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Our study aimed to compare the anatomical features of the eyeball, lens, and retina between the two raptor birds of different visual active clock hours: the diurnal common kestrel (Falco tinnunculus rupicilaeformis) and the nocturnal little owl (Athene noctua glaux) using gross, morphometric analysis, histological, and scanning and transmission electron microscopy techniques. The semi-spherical eyeball of the kestrel had less convexity on the anterior surface than on the posterior surface; meanwhile, it was relatively larger in the owl. There is a relationship between the corneal diameter (CD) and the eye axial length (AL). There were significant differences in the retinal layer thickness between the two raptors, in which the diurnal kestrel had a thinner pigmented epithelium and photoreceptor layers compared to the nocturnal owl. Moreover, the inner nuclear and outer nuclear, inner plexiform, and outer plexiform layers in the diurnal kestrel were larger than those in the nocturnal owl. The differences in the pigmented epithelium layer lead to the higher visual acuity and better color vision of the diurnal kestrel compared to the nocturnal owl. The photoreceptor layer in diurnal kestrel was composed of single large and double cones, which are composed of chief cones and accessory cones; meanwhile, the photoreceptor layer in nocturnal owl had only single elongated rods. We concluded that the lens and retina of the two raptors revealed great variations in reflecting the adaptation of each bird to different modes of life. The statistical analysis found a strong positive correlation between the axial length of the eye and the corneal diameter in both birds, as indicated by the Pearson correlation coefficient., Competing Interests: Declarations. Ethics approval and consent to participate: This study has been carried out with ethical permission from the Faculty of Veterinary Medicine, Alexandria University, and approved by the Institutional Animal Care and Use Committee (ALEXU-IACUC) (Approval code: 01/2/2023/199). All methods were performed in accordance with relevant guidelines and regulations by the Basel Declaration and the International Council for Laboratory Animal Science (ICLAS). The study was carried out in compliance with the ARRIVE guidelines. The informed consent was obtained from all owners. Consent for publication: Not Applicable. Consent to participate: Not applicable. Conflict of interest: None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (© 2024. The Author(s).)

Primates, the most colorful mammalian radiation, have previously served as an interesting model to test the functions and evolutionary drivers of variation in eye color. We assess the contribution of photo-regulatory and communicative functions to the external eye appearance of nine macaque species representing all the branches of their radiation. Macaques' well described social structure and wide geographical distribution make them interesting to explore. We find that (1) the posterior option of the anterior eyeball is more pigmented closer to the equator, suggesting photoprotective functions. We also find that (2) the temporal side of the eyeball is more heavily pigmented than the nasal side. This suggests that eyeball pigmentation in macaques is distributed to reduce damage to the corneal limbus. The inclusion of a translocated population of M. fuscata in our analyses also suggests that external eye appearance may change quickly, perhaps owing to phenotypic plasticity. We find no evidence that communicative functions drive variation in external eye appearance in macaques. These results suggest that the amount of light in a species' environment drives variation in eye coloration across macaque species. Furthermore, the geographical distribution of macaques hints at important factors that have yet to be accounted for, such as the reflectivity of the terrain a given species inhabits., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Objective: To review data on the advances in equine ophthalmic imaging that have been made during the past 5 years and highlight advantages of using multiple imaging modalities to improve clinical observational skills and improve diagnostic accuracy., Methods: A literature review from 2019 through 2024 of equine ophthalmic digital photography, fundus photography, ocular and orbital ultrasonography (US), ultrasound biomicroscopy (UBM), confocal microscopy (CM), spectral domain optical coherence tomography (SD-OCT), radiography, CT, and MRI., Results: Digital photography remains the cornerstone of equine ophthalmic imaging for documenting examination findings, sharing information with colleagues, and consulting with specialists. Digital images also allow for in-depth postexamination review and evaluation, often revealing subtleties that may have otherwise gone undetected during the ophthalmic examination. Advanced imaging modalities are being used more frequently in equine ophthalmology, especially those that can be used with the horses standing under sedation, including US, UBM, SD-OCT, CM, and CT., Discussion: Advances in equine ophthalmic imaging have led to many new clinical discoveries and to an increase in our knowledge of ocular anatomy and diseases in the horse. Many of these advanced diagnostic imaging modalities, such as MRI, CT, SD-OCT, and CM, are cost prohibitive and require substantial operator training to ensure proficiency. However, their availability in tertiary referral centers, such as veterinary teaching hospitals and large equine clinics/practices, is becoming more widespread., Conclusions: Advanced equine ophthalmic imaging data contributes substantially to our general understanding of clinical and applied anatomy and improves our understanding of the underlying pathogenesis associated with specific diseases.

The Drosophila melanogaster compound eye is a well-structured and comprehensive array of around 800 ommatidia, exhibiting a symmetrical and hexagonal pattern. This regularity and ease of observation make the Drosophila eye system a powerful tool to model various human neurodegenerative diseases. However, ways of quantifying abnormal phenotypes, such as manual ranking of eye severity scores, have limitations, especially when ranking weak alterations in eye morphology. To overcome these limitations, computational approaches have been developed such as Flynotyper. The use of a ring light allows for better qualitative images accessing the intactness of individual ommatidia. However, these images cannot be analyzed by Flynotyper directly due to shadows on ommatidia introduced by the ring light. Here, we describe an unbiased way to quantify rough eye phenotypes observed in Drosophila disease models by combining two software, ilastik and Flynotyper. By preprocessing the images with ilastik, successful quantification of the rough eye phenotype can be achieved with Flynotyper.

Aim: Utilizing a combination of micro-computed tomography (micro-CT) and anatomical techniques for the volumetric assessment of the eyeball and its constituents in Bama Miniature Pigs, New Zealand rabbits, and Sprague-Dawley(SD) rats., Method: Six Bama Miniature pigs, New Zealand rabbits, and SD rats were enrolled in the study. Micro-CT and gross volumetric estimation of ocular volume were employed to acquire data on ocular volume, anterior chamber volume, lens volume, and vitreous cavity volume for each eye., Results: The eyeball volume of pigs ranges from approximately 5.36 ± 0.27 to 5.55 ± 0.28 ml, the lens volume from approximately 0.33 ± 0.02 to 0.37 ± 0.06 ml, the anterior chamber volume from approximately 0.19 ± 0.05 to 0.28 ± 0.04 ml, and the vitreous volume is approximately 3.20 ± 0.18 ml. For rabbits, the eye volume, lens volume, anterior chamber volume, and vitreous volume range from approximately 3.02 ± 0.24 to 3.04 ± 0.24 ml, 0.41 ± 0.02 to 0.44 ± 0.02 ml, 0.23 ± 0.04 to 0.26 ± 0.05 ml, and 1.54 ± 0.14 ml, respectively. In SD rats, the volumes are 0.14 ± 0.02 to 0.15 ± 0.01 ml for the eyeball, 0.03 ± 0.00 to 0.03 ± 0.00 ml for the lens, 0.01 ± 0.00 to 0.01 ± 0.01 ml for the anterior chamber, and 0.04 ± 0.01 ml for the vitreous volume., Conclusion: The integration of micro-CT and gross volumetric estimation of ocular volume proves effective in determining the eyeball volume in Bama Miniature Pigs, New Zealand rabbits, and SD rats. Understanding the volume distinctions within the eyeballs and their components among these experimental animals can lay the groundwork for ophthalmology-related drug research., Competing Interests: NO authors have competing interests., (Copyright: © 2024 Wu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Aquatic birds are notable among the global avifauna for living in environments exposed to large amounts of light. Despite growing evidence that visual adaptations to light underly the ecology and evolution of the avian tree of life, no comprehensive comparative analysis of visual acuity as approximated by eyes size exists for the global aquatic avifauna. Here, I use Stanley Ritland's unpublished dataset of measurements for axial length collected from museum specimens to explore the ecology and evolution of eye size variation for half of the aquatic avifauna (N = 464 species). After correcting for body mass allometry and incorporating phylogenetic relationships, aquatic species had significantly smaller eyes compared to terrestrial species. Furthermore, species using hyperopic foraging manoeuvres, exhibiting carnivorous and insectivorous diets, and displaying nocturnal behaviour had larger eyes. Plunge-divers (e.g. boobies and tropic birds) and stalkers (e.g. herons) had the largest relative eye sizes, especially species identifying prey at higher altitudes or longer distances. Underwater pursuit-divers foraging at greater depths had larger eyes, likely due to the dramatic attenuation of light in the deep ocean. Overall, residual eye size was phylogenetically conserved (l = 0.94), with phylogeny alone explaining 62% of residual eye size variation. Collectively, these results suggest that the relatively bright environments found in aquatic ecosystems negate the adaptive benefits of costly metabolic investments associated with developing and maintaining larger eyes, while also reducing the potential occurrence of disability glare. Strong correlations between eye size and foraging ecology in different aquatic environments corroborate similar comparative studies of terrestrial birds and underscore the central role that vision has played in driving the ecology and evolution of the global avifauna., (© 2024 The Author(s). Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.)

Understanding the origin of novel morphological traits is a long-standing objective in evolutionary developmental biology. We explored the developmental genetic mechanisms that underpin the formation of a textbook example of evolutionary novelties, the cephalic horns of beetles. Previous work has implicated the gene regulatory networks associated with compound eye and ocellar development in horn formation and suggested that horns and compound eyes may influence each other's sizes. Therefore, we investigated the functional significance of genes central to visual system formation in the initiation, patterning, and size determination of head horns across three horned beetle species. We find that while the downregulation of canonical eye patterning genes reliably reduces or eliminates compound eye formation, it does not alter the position or shape of head horns yet does result in an increase in relative horn length. We discuss the implications of our results for our understanding of the genesis of cephalic horns in particular and evolutionary novelties in general., (© 2024 The Authors. Evolution & Development published by Wiley Periodicals LLC.)

A rodent eyeball is a powerful tool for researching the pathomechanisms of many ophthalmic diseases, such as glaucoma, hypertensive retinopathy, and many more. Preclinical experiments enable researchers to examine the efficacy of novel drugs, develop new methods of treatment, or seek new pathomechanisms involved in the disease's onset or progression. A histological examination provides a lot of information necessary to assess the effects of the conducted experiments and can reveal degeneration, tissue remodeling, infiltration, and many other pathologies. In clinical research, there is rarely any chance of obtaining eye tissue suitable for a histological examination, which is why researchers should take advantage of the opportunity offered by the examination of eyeballs from rodents. This manuscript presents a protocol for the histological preparation of rodent eyeballs' sections. The procedure is presented for the eyeballs of mice and rats and has the following steps: (i) harvesting the eyeball, (ii) preserving the eyeball for further analysis, (iii) processing the tissue in paraffin, (iv) preparing slides, (v) staining with hematoxylin and eosin, (vi) assessing the tissue under a light microscope. With the proposed method, the retina can be easily visualized and assessed in detail.

Intraspecific variation in vertebrate eye size is well known. Ecological factors such as light availability are often correlated with shifts in relative eye size. However, experimental tests of selection on eye size are lacking. Trinidadian killifish (Anablepsoides hartii) are found in sites that differ in predation intensity. Sites that lack predators are characterized by lower light, high killifish densities, low resource availability, and intense competition for food. We previously found that killifish in sites that lack predators have evolved a larger "relative" eye size (eye size corrected for body size) than fish from sites with predators. Here, we used transplant experiments to test how selection operates on eye size when fish that are adapted to sites with predators are translocated into sites where predators are absent. We observed a significant "population × relative eye size" interaction; the relationship between relative eye size and a proxy for fitness (rates of individual growth) was positive in the transplanted fish. The trend was the opposite for resident fish. Such results provide experimental support that larger eyes enhance fitness and are favoured in environments characterized by low light and high competition., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Evolutionary Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Eye size affects many aspects of visual function, but eyes are costly to grow and maintain. The allometry of eyes can provide insight into this trade-off, but this has mainly been explored in species that have two eyes of equal size. By contrast, animals possessing larger visual systems can exhibit variable eye sizes within individuals. Spiders have up to four pairs of eyes whose sizes vary dramatically, but their ontogenetic, static, and evolutionary allometry has not yet been studied in a comparative context. We report variable dynamics in eye size across 1,098 individuals in 39 species and 8 families, indicating selective pressures and constraints driving the evolution of different eye pairs and lineages. Supplementing our sampling with a recently published phylogenetically comprehensive dataset, we confirmed these findings across more than 400 species; found that ecological factors such as visual hunting, web building, and circadian activity correlate with eye diameter; and identified significant allometric shifts across spider phylogeny using an unbiased approach, many of which coincide with visual hunting strategies. The modular nature of the spider visual system provides additional degrees of freedom and is apparent in the strong correlations between maximum/minimum investment and interocular variance and three key ecological factors. Our analyses suggest an antagonistic relationship between the anterior and posterior eye pairs. These findings shed light on the relationship between spider visual systems and their diverse ecologies and how spiders exploit their modular visual systems to balance selective pressures and optical and energetic constraints., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Many invertebrates possess more than two pairs of eyes - but does eye redundancy aid in ecological diversification? A new study finds varied size adaptation of different eye pairs in spiders, demonstrating how developmental modularity of multi-eyed systems effectively balances selective pressures., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

We analysed the skulls and faces of Korean subjects using anthropometric methods to understand the anatomical characteristics of the eyeball and eye orbit region of Korean population and to determine the correlations between the hard and soft tissues around the eyeball and eye orbit region. In total, 82 sections in the region were measured to determine the correlations; among them, 34 showed significant differences by sex, and 6 showed significant differences by age. As the distance from the centre of the eye lens to the eye orbit is calculated as a ratio, we determined that the centre of the eye lens is located relatively on the lateral and superior position in each eye orbit in front view. Fourteen sections that could be used for craniofacial reconstruction/approximation in men and women were selected. Regression equations were derived according to the correlation of each section, and their reliabilities were verified by out of sample validation tests. Therefore, our results increase the accuracy of eyeball position determination, which would be useful for more efficient craniofacial reconstruction/approximation of the Korean population and should improve the efficiency of facial recognition., (© 2024. The Author(s).)

Objectives: The red panda is currently the only surviving member of the Ailuridae family in the Caniformia suborder. In this study, we provide data on anatomical, morphometric, histological and histochemical examination of the orbital region, eyelids, orbital gland, and eye tunics in two adult males Ailurus fulgens fulgens from the Wroclaw Zoological Garden, Poland., Methods: The study involved morphometric analysis of the eyeball and selected accessory organs of the eye, along with analysis of the bony orbit, including its morphometry, macroscopic, and microscopic evaluation. Microscopic evaluation encompassed histological and histochemical staining, with the former involving hematoxylin & eosin (H&E), Movat pentachrome, picro-Mallory trichrome, Fontana-Masson, and the latter including PAS, AB pH 1.0, AB pH 2.5; AB pH 2.5/PAS, and HDI., Results: The upper (UE) and lower (LE) eyelids presented well-developed tarsal glands, sebaceous glands, and a characteristic simple alveolar gland (producing a mucous secretion). The palpebral part of the lacrimal gland was present. A single lymphoid follicle was observed only in the upper eyelids. The superficial gland of the third eyelid (SGTE) was a multilobar acinar complex that produces mucous secretion and is contained within the interlobular ducts of numerous aggregates of lymph nodes. The third eyelid (TE) was T-shaped and composed of hyaline tissue, containing CALT. The lacrimal gland (LG) also revealed a multilobar acinar complex that produced mucous secretion, with a single lymphoid follicle. The cornea consisted of 4 layers, as Bowman's membrane was absent. The Vogt palisades composed of 7-10 layers of epithelial cells were demonstrated. The pupil was horizontally ovoid at rest (post-mortem). The sphincter pupil and the dilator pupil were well developed. Macroscopically, the tapetum lucidum appeared as a milky, non-opalescent crescent. Histologically, the choroidal tapetum lucidum cellulosum consisted of 5 to 9 layers of loosely packed oval cells. The retina showed a composition similar to that of terrestrial nocturnal carnivores., Conclusions: The results of our research indicate that the anatomical features of the eye and orbital region in the red panda share similarities with those described in the Musteloidea clade, as well as the Canidae and Ursidae families., (© 2024. The Author(s).)

This study compared skull morphology and ocular parameters in brachycephalic (BC, n = 16) and nonbrachycephalic (NB, n = 16) dogs using head CT scans. The results of a Schirmer tear test I (STT I), intraocular pressure (IOP), ocular biometry, external structure, ocular protrusion, and palpebral fissure dimensions were evaluated and compared between BC and NB dogs. There were no statistically significant differences in the STT I results, IOP, globe dimensions, globe volume, internal structure, and external structure between BC and NB dogs (P > .05). Brachycephalic dogs exhibited significantly greater ocular protrusion and significantly larger palpebral fissure dimensions compared with NB dogs. For all dogs, we found a strong positive correlation between globe volume and body weight (r = 0.836, P = .0000). The globe volumes, external structure parameters, and ocular protrusion were normalized by body weight and were also significantly larger in BC dogs compared with NB dogs (P < .001). The ocular protrusion (r = 0.521, P < .0000) and horizontal palpebral fissure (r = 0.372, P = .0024) showed a moderate positive correlation with the cephalic index (CI). Additionally, normalized globe volume (r = 0.435, P = .0003), normalized orbital depth (r = 0.419, P = .0005), and normalized retrobulbar depth (r = 0.444, P = .0002) had a moderate positive correlation with the CI. The study emphasizes how the distinctive skull structure of BC dogs, with shortened facial bones and thickened retrobulbar soft tissue, influences their ocular appearance and raises the risk of eye problems., (© 2024 American College of Veterinary Radiology.)

Deep-sea fishes must overcome extremely large nearest-neighbour distances and darkness to find mates. Sexual dimorphism in the size of luminescent structures in many deep-sea taxa, including dragonfishes (family Stomiidae), indicates reproductive behaviours may be mediated by visual signalling. This presents a paradox: if male photophores are larger, females may find males at shorter distances than males find females. Solutions to this gap may include females closing this gap or by males gathering more photons with a larger eye. We examine the eye size of two species of dragonfishes ( Malacosteus niger and Phostomias guernei ) for sexual dimorphism and employ a model of detection distance to evaluate the potential for such dimorphism to bridge the detection gap. This model incorporates the flux of sexually dimorphic postorbital photophores and eye lens size to predict detection distances. In both species, we found a significant visual detection gap in which females find males before males find females and that male lens size is larger, marking the second known case of size dimorphism in the actinopterygian visual system. Our results indicate the larger eye affords males a significant improvement in detection distance. We conclude that this dimorphic phenotype may have evolved to close the detection gap.

When populations experience different sensory conditions, natural selection may favor sensory system divergence, affecting peripheral structures and/or downstream neural pathways. We characterized the outer eye morphology of sympatric Heliconius butterflies from different forest types and their first-generation reciprocal hybrids to test for adaptive visual system divergence and hybrid disruption. In Panama, Heliconius cydno occurs in closed forests, whereas Heliconius melpomene resides at the forest edge. Among wild individuals, H. cydno has larger eyes than H. melpomene, and there are heritable, habitat-associated differences in the visual brain structures that exceed neutral divergence expectations. Notably, hybrids have intermediate neural phenotypes, suggesting disruption. To test for similar effects in the visual periphery, we reared both species and their hybrids in common garden conditions. We confirm that H. cydno has larger eyes and provide new evidence that this is driven by selection. Hybrid eye morphology is more H. melpomene-like despite body size being intermediate, contrasting with neural trait intermediacy. Overall, our results suggest that eye morphology differences between H. cydno and H. melpomene are adaptive and that hybrids may suffer fitness costs due to a mismatch between the peripheral visual structures and previously described neural traits that could affect visual performance., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE). All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

External eye appearance in avian taxa has been proposed to be driven by social and ecological functions. Recent research in primates suggests, instead, that, photoprotective functions are important drivers of external eye appearance. Using similar methods, we examined the variation in external eye appearance of 132 parrot species (Psittaciformes) in relation to their ecology and sociality. Breeding systems, flock size and sexual dimorphism, as well as species' latitude and maximum living altitude, and estimated UV-B incidence in species' ranges were used to explore the contribution of social and ecological factors in driving external eye appearance. We measured the hue and brightness of visible parts of the eye and the difference in measurements of brightness between adjacent parts of the eye. We found no link between social variables and our measurements. We did, however, find a negative association between the brightness of the inner part of the iris and latitude and altitude. Darker inner irises were more prevalent farther away from the equator and for those species living at higher altitudes. We found no link between UV-B and brightness measurements of the iris, or tissue surrounding the eye. We speculate that these results are consistent with an adaptation for visual functions. While preliminary, these results suggest that external eye appearance in parrots is influenced by ecological, but not social factors., (© 2024. The Author(s).)

Introduction: It is important to generate predictable statistical models by increasing the number of variables on the human skeletal and soft tissue structures on the face to increase the accuracy of human facial reconstructions. The purpose of this study was to determine mouth width 3-dimensionally based on statistical regression model., Material and Methods: Cone-beam computed tomography scan data from 130 individuals were used to measure the horizontal and vertical dimensions of orbital and nasal structures and intercanine width. The correlation between these hard tissue variables and the mouth width was evaluated using the statistical regression model., Results: Orbital width, nasal width, and intercanine width were found to be strong predictors of the mouth width determination and were used to generate the regression formulae to find the most approximate position of the mouth., Conclusion: These specific variables may contribute to improving the accuracy of mouth width determination for oral and maxillofacial reconstructions., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

One of the least studied eyes of any beetle taxon are those of the scarabaeoid family Passalidae. Some members of this family of around 600 species worldwide are known to have superposition eyes (Aceraius grandis; A. hikidai) while others have apposition eyes (Cylindrocaulus patalis; Ceracupes yui). In C. yui of nearly 3 cm body length (this paper) the retinal layer is very thin and occupies approximately half of an ommatidium's total length, the latter amounting to 284 and 266 μm in the respective dorsal and ventral eye regions. The two eye regions are almost completely separated by a prominent cuticular canthus, a feature usually associated with the presence of a tracheal tapetum, a clear-zone between dioptric and light-perceiving structures and a regular array of smooth facets. In C. yui the facets are smooth (but not very regular) and a tracheal tapetum and a clear-zone are absent. The rhabdoms, formed by 8-9 retinula cells, are complicated, multilobed structures with widths and lengths of around 15 and 80 μm, respectively. The combination of some superposition and mostly apposition eye features, e.g., extensive corneal exocones, relatively small number of ommatidia, absence of a clear-zone and tracheal bush, suggest an adaptation of this species' eye to the fossorial lifestyle of C. yui, and, thus, a manifestation of the passalid eye's plasticity., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Keeping the head in a neutral position is requisite for glasses/lenses/head-up designs, the suitability of oculo-plastic surgery and for the grading the eye shift. Anatomically incompatible glasses are one of the common problems affecting accommodation, reducing comfort and disturbing by causing symptoms such as dizziness and nausea. The oculo-palpebral measurements act as a key determinant in symmetrical facial attractiveness. This study aims to investigate the most effective oculo-palpebral landmarks, head-neutral as the ideal position, taking into account of individual anatomical differences of these patients., Methods: 100 females and 100 males aged between 18 and 20 years were photographed. Digital photogrammetric measurements were made with the ImageJ program. Interpupillary and interhelical distances, besides bilateral palpebral fissure length and height, and iris diameter were calculated on front-facing photographs., Results: Mean interpupillary distance was measured wider in males than in females. The mean length of palpebral fissure was 31 mm; palpebral fissure height was 10 mm. These figures were valid in both eyes and gender. The interhelical distance was calculated as the mean and was measured longer in men. Since the measurement values were the same in both sexes and on both sides, they were determined as important landmarks for controlling the head-neutral position, evaluating whether there was a deviation in the eye, and measuring the numerical value when detected., Conclusion: It is essential to check the side-symmetry of the patient's palpebral fissure height, palpebral fissure length, diameter of iris and corneal depth during oculo-plastic invention and artificial design., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

The compound eyes of insects exhibit stunning variation in size, structure, and function, which has allowed these animals to use their vision to adapt to a huge range of different environments and lifestyles, and evolve complex behaviors. Much of our knowledge of eye development has been learned from Drosophila, while visual adaptations and behaviors are often more striking and better understood from studies of other insects. However, recent studies in Drosophila and other insects, including bees, beetles, and butterflies, have begun to address this gap by revealing the genetic and developmental bases of differences in eye morphology and key new aspects of compound eye structure and function. Furthermore, technical advances have facilitated the generation of high-resolution connectomic data from different insect species that enhances our understanding of visual information processing, and the impact of changes in these processes on the evolution of vision and behavior. Here, we review these recent breakthroughs and propose that future integrated research from the development to function of visual systems within and among insect species represents a great opportunity to understand the remarkable diversification of insect eyes and vision., (© 2024 The Authors. BioEssays published by Wiley Periodicals LLC.)

The ocean's midwater is a uniquely challenging yet predictable and simple visual environment. The need to see without being seen in this dim, open habitat has led to extraordinary visual adaptations. To understand these adaptations, we compared the morphological and functional differences between the eyes of three hyperiid amphipods- Hyperia galba , Streetsia challengeri and Phronima sedentaria . Combining micro-CT data with computational modelling, we mapped visual field topography and predicted detection distances for visual targets viewed in different directions through mesopelagic depths. Hyperia 's eyes provide a wide visual field optimized for spatial vision over short distances, while Phronima 's and Streetsia 's eyes have the potential to achieve greater sensitivity and longer detection distances using spatial summation. These improvements come at the cost of smaller visual fields, but this loss is compensated for by a second pair of eyes in Phronima and by behaviour in Streetsia . The need to improve sensitivity while minimizing visible eye size to maintain crypsis has likely driven the evolution of hyperiid eye diversity. Our results provide an integrative look at how these elusive animals have adapted to the unique visual challenges of the mesopelagic.

High-resolution object vision - the ability to separate, classify, and interact with specific objects in the environment against the visual background - has only been conclusively shown to have evolved in three of the thirty-five animal phyla: chordates, arthropods, and mollusks (cephalopods) 1 . However, alciopid polychaetes (Phyllodocidae, Alciopini), which possess a pair of bulbous camera-type eyes, have also been hypothesized to achieve high acuity. In this study, we examined three species of night-active pelagic alciopids from the Mediterranean Sea. Our optical, morphological, and electrophysiological investigations show that their eyes have high spatial acuity and temporal resolution, supporting the notion that they are capable of active, high-resolution object vision. These results encourage interesting hypotheses about the visual ecology of these enigmatic polychaetes., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The eye, an anatomical extension of the central nervous system (CNS), exhibits many molecular and cellular parallels to the brain. Emerging research demonstrates that changes in the brain are often reflected in the eye, particularly in the retina 1 . Still, the possibility of an immunological nexus between the posterior eye and the rest of the CNS tissues remains unexplored. Here, studying immune responses to herpes simplex virus in the brain, we observed that intravitreal immunization protects mice against intracranial viral challenge. This protection extended to bacteria and even tumours, allowing therapeutic immune responses against glioblastoma through intravitreal immunization. We further show that the anterior and posterior compartments of the eye have distinct lymphatic drainage systems, with the latter draining to the deep cervical lymph nodes through lymphatic vasculature in the optic nerve sheath. This posterior lymphatic drainage, like that of meningeal lymphatics, could be modulated by the lymphatic stimulator VEGFC. Conversely, we show that inhibition of lymphatic signalling on the optic nerve could overcome a major limitation in gene therapy by diminishing the immune response to adeno-associated virus and ensuring continued efficacy after multiple doses. These results reveal a shared lymphatic circuit able to mount a unified immune response between the posterior eye and the brain, highlighting an understudied immunological feature of the eye and opening up the potential for new therapeutic strategies in ocular and CNS diseases., (© 2024. The Author(s).)

Background: Insects have evolved complex visual systems and display an astonishing range of adaptations for diverse ecological niches. Species of Drosophila melanogaster subgroup exhibit extensive intra- and interspecific differences in compound eye size. These differences provide an excellent opportunity to better understand variation in insect eye structure and the impact on vision. Here we further explored the difference in eye size between D. mauritiana and its sibling species D. simulans., Results: We confirmed that D. mauritiana have rapidly evolved larger eyes as a result of more and wider ommatidia than D. simulans since they recently diverged approximately 240,000 years ago. The functional impact of eye size, and specifically ommatidia size, is often only estimated based on the rigid surface morphology of the compound eye. Therefore, we used 3D synchrotron radiation tomography to measure optical parameters in 3D, predict optical capacity, and compare the modelled vision to in vivo optomotor responses. Our optical models predicted higher contrast sensitivity for D. mauritiana, which we verified by presenting sinusoidal gratings to tethered flies in a flight arena. Similarly, we confirmed the higher spatial acuity predicted for Drosophila simulans with smaller ommatidia and found evidence for higher temporal resolution., Conclusions: Our study demonstrates that even subtle differences in ommatidia size between closely related Drosophila species can impact the vision of these insects. Therefore, further comparative studies of intra- and interspecific variation in eye morphology and the consequences for vision among other Drosophila species, other dipterans and other insects are needed to better understand compound eye structure-function and how the diversification of eye size, shape, and function has helped insects to adapt to the vast range of ecological niches., (© 2024. The Author(s).)

The complex anatomy and physiological barriers of the eye make delivering ocular therapeutics challenging. Generally, effective drug delivery to the eye is hindered by rapid clearance and limited drug bioavailability. Biomaterial-based approaches have emerged to enhance drug delivery to ocular tissues and overcome existing limitations. In this review, some of the most promising long-acting injectables (LAIs) in ocular drug delivery are explored, focusing on novel design strategies to improve therapeutic outcomes. LAIs are designed to enable sustained therapeutic effects, thereby extending local drug residence time and facilitating controlled and targeted drug delivery. Moreover, LAIs can be engineered to enhance drug targeting and penetration across ocular physiological barriers., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Introduction: Examining the retina represents a non-invasive method to evaluate abnormalities pertaining to the nervous and cardiovascular systems. Evidence indicates that physical activity is a non-pharmacological intervention to enhance the nervous and cardiovascular systems. However, little is unknown about its effects on ocular characteristics in children and adolescents. The purpose of this study was to examine the effects of physical activity interventions on ocular characteristics in children and adolescents., Method: The electronic bases Web of Science, Embase, Cochrane Library, PubMed, SPORTDiscus, CINAHL, and ERIC were searched from inception to May 2023. Incorporated were randomized controlled trials or quasi-experimental designs that had implemented acute or chronic physical activity interventions among children and adolescents to evaluate various eye-related attributes via clinical examinations or surveys. Two authors independently performed the data extraction and risk of bias assessment, utilizing the Physiotherapy Evidence Database checklist., Results: A total of 474 articles were identified, of which eight articles underwent a systematic review, and six were chosen for meta-analysis. Chronic physical activity interventions positively impacted central retinal artery equivalent (CRAE) with a small to moderate effect (SMD = 0.21; 95% CI 0.04 to 0.39, p = 0.034, I 2  = 0%) and central retinal venular equivalent (CRVE) with a small effect (SMD = 0.098; 95% CI 0.08 to 0.11; p = 0.008, I 2  = 0%). Intraocular pressure, kinetic visual acuity, and eye strain also improved significantly after physical activity interventions., Discussion: Participating in chronic physical activity programs appear to impact children and adolescents' eye-related attributes positively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The striking structural variation seen in arthropod visual systems can be explained by the overall quantity and spatio-temporal structure of light within habitats coupled with developmental and physiological constraints. However, little is currently known about how fine-scale variation in visual structures arises across shorter evolutionary and ecological scales. In this study, we characterise patterns of interspecific (between species), intraspecific (between sexes) and intraindividual (between eye regions) variation in the visual system of four ithomiine butterfly species. These species are part of a diverse 26-million-year-old Neotropical radiation where changes in mimetic colouration are associated with fine-scale shifts in ecology, such as microhabitat preference. Using a combination of selection analyses on visual opsin sequences, in vivo ophthalmoscopy, micro-computed tomography (micro-CT), immunohistochemistry, confocal microscopy and neural tracing, we quantify and describe physiological, anatomical and molecular traits involved in visual processing. Using these data, we provide evidence of substantial variation within the visual systems of Ithomiini, including: (i) relaxed selection on visual opsins, perhaps mediated by habitat preference, (ii) interspecific shifts in visual system physiology and anatomy, and (iii) extensive sexual dimorphism, including the complete absence of a butterfly-specific optic neuropil in the males of some species. We conclude that considerable visual system variation can exist within diverse insect radiations, hinting at the evolutionary lability of these systems to rapidly develop specialisations to distinct visual ecologies, with selection acting at the perceptual, processing and molecular level., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

Due to the unique morphology of their adult visual system, stalk-eyed flies represent an important model of exaggerated trait evolution through sexual selection. Early physiological measurements indicated wavelength sensitivity peaks in the ultraviolet (360 nm), blue (450), blue-green (490 nm), and red (>550 nm) ranges in the compound eye retina of the stalk-eyed fly Teleopsis dalmanni, consistent with the trichromatic color and broad range motion detection vision system of brachyceran Diptera. A previous study of dipteran opsin gene diversification, however, detected only homologs of members of the long wavelength range sensitive opsin subfamilies Rh2 and Rh6 in T. dalmanni. Here, I report findings from analyzing the most recent T. dalmanni genome assembly, which revealed the conservation of most brachyceran opsin homologs except for the UV wavelength range-sensitive homolog Rh4. These results and other examples highlight the caution that needs to be applied to gene loss conclusions., (© 2023 Wiley Periodicals LLC.)

AbstractSea stars are a major component of the megabenthos in most marine habitats, including those within the deep sea. Being radially symmetric, sea stars have sensory structures that are evenly distributed along the arms, with a compound eye located on each arm tip of most examined species. Surprisingly, eyes with a spatial resolution that rivals the highest acuity known among sea stars so far were recently found in Novodinia americana , a member of the deep-sea sea star order Brisingida. Here, we examined 21 species across 11 brisingid genera for the presence of eyes; where eyes were present, we used morphological characteristics to evaluate spatial resolution and sensitivity. This study found that eyes were present within 43% of the examined species. These brisingid eyes were relatively large compared to those of other deep-sea sea stars, with a high number of densely packed ommatidia. One of the examined species, Brisingaster robillardi , had more than 600 ommatidia per eye, which is the highest number of ommatidia found in any sea star eye so far. Combined, the results indicate that brisingid eyes are adapted for spatial resolution over sensitivity. Together with results showing that many brisingids are bioluminescent, this relatively high spatial resolution suggests that the group may use their eyes to support visually guided intraspecific communication based on bioluminescent signals. Phylogenetic analysis indicated that the common ancestor of brisingids had eyes ( P = 0.72) and that eyes were lost once within the clade.

Larval stomatopods have generally been described as having a typical larval crustacean compound eye, which lacks the visual pigment diversity and morphological specializations of the well-studied stomatopod adult eye. However, recent work has suggested that larval stomatopod eyes are more complex than previously described. In this study, we provide physiological and behavioral evidence of at least three distinct photoreceptor classes in three species of larval stomatopods: Gonodactylellus n. sp., Gonodactylaceus falcatus and Pullosquilla n. sp. First, electroretinogram recordings were used to measure the spectral sensitivity of each species. Evidence for at least three spectral classes were identified in each: an ultraviolet, peaking at 340-376 nm; a short-wavelength blue, peaking at 455-464 nm; and a long-wavelength orange, peaking at 576-602 nm. Next, the behavioral response to light was investigated. We found that each species demonstrated positive phototactic responses to monochromatic stimuli across the UV-visible spectrum. In wavelength preference trials, distinct preferences among species were identified when different colored light stimuli were presented simultaneously. All species displayed a strong response to the UV stimulus, as well as responses to blue and orange stimuli, although at different response strengths, but no response to green. The results of this study demonstrate that larval stomatopods not only have multiple physiologically active spectral classes but they also display clear and distinct responses to wavelengths across the spectrum. We propose that the spectral classes demonstrated in each are related to visually guided ecological tasks of the larvae, which may differ between species., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

The link between human ocular morphology and attractiveness, especially in the context of its potential adaptive function, is an underexplored area of research. In our study, we examined the association between facial attractiveness and three sexually dimorphic measures of ocular morphology in White Europeans: the sclera size index, width-to-height ratio, and relative iris luminance. Sixty participants (30 women) assessed the attractiveness of the opposite-sex photographs of 50 men and 50 women. Our results show that in both men and women, none of the three measures was linked to the opposite sex ratings of facial attractiveness. We conclude that those ocular morphology measures may play a limited role in human mate preferences., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Danel et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: The present study aimed to determine the effects of age, sex, reproductive status, skull type, and nasolacrimal duct (NLD) patency on tear production and tear film breakup time (TBUT) in normal dogs., Animals Studied: The ophthalmic data of 82 healthy adult dogs were evaluated in this study., Procedures: Age, sex, breed, and reproductive status were recorded. Schirmer tear test (STT) and TBUT were assessed in all dogs, and interferometry was available for the selected dogs. The Jones test was used to evaluate NLD patency. The cephalic index (CI) was calculated for each dog (skull width/skull length ×100)., Results: Mean (SD) values for the STT results for the right (OD) and left (OS) eyes were 20.6 (2.7) and 20.2 (2.7) mm/min, respectively. Mean (SD) TBUT values for OD and OS were 6.5 (2.5) and 6.1 (2.3) mm/min in all dogs, respectively. Sex and reproductive status had no significant effect on STT and TBUT (P [OU]  > 0.05). Skull type significantly affected TBUT in both eyes (P (OD)  = 0.01, P (OS)  = 0.003), but had no effect on STT (P [OU]  > 0.3). Age had no correlation with STT and TBUT in either eye (P [OU]  > 0.05). STT and TBUT had no correlation in either eye (P [OU]  > 0.2). NLD patency had no significant effect on STT or TBUT (P [OU]  > 0.1)., Conclusions: The results of this study showed lower TBUT values in brachycephalic breeds than in non-brachycephalic breeds. A compensatory increase in STT values was observed in dogs with low TBUT values., (© 2022 American College of Veterinary Ophthalmologists.)

Objective: To present a multifaceted approach to ophthalmology undergraduate medical education and to assess the efficacy of an eye dissection laboratory in enhancing medical student learning., Design: Curriculum review, validation, and student feedback evaluations., Participants: Year 2 medical students enrolled in the University of Toronto's Doctor of Medicine Program., Methods: Student feedback evaluations were compiled from the University of Toronto undergraduate medical education student surveys before 2012-2016 and following introduction of the redesigned foundations ophthalmology curriculum at the University of Toronto (2017-2018). Students who participated in the Eye Dissection Lab as part of the newly designed curriculum completed the pre- and postsession satisfaction and overall interest in ophthalmology questionnaires and a knowledge-based test., Results: Analysis of 1640 student evaluations demonstrated an increase in ophthalmology curriculum rating following the launch of the foundations ophthalmology curriculum (p = 0.015). Among the 335 students who completed the eye dissection lab, there was a significant increase in the average scores for the satisfaction questionnaire, knowledge-based test, and level of interest in the field of ophthalmology from before and after the session, with improvements in scores noted in 91%, 42%, and 36% of the educational parameters of the participants, respectively (p < 0.001)., Conclusions: The newly designed foundations ophthalmology curriculum and the eye dissection lab at the University of Toronto serve as effective means for enhancing ophthalmology teaching in medical schools across Canada., (Copyright © 2021 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

The trilobite head served multiple functions and was composed of several fused segments. Yet, the underlying organization of the trilobite head, and whether patterns are conserved across trilobites, remains unclear. Modeling the head as being composed of modules, or subunits that vary and thus have the potential to evolve semi-independently can reveal underlying patterns of organization. Hypotheses of modular organization based on the comparative developmental biology of arthropods were evaluated using geometric morphometrics. Two-dimensional (semi)landmark datasets collected from the cranidia of two Ordovician trilobite species, Calyptaulax annulata (Phacopida) and Cloacaspis senilis (Olenida sensu Adrain, 2011) were analyzed. The degree and pattern of modularity were assessed using the covariance ratio (CR), which compares the covariation within putative modules to the covariation between them, and the fit of different models was compared using an effect size measure derived from the CR. When treating the eyes as a distinct module, the best modular hypothesis identified for C. annulata shows the eyes and anteriormost region of the head integrated as a single module. The best modular hypotheses for C. senilis are more complex but the eyes still covary mostly strongly with the anterior part of the head. The latter is also the case for all other well-supported models for both species. These results can be interpreted as a developmental signal corresponding to the anteriormost ocular segment of early arthropods that is retained throughout development, despite any likely selective pressures related to functional needs., (© 2022 The Authors. Evolution & Development published by Wiley Periodicals LLC.)

External eye appearance across primate species is diverse in shape and colouration, yet we still lack an explanation for the drivers of such diversity. Here we quantify substantial interspecific variation in eye shape and colouration across 77 primate species representing all extant genera of anthropoid primates. We reassess a series of hypotheses aiming to explain ocular variation in horizontal elongation and in colouration across species. Heavier body weight and terrestrial locomotion are associated with elongated eye outlines. Species living closer to the equator present more pigmented conjunctivae, suggesting photoprotective functions. Irises become bluer in species living further away from the equator, adding to existing literature supporting a circadian clock function for bluer irises. These results shift the current focus from communicative, to ecological factors in driving variation in external eye appearance in anthropoid primates. They also highlight the possibility that similar ecological factors contributed to selection for blue eyes in ancestral human populations living in northern latitudes., (© 2022. The Author(s).)

The sizes of the eye structures, such as the lens diameter and the axial length, are important factors for the visual performance and are considered to be related to the mode of life. Although the size of these soft structures cannot be directly observed in fossil taxa, such information may be obtained from measuring size and morphology of the bony scleral ossicle ring, which is present in the eyes of extant saurospids, excluding crocodiles and snakes, and is variously preserved in fossil taxa. However, there have been only a few studies investigating the relationships between the size, the scleral ossicle ring, and soft structures of the eye. We investigated such relationships among the eye structures in extant Squamata, to establish the basis for inferring the size of the soft structures in the eye in fossil squamates. Three-dimensional morphological data on the eye and head region of 59 lizard species covering most major clades were collected using micro-computed tomography scanners. Strong correlations were found between the internal and external diameters of the scleral ossicle ring and soft structures. The tight correlations found here will allow reliable estimations of the sizes of soft structures and inferences on the visual performance and mode of life in fossil squamates, based on the diameters of their preserved scleral ossicle rings. Furthermore, the comparison of the allometric relationships between structures in squamates eyes with those in avian eyes suggest the possibility that the similarities of these structures closely reflect the mechanism of accommodation., (© 2022 The Authors. Journal of Morphology published by Wiley Periodicals LLC.)

Animals vary widely in body size within and across species. This has consequences for the function of organs and body parts in both large and small individuals. How these scale, in relation to body size, reveals evolutionary investment strategies, often resulting in trade-offs between functions. Eyes exemplify these trade-offs, as they are limited by their absolute size in two key performance features: sensitivity and spatial acuity. Due to their size polymorphism, insect compound eyes are ideal models for studying the allometric scaling of eye performance. Previous work on apposition compound eyes revealed that allometric scaling led to poorer spatial resolution and visual sensitivity in small individuals, across a range of insect species. Here, we used X-ray microtomography to investigate allometric scaling in superposition compound eyes-the second most common eye type in insects-for the first time. Our results reveal a novel strategy to cope with the trade-off between sensitivity and spatial acuity, as we show that the eyes of the hummingbird hawkmoth retain an optimal balance between these performance measures across all body sizes.

Purpose: To compare axial length (AL) measurements obtained by optical biometry (OB) and immersion ultrasound (iUS) to investigate the agreement between the 2 techniques and how to use OB constants for eyes with AL by iUS., Setting: Multicenter study., Design: Retrospective observational case series., Methods: Agreement between OB and iUS ALs was investigated in 4 subsets. Also, in a test database, the prediction error (PE) for iUS AL was assessed with 4 methods: (1) data-optimized constants; (2) user group for laser interference biometry (ULIB) constants with iUS biometry; (3) with recalibrated AL; and (4) ULIB A-constant - 0.23., Results: A Combined 1970 eyes were measured with both OB and iUS biometry. OB mean AL was 0.0873 mm longer than iUS AL. The latter was made equivalent to OB ALs with this equation: Recalibrated iUS AL = 1.0228 × iUS AL - 0.4556. In a fifth database (n = 1079) with OB AL measurements only, after AL was artificially shortened by 0.0873 mm, the original A-constant had to be reduced by 0.23 to maintain a zero PE. In a sixth database (n = 127) with iUS AL, the original ULIB A-constant provided the poorest outcomes. Using either recalibrated iUS AL or ULIB A-constant - 0.23 zeroed out the mean PE and achieved the lowest median absolute error., Conclusions: AL measurements by iUS can be used with ULIB constants for OB by subtracting 0.23 from the A-constant; alternatively, the iUS AL may be recalibrated. The recalibrated iUS AL should be treated as AL measurements obtained by OB. It is longer than iUS AL in long eyes., (Copyright © 2021 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Knowledge of the energy deposition in different eye components is a critical decision-making to the overall effectivity of ocular melanoma treatment with plaques loaded with low-energy sources. The aim of this study is using the GATE 8.2 Monte Carlo code to calculate the 3D dose distribution in a realistic eye model. At first, we validated the GATE simulation for 125 I, 103 Pd, and 131 Cs seeds by calculating the dose rate constant, radial dose function, and anisotropy function of the three radioactive sources. Then, a 12-mm Collaborative Ocular Melanoma Study (COMS) eye plaque was simulated in the eye phantoms to evaluate dose distribution due to low-energy gamma emitters on the three simulated medium-sized tumors. The findings of this study indicate that the estimated doses received by different eye substructures strongly depend on the source type. The results show that the type of seeds used in the plaque, as well as the size of the eye tumor, have significant effects on the dose deposition in the different structures of the eye and dose deposition uniformity. Moreover, comparing different radionuclides showed that the COMS plaque fully loaded with 103 Pd presents a higher dose delivery to the tumor and a lower one to the critical structures for medium-sized tumors, while the plaque fully loaded with 131 Cs produces the most uniform dose distribution in the tumor., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The purpose of this study was to examine the effects of age, gender and population origin on human globe and corneal dimensions and to explore the relationships between the dimensions. Human post-mortem eyes were obtained in Hyderabad (n = 223; range, 0-85 years) and Miami (n = 486; range, 6-103 years). The eyes were freed of extraneous tissues and globe antero-posterior length (GAPL), mean globe diameter (MGD) (average of horizontal and vertical), and corneal horizontal (HCD) and vertical (VCD) diameters were measured using digital calipers. The relationships of age, gender and population origin with globe and corneal dimensions and the relationships between the dimensions were assessed by bivalent and multiple regression analyses. Globe and cornea dimensions increase asymptotically with age until around the late teens but do not change thereafter. Bivariate and multivariate regression analyses of the >20-year-old eyes showed that population was significantly correlated with GAPL, MGD, HCD and VCD. Male globes and corneas were larger than those from females, but the difference did not appear to be statistically significant. All Hyderabad dimensions were significantly larger than those from the Miami. Neither GAPL nor MGD were correlated with the corneal dimensions. GAPL was significantly correlated with MGD as was HCD with VCD., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Recent reports have challenged the notion that the lens is immune-privileged. However, these studies have not fully identified the molecular mechanism(s) that promote immune surveillance of the lens. Using a mouse model of targeted glutathione (GSH) deficiency in ocular surface tissues, we have investigated the role of oxidative stress in upregulating cytokine expression and promoting immune surveillance of the eye. RNA-sequencing of lenses from postnatal day (P) 1-aged Gclc f/f ;Le-Cre Tg/- (KO) and Gclc f/f ;Le-Cre -/- control (CON) mice revealed upregulation of many cytokines (e.g., CCL4, GDF15, CSF1) and immune response genes in the lenses of KO mice. The eyes of KO mice had a greater number of cells in the aqueous and vitreous humors at P1, P20 and P50 than age-matched CON and Gclc w/w ;Le-Cre Tg/- (CRE) mice. Histological analyses revealed the presence of innate immune cells (i.e., macrophages, leukocytes) in ocular structures of the KO mice. At P20, the expression of cytokines and ROS content was higher in the lenses of KO mice than in those from age-matched CRE and CON mice, suggesting that oxidative stress may induce cytokine expression. In vitro administration of the oxidant, hydrogen peroxide, and the depletion of GSH (using buthionine sulfoximine (BSO)) in 21EM15 lens epithelial cells induced cytokine expression, an effect that was prevented by co-treatment of the cells with N-acetyl-l-cysteine (NAC), a antioxidant. The in vivo and ex vivo induction of cytokine expression by oxidative stress was associated with the expression of markers of epithelial-to-mesenchymal transition (EMT), α-SMA, in lens cells. Given that EMT of lens epithelial cells causes posterior capsule opacification (PCO), we propose that oxidative stress induces cytokine expression, EMT and the development of PCO in a positive feedback loop. Collectively these data indicate that oxidative stress induces inflammation of lens cells which promotes immune surveillance of ocular structures., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Myopia is a focal issue affecting the eye health of children and adolescents in China. Hyperopia reserve is the refractive state before the occurrence of myopia. As the result of dynamic matching between the axial length, cornea and lens, it is of great significance to the prevention and control of myopia. There has been a lack of the reference basis for children's eyeball development parameters and the influence of genetic factors, especially the changing law of the above-mentioned parameters in the process of children's "emmetropization". To promote the prevention and control of myopia in children and adolescents and to standardize population screening and clinical treatment, based on the survey data of refractive errors in children and adolescents from different regions, a consensus has been reached on the reference interval of hyperopia reserve, axial length and corneal curvature and related genetic factors of emmetropia at different ages among school-age children by the Public Health Ophthalmology Branch of the Chinese Preventive Medicine Association.

Psoriasis is a chronic immune-mediated inflammatory skin condition that commonly presents with red, thickened, and scaling plaques. Given the prominent cutaneous manifestations of psoriasis, more subtle ophthalmic findings of the disease may initially go undetected, with the potential for significant ocular morbidity. Associated ocular disease can involve nearly any structure of the eye, with the eyelids most commonly being affected, resulting in relatively common signs and symptoms of ocular surface discomfort. The presence of intraocular inflammation (i.e., uveitis) or retinal involvement carry a heightened risk of vision loss, and are often more difficult to diagnose outside of the ophthalmology clinic. Early detection and treatment of ocular disease can limit morbidity and are critical to the management of these patients, which requires coordination of care between dermatologists and ophthalmologists. The objective of this article was to review the most common ocular conditions that affect psoriatic patients, when to consider referral to an ophthalmologist, and to summarize the adverse ocular effects of current psoriasis treatments., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Do gender, age, body mass and height influence eye biometrical properties in young adults?, Methods: A total of 155 eyes (92 female, 63 male) of healthy subjects between the ages of 18 and 39 years were included in the study. The subjects' gender and age were recorded, and their body mass, height and biometrical properties of the eyes were measured., Results: The male subjects had significantly thicker and flatter corneas and lower minimal rim-to-disk ratios than the female subjects did. In both genders, age showed strong, negative correlations with anterior chamber depth and pupil diameter and a positive correlation with lens thickness. We also found significant, negative correlations between body height and mass with keratometry measurements, negative correlations between body height and optic disk rim area and rim volume, and positive correlations between body mass and axial length in both genders., Conclusions: Biometric eye parameters differ among people. In addition to age and gender, which are usually taken into consideration when interpreting ocular biometry findings, we strongly suggest that body height and mass should be also routinely considered when interpreting eye biometry data, as these factors have an impact on ocular biometry.

In order to meet the demands of myopia prevention, as well as the increasing needs of measurement for refractive and cataract operations in China, a new axial length (AL) measurement system combining an improved Twyman-Green interferometer with digital signal processing has been established. The ALs of 33 eyes of different optical refractive subjects (-8.50 ~ 0.50 D) were measured with the New AL and intraocular lens (IOL) master. The repeatability of measurements with the New AL was assessed using coefficient of variation (CoV) and intra-group correlation coefficient (ICC). Comparison, correlation, linear regression and agreement of AL between devices were analyzed. There was good repeatability (CoV = 0.0617%, ICC = 0.9999) with the New AL and great agreement has been obtained with both devices. These show that the New AL is capable of providing precise AL values over the normal AL range compared to the IOL master, and indicate that the New AL developed can be used for routine clinical AL measurements., (© 2021 Wiley-VCH GmbH.)