Search

Identification of retinal diseases in automated screening methods, such as those used in clinical settings or computer-aided diagnosis, usually depends on the localization and segmentation of the Optic Disc (OD) and fovea. However, this task is difficult since these anatomical features have irregular spatial, texture, and shape characteristics, limited sample sizes, and domain shifts due to different data distributions across datasets. This study proposes a novel Multiresolution Cascaded Attention U-Net (MCAU-Net) model that addresses these problems by optimally balancing receptive field size and computational efficiency. The MCAU-Net utilizes two skip connections to accurately localize and segment the OD and fovea in fundus images. We incorporated a Multiresolution Wavelet Pooling Module (MWPM) into the CNN at each stage of U-Net input to compensate for spatial information loss. Additionally, we integrated a cascaded connection of the spatial and channel attentions as a skip connection in MCAU-Net to concentrate precisely on the target object and improve model convergence for segmenting and localizing OD and fovea centers. The proposed model has a low parameter count of 0.8 million, improving computational efficiency and reducing the risk of overfitting. For OD segmentation, the MCAU-Net achieves high IoU values of 0.9771, 0.945, and 0.946 for the DRISHTI-GS, DRIONS-DB, and IDRiD datasets, respectively, outperforming previous results for all three datasets. For the IDRiD dataset, the MCAU-Net locates the OD center with an Euclidean Distance (ED) of 16.90 pixels and the fovea center with an ED of 33.45 pixels, demonstrating its effectiveness in overcoming the common limitations of state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to investigate the macular structure and foveal pit characteristics in the unilateral full-thickness macular hole (FTMH) patients and healthy fellow eyes. Methods: Our retrospective investigation included patients with unilateral FTMH as the study group, and age- and sex-matched individuals without vitreomacular diseases as the control group, all from one medical center. FTMHs were categorized into those with epiretinal proliferation, those without epiretinal proliferation, or those lacking vitreomacular separation. Macular parameters including foveal base width (FBW), central foveolar thickness (CFT), central subfield thickness (CST), central subfield volume, and retinal artery trajectory (RAT) were measured via optical coherence tomography and fundus photography. Comparisons of these parameters were made among lesioned eyes, contralateral healthy eyes and normal controls, as well as among different subgroups. Results: Sixty-eight unilateral FTMH patients (39 women and 29 men) and 68 normal controls were enrolled. The fellow eyes of unilateral FTMH showed larger FBWs (446.8 ± 98.2 μm) than controls (338.4 ± 80.6 μm, p < 0.001). The lesioned and fellow eyes of unilateral FTMH had smaller RAT values (0.19 ± 0.06 and 0.14 ± 0.04) than controls (0.37 ± 0.14, p < 0.001), indicating wider RAT in both groups. No significant macular structure parameter differences were observed among different FTMH subgroups. Females exhibited larger FBW, thinner CFT and CST, and wider RAT than the age-matched males (p < 0.05). Conclusions: Patients with unilateral FTMH had a wider RAT in both the lesioned and healthy eyes and a wider FBW in their healthy fellow eyes than in controls. Such macular structure characteristics may be prone to macular hole formation. [ABSTRACT FROM AUTHOR]

Abstract Identification of retinal diseases in automated screening methods, such as those used in clinical settings or computer-aided diagnosis, usually depends on the localization and segmentation of the Optic Disc (OD) and fovea. However, this task is difficult since these anatomical features have irregular spatial, texture, and shape characteristics, limited sample sizes, and domain shifts due to different data distributions across datasets. This study proposes a novel Multiresolution Cascaded Attention U-Net (MCAU-Net) model that addresses these problems by optimally balancing receptive field size and computational efficiency. The MCAU-Net utilizes two skip connections to accurately localize and segment the OD and fovea in fundus images. We incorporated a Multiresolution Wavelet Pooling Module (MWPM) into the CNN at each stage of U-Net input to compensate for spatial information loss. Additionally, we integrated a cascaded connection of the spatial and channel attentions as a skip connection in MCAU-Net to concentrate precisely on the target object and improve model convergence for segmenting and localizing OD and fovea centers. The proposed model has a low parameter count of 0.8 million, improving computational efficiency and reducing the risk of overfitting. For OD segmentation, the MCAU-Net achieves high IoU values of 0.9771, 0.945, and 0.946 for the DRISHTI-GS, DRIONS-DB, and IDRiD datasets, respectively, outperforming previous results for all three datasets. For the IDRiD dataset, the MCAU-Net locates the OD center with an Euclidean Distance (ED) of 16.90 pixels and the fovea center with an ED of 33.45 pixels, demonstrating its effectiveness in overcoming the common limitations of state-of-the-art methods.

Abstract Documenting the organization of the retinal capillaries is of importance to understand the visual consequences of vascular diseases which may differentially affect the microvascular layers. Here we detailed the spatial organization of the macular capillaries in ten healthy human subjects using a prototypic adaptive optics-enhanced optical coherence tomography angiography (AO-OCTA) system. Within the central 6° × 6°, the radial peripapillary capillaries and the superficial, intermediate and deep vascular plexuses (SVP, IVP and DVP, respectively) were consistently resolved. In 8 out of the 10 eyes, the capillary segments composing the perifoveal arcade (PFA) were perfused only by the SVP, while drainage of the PFA showed more variability, comprising a case in which the PFA was drained by the DVP. Around the center, a distinct central avascular zone could be documented for each layer in 7 of the 10 cases; in three eyes, the IVP and SVP merged tangentially around the center. In all eyes, the foveal avascular zone was larger in the DVP than in the SVP and IVP. In one eye with incomplete separation of the inner foveal layers, there was continuity of both the SVP and the IVP; a central avascular zone was only present in the DVP. The diversity of perfusion and drainage patterns supported a connectivity scheme combining parallel and serial organizations, the latter being the most commonly observed in perifoveal vessels. Our results thus help to further characterize the diversity of organization patterns of the macular capillaries and to robustly analyze the IVP, which will help to characterize early stages of microvascular diseases.

The fovea of the human retina, a specialization for acute and color vision, features a high concentration of cone photoreceptors. A pit on the inner retinal aspect is created by the centrifugal migration of post-receptoral neurons. Foveal cells are specified early in fetal life, but the fovea reaches its final configuration postnatally. Pre-term birth retards migration resulting in a small pit, a small avascular zone, and nearly continuous inner retinal layers. To explore the involvement of Müller glia, we used serial-section electron microscopic reconstructions to examine the morphology and neural contacts of Müller glia contacting a single foveal cone in a 28-year-old male organ donor born at 28 weeks of gestation. A small nondescript foveal avascular zone contained massed glial processes that included a novel class of 'inner' Müller glia. Similar to classic 'outer' Müller glia that span the retina, inner Müller glia have bodies in the inner nuclear layer (INL). These cells are densely packed with intermediate filaments and insert processes between neurons. Unlike 'outer' Müller glia, 'inner' Müller glia do not reach the external limiting membrane but instead terminate at the outer plexiform layer. One completely reconstructed inner cell ensheathed cone pedicles and a cone-driven circuit of midget bipolar and ganglion cells. Inner Müller glia outnumber foveal cones by 1.8-fold in the outer nuclear layer (221,448 vs. 123,026 cells/mm²). Cell bodies of inner Müller glia outnumber those of outer Müller glia by 1.7-fold in the INL (41,872 vs. 24,631 cells/ mm²). Müller glia account for 95 and 80% of the volume of the foveal floor and Henle fiber layer, respectively. Determining whether inner cells are anomalies solely resulting from retarded lateral migration of inner retinal neurons in pre-term birth requires further research. [ABSTRACT FROM AUTHOR]

Documenting the organization of the retinal capillaries is of importance to understand the visual consequences of vascular diseases which may differentially affect the microvascular layers. Here we detailed the spatial organization of the macular capillaries in ten healthy human subjects using a prototypic adaptive optics-enhanced optical coherence tomography angiography (AO-OCTA) system. Within the central 6° × 6°, the radial peripapillary capillaries and the superficial, intermediate and deep vascular plexuses (SVP, IVP and DVP, respectively) were consistently resolved. In 8 out of the 10 eyes, the capillary segments composing the perifoveal arcade (PFA) were perfused only by the SVP, while drainage of the PFA showed more variability, comprising a case in which the PFA was drained by the DVP. Around the center, a distinct central avascular zone could be documented for each layer in 7 of the 10 cases; in three eyes, the IVP and SVP merged tangentially around the center. In all eyes, the foveal avascular zone was larger in the DVP than in the SVP and IVP. In one eye with incomplete separation of the inner foveal layers, there was continuity of both the SVP and the IVP; a central avascular zone was only present in the DVP. The diversity of perfusion and drainage patterns supported a connectivity scheme combining parallel and serial organizations, the latter being the most commonly observed in perifoveal vessels. Our results thus help to further characterize the diversity of organization patterns of the macular capillaries and to robustly analyze the IVP, which will help to characterize early stages of microvascular diseases. [ABSTRACT FROM AUTHOR]

The fovea is a small region within the central retina that is responsible for our high acuity daylight vision. Chickens also have a high acuity area (HAA), and are one of the few species that enables studies of the mechanisms of HAA development, due to accessible embryonic tissue and methods to readily perturb gene expression. To enable such studies, we characterized the development of the chick HAA using single molecule fluorescent in situ hybridization (smFISH), along with more classical methods. We found that Fgf8 provides a molecular marker for the HAA throughout development and into adult stages, allowing studies of the cellular composition of this area over time. The radial dimension of the ganglion cell layer (GCL) was seen to be the greatest at the HAA throughout development, beginning during the period of neurogenesis, suggesting that genesis, rather than cell death, creates a higher level of retinal ganglion cells (RGCs) in this area. In contrast, the HAA acquired its characteristic high density of cone photoreceptors post-hatching, which is well after the period of neurogenesis. We also confirmed that rod photoreceptors are not present in the HAA. Analyses of cell death in the developing photoreceptor layer, where rods would reside, did not show apoptotic cells, suggesting that lack of genesis, rather than death, created the "rod-free zone" (RFZ). Quantification of each cone photoreceptor subtype showed an ordered mosaic of most cone subtypes. The changes in cellular densities and cell subtypes between the developing and mature HAA provide some answers to the overarching strategy used by the retina to create this area and provide a framework for future studies of the mechanisms underlying its formation. [Display omitted] • Fgf8 provides a molecular marker for the developing chick high acuity area (HAA). • The retinal ganglion cell layer is thickest within the HAA from early embryonic stages. • The HAA has lowest density of cones embryonically and highest density after hatching. • Almost no apoptotic cell death was observed for photoreceptors in rod-free zone of HAA. • Early specialization of the HAA suggests that there is a distinct progenitor pool for this area. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the preoperative and postoperative change in retinal sensitivity in relation to the distance to the retinal detachment (RD) in patients with fovea‐on RD. Methods: We prospectively evaluated 13 patients with fovea‐on RD and a healthy control eye. Preoperatively, OCT scans of the RD border and the macula were obtained. The RD border was highlighted on the SLO image. Microperimetry was used to assess the retinal sensitivity at the macula, the RD border and the retina around the RD border. At 6 weeks, 3 and 6 months postoperatively, follow‐up examinations of OCT and microperimetry were performed in the study eye. Microperimetry was performed once in control eyes. Microperimetry data were overlaid on the SLO image. The shortest distance to the RD border was calculated for each sensitivity measurement. The change in retinal sensitivity was calculated as control‐study. The relation between the change in retinal sensitivity and the distance to the RD border was assessed using a locally weighted scatterplot smoothing curve. Results: Preoperatively, the greatest loss in retinal sensitivity was 21 dB at 3° inside the RD which decreased linearly, through the RD border, and reached a plateau of 2 dB at 4°. For 6 weeks and 3 months postoperatively, the greatest retinal sensitivity loss remained at 3° inside the RD but was 4 dB and sensitivity loss decreased linearly to a plateau of 0 dB at 5° outside the RD. At 6 months postoperatively, the greatest sensitivity loss was 2 dB at 3° inside the RD, and decreased linearly to a plateau of 0 dB at 2° outside the RD. Conclusions: Retinal damage extends beyond the detached retina. Retinal sensitivity loss of the attached retina decreased drastically as the distance to the RD increased. Postoperative recovery occurred for both attached and detached retina. [ABSTRACT FROM AUTHOR]

During collective vigilance, it is commonly assumed that individual animals compromise their feeding time to be vigilant against predators, benefiting the entire group. One notable issue with this assumption concerns the unclear nature of predator ‘detection’, particularly in terms of vision. It remains uncertain how a vigilant individual utilizes its high-acuity vision (such as the fovea) to detect a predator cue and subsequently guide individual and collective escape responses. Using fine-scale motion-capture technologies, we tracked the head and body orientations of pigeons (hence reconstructed their visual fields and foveal projections) foraging in a flock during simulated predator attacks. Pigeons used their fovea to inspect predator cues. Earlier foveation on a predator cue was linked to preceding behaviors related to vigilance and feeding, such as head-up or down positions, head-scanning, and food-pecking. Moreover, earlier foveation predicted earlier evasion flights at both the individual and collective levels. However, we also found that relatively long delay between their foveation and escape responses in individuals obscured the relationship between these two responses. While our results largely support the existing assumptions about vigilance, they also underscore the importance of considering vision and addressing the disparity between detection and escape responses in future research.

In primates, high-acuity vision is mediated by the fovea, a small specialized central region of the retina. The fovea, unique to the anthropoid lineage among mammals, undergoes notable neuronal morphological changes during postnatal maturation. However, the extent of cellular similarity across anthropoid foveas and the molecular underpinnings of foveal maturation remain unclear. Here, we used high-throughput single-cell RNA sequencing to profile retinal cells of the common marmoset (Callithrix jacchus), an early divergent in anthropoid evolution from humans, apes, and macaques. We generated atlases of the marmoset fovea and peripheral retina for both neonates and adults. Our comparative analysis revealed that marmosets share almost all their foveal types with both humans and macaques, highlighting a conserved cellular structure among primate foveas. Furthermore, by tracing the developmental trajectory of cell types in the foveal and peripheral retina, we found distinct maturation paths for each. In-depth analysis of gene expression differences demonstrated that cone photoreceptors and Müller glia (MG), among others, show the greatest molecular divergence between these two regions. Utilizing single-cell ATAC-seq and gene-regulatory network inference, we uncovered distinct transcriptional regulations differentiating foveal cones from their peripheral counterparts. Further analysis of predicted ligand-receptor interactions suggested a potential role for MG in supporting the maturation of foveal cones. Together, these results provide valuable insights into foveal development, structure, and evolution. [ABSTRACT FROM AUTHOR]

Purpose: Williams-Beuren syndrome (WBS) is a rare genetic disease characterized by psychomotor delay, cardiovascular, musculoskeletal, and endocrine problems. Retinal involvement, which is not well characterized, has also been described. The purpose of this cross-sectional study is to describe the characteristics in optical coherence tomography (OCT) and OCT-angiography (OCTA) of patients with WBS. Methods: We included patients with WBS confirmed by genetic analysis. The patients underwent OCT (30° × 25°, 61 B-scans) and OCTA (10° × 10° and 20° × 20°) examinations, all centered on the. Data on retinal thickness (total, inner and outer layers) and foveal morphology on OCT and vessel and perfusion density in OCTA (VD and PD, respectively) were collected. These data were compared with an age-matched control group. Results: 22 eyes of 22 patients with WBS (10 females, mean age 31.5 years) were included. Retinal thickness (and specifically inner retinal layers) in OCT was significantly reduced in all sectors (central, parafoveal, and perifoveal) compared to the control group (p < 0.001 in all sectors). Fovea in WBS eyes was broader and shallower than controls. The PD and VD in both 10 and 20 degrees of fields in OCTA was significantly reduced in patients with WBS, in all vascular plexa (all p < 0.001). Conclusions: This study is the first to quantify and demonstrate retinal structural and microvascular alterations in patients with WBS. Further studies with longitudinal data will reveal the potential clinical relevance of these alterations. [ABSTRACT FROM AUTHOR]

Identification of the optic disc and fovea is crucial for automating the diagnosis and screening of retinal diseases. Based on quantitative calculations, this study presents a decision support system for doctors that automatically detect optic nerve hypoplasia. For disease diagnosis, U-Net architecture is used, which uses a pre-trained ResNet encoder to segment the optic disc and fovea structures. An important aspect of the proposed technique is that pretrained ResNet and U-Net are used together, providing robust performance in the detection of optic nerve hypoplasia. Our proposed architecture was tested on retinal images from Messidor, Diaretdb1, DRIVE, HRF, APTOS, and IDRID. In addition, a special database called ONH-NET was created based on 189 retinal images obtained from Düzce University, Department of Ophthalmology. Messidor database test images showed, 0. 9069 IOU Score, 0.9626 Sensitivity, 0.9411 Precision, 0.9974 Accuracy and 0.9505 dice-coefficient values in optic disc detection, and 0.8282 IOU score, 0.8442 sensitivity, 0.8252 precision, 0.8992 Accuracy, 0.7873 dice coefficient values were obtained in fovea detection. We computed diameter optic disc to macula radius ratios from segmented optic disc and fovea for screening optic nerve hypoplasia and achieved 100% success. [ABSTRACT FROM AUTHOR]

To compare peak cone density predicted from outer segment length measured on optical coherence tomography with direct measures of peak cone density from adaptive optics scanning light ophthalmoscopy. Data from 42 healthy participants with direct peak cone density measures and optical coherence tomography line scans available were used in this study. Longitudinal reflectivity profiles were analyzed using two methods of identifying the boundaries of the ellipsoid and interdigitation zones to estimate maximum outer segment length: peak-to-peak and the slope method. These maximum outer segment length values were then used to predict peak cone density using a previously described geometrical model. A comparison between predicted and direct peak cone density measures was then performed. The mean bias between observers for estimating maximum outer segment length across methods was less than 2 µm. Cone density predicted from the peak-to-peak method against direct cone density measures showed a mean bias of 6,812 cones/mm2 with 50% of participants displaying a 10% difference or less between predicted and direct cone density values. Cone density derived from the slope method showed a mean bias of −17,929 cones/mm2 relative to direct cone density measures, with only 41% of participants demonstrating less than a 10% difference between direct and predicted cone density values. Predicted foveal cone density derived from peak-to-peak outer segment length measurements using commercial optical coherence tomography show modest agreement with direct measures of peak cone density from adaptive optics scanning light ophthalmoscopy. The methods used here are imperfect predictors of cone density, however, further exploration of this relationship could reveal a clinically relevant marker of cone structure. [ABSTRACT FROM AUTHOR]

Caudal malocclusions in cats may result in a variety of traumatic lesions affecting the soft tissues of the ipsilateral mandible such as fovea, gingival cleft, and proliferative lesions. Fifty-one cats diagnosed with a traumatic caudal malocclusion were compared with a control hospital population and evaluated for prevalence with respect to breed and sex. Twenty-two cats that were treated had radiographic, clinical findings, and the outcome of treatment (extraction or odontoplasty) recorded. Maine Coon, Persian, and male neutered cats were overrepresented while Domestic Shorthairs were underrepresented within the study population. Radiographically, 50% of the fovea lesions had an area of decreased bone density in the region of the lesion and none of these had evidence of periodontal disease. All gingival cleft lesions had radiographic changes consistent with periodontal disease. 15.4% of proliferative lesions presented with radiographic changes, with only half of those presenting with both radiographic and clinical evidence of periodontal disease. Eleven cats were treated by odontoplasty and eleven by extraction. One cat treated by odontoplasty developed new lesions caudally, and another had persistence of the initial lesions. Two cats in the extraction group developed new lesions rostral to the extracted teeth. In most instances, odontoplasty or extraction resulted in successful soft tissue lesion resolution. In rare cases, additional treatment was necessary due to either persistence or development of new lesions. [ABSTRACT FROM AUTHOR]

This study examined whether temporal crowding--the impaired object identification when distracting objects precede and succeed it--occurs at the fovea and if so whether its magnitude is reduced. We presented a central sequence of three oriented items separated by relatively long intervals (200/400 ms) and used an orientation estimation task with mixture-model analyses. We found clear evidence of temporal crowding with central vision, even with 400 ms intervals. Critically, reduced encoding precision surfaced as a robust and unique characteristic of temporal crowding. The magnitude of central and peripheral temporal crowding was similar suggesting the involvement of higher visual areas. Precision impairment emerged even when only the target contained orientation information, excluding "response competition" as the sole interference mechanism; yet it was larger when all items included orientation information, underscoring the importance of orientation-selective mechanisms. Overall, we showthat even with central simple stimuli, the formation of a stable visual representation is surprisingly slow. [ABSTRACT FROM AUTHOR]

The fovea of the human retina, a specialization for acute and color vision, features a high concentration of cone photoreceptors. A pit on the inner retinal aspect is created by the centrifugal migration of post-receptoral neurons. Foveal cells are specified early in fetal life, but the fovea reaches its final configuration postnatally. Pre-term birth retards migration resulting in a small pit, a small avascular zone, and nearly continuous inner retinal layers. To explore the involvement of Müller glia, we used serial-section electron microscopic reconstructions to examine the morphology and neural contacts of Müller glia contacting a single foveal cone in a 28-year-old male organ donor born at 28 weeks of gestation. A small non-descript foveal avascular zone contained massed glial processes that included a novel class of ‘inner’ Müller glia. Similar to classic ‘outer’ Müller glia that span the retina, inner Müller glia have bodies in the inner nuclear layer (INL). These cells are densely packed with intermediate filaments and insert processes between neurons. Unlike ‘outer’ Müller glia, ‘inner’ Müller glia do not reach the external limiting membrane but instead terminate at the outer plexiform layer. One completely reconstructed inner cell ensheathed cone pedicles and a cone-driven circuit of midget bipolar and ganglion cells. Inner Müller glia outnumber foveal cones by 1.8-fold in the outer nuclear layer (221,448 vs. 123,026 cells/mm2). Cell bodies of inner Müller glia outnumber those of outer Müller glia by 1.7-fold in the INL (41,872 vs. 24,631 cells/ mm2). Müller glia account for 95 and 80% of the volume of the foveal floor and Henle fiber layer, respectively. Determining whether inner cells are anomalies solely resulting from retarded lateral migration of inner retinal neurons in pre-term birth requires further research.

Purpose: To report a case of a refractory foveal microaneurysm (MA) that was successfully treated by use of a new surgical procedure. Observations: This study involved a 79-year-old female with an active foveal MA associated with branch retinal vein occlusion in her left eye. Despite anti-vascular endothelial growth factor treatments, the MA remained active without closure, and best-corrected visual acuity (VA) gradually decreased from 20/20 to 20/200. After our new surgical procedure was explained in detail to the patient, written informed consent was obtained from the patient and the surgery was performed. Briefly, following pars plana vitrectomy, the internal limiting membrane in her left eye was peeled and the retina of the external wall of the MA was then gently incised. The exposed MA was then directly grabbed and pulled up onto the retina using 27-gauge microforceps, and photocoagulation was performed. At 3-months postoperative, closure of the MA and improvement in the retinal findings were observed, and best-corrected VA improved to 20/67. Conclusions and importance: We report a case of a refractory foveal MA that was successfully treated with a novel surgical technique that closed the MA, avoided thermal damage to the surrounding tissue, and resulted in improved postoperative VA.

Aims: To measure the foveal pit morphology parameters and evaluate their correlations with age and sex. Settings and Design: A retrospective cross-sectional matched comparison study in a tertiary center. Methods and Materials: Forty men and 40 age-matched women who had normal macular structures and foveal contours were enrolled. Foveal pit parameters including top width, base width, nasal width, temporal width, minimal thickness, nasal thickness, temporal thickness, nasal height, temporal height, nasal slope, and temporal slope were measured on horizontal B-scan macular optical coherence tomography and compared between men and women. Statistical Analysis Used: Paired t-tests and Pearson's correlation analysis. Results: The average patient age was 51.4 ± 17.5 (21–84) years. Women had a wider base width (313.1 ± 68.0 μm vs 266.8 ± 70.9 μm, P = 0.006), wider temporal width (1043.1 ± 245.6 μm vs 968.9 ± 261.0 μm, P = 0.006), thinner nasal thickness (345.6 ± 36.2 μm vs 359.7 ± 35.8 μm, P = 0.048), and flatter temporal slope (11.60 ± 2.52° vs 12.98 ± 2.68°, P = 0.016) than men. With age, the base width (r = 0.35, P = 0.025) and temporal width (r = 0.54, P = 0.0003) tended to be wider and the temporal slope was flatter (r = -0.45, P = 0.003) in women but not men. The minimal thickness tended to be thinner in the elderly group (r = 0.038, P = 0.015). Conclusions: Women had a significantly wider base width, wider temporal width, thinner nasal thickness, and flatter temporal slope of the foveal pit than age-matched men. The base width and temporal width were wider and the temporal slope was flatter with age in women but not men.

Objectives: This study aimed to examine the choroidal thicknesses (ChT) changes before and after resolution of subretinal fluid in patients with central serous chorioretinopathy (CSR) and in their fellow eyes. Materials and Methods: Patients with acute CSR were studied and followed until subretinal fluid resolved. Sixty-eight eyes from 34 CSR cases (24 men and 10 women, mean age of 37.34±6.2, range 27-50) were examined. Their ChT was measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Imaging repeated after sub-retinal fluid resolution. ChT changes were analyzed before and after the resolution of subretinal fluid in both eyes. Results: Mean ChTs in CSR eyes were 387±97 µm, 414±97 µm, and 384±87 µm in 1 mm temporally away from the center, central sub-fovea, and 1 mm nasally away from the center, respectively; and those in the fellow eyes were 283±55 µm, 303±60 µm, and 282±56 µm in the same order. ChT decreased significantly (P≤0.001) to 305±82 µm, 334±86 µm, and 313±76 µm in CSR eyes and to 242±52 µm, 262±55 µm, and 246±48 µm in contralateral eyes in the temporal, central sub-foveal, and nasal sequences after subretinal fluid resolution, respectively. There was a strong correlation between the ChT in active phase and the ChT in resolved phase in both affected and fellow eyes. There was no detectable correlation between central sub-foveal fluid height and sub-foveal choroidal thickness in the affected and fellow eye (P=0.23). Conclusion: Nasal and temporal comparison of the affected and fellow eyes before and after fluid resolution showed that the nasal choroid was thinner than temporal choroid (as the average population) in active phase. In the resolution phase, however, it was the temporal choroid that was thinner than the nasal choroid, and the resolution pattern was not asymmetric.

Optic Atrophy (OA) can be associated with the development of microcystic macular edema (MME) in the perifoveal retinal inner nuclear layer (INL). We aimed here to retrospectively determine the prevalence of MME in patients with non-glaucomatous OA in our tertiary ophthalmology department between 2015 and 2020. We then examined how MME affected the thicknesses of the different retinal layers and the differences in demographic and clinical characteristics between those patients who developed MME and those who did not. A total of 643 eyes (429 patients) were included (mean age 45.9 ± 17.8 years, 52% female). MME developed in 95 (15%) eyes and across all etiologies of OA except for toxic/nutritional causes, but the prevalence of MME varied between the different etiologies. The development of MME was associated with thinning of the ganglion cell layer (11.0 vs. 9.6 μm; p = 0.001) and the retinal nerve fiber layer (10.1 vs. 9.15 μm; p = 0.024), with INL thickening in the 3- and 6-mm diameter areas of the central fovea. Patients developing MME had significantly worse distance best-corrected visual acuity than those not developing MME (0.62 vs. 0.38 logMAR; p = 0.002). Overall, the presence of MME in OA cannot be used to guide the diagnostic work-up of OA.

The human fovea is known for its distinctive pit‐like appearance, which results from the displacement of retinal layers superficial to the photoreceptors cells. The photoreceptors are found at high density within the foveal region but not the surrounding retina. Efforts to elucidate the mechanisms responsible for these unique features have ruled out cell death as an explanation for pit formation and changes in cell proliferation as the cause of increased photoreceptor density. These findings have led to speculation that mechanical forces acting within and on the retina during development underly the formation of foveal architecture. Here we review eye morphogenesis and retinal remodeling in human embryonic development. Our meta‐analysis of the literature suggests that fovea formation is a protracted process involving dynamic changes in ocular shape that start early and continue throughout most of human embryonic development. From these observations, we propose a new model for fovea development. [ABSTRACT FROM AUTHOR]

The terms fossa and fovea are found in Terminologia Anatomica, however, there is no clear difference between both terms. Therefore, the objective of this study was to determine the coherence between the lexical, morphological and etymological relationship of the term's fossa and fovea with their use in Terminologia Anatomica. The terms fossa and fovea were consulted in Terminologia Anatomica (Federative International Programme for Anatomical Terminology, 2019) and in International Anatomical Terminology (Federative Committee on Anatomical Terminology, 2001). Subsequently, a search for both terms was carried out in Latin-Spanish and English-Latin dictionaries. Finally, the terms fossa and fovea were consulted in the Diccionario de la Real Academia Española and in the Diccionario panhispánico de términos médicos de la Real Academia Nacional de Medicina de España to know the definitions in the medical area. The search reported that the term "fossa" comes from the Latin fossa, which means "excavation, ditch, ditch; hole, hole." For its part, "fovea" comes from the Latin fovea, which means "small hole." Therefore, the difference between fossa and fovea is determined by their size according to their definitions. However, in Terminologia Anatomica, structures have been described with the diminutive of fossa and fovea, which makes the differentiation of the terms according to their size more complex. Furthermore, the lack of unification in the nomenclature between fossa, fovea and their diminutives generates great confusion and inconsistencies in the translations from Latin to English and Spanish in Terminologia Anatomica that reduce the precision of the nomenclature. Therefore, we propose the unification of the terms fossa and fovea based on the size of the anatomical depression and clarify their translation into English and Spanish. [ABSTRACT FROM AUTHOR]

Aims: To measure the foveal pit morphology parameters and evaluate their correlations with age and sex. Settings and Design: A retrospective cross-sectional matched comparison study in a tertiary center. Methods and Materials: Forty men and 40 age-matched women who had normal macular structures and foveal contours were enrolled. Foveal pit parameters including top width, base width, nasal width, temporal width, minimal thickness, nasal thickness, temporal thickness, nasal height, temporal height, nasal slope, and temporal slope were measured on horizontal B-scan macular optical coherence tomography and compared between men and women. Statistical Analysis Used: Paired t-tests and Pearson's correlation analysis. Results: The average patient age was 51.4 ± 17.5 (21–84) years. Women had a wider base width (313.1 ± 68.0 μm vs 266.8 ± 70.9 μm, P = 0.006), wider temporal width (1043.1 ± 245.6 μm vs 968.9 ± 261.0 μm, P = 0.006), thinner nasal thickness (345.6 ± 36.2 μm vs 359.7 ± 35.8 μm, P = 0.048), and flatter temporal slope (11.60 ± 2.52° vs 12.98 ± 2.68°, P = 0.016) than men. With age, the base width (r = 0.35, P = 0.025) and temporal width (r = 0.54, P = 0.0003) tended to be wider and the temporal slope was flatter (r = -0.45, P = 0.003) in women but not men. The minimal thickness tended to be thinner in the elderly group (r = 0.038, P = 0.015). Conclusions: Women had a significantly wider base width, wider temporal width, thinner nasal thickness, and flatter temporal slope of the foveal pit than age-matched men. The base width and temporal width were wider and the temporal slope was flatter with age in women but not men. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to report the findings of a hyperreflective nodular epiretinal gliosis observed with optical coherence tomography presumed to be due to subclinical hyaloidal traction causing Müller cell cone gliosis. Methods: Retrospective, observational case series. Results: Six eyes of six patients (mean age: 57 years, range 35-81 years) presented with a nodular epiretinal gliosis and had an average follow-up interval of 26 months (range 1-82 months). The mean baseline best-corrected visual acuity was 0.25 ± 0.17 (Snellen equivalent 20/38.3 ± 16.9). Fundus photography demonstrated a yellowish lesion overlying the fovea. Optical coherence tomography imaging revealed a hyperreflective preretinal lesion with a mean vertical length of 267 mm (range 185-497) and a mean greatest linear diameter of 312 μm (range 124-640). There was no vitreoretinal abnormality including vitreomacular traction or epiretinal membrane noted in any eye, and two of six eyes displayed a definitive posterior vitreous detachment. These nodules may have occurred before and persisted even after a posterior vitreous detachment or may have been acquired after the posterior vitreous detachment. The nodules typically remained stable with minimal change although in one eye, a posterior vitreous detachment occurred 6 months after initial presentation and lifted the gliosis off of the retinal surface where it remained attached to the posterior hyaloid. Conclusion: Foveal nodular epiretinal gliosis may occur due to subclinical hyaloidal traction on the Müller cell cone even without obvious vitreoretinal interface abnormality on optical coherence tomography. [ABSTRACT FROM AUTHOR]

PurposeTo characterize the effect of sampling window size on maps of foveal cone density derived from adaptive optics scanning light ophthalmoscope (AOSLO) images of the cone mosaic.MethodsForty-four AOSLO-derived montages of the foveal cone mosaic (300 x 300µm) were used for this study (from 44 individuals with normal vision). Cone photoreceptor coordinates were semi-automatically identified by one experienced grader. From these coordinates, cone density matrices across each foveal montage were derived using 10 different sampling window sizes containing 5, 10, 15, 20, 40, 60, 80, 100, 150, or 200 cones. For all 440 density matrices, we extracted the location and value of peak cone density (PCD), the cone density centroid (CDC) location, and cone density at the CDC.ResultsAcross all window sizes, PCD values were larger than those extracted at the CDC location, though the difference between these density values decreased as the sampling window size increased (p

Purpose: To describe the mechanisms of postoperative foveal restoration in three patients with bacillary layer detachment (BALAD) associated with macula-off rhegmatogenous retinal detachment. Observations: BALAD associated with macula-off rhegmatogenous retinal detachment presented with two different morphologies: with an intact foveal roof (case 1) and lamellar, with an open foveal roof (cases 2 and 3). In case 1 visual acuity significantly improved and foveal morphology completely restored at postoperative month 6, with a marked increase in foveal thickness. Case 2 presented with a lamellar BALAD in a long-standing retinal detachment, and it was treated with scleral buckling with an unfavourable evolution into a full-thickness hole in the early postoperative period. It was then addressed with internal limiting membrane peeling and inverted flap, which resulted in the resolution of the lesion, but with limited postoperative visual and anatomical recovery. Case 3 lamellar BALAD was directly addressed with pars plana vitrectomy, ILM peeling and inverted flap, with a remarkable foveal anatomical restoration and visual acuity improvement over the follow-up period. Conclusions and importance: The process of foveation may play a key role in the healing process of BALAD associated with rhegmatogenous retinal detachment. Lamellar BALAD should be considered and treated as a FTMH associated with retinal detachment. The two BALAD subtypes may represent different clinical stages of the BALAD spectrum.

The increase of brain neuron number in relation with brain size is currently considered to be the major evolutionary path to high cognitive power in amniotes. However, how changes in neuron density did contribute to the evolution of the information-processing capacity of the brain remains unanswered. High neuron densities are seen as the main reason why the fovea located at the visual center of the retina is responsible for sharp vision in birds and primates. The emergence of foveal vision is considered as a breakthrough innovation in visual system evolution. We found that neuron densities in the largest visual center of the midbrain – i.e., the optic tectum – are two to four times higher in modern birds with one or two foveae compared to birds deprived of this specialty. Interspecies comparisons enabled us to identify elements of a hitherto unknown developmental process set up by foveate birds for increasing neuron density in the upper layers of their optic tectum. The late progenitor cells that generate these neurons proliferate in a ventricular zone that can expand only radially. In this particular context, the number of cells in ontogenetic columns increases, thereby setting the conditions for higher cell densities in the upper layers once neurons did migrate. [Display omitted] • The advent of the fovea was a breakthrough innovation in bird evolution. • Foveal vision requires increased neuron densities in the optic tectum. • Neuron densities are different when the foveae are deep or shallow. • Ganglion cell densities are higher in the shallow foveae than in the deep ones. [ABSTRACT FROM AUTHOR]

Purpose: During routine eye examinations, we noticed widened and flattened foveal pits with loss of normal V-shaped foveal profile and a pseudohole-like appearance in some otherwise healthy hypermetropic children. Our purpose was to describe clinical significance and multimodal imaging features of this incidental finding. Methods: Prospectively, 25 eyes of 13 hypermetropic children with these foveal changes and 36 eyes of 19 hypermetropic children with normal foveal appearance were enrolled. The macular thickness measurements and foveal parameters including pit diameter, depth, base, and area obtained by optical coherence tomography (OCT) (Heidelberg Spectralis, Heidelberg Engineering, Heidelberg, Germany), macular superficial and deep vessel density (VD) and foveal avascular zone values obtained by optical coherence tomography angiography (Avanti RTVue‑XR; Optovue, Fremont, CA, USA) were noted. The correlations of these parameters with visual function were evaluated. Results: In the study group, significantly widened and flattened pit contours with decreased central foveal thickness (p = 0.01), and increased distance between foveal edges (p < 0.001) were observed. While the whole image superficial macular VD was similar between the groups (p = 0.74), a significant decrease in deep macular VD was observed in the study group (p = 0.01). None of these changes were correlated with visual acuity. Conclusion: Wider and flattened foveal pits described here represent a newly defined variation in healthy hypermetropic children. Although a correlation with visual acuity was not evident, these changes in foveal profile are shown to be related with macular microvascular changes in deep capillary plexus. Awareness of these morphologic changes will help clinicians in the differential diagnosis of macular pseudohole. [ABSTRACT FROM AUTHOR]

Diabetic macular edema (DME) is a condition of retinal swelling due to the accumulation of leaked plasma in the extracellular space in the retina, known as the macula. DME is a chronic progressive retinal disorder that likely results in permanent complete blindness. The early signs of DME are not discernible by merely suspecting the fundus picture with the naked eye. Therefore, a computer-assisted diagnostic system could aid ophthalmologists in screening, diagnosing, and treating DME. This study proposes an efficient and complete model for early diagnosis and staging of DME. To overcome the challenges in precise localization of fovea, blood vessel network extraction, and accurate lesion segmentation, improved image relative subtraction, Gabor wavelet filter, and novel advanced fuzzy c-means clustering algorithms are introduced, respectively. Finally, the Bayesian classifier using the Gaussian function with expectation maximization is used for DME grading. The accurate optic disc and fovea localization, exudates’ segmentation, and classification improved the overall system’s performance. The proposed model achieves an average accuracy of 96.17%, 98.60%, 97.85%, and 98.80% for optic disc detection, fovea localization, exudates segmentation, and DME classification, respectively. The performance of the proposed model compared to the competitive studies illustrates the superiority of the suggested methodology.

Background: RS3PE (remitting seronegative symmetrical synovitis with edema and pitting) is a rare entity of unknown etiology that has been related to genetic predisposition due to the presence of HLA-A2 in 50% of cases and less frequently HLA-B7. Its pathogenesis is unknown, but it has been related to growth factors, and some mediators (TNF, IL-6). It is common in elderly people and the course of this illness presents with acute symmetrical polyarthritis, accompanied by edema in hands and feet. The diagnosis requires a high index of suspicion and to differentiate it from other entities such as rheumatoid arthritis, complex regional pain syndrome, rheumatic polymyalgia, in addition to ruling out malignant neoplasms, since there are many reports of its association with both solid and hematological neoplasms, being of bad prognosis when there is association. When there is no association with cancer, it responds well to the use of low doses of steroids and its prognosis is usually favorable. Clinical case: 80-year-old woman with an acute onset with polyarthralgia, functional limitation associated with pitting edema in hands and feet. After approaching the patient and ruling out associated neoplasms, it was diagnosed RS3PE. It was managed with prednisone, observing a good response, with remission of the manifestations at 6 weeks and subsequent suspension of the steroid. Conclusions: RS3PE is a rare entity, and a high index of suspicion is required for the diagnosis. A complete approach is important to rule out cancer in patients affected with this syndrome. Prednisone continues to be the best therapeutic option. [ABSTRACT FROM AUTHOR]

A 28-year-old young Caucasian female patient without a history of trauma or vascular disease presented with blurred vision and paracentral scotoma in her left eye. Fundus examination showed a small foveal hemorrhage in the superficial retinal layers. Initial visual acuity was 20/50 in the LE. After 2 weeks, visual acuity increased to 20/20, and hemorrhage was resolved in optical coherence tomography angiography (OCT-A) spontaneously. No vascular lesion was seen in any layer of the retina in OCT-A analysis. [ABSTRACT FROM AUTHOR]

In this work, we propose a multi-task learning-based approach towards the localization of optic disc and fovea from human retinal fundus images using a deep learning-based approach. Formulating the task as an image-based regression problem, we propose a Densenet121-based architecture through an extensive set of experiments with a variety of CNN architectures. Our proposed approach achieved an average mean absolute error of only 13pixels (0.04%), mean squared error of 11 pixels (0.005%), and a root mean square error of only 0.02 (13%) on the IDRiD dataset. [ABSTRACT FROM AUTHOR]

The macula, as the central part of the retina, plays an important role in the reading process. However, its morphology has not been previously studied in the context of dyslexia. In this research, we compared the thickness of the fovea, parafovea and perifovea between dyslexic subjects and normal controls, in 11 retinal segmentations obtained by optical coherence tomography (OCT). With this aim, we considered the nine sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid and also summarized data from sectors into inner ring subfield (parafovea) and outer ring subfield (perifovea). The thickness in all the four parafoveal sectors was significantly thicker in the complete retina, inner retina and middle retina of both eyes in the dyslexic group, as well as other macular sectors (fovea and perifovea) in the inner nuclear layer (INL), inner plexiform layer (IPL), IPL + INL and outer plexiform layer + outer nuclear layer (OPL + ONL). Additionally, the inner ring subfield (parafovea), but not the outer ring subfield (perifovea), was thicker in the complete retina, inner retina, middle retina (INL + OPL + ONL), OPL + ONL, IPL + INL and INL in the dyslexic group for both eyes. In contrast, no differences were found between the groups in any of the sectors or subfields of the outer retina, retinal nerve fiber layer, ganglion cell layer or ganglion cell complex in any eye. Thus, we conclude from this exploratory research that the macular morphology differs between dyslexic and normal control subjects, as measured by OCT, especially in the parafovea at middle retinal segmentations. [ABSTRACT FROM AUTHOR]

The retina is the visible component of the nervous system that links directly to the brain; hence, analyzing and extracting features of the retinal fundus image is essential in ophthalmology. Unfortunately, most retinal fundus images suffer from degradation or distortions, resulting from different imaging qualities during capture and infection by a disease of the eye, such as Glaucoma, Retinoblastoma, Diabetic Retinopathy (DR), Myopia, and Macular Edema. As a result, these changes make it difficult to identify regions of the retina that assist in diagnosing the disease. For instance, many retina diseases diagnosis is impossible to detect without detecting the optic disc (OD) correctly. All these issues motivate us to suggest an algorithm for the localization of the OD that is important for assisting in diagnosing some eye diseases. The proposed algorithm includes several stages. Firstly, we focus on gathering seventeen datasets that make the suggested algorithm more popular, where a group of images belongs to four datasets used in training and the rest in testing. Secondly, the quality of the image improves in three steps, crops the Field of View (FOV), which carries essential information in the retinal image, removing pixels at the top and bottom of the FOV because they represent redundant information, and we suggested a new method for enhancing the illumination and contrast of the retinal fundus image. Thirdly, we proposed using a You only look once (YOLO) for the localization of OD. The method locates the OD exactly (drawing box around the OD and each side of the box touches the OD), not the region around it as in the previous methods. The current method works excellently with all the challenges that may face in the detection and localization of the OD. The proposed model tested with about 6000 different images from various datasets and challenges The accuracy obtained was 100% with an average time of 0.19 seconds. These results were very good compared with previous works in terms of accuracy, average time, and the number of tested images. [ABSTRACT FROM AUTHOR]

The issues in the organization of the human retina are analyzed from the point of view of cybernetics. In particular, hypotheses are formed regarding the conditions of the concentric organization of receptive fields, the extraction of informative features, the possibilities of restructuring the receptive fields and their limitations, the transmission of information through ganglion cells with its binding to the location on the retina, as well as regarding the peculiarities of the visual system in different modes. The conditions for the correct operation of on- and off-centers of receptive fields based on bipolars with a cone as the central zone of excitation and the surrounding rods as an inhibition zone, organized with the help of horizontal cells for the on-center, and vice versa for the off-center, are determined. The conditions for the extraction of informative features based on on- and off-centers in the form of point values of brightness differences between neighboring elements are substantiated. The rigid organization of the receptive fields of ganglion cells and the limited possibilities of its reconstruction are substantiated. A hypothesis on the organization of the transmission of information about brightness differences from bipolar cells through ganglion cells under the control of amacrine cells with reference to the location of the retina is proposed. A hypothesis on the continuous perception of the image by the retina receptors and the discrete perception of information by the brain is formulated. The features of the visual system in the modes of contemplation, searching for an object in an image, tracking it, and detailed examination and recognition are considered. [ABSTRACT FROM AUTHOR]

Appropriate patterning of the retina during embryonic development is assumed to underlie the establishment of spatially localised specialisations that mediate the perception of specific visual features. For example, in zebrafish, an area involved in high acuity vision (HAA) is thought to be present in the ventro-temporal retina. Here, we show that the interplay of the transcription factor Rx3 with Fibroblast Growth Factor and Hedgehog signals initiates and restricts foxd1 expression to the prospective temporal retina, initiating naso-temporal regionalisation of the retina. Abrogation of Foxd1 results in the loss of temporal and expansion of nasal retinal character, and consequent absence of the HAA. These structural defects correlate with severe visual defects, as assessed in optokinetic and optomotor response assays. In contrast, optokinetic responses are unaffected in the opposite condition, in which nasal retinal character is lost at the expense of expanded temporal character. Our study indicates that the establishment of temporal retinal character during early retinal development is required for the specification of the HAA, and suggests a prominent role of the temporal retina in controlling specific visual functions. [ABSTRACT FROM AUTHOR]

Aging is the greatest risk factor for chronic human diseases, including many eye diseases. Geroscience aims to understand the effects of the aging process on these diseases, including the genetic, molecular, and cellular mechanisms that underlie the increased risk of disease over the lifetime. Understanding of the aging eye increases general knowledge of the cellular physiology impacted by aging processes at various biological extremes. Two major diseases, age-related cataract and age-related macular degeneration (AMD) are caused by dysfunction of the lens and retina, respectively. Lens transparency and light refraction are mediated by lens fiber cells lacking nuclei and other organelles, which provides a unique opportunity to study a single aging hallmark, i.e., loss of proteostasis, within an environment of limited metabolism. In AMD, local dysfunction of the photoreceptors/retinal pigmented epithelium/Bruch's membrane/choriocapillaris complex in the macula leads to the loss of photoreceptors and eventually loss of central vision, and is driven by nearly all the hallmarks of aging and shares features with Alzheimer's disease, Parkinson's disease, cardiovascular disease, and diabetes. The aging eye can function as a model for studying basic mechanisms of aging and, vice versa, well-defined hallmarks of aging can be used as tools to understand age-related eye disease. • Review of common mechanisms and contrasts between age related cataracts and macular degeneration • Analysis of multitasking functions of the retinal pigment epithelium and general biology of aging • Up-to-date summary of aging compensatory mechanisms in lens and retinal pigmented epithelium • Novel insights into the origin of lens crystallins in the drusen deposits • Summary of recent finding regarding structure and function of individual crystallin proteins [ABSTRACT FROM AUTHOR]

To describe a surgical approach for open repair of the triangular fibrocartilage complex foveal avulsion via ulnar styloid osteotomy, and to assess its clinical results. We reviewed 12 patients with distal radioulnar joint (DRUJ) instability due to isolated foveal avulsion of DRUJ ligaments. Wrist arthroscopy was conducted for all patients to exclude the presence of concomitant tear of the superficial part of the triangular fibrocartilage complex and to corroborate the diagnosis with a positive hook test. Through an ulnar approach between flexor and extensor carpi ulnaris, an ulnar styloid osteotomy was performed under image intensifier control just ulnar to the fovea of the head of the ulna. The avulsed foveal attachment was anchored through transosseous sutures passing from the fovea to the neck of the ulna. The ulnar styloid was fixed by means of screws or tension band wires. Outcome measures included clinical assessment of pain (visual analog scale), grip strength, DRUJ instability, range of motion of the wrist, and modified Mayo wrist score. Radiographic assessment was done to determine union of the ulnar styloid osteotomy, DRUJ subluxation, and any hardware-related problems. Outcome measures were evaluated after a mean follow-up of 21 months. Healing of the osteotomy was obtained in all cases by 11 weeks. The DRUJ laxity, visual analog scale, and modified Mayo wrist score improved, while grip strength and range of motion remained unchanged. One patient had prominent hardware necessitating removal after union of the osteotomy. There were no reported cases of injury or neuropraxia of the dorsal cutaneous branch of the ulnar nerve. Open repair of an avulsed foveal attachment of the triangular fibrocartilage complex using an ulnar styloid osteotomy is an alternative to either open or arthroscopic repair approaches. Therapeutic IV. [ABSTRACT FROM AUTHOR]

A 44-year-old female with a vision of 10/200 in the right eye had double pits in the temporal segment of the optic disc with serous macular detachment. Spectral-domain optical coherence tomography (SD-OCT) confirmed serous retinal detachment, an outer layer hole, and double optic disc pits. The patient underwent pars plana vitrectomy with modified ILM flap surgery involving fovea-sparing internal limiting membrane peeling (FSIP) technique with inverted ILM flap tucking with gas tamponade. Post surgery, the communications between perineural and intraretinal spaces were obliterated with flaps of ILM covering the pits, with reduced serous macular detachment and BCVA of 20/120. FSIP with inverted internal limiting membrane flap tuck can be an effective technique to manage rare cases of double ODP-M.

The macula and fovea comprise a highly sensitive visual detection tissue that is susceptible to common disease processes like age-related macular degeneration (AMD). Our understanding of the molecular determinants of high acuity vision remains unclear, as few model organisms possess a human-like fovea. We explore transcription factor networks and receptor-ligand interactions to elucidate tissue interactions in the macula and peripheral retina and concomitant changes in the underlying retinal pigment epithelium (RPE)/choroid. Poly-A selected, 100 bp paired-end RNA-sequencing (RNA-seq) was performed across the macular/foveal, perimacular, and temporal peripheral regions of the neural retina and RPE/choroid tissues of four adult Rhesus macaque eyes to characterize region- and tissue-specific gene expression. RNA-seq reads were mapped to both the macaque and human genomes for maximum alignment and analyzed for differential expression and Gene Ontology (GO) enrichment. Comparison of the neural retina and RPE/choroid tissues indicated distinct, contiguously changing gene expression profiles from fovea through perimacula to periphery. Top GO enrichment of differentially expressed genes in the RPE/choroid included cell junction organization and epithelial cell development. Expression of transcriptional regulators and various disease-associated genes show distinct location-specific preference and retina-RPE/choroid tissue-tissue interactions. Regional gene expression changes in the macaque retina and RPE/choroid is greater than that found in previously published transcriptome analysis of the human retina and RPE/choroid. Further, conservation of human macula-specific transcription factor profiles and gene expression in macaque tissues suggest a conservation of programs required for retina and RPE/choroid function and disease susceptibility.

To investigate the choroidal vascularity alterations of macula and peripapillary area in eyes with unilateral Fuchs uveitis (FU). This study included 18 eyes with unilateral FU and 18 healthy fellow eyes. The choroidal vascularity index (CVI) was analyzed, and the results were compared between eyes with FU and healthy fellow eyes (control group). The mean subfoveal (s)CVI (%) value was significantly lower in the FU group as compared with the control group: 60.92 ± 2.63 vs. 64.01 ± 2.54, respectively (p =.001). The mean pCVI (%) values of superior and inferior quadrant were significantly lower in the Fuchs group as compared with the control group:58.87 ± 4.48 vs. 61.98 ± 3.32, respectively, in superior quadrant (p =.035); and 57.29 ± 6.65 vs. 61.44 ± 4.76, respectively, in inferior quadrant (p =.014). The chronic continuous inflammation in FU causes inflammation-mediated thinning in the vascular area of the subfoveal and peripapillary choroid. The changes in the peripapillary region are remarkable in terms of the further glaucoma risk of these eyes. [ABSTRACT FROM AUTHOR]

This study's goal is to determine the accuracy of a linear classifier that predicts the prognosis of patients with macular edema (ME) due to a branch retinal vein occlusion during the maintenance phase of antivascular endothelial growth factor (anti-VEGF) therapy. The classifier was created using the clinical information and optical coherence tomographic (OCT) findings obtained up to the time of the first resolution of ME. In total, 66 eyes of 66 patients received an initial intravitreal injection of anti-VEGF followed by repeated injections with the pro re nata (PRN) regimen for 12 months. The patients were divided into two groups: those with and those without good vision during the PRN phase. The mean AUC of the classifier was 0.93, and the coefficients of the explanatory variables were: best-corrected visual acuity (BCVA) at baseline was 0.66, BCVA at first resolution of ME was 0.51, age was 0.21, the average brightness of the ellipsoid zone (EZ) was −0.12, the intactness of the external limiting membrane (ELM) was −0.14, the average brightness of the ELM was −0.17, the brightness value of EZ was −0.17, the area of the outer segments of the photoreceptors was −0.20, and the intactness of the EZ was −0.24. This algorithm predicted the prognosis over time for individual patients during the PRN phase. [ABSTRACT FROM AUTHOR]

Non-human animals tend to solve behavioral tasks using local information. Pigeons are particularly biased toward using the local features of stimuli to guide behavior in small-scale environments. When behavioral tasks are performed in large-scale environments, pigeons are much better global processors of information. The local and global strategies are mediated by two different fovea in the pigeon retina that are associated with the tectofugal and thalamofugal pathways. We discuss the neural mechanisms of pigeons' bias for local information within the tectofugal pathway, which terminates at an intermediate stage of extracting shape complexity. We also review the evidence suggesting that the thalamofugal pathway participates in global processing in pigeons and is primarily engaged in constructing a spatial representation of the environment in conjunction with the hippocampus. [ABSTRACT FROM AUTHOR]

Detection of abnormalities in human eye is one of the well-established research areas of Machine Learning. Deep Learning techniques are widely used for the diagnosis of Retinal Diseases (RD). Fovea is one of the significant parts of retina which would be prevented before the involvement of Perforated Blood Vessels (PBV). Retinopathy Images (RI) contains sufficient information to classify structural changes incurred upon PBV but Macular Features (MF) and Fovea Features (FF) are very difficult to detect because features of MF and FF could be found with Similar Color Movements (SCM) with minor variations. This paper presents novel method for the diagnosis of Irregular Fovea (IF) to assist the doctors in diagnosis of irregular fovea. By considering all above problems this paper proposes a three-layer decision support system to explore the hindsight knowledge of RI and to solve the classification problem of IF. The first layer involves data preparation, the second layer builds the decision model to extract the hidden patterns of fundus images by using Deep Belief Neural Network (DBN) and the third layer visualizes the results by using confusion matrix. This paper contributes a data preparation algorithm for irregular fovea and a highest estimated classification accuracy measured about 96.90%. [ABSTRACT FROM AUTHOR]

Purpose: Markers for the relationships between structural and microvasculature measures given by optical coherence tomography angiography are necessary to increase the diagnostic and prognostic value of this technique. The aim of this study was to investigate relationships between structural and microvasculature measures around the fovea in healthy eyes of healthy children. Methods: Observational cross‐sectional study involving children aged 8–17 years, born at full‐term, with no eye disease. The better of two 3 × 3 mm macular scans obtained with a Cirrus 5000HD‐OCT was analysed. Images were corrected for lateral magnification errors. Vessel density and perfusion were measured with ImageJ/Fiji software for the superficial capillary plexus. Structural measures including foveal and macular thicknesses were performed manually. Results: The sample included 86 participants, 51 (59%) females. Mean age was 12.4 years (SD = 2.5); mean best‐corrected acuity was −0.10 logMAR (SD = 0.09); mean refractive error was +0.59 D (SD = 1.3) and mean axial length was 23.1 mm (SD = 0.86). Mean area of the foveal avascular zone (AFAZ) was 0.20 mm2 (SD = 0.88); median fovea‐to‐macula thickness ratio (FMTR) was 0.63 (IQR = 0.08); mean central vessel density was 12.42 mm−1 (SD = 2.78) and mean central perfusion was 38.66% (SD = 3.83). AFAZ was correlated with central vessel density (p < 0.001), perfusion (p < 0.001), foveal thickness (p < 0.001) and FMTR (p < 0.001). Central vessel density was correlated with foveal thickness (p < 0.001) and FMTR, (p = 0.01). Central perfusion was correlated with foveal thickness (p < 0.001) and FMTR, (p = 0.003). Conclusion: In this study, foveal thickness, FMTR and foveal microvasculature measurements were correlated. Clinicians need to be aware that shallow foveal pits and persistent foveal microvasculature are likely to occur in optical coherence tomography angiography images. In healthy eyes from healthy children, an atypical high FMTR and a small AFAZ may be associated with incomplete foveal development. The mechanism and functional implications of this remain unknown. [ABSTRACT FROM AUTHOR]

Purpose: To identify the eyes with macular edema (ME) due to a branch retinal vein occlusion (BRVO) that have good visual acuity during the continuous anti-vascular endothelial growth factor (anti-VEGF) treatment based on the patients' clinical information and optical coherence tomography (OCT) images by using machine learning. Methods: Sixty-six eyes of 66 patients received 1 anti-VEGF injection followed by repeated injections in the pro re nata (PRN) regimen for 12 months. The patients were divided into two groups: those with and those without good vision during the 1-year experimental period. Handcraft features were defined from the OCT images at the time of the first resolution of the ME. Variables with a significant difference between the groups were used as explanatory variables. A classifier was created with handcrafted features based on a support vector machine (SVM) that adjusted parameters for increasing maximal precision. Results: The age, best-corrected visual acuity (BCVA) at the baseline, BCVA at the first resolution of the ME, integrity and reflectivity of the external limiting membrane (ELM), the ellipsoid zone (EZ), and area of the outer segments of the photoreceptors were selected as explanatory variables. The classification performance was 0.806 for accuracy, 0.768 for precision, 0.772 for recall, and 0.752 for the F-measure. Conclusion: The use of the SVM of the patient's clinical information and OCT images can be helpful for determining the prognosis of the BCVA during continued pro re nata anti-VEGF treatment in eyes with ME associated with BRVO. [ABSTRACT FROM AUTHOR]

AIM: To document with spectral-domain optical coherence tomography the morphological regeneration of the fovea after resolution of cystoid macular edema (CME) without and with internal limiting membrane (ILM) detachment and to discuss the presumed role of the glial scaffold for foveal structure stabilization. METHODS: A retrospective case series of 38 eyes of 35 patients is described. Of these, 17 eyes of 16 patients displayed foveal regeneration after resolution of CME, and 6 eyes of 6 patients displayed CME with ILM detachment. Eleven eyes of 9 patients displayed other kinds of foveal and retinal disorders associated with ILM detachment. RESULTS: The pattern of edematous cyst distribution, with or without a large cyst in the foveola and preferred location of cysts in the inner nuclear layer or Henle fiber layer (HFL), may vary between different eyes with CME or in one eye during different CME episodes. Large cysts in the foveola may be associated with a tractional elevation of the inner foveal layers and the formation of a foveoschisis in the HFL. Edematous cysts are usually not formed in the ganglion cell layer. Eyes with CME and ILM detachment display a schisis between the detached ILM and nerve fiber layer (NFL) which is traversed by Müller cell trunks. ILM detachment was also found in single eyes with myopic traction maculopathy, macular pucker, full-thickness macular holes, outer lamellar holes, and glaucomatous parapapillary retinoschisis, and in 3 eyes with Müller cell sheen dystrophy (MCSD). As observed in eyes with MCSD, cellophane maculopathy, and macular pucker, respectively, fundus light reflections can be caused by different highly reflective membranes or layers: the thickened and tightened ILM which may or may not be detached from the NFL, the NFL, or idiopathic epiretinal membranes. In eyes with short single or multiple CME episodes, the central fovea regenerated either completely, which included the disappearance of irregularities of the photoreceptor layer lines and the reformation of a fovea externa, or with remaining irregularities of the photoreceptor layer lines. CONCLUSION: The examples of a complete regeneration of the foveal morphology after transient CME show that the fovea may withstand even large tractional deformations and has a conspicuous capacity of structural regeneration as long as no cell degeneration occurs. It is suggested that the regenerative capacity depends on the integrity of the threedimensional glial scaffold for foveal structure stabilization composed of Müller cell and astrocyte processes. The glial scaffold may also maintain the retinal structure after loss of most retinal neurons as in late-stage MCSD.

Abstract Purpose To report a patient with impaired vision due to foveal involvement of toxoplasmic retinochoroiditis, who was successfully treated with intravitreal clindamycin and dexamethasone and oral therapy with azithromycin, trimethoprim-sulfamethoxazole, and prednisolone and led to successful visual and anatomic recovery. Case presentation A 32-year-old man presented with three-day history of gradually decreasing visual acuity, redness, pain and photophobia of the right eye. Anterior chamber cellular reaction, vitritis and a white retinochoroiditis patch with adjacent retinal vasculitis in the fovea was suggestive of the toxoplasmic retinochoroiditis. He was treated with intravitreal clindamycin and dexamethasone injection followed by six-week regimen of azithromycin, trimethoprim-sulfamethoxazole, and prednisolone. In serial optical coherence tomography imaging, retinitis patch changed to cavitary foveal destruction. Fovea reorganized gradually, and visual acuity concurrently improved from counting finger 3 m to 20/25. Conclusion In foveal toxoplasmic retinochoroiditis lesions, timely treatment is associated with retinal reorganization and visual improvement.