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Although tumors of the eye and its supporting tissues in domestic animals are relatively rare, they assume an enhanced importance because of the visibility and effect on function of even small tumors within, or adjacent to, the eyes. Melanomas of the conjunctiva are rare tumors of dogs and cats. Ocular squamous cell carcinoma (SCC) is easily the most common and economically important neoplasm of the eye in cattle. Vascular endothelial neoplasms of the conjunctiva, nictitans, and even the avascular cornea are reported in several species, but they are seen most commonly in dogs, cats, and horses. Ocular melanoma in horses is often seen in conjunction with systemic melanomas and rarely is seen as a solitary spontaneous tumor separate from systemic disease. Iridociliary epithelial tumors are rare tumors, but they are the second most common primary intraocular tumor in dogs and cats. Canine uveal schwannomas of blue‐eyed dogs present as nodular nonpigmented masses of the uvea.

Attempts have been made for the past five years to tissue type corneal donors prospectively and to select the most compatible material for grafting. The problems encountered are: (1) Failure to obtain blood for tissue typing. (2) Failure to contact the potential recipient or persuade him to have the graft. (3) When a patient has been admitted as an emergency requiring urgent transplantation, no donor has been available. As these recipients were grafted with corneas from an eye bank, no donor blood was obtainable and therefore tissue typing was impossible. (4) No case of identity of HL‐A antigens was achieved between donor and recipient, and therefore no good match is available for comparison with the poorly matched material. All patients except one required some immunosuppressive treatment, suggesting that mild rejection phenomena occur even in apparently well‐tolerated grafts. There was a significant association between preoperative vascularization of the cornea and rejection changes in the subsequent graft. It would seem therefore that tissue matching is probably unnecessary in patients with avascular corneas. Twenty‐seven out of 33 patients with previously vascularized corneas showed rejection changes. In half of these the changes were reversible, resulting in a clear graft; the rest became opaque. Within the group with preoperative vascularization there was no significant difference between the HL‐A match grades of those grafts that cleared and those that became opaque. This is not surprising because the final series of tissue‐typed material is very small and no perfectly matched material was available for comparison. In order to obtain evidence on whether HL‐A matching of donor and recipient can improve the prognosis of corneal grafts in preoperatively vascularized corneas we suggest that the assistance of the National Organ Matching and Distribution Services at Bristol be sought to obtain some perfectly matched grafts so that a valid comparison can be made.

Fabry disease (FD) is an X-linked lysosomal storage disorder, causing Gb-3 (globotriaosylceramide) buildup in cellular lysosomes throughout the body, in particular in blood vessel walls, neuronal cells, and smooth muscle. The gradual accumulation of this glycosphingolipid in numerous eye tissues causes conjunctival vascular abnormalities, corneal epithelial opacities (cornea verticillata), lens opacities, and retinal vascular abnormalities. Although a severe vision impairment is rare, these abnormalities are diagnostic indicators and prognostics for severity. Cornea verticillata is the most common ophthalmic feature in both hemizygous men and heterozygous females. Vessel tortuosity has been linked to a faster disease progression and may be useful in predicting systemic involvement. New technologies such as optical coherence tomography angiography (OCTA) are useful for monitoring retinal microvasculature alterations in FD patients. Along with OCTA, corneal topographic analysis, confocal microscopy, and electro-functional examinations, contributed to the recognition of ocular abnormalities and have been correlated with systemic involvement. We offer an update regarding FD ocular manifestations, focusing on findings derived from the most recent imaging modalities, to optimize the management of this pathology.

Background/Objectives: The aim of this study was to evaluate the relationship between foveal avascular zone (FAZ) enlargement, retinal ganglion cell (RGC) dysfunction, and structural retinal measurements in glaucoma suspects (GS), using pattern electroretinogram (PERG) and optical coherence tomography angiography (OCTA) parameters. Methods: Thirty-one eyes (20 subjects) of GS status underwent comprehensive ophthalmologic evaluation including steady-state PERG, optical coherence tomography (OCT), and OCTA. FAZ area was measured using ImageJ software (version 1.54p), and PERG parameters (Magnitude, MagnitudeD, and MagnitudeD/Magnitude ratio) were analyzed. Partial correlation analyses were performed to assess associations between FAZ area, PERG parameters, and structural metrics including retinal nerve fiber layer (RNFL), ganglion cell layer–inner plexiform layer (GCL + IPL), and macular thickness. Results: After controlling for age, sex, central corneal thickness (CCT), intraocular pressure (IOP), and spherical equivalent, partial correlation analysis showed that FAZ area was significantly associated with both lower Magnitude (r < −0.503, p < 0.05) and MagnitudeD (r < −0.507, p < 0.05) values. PERG parameters were significantly correlated with superior and average RNFL thickness, as well as superior and superior temporal GCL + IPL thickness. FAZ area was significantly associated with multiple GCL + IPL and macular thickness sectors, but not with RNFL thickness. Conclusions: FAZ enlargement is significantly associated with RGC dysfunction and inner retinal layer thinning in GS.

Some of the earliest studies of glycans were performed on mammalian corneas and lenses with many of the key concepts we currently recognize as being fundamental to our understanding of basic cell biology arising from these studies. Proteoglycans and their glycosaminoglycan (GAG) side chains are essential components of the extracellular matrix (ECM) of the lens capsule. They also are present in the anterior corneal epithelial basement membrane and the posterior (Decemet's) basement membrane, and they organize collagen fiber diameters and spacing in the corneal stroma to maintain stromal clarity. Studies using genetically engineered mice and characterization of spontaneously arising mutations in genes controlling proteoglycan synthesis have generated new insight into the roles played by proteoglycans in signal transduction. We now know that proteoglycans and GAGs can regulate cell signaling and the maintenance of avascularity and immune privilege that are hallmarks of these tissues. In addition, proteoglycan‐rich matrices provide the pathways for immune cells to populate the surface of the lens as a response to corneal wounding and in a model of experimental autoimmune uveitis. Here we describe what is known about proteoglycans and GAGs in the cornea and lens. This knowledge has begun to provide promising leads into new proteoglycan‐based treatments aimed at restoring and maintaining homeostasis in the cornea. Future studies are needed to determine how these new drugs impact the recruitment of immune cells to the lens for functions in restoring/maintaining homeostasis in the eye.

Various ocular diseases and high myopia influence the anatomical reference point Foveal Avascular Zone (FAZ) dimensions. Therefore, it is important to segment and quantify the FAZs dimensions accurately. To the best of our knowledge, there is no automated tool or algorithms available to segment the FAZ's deep retinal layer. The paper describes a new open-access software with a Graphical User Interface (GUI) and compares the results with the ground truth (manual segmentation). Ninety-three healthy normal subjects included 30 emmetropia and 63 myopic subjects without any sight-threatening retinal conditions, were included in the study. The 6mm x 6mm using the Angioplex protocol (Cirrus 5000 Carl Zeiss Meditec Inc., Dublin, CA) was used, and all the images were aligned with the centre of the fovea. Each FAZ image corresponding to dimensions 420×420 pixels were used in this study. These FAZ image dimensions for the superficial and deep layers were quantified using the New Automated Software Method (NAM). The NAM-based FAZ dimensions were validated with the ground truth. The age distribution for all 93 subjects was 28.02 ± 10.79 (range, 10.0-66.0) years. For normal subjects mean ± SD age distribution was 32.13 ± 16.27 years. Similarly, the myopia age distribution was 26.06 ± 6.06 years. The NAM had an accuracy of 91.40%. Moreover, the NAM on superficial layer FAZ gave a Dice Similarity Coefficient (DSC) score of 0.94 and Structural Similarity Index Metric (SSIM) of 0.97, while the NAM on deep layer FAZ gave a DSC score of 0.96 and SSIM of 0.98. A clinician-based GUI software was designed and tested on the FAZ images from deep and superficial layers. The NAM outperformed the device's inbuilt algorithm when measuring the superficial layer. This open-source software package is in the public domain and can be downloaded online.

Slit-lamp examination revealed OU localized depression of posterior corneal curvature measuring 4 mm in diameter suggestive of posterior keratoconus [Figure 1]a and [Figure 1]d, which was confirmed on anterior segment OCT [Figure 1]b and [Figure 1]e. Typical oil droplet reflex was noted on retro-illumination [Figure 1]c and [Figure 1]f. Rest of the anterior segment was normal in OU. Atypical presentation of FEVR with associated retinal detachment and subtle posterior keratoconus makes our case a diagnostic challenge. [...]FEVR can occur in the setting of posterior keratoconus.

Ehlers-Danlos syndrome (EDS) is a hereditary connective tissue disorder caused by defective collagen synthesis and categorized into 11 types based on genetic mutations and clinical features.(1) Its principal clinical characteristics include hyperelasticity and vulnerability of the skin and joints to laxity, and fragility of blood vessels. We recently performed vitreous surgery with introduction of an artificial cornea and corneal allograft transplantation in a boy with EDS type VI, whose visual acuity had decreased rapidly because of vitreous hemorrhage. An ultrasound examination revealed posterior vitreous detachment with fresh vitreous hemorrhage. After vitrectomy with introduction of an artificial cornea and cornea allograft transplant were carried out, visual acuity improved to 0.05 and was maintained for at least 22 months. Abnormal collagen synthesis is thought to lead to systemic disorders such as hyperelasticity, vulnerability to skin and joint laxity, and fragile blood vessels in patients with Ehlers-Danlos syndrome.