Background: Understanding factors that contribute to posterior capsular opacification (PCO) development is a significant public concern as treatment can lead to complications. In order to prevent PCO, a better understanding of intraocular lens (IOL) characteristics, including design and material, and patient interaction is required. Herein, we performed a retrospective multivariable analysis to determine which factors (IOL and patient based) were least likely to result in PCO.
Methods: One hundred eighty post-mortem eyes with implanted IOLs were collected from the Minnesota Eye Bank, along with clinical history, including date of cataract surgery and IOL model number. The capsular bag (CB) with the IOL implant was removed from all eyes to obtain digital images. PCO outcome was quantified on CB images using an objective, automated custom image analyzer (Medical Parachute Automated Detector Opacification Software). The software measured intensity and area of the opacification within the IOL optic edge, intra-optic edge (IOE = intensity/area), and in Soemmering’s ring (SR = intensity/area). Epidemiologic analysis assessed which IOL characteristics and patient-related factors correlated with PCO. IOL factors included material, edge design, lens filter, company, IOL model, decentration and time from cataract surgery to death. Patient factors included sex, age and diabetes, among others.
Results: Multivariate analyses showed non-diabetic patients had less PCO (P=0.05). Individuals 50–80 years old compared to 80+ had lower SR PCO (P=0.04). Non-blue light filter IOLs had lower SR and IOE PCO compared to filter IOLs (P=0.03, 0.001). Square and frosted optic edge design had lower SR and IOE PCO rates compared to OptiEdge and round optic edge design (P=0.002, 0.02). The IOL model that had the least PCO was the ZA9003 model, but this was only significant for SR and not IOE PCO (P=0.04). Adjusting for patient-factors, IOL lens model was no longer a confounding factor for PCO. Patients with an IOL implanted for <7 years had lower SR PCO, whereas lower IOE PCO was only seen in implants <4 years old (P=0.0001, 0.04).
Conclusions: In order to generate a lens that does not develop PCO, it is critical to understand the IOL- and patient-related factors that lead to PCO development. Based on our data, the most susceptible patients are elderly and diabetic, and it may be preferable to implant a square and frosted edge lens without blue-light filtering in this cohort.
Background: Epidermolysis bullosa (EB) is a heterogynous group of skin disorders characterized by formation of blisters and erosions of the skin in response to minor trauma. Subtypes include EB simplex (EBS), junctional EB (JEB), dystrophic form of EB (DEB) and finally Kindler syndrome (KS). In addition to dermal manifestation, patients can present with various ophthalmic pathologies.
Methods: We reviewed the pathobiology, epidemiology and management of ocular manifestations as well as current and future innovative therapies for EB.
Results: The severity and incidence of ocular involvement were the highest in the recessive DEB-generalized severe and JEB-generalized severe subtypes. Recurrent corneal erosions and blisters were the most common finding and seem to correlate with skin disease. Other manifestations include corneal scaring, blepharitis, ectropion, symblepharon, infantile cataracts, lacrimal duct obstruction as well as meibomian gland deficiency.
Conclusions: Ophthalmology consult as well as regular follow-up are essential in the multi-disciplinary approach of this disease. Indeed, parents’ and patients’ education as well as early diagnosis and treatment are crucial to prevent permanent and long-term visual disabilities.
Abstract: Optical coherence tomography (OCT) angiography is a new non-invasive imaging modality which is providing clinicians with an alternative to traditional dye-based angiography. The images are obtained using the concept of motion contrast and provide a quicker safer way to image the retinal and choroidal circulation. Not only are there practical aspects to support its integration but new insights are being made into the path; hysiology of various retinal choroidal diseases due to its ability to provide a 3-dimensional view of the vasculature which can be segmented in many ways to focus in on the circulation of a given anatomic region of the retina. We are currently in the phase of integration of this new technology into our practices.
Background: The guiding principle of functional brain mapping is that the cortex exhibits a spatial pattern of response reflecting its underlying functional organization. We know that large-scale patterns are common across individuals—everyone roughly has the same visual areas for example, but we do not know about small patterns, like the distribution of ocular dominance and orientation columns. Studies investigating the temporal aspect of brain-to-brain similarity have shown that a large portion of the brain is temporally synchronized across subjects (Hasson et al., 2004), but spatial pattern similarity has been scarcely studied, let alone at a fine scale. In the current study, we investigated fine-scale spatial pattern similarity between subjects during movie viewing and generated a map of prototypical patterns spanning the visual system. Characteristics of the map, such as spatial pattern size and distribution, reveal properties of the underlying structure and organisation of the visual cortex. These results will guide future brain mapping studies in decoding the informative spatial patterns of the visual cortex and increasing the resolution of current brain maps.
Methods: We had 56 subjects watch two movie clips from “Under the Sea 3D:IMAX” during an fMRI scan. Each clip was 5 minutes in length and was presented in 2D and 3D, in random order. We calculated the intersubject correlation of the spatial pattern inside predefined searchlights of diameter 3, 5, 7, 9 and 11 mm, covering the entire brain. A single threshold permutations test was used to test for significance: we generated 1,000 permutations made from scrambling the spatial patterns inside each searchlight of every subject, pooled these permutations together to generate a large distribution and used the 95th percentile to threshold the actual measurements. We compared these spatial pattern correlations to convexity variance between subjects to determine whether spatial pattern correlation could be explained by differing degrees of alignment across the cortex. We also compared spatial pattern correlation during 2D and 3D movie presentation.
Results: We found significant correlations in spatial pattern between subjects in the majority of early visual cortex, as well as higher visual areas. We found that mean spatial pattern similarity in a visual area tended to decrease as we move up the visual hierarchy. Spatial pattern correlation showed significant positive correlation with convexity variance for most visual areas, meaning that as anatomical misalignment increased, patterns became more similar. Spatial pattern correlation therefore cannot be explained by anatomical misalignment. Lastly, spatial pattern correlations tended to be higher for 3D movie presentation compared to 2D.
Conclusions: Our results suggest that many processes in early visual areas and even higher visual areas process visual information the same way in different individuals. Our results expand past studies by exploring spatial patterns instead of temporal patterns and studying at a fine-scale. This is the first study, to our knowledge, exploring fine-scale spatial patterns across the visual system. Our results show that fine-scale structures underlying activation patterns may be highly similar across subjects, pointing to a more ingrained organisation of the visual system than previously believed. This map we termed the “protoSPACE map”, may one day result in the detection of more subtle abnormalities that arise only during realistic vision in situations such as schizophrenia or mild traumatic brain injury, where traditional anatomical MRI scans report no changes.
Background: Stereoscopic Vision uses the disparity between the two images received by the two eyes in order to create a tridimensional representation. With this study, we aimed at providing an estimate of binocular vision at a level prior to disparity processing. In particular, we wanted to assess the spatial properties of the visual system for detecting interocular correlations (IOC).
Methods: We developed dichoptic stimuli, made of textures which IOC is sinusoidally modulated at various correlation spatial frequencies. Then, we compared the sensitivity to these stimuli to the sensitivity to analogous stimuli with disparity modulation.
Results: We observed that IOC sensitivity presents a low-pass/band-pass profile and increases as a function of presentation duration and contrast, in a similar way as disparity sensitivity.
Conclusions: IOC sensitivity is weakly—though significantly—correlated with disparity sensitivity in the general population, which suggests that it could provide a marker for binocular vision, prior to disparity processing.
