Vision (Switzerland)最新文献

Reports of individual differences in vividness of visual mental imagery (VMI) scores raise complex questions: Are Vividness of Visual Imagery Questionnaire (VVIQ) score differences actually measuring anything? What functions do these differences serve? What is their neurological foundation? A new analysis examined visual short-term memory (VSTM) and volumes of the hippocampi, primary visual cortices, and other cortical regions among vivid and non-vivid visual imagers. In a sample of 53 volunteers aged 54 to 80 with MRI scans, the performance of ten Low VVIQ scorers was compared to that of ten High VVIQ scorers. The groups included an aphantasic with a minimum VVIQ score and a hyperphantasic with a maximum VVIQ score. The study examined volumes for 12 hippocampal subfields, 11 fields implicated in visual mental imagery including area V1 and the fusiform gyrus, and 7 motor regions. In comparison to the Low VVIQ group, High VVIQ group yielded: (i) significantly more accurate VSTM performance; and (ii) significantly larger volumes of the hippocampi and primary visual cortex. Across 47 brain regions, the average volume for the High VVIQ group exceeded that of the Low VVIQ group by 11 percent. For 47 subfields, the volumes of the hphantasic exceeded those of the aphantasic person by an average of 57 percent. Females had more accurate visual short-term memory than males and younger people were more accurate than older people. The larger visual memory capacity of females was unmatched by larger regional volume differences, which suggests that the sex difference in visual memory is caused by factors other than cortical regional size. The study confirms the existence of robust empirical associations between VMI vividness, short-term memory, regional volume of hippocampal subfields and area V1.

Evidence based practice enhances healthcare delivery and prevents unsafe procedures. While competency based assessments of resident cataract surgery are standard, evidence based analysis of refractive outcomes remains underutilized in educational curricula. This retrospective single center study evaluated refractive outcomes from 21 novice ophthalmology resident surgeons. Three independent groups were compared based on formal constant optimization for intraocular lens (IOL) calculation: non-optimized Haigis (n = 216), a0-optimized (n = 94), and a0/a1/a2-optimized (n = 121). All surgeries were supervised by a single attending surgeon. Mean absolute error (MAE) and the percentage of eyes within ±0.25 D and ±0.50 D of predicted spherical equivalent (SEQ) were calculated. Also, systematic bias in effective lens position (ELP) was analyzed to update manufacturer IOL constants. MAE improved from 0.44 D (non-optimized) to 0.35 D (a0-optimized p = 0.009) and 0.19 D (a0/a1/a2-optimized p < 0.001). The percentage within ±0.50 D increased from 65.7% to 74.4% to 95.0%, respectively. With ELP bias correction, updated A constant and ACD were 119.266 and 5.755 mm. a0/a1/a2-optimized outcomes were comparable to ELP bias correction for the Barrett UII, Kane, and Hill-RBF formulas. Evidence based optimization of IOL constants significantly enhances novice resident surgical outcomes, achieving parity with prediction models. A formal curriculum on IOL calculation and optimization is warranted.

Pupil cycle time (PCT) estimates the dynamics of a biofeedback loop established between pupil size and stimulus luminance, size or colour. The PCT is useful for probing the functional integrity of the retinopupillary circuits, and is therefore potentially applicable for assessing the effects of damage due to retinopathies or neuropathies. In previous studies, PCT was measured by manually counting the number of pupil oscillations during a fixed period to calculate the PCT. This method is scarce, requires a good expertise and cannot be used to estimate several PCT parameters, such as the oscillation amplitude or variability. We have developed a computerised setup based on eye-tracking that expands the possibilities of characterising PCT along several dimensions: oscillation frequency and regularity, amplitude and variability, which can be used with a large palette of stimuli (different colours, sizes, shapes or locations), and further allows measuring blinking frequency and eye movements. We used this method to characterise the PCT in young control participants as well as in patients with several pathologies, including age-related macular degeneration (AMD), diabetic retinopathy (DR), retinitis pigmentosa (RP), Stargardt disease (SD), and Leber hereditary optic neuropathy (LHON). We found that PCT is very regular and stable in young healthy participants, with little inter-individual variability. In contrast, several PCT features are altered in older healthy participants as well as in ocular diseases, including slower dynamics, irregular oscillations, and reduced oscillation amplitude. The distinction between patients and healthy participants based on the calculation of the area under the curve of the receiver operating characteristics (AUC of ROC) were dependent on the pathologies and stimuli (0.7 < AUC < 1). PCT nevertheless provides relevant complementary information to assess the physiopathology of ocular diseases and to probe the functioning of retino-pupillary circuits.

The effects of Transcranial Magnetic Stimulation (TMS) depend on stimulation parameters such as intensity, location, frequency, and duration. In clinical practice, these parameters are often adapted from studies carried out in healthy individuals. However, in this narrative review, we indicate that the impact of TMS is also highly state-dependent, meaning it is influenced by the excitability of the targeted brain region at the time of stimulation. This state-dependency complicates the translation of findings from healthy individuals to clinical populations, as neurological disorders often alter brain states, limiting the applicability of standard stimulation protocols. To address this challenge, stimulation parameters must be chosen within a framework that accounts for the interaction between external stimulation and the brain's internal state. Such an approach enhances the specificity of interventions, allowing for targeted modulation of neural populations by manipulating brain states prior to stimulation. State-dependent TMS has shown promise in conditions like cortical blindness and amblyopia, where tailored approaches based on the brain state associated with the condition have facilitated more precise and effective treatments. We advocate that integrating state-dependent knowledge tailored to the specifics of visual disorders alongside judicious selection of stimulation parameters holds the potential to establish a comprehensive paradigm for future investigations.

This retrospective review examines whether there is a difference in all-cause mortality in patients who required surgical intervention for neovascular glaucoma (NVG, N = 186) versus primary open-angle glaucoma (POAG, N = 190). Cox proportional hazard models compared mortality across three models: unadjusted, age-adjusted (Model 1), and age-, hypertension-, and diabetes-adjusted (Model 2). In all models, NVG patients who required glaucoma surgery had a higher all-cause mortality rate compared to those with POAG who underwent similar procedures: unadjusted (HR 2.22, (1.59, 3.10), p < 0.0001), Model 1 (HR 2.99, 95% CI (2.12, 4.22), p < 0.0001), and Model 2 (HR 1.88, 95% CI (1.27, 2.80), p < 0.0018). In Model 1, those with NVG due to PDR had a higher all-cause mortality rate after glaucoma surgery than those with NVG secondary to CRVO (HR 2.00, 95% CI (1.19, 3.45), p < 0.0095). Patients treated with CPC had higher all-cause mortality rates than those treated with tube shunt in all models: unadjusted (HR 1.82, 95% CI (1.33, 2.47), p < 0.0001), Model 1 (HR 1.91, 95% CI (1.40, 2.61), p < 0.0001), and Model 2 (HR 1.50, 95% CI (1.04, 2.16), p < 0.03). We observed a higher all-cause mortality rate among patients with NVG requiring glaucoma surgery compared to those with POAG requiring similar surgeries, which could suggest that NVG patients requiring glaucoma surgery had more compromised systemic health.

Some estimates suggest that one in seven good readers and the majority of children with reading difficulties suffer from oculomotor dysfunction (OMD), an umbrella term for abnormalities in comfortable and accurate fixations, pursuits, and saccades. However, national vision evaluation programs worldwide are often limited to distance visual acuity (dVA), not testing for OMD despite its high prevalence and the ease of detecting it in brief optometric evaluations. We hypothesized that reading acquisition is dependent on good oculomotor functions, and therefore inadequate oculomotor control will be associated with reading difficulties. We retrospectively examined and compared oculomotor evaluations (using DEM and NSUCO) and reading assessments (using standardized national reading norms) of a normative class (28 first graders (6-7 yr. olds)) that were independently obtained while blind to the other assessment. Better oculomotor performance as estimated by DEM was associated with better reading performance, and almost a third (29.6%) of the children were categorized by DEM as having OMD-related difficulties. Control analysis revealed dVA was not positively associated with reading performance. Linear regression analyses further corroborated these findings. Since this study is based on a small cohort and since there are studies suggesting that DEM may actually reflect visual processing speed or cognitive factors rather than oculomotor function, replications are needed to substantiate the direct contribution of oculomotor functions to reading acquisition. Young children struggling with reading may benefit from a comprehensive visual evaluation, including oculomotor testing, to provide a more thorough assessment of their learning-related difficulties.

Concealing images has been a concern of artists and scientists, as have the conditions that can reveal them. It is relatively easy to hide images in pictures, but this is of little value if they remain hidden. The skill is in revealing previously concealed images. Three aspects of hiding images are examined, two of which are monocular and the third is binocular. Firstly, high-contrast patterns, like Street figures and Mooney faces, have been used in psychological tests of pattern recognition, and Gestalt grouping principles can result in concealing images. Second, it is possible to hide low spatial frequency content carried by high-spatial-frequency patterns. A wider range of carriers than gratings can be used, like graphics, photographs, and combinations of them (photo-graphics). Pictorial images can be concealed in terms of detection or recognition. In both cases, there is interplay between the global features of the concealed image and the local elements that carry it. Third, randomly textured stereograms reveal to two eyes what is concealed from each one alone-stereoscopic depth. The dimension of stereoscopic depth can be manipulated, as can that of binocular rivalry, to conceal images.

The purpose of this study is to evaluate the potential impact of small aperture optics on corneal aberrations in post-RK patients. Preoperative data was evaluated from 32 eyes of 23 post-RK patients. Scheimpflug tomography was used to obtain measurements of corneal HOAs at 6-mm, 4-mm, and 2-mm corneal plane aperture diameters. The data was extrapolated using a non-linear fit to estimate HOAs that would be obtained with the 1.6 mm effective pinhole IOL aperture at the corneal plane for individual patients. The average RMS HOAs estimated for the 1.6 mm aperture was 0.063 ± 0.015 μm compared to 0.185 ± 0.029 μm for the natural pupil size. A postoperative RK case with an IC-8^® Apthera™ unilateral implantation demonstrated a 70% reduction in HOAs by objective measurement and prediction, plus a 2-line improvement in CDVA. Prediction modeling revealed that HOAs may be reduced in post-RK patients following pinhole IOL implantation, compared to the natural photopic pupil size. Furthermore, the approach can be used to guide which post-RK patients would benefit from a small aperture IOL during cataract surgery.

Macular hole (MH) surgery generally has a high success rate, but finding anatomical plug for refractory cases remains challenging. The human amniotic membrane (hAM), with its anti-inflammatory and regenerative properties, has emerged as a potential option. This study aims to report the anatomical and functional outcomes of human amniotic membrane (hAM) graft as an intervention to repair refractory macular hole cases where wide internal limiting membrane (ILM) peeling was unsuccessful. A retrospective chart review was conducted at a single center, with the main outcomes being closure rate and postoperative BCVA at 6 months. Eleven eyes of 11 patients with refractory macular holes were identified and included in the study. Participants were predominantly males (72.73%) with a mean age of 49.27 years. Nine eyes achieved successful MH closure with a single intervention and showed no recurrence during the 6-month follow-up. Mean BCVA at 3 and 6 months improved significantly (p = 0.0207) from 1.747 ± 0.74 logMAR to 1.210 ± 0.51 logMAR and 0.939 ± 0.47 logMAR (range 2.079-0.301 logMAR). The use of human amniotic membrane (hAM) graft seems to be a viable and effective alternative for the treatment of refractory macular holes. However, further larger prospective controlled studies are necessary to confirm our results.

We provide a summary of the research conducted in our laboratory on the relationship between ocular proprioception, general proprioception, and dyslexia. Dyslexic children show a marked proprioceptive deficit which affects motor control, attention and spatial perception. The spatial disturbances are expressed by the presence of a vertical microheterophoria which has very specific characteristics. It is associated with abnormal tone of the oblique muscles and can be modified by means of very low powered prisms and/or remote sensory stimulation. When ocular proprioception is modified, sounds cause stochastic visual losses. This may interfere with the association between phonemes and graphemes, which is necessary for learning to read. The effects of a generalized nocturnal proprioceptive disorder may play a role in the abnormal brain development that has been observed in dyslexic children.