni-adjusted p = 0.04). For the negative fusional reserve, differences were not significant for either the break or recovery points (U = -0.10, p = 0.92 and t(19) = 1.17, p = 0.26, respectively).

Conclusion: Subjective and objective responses exhibited good agreement when measured with the ramp and step methods.

Introduction and purpose: The developmental eye movement (DEM) test is designed to assess saccadic eye movements and visual-verbal automaticity in children. This study aimed to assess whether there is a need for independent DEM Hebrew norms and to compare DEM results for Hebrew-speaking children with eight other language norms.

Methods: The DEM test was administered to 224 Hebrew-speaking children aged 6-13 years who met the inclusion criteria and read the numbers in Hebrew. Test C of the DEM was performed twice, once from right (R) to left (L) and once from L to R, in random order. Age group and language comparisons, including vertical and horizontal reading speeds, errors and horizontal/vertical (H/V) ratios in both directions were analysed.

Results: The participants were almost evenly distributed between the sexes (46.8% female). Statistically significant differences were found between age groups (6-9 and 10-13 years) for vertical and horizontal reading speeds and H/V ratios in both directions (p < 0.001). Older children, as compared to younger children, exhibited faster vertical and horizontal times, with fewer errors, as well as lower ratios (p < 0.001). No significant difference was noted between reading directions for horizontal time and H/V ratio within both age groups (6-9 year olds: p = 0.27 and p = 0.06; 10-13 year olds: p = 0.89 and p = 0.49, respectively). Comparison of DEM norms across languages showed significant differences, with post-hoc analysis revealing specific language-related variations. DEM results for Hebrew-speaking children had similar outcomes to both original English and French values.

Conclusions: This study compared DEM results of Hebrew-speaking children and scores across nine languages. DEM test values for Hebrew-speaking children aligned with norms from other languages, particularly the French and original English norms, with consistent ratio scores. It is recommended for practitioners who test Hebrew-speaking children to continue using the original English norms and to enable the children to read using their preferred reading direction.

Purpose: Attention deficit and hyperactivity disorder (ADHD) is a neurodevelopmental condition commonly seen in children and adolescents, characterised by an increase in distractibility or inattention. Several studies have noted a higher rate of visual problems in this group, especially convergence insufficiency (CI), but when using different diagnostic criteria. The aim of this study was to evaluate visual function in ADHD children and non-ADHD controls to compare the different signs for diagnosis of CI.

Method: In this prospective case-control study, a group of children aged 7-17 years, diagnosed with ADHD before the start of pharmacological treatment and matched for age and gender with non-ADHD controls were examined. Visual acuity (VA), objective and subjective refraction, accommodative amplitude and facility, heterophoria, positive and negative fusional vergences (PFV and NFV) and stereopsis were assessed.

Results: Sixty participants (30 ADHD and 30 non-ADHD controls) were evaluated. There was no significant difference between the two groups for VA, refraction and accommodative abilities. There were significant differences in PFV and NFV: PFV break/recovery values for the ADHD and control groups were 18.9/16.2∆ and 26.9/22.1∆, respectively. Respective values for NFV were 15.7/13∆ and 19.3/15.9∆. Using the three signs of receded near point of convergence (NPC), decreased PFV and exophoria 4∆ greater at near than distance, the prevalence of CI was equivalent for the ADHD and controls (p = 0.34) If only two signs were considered for the CI diagnosis, (i.e., receded NPC and decreased PFV), then prevalence was significantly greater for the ADHD group (p < 0.01).

Conclusions: These results show a higher prevalence of binocular vision problems in the ADHD group. This suggests a relationship between vergence problems and ADHD, but the direction of this link remains unclear. Further studies with specific samples may be needed to understand fully the association between binocular vision disorders and ADHD.