How does atmospheric pressure cold helium plasma affect the biomechanical behaviour on alkali-lesioned corneas?

BACKGROUND: Melting corneal ulcers are a serious condition that affects a great number of animals and people around the world and it is characterised by a progressive weakening of the tissue leading to possible severe ophthalmic complications, such as visual impairment or blindness. This disease is routinely treated with medical therapy and keratoplasty, and recently also with alternative regenerative therapies, such as cross-linking, amniotic membrane transplant, and laser. Plasma medicine is another recent example of regenerative treatment that showed promising results in reducing the microbial load of corneal tissue together with maintaining its cellular vitality. Since the effect of helium plasma application on corneal mechanical viscoelasticity has not yet been investigated, the aim of this study is first to evaluate it on ex vivo porcine corneas for different exposition times and then to compare the results with previous data on cross-linking treatment. RESULTS: 94 ex vivo porcine corneas divided into 16 populations (healthy or injured, fresh or cultured and treated or not with plasma or cross-linking) were analysed. For each population, a biomechanical analysis was performed by uniaxial stress-relaxation tests, and a statistical analysis was carried out considering the characteristic mechanical parameters. In terms of equilibrium normalised stress, no statistically significant difference resulted when the healthy corneas were compared with lesioned plasma-treated ones, independently of treatment time, contrary to what was obtained about the cross-linking treated corneas which exhibited more intense relaxation phenomena. CONCLUSIONS: In this study, the influence of the Helium plasma treatment was observed on the viscoelasticity of porcine corneas ex vivo, by restoring in lesioned tissue a degree of relaxation similar to the one of the native tissue, even after only 2 min of application. Therefore, the obtained results suggest that plasma treatment is a promising new regenerative ophthalmic therapy for melting corneal ulcers, laying the groundwork for further studies to correlate the mechanical findings with corneal histology and ultrastructural anatomy after plasma treatment.

Corneal stromal ulcerations in a referral population of dogs and cats in the Netherlands (2012-2019): Bacterial isolates and antibiotic resistance.

OBJECTIVE: To evaluate bacterial isolates from corneal stromal ulcerations in dogs and cats in the Netherlands, review their antibiotic susceptibility, determine whether recent topical treatment affected bacterial culture results, and investigate whether (multi-drug) resistance patterns changed over time. ANIMALS STUDIED: Client-owned dogs and cats were diagnosed with corneal stromal ulceration at the Utrecht University Clinic for Companion Animals between 2012 and 2019. PROCEDURES: Retrospective analysis. RESULTS: In total, 163 samples were collected from 122 dogs (130 samples) and 33 cats. Positive cultures were obtained from 76 canine and 13 feline samples (59% and 39%, respectively) and included Staphylococcus (42 in dogs, 8 in cats), Streptococcus (22 in dogs, 2 in cats), and Pseudomonas (9 in dogs, 1 in cats) species. Significantly fewer positive cultures were found in dogs and cats previously treated with topical antibiotics (χ2  = 6.52, p = .011 and χ2  = 4.27, p = .039, respectively). Bacterial resistance to chloramphenicol was more common in dogs previously treated with chloramphenicol (χ2  = 5.24, p = .022). The incidence of acquired antibiotic resistance did not increase significantly over time. In dogs, the incidence of multi-drug-resistant isolates increased significantly between 2012-2015 and 2016-2019 (9.4% vs. 38.6%, p = .0032). CONCLUSIONS: Staphylococcus, Streptococcus, and Pseudomonas species were the most common bacteria associated with canine and feline corneal stromal ulcerations. Previous treatment with antibiotics affected bacterial culture results and antibiotic sensitivity. Although the overall incidence of acquired antibiotic resistance did not change over time, the incidence of multi-drug-resistant isolates in dogs increased over an 8-year period.

Calcification and osseous metaplasia of the meibomian glands of a horse.

OBJECTIVE: To report the clinical history, surgical management, and histologic findings of meibomian gland calcification and osseous metaplasia in a horse. ANIMAL STUDIED: A 21-year-old Selle Français gelding presented with a 9 months history of blepharitis, blepharospasm, and epiphora affecting the right eye. The horse was diagnosed with meibomianitis and impaction with associated granulomas, but not treated surgically for 6 years. PROCEDURES: Physical and ophthalmic examinations, and systemic bloodwork were performed. A diamond burr debridement was performed on a corneal ulceration, and meibomian gland nodules were excised and examined histologically. RESULTS: Multiple firm concretions were associated with the palpebral conjunctiva of each eyelid. The largest nodule (5 × 4 × 10 mm) was excised from the lower right eyelid. Histology revealed dilated meibomian ducts with mineralized inspissated secretions surrounded by fibrosis and osseous metaplasia. Following nodule excision and corneal ulcer resolution, no blepharospasm or epiphora recurred for a follow-up period of 15 months. CONCLUSION: Calcification and osseous metaplasia of the meibomian glands was identified in a Selle Français gelding. It is suspected that inspissated meibomian secretions led to a local granulomatous reaction with secondary dystrophic calcification and osseous metaplasia.

A remote fluorescein staining and photography protocol for monitoring of ulcerative keratitis in small animal patients: A pilot study.

OBJECTIVE: To describe a protocol for corneal ulcer monitoring utilizing daily fluorescein staining and evaluation of owner-acquired anterior segment images. ANIMAL STUDIED: Nine client-owned small animal patients (eight dogs, one cat) diagnosed with superficial corneal ulcers at the University of Georgia Veterinary Capitalize Hospital. PROCEDURE(S): In addition to routine ulcer therapy, patients were discharged with supplies to perform daily fluorescein staining including a Quikvue® cobalt blue light camera adapter. Fluorescein staining was performed daily, photographs and/or videos were acquired at home by the patient's owner(s), and images were analyzed daily by trained personnel. In-house examinations were performed weekly and within 24 h after the ulcer had appeared healed on photographs. RESULTS: All (9/9) owners were able to take interpretable photographs. The majority (6/9) of patients had images successfully detailing their ulcer healing progress. One (1/9) patient appeared healed on images, but on subsequent examination had persistent ulceration covered by third eyelid elevation. Two (2/9) patients had persistent ulceration, consistent on both images and examination, but exited the study prematurely prior to ulcer healing. CONCLUSIONS: Remote fluorescein staining and image evaluation can be considered as an adjunct for monitoring ulcer healing but should not be used alone or as a substitute for ophthalmic examinations. Ulcers under the third eyelid have potential to be missed on image evaluation alone.

Treatment of corneal ulceration and bullous keratopathy using a nictitating membrane flap in two horses.

OBJECTIVE: The aim of this study was to describe placement of a nictitating membrane flap as a treatment for corneal ulceration and bullous keratopathy in two horses. ANIMALS STUDIED: A 13-year-old American Saddlebred mare presented for severe corneal edema, superficial stromal ulceration, and a central bulla of the left eye. A 4-year-old Trakhener stallion also presented with a large axial bulla of the left eye with concurrent severe corneal edema and a deep stromal ulcer. PROCEDURE: A complete ophthalmic examination was performed. Samples were obtained for corneal cytology, and both horses were started on aggressive medical therapy. Both underwent general anesthesia for placement of a nictitating membrane flap and a subpalpebral lavage system (SPLS). RESULTS: Corneal cytology for each horse revealed a mixed bacterial population. Moderate Pseudomonas aeruginosa was cultured from the mare, while Aspergillus species and a few Enterococcus gallinarum were cultured from the stallion. The bullae in both horses resolved at 3 and 4 weeks and vision returned in the affected eye 4.5 and 3 months postoperatively at the last follow-up, respectively. CONCLUSION: Aggressive medical management with concurrent placement of a nictitating membrane flap is effective to treat bullous keratopathy in two horses. The described treatments could be used to treat horses that develop severe or progressive bullous corneal lesions.

In vitro susceptibility of canine corneal bacterial pathogens to three cross-linking protocols.

OBJECTIVE: To assess in vitro antibacterial efficacy of three cross-linking (XL) protocols on bacteria associated with canine ulcerative keratitis. METHODS: Three XL protocols: UVA 3 mW/cm2 for 60 min, UVA 3 mW/cm2 for 30 min, and UVA 30 mW/cm2 for 3 min with and without application of riboflavin and a riboflavin-only protocol were performed in vitro on the four most common bacterial genera isolated from cases of canine ulcerative keratitis treated at Dick White Referrals, UK. Zones of bacterial growth inhibition (GIZ) associated with treatment were measured and compared. RESULTS: The four most common isolates were Pseudomonas aeruginosa (PA) (48/140, 34.3%), Streptococcus spp. (32/140, 22.9%), Staphylococcus spp. (24/140, 17.1%) and Escherichia coli (EC) (11/140, 7.9%). PA, EC, Streptococcus canis (SC), and Staphylococcus pseudintermedius (SP), isolated from canine corneas, were selected for testing. EC and SC demonstrated growth inhibition following all UVA/riboflavin protocols. PA and SP only displayed growth inhibition following the 60 min UVA/riboflavin protocol. GIZ areas for 60 min UVA/riboflavin protocols were significantly greater than 30 and 3 min UVA/riboflavin protocols (p < .01) and there was no significant difference between 30 and 3 min UVA/riboflavin protocols. In respect to GIZ areas, EC was significantly more susceptible to XL than SP (p = <.01). CONCLUSIONS: All UVA/riboflavin XL protocols caused growth inhibition of EC and SC in vitro. PA and SP did not show clear growth inhibition in vitro following exposure to XL protocol settings of UVA 3 mW/cm2 for 30 min and UVA 30 mW/cm2 for 3 min.

Evaluation of a commercial NGS service for detection of bacterial and fungal pathogens in infectious ulcerative keratitis.

OBJECTIVES: To compare results from a commercial next-generation sequencing (NGS) service to corneal cytology and culture for identification of causative organisms in veterinary patients presenting for infectious ulcerative keratitis (IUK). PROCEDURE: Swabs for corneal aerobic and fungal cultures and DNA swabs for NGS were submitted for canine and equine normal controls (n = 11 and n = 4, respectively) and IUK patients (n = 22 and n = 8, respectively) for which microbrush cytology specimens confirmed the presence of infectious organisms. The sensitivity of the NGS results was compared with bacterial and fungal culture results. Concordance between the NGS and culture results was determined. RESULTS: The NGS results were positive for bacterial and fungal organisms in 5 and 1 normal and 18 and 1 IUK cases, respectively. Bacterial and fungal cultures were positive for 7 and 2 normal and 20 and 5 IUK cases, respectively. Sensitivity of NGS was 82.14% (95% confidence interval (CI), 63.11% to 93.94%) and specificity was 76.47% (95% CI, 50.10% to 93.19%). Concordance (complete and partial) between identified bacterial and fungal organisms was found in 79% and 100% of cases, respectively. NGS identified organisms in 3 culture-negative IUK samples. CONCLUSION: A commercial NGS service may be useful in the identification of causative agents in IUK cases with a sensitivity greater than the sensitivity previously reported for aerobic culture. Further testing is needed to determine the clinical significance of additional organisms isolated by NGS from infected cases, as well as organisms isolated from normal corneas.

Presumed erlotinib-induced bilateral corneal ulcers in a dog with lung tumor.

OBJECTIVE: To report the corneal toxicity of erlotinib in dogs. ANIMAL STUDIED: A 13-year-old castrated male Maltese dog. RESULTS: A dog with lung cancer presented with a month-long history of mucoid discharge and blepharospasm in both eyes. Corneal ulcerations with stromal thinning were diagnosed in both eyes, which were refractory after 2 weeks of treatment with topical antibiotics and artificial tears. The dog was orally administered erlotinib (Tarceva®) by his owner for 2 months to treat his lung cancer. Urgent withholding of erlotinib was recommended, and after 2 weeks of discontinuation, the corneal defects resolved; however, corneal thinning remained until the six-month follow-up. CONCLUSIONS: To the best of author's knowledge, this is the first report in the veterinary literature that describes bilateral corneal ulcers associated with erlotinib administration in a dog.

Effects of commercial amniotic membrane extract on the re-epithelialization time and the early expression of matrix metalloproteinase-9 in cats with experimentally induced corneal ulcers.

OBJECTIVES: To investigate whether a commercially available amniotic membrane extract (AME) can accelerate corneal wound healing and suppress the early expression of MMP-9 in the tears of cats with experimentally induced superficial ulcerative keratitis. PROCEDURES: A total number of 16 cats were included. At the end of keratectomy, cats in the treatment group (TG, n = 8) received 40 µl of AME (EyeQ® Amniotic Eye Drops, Vetrix®) four times daily, while cats in the control group (CG, n = 8) received 40 µl of saline at the same time points. Tears were collected 24 and 48 h after keratectomy, and the total MMP-9 was quantified by ELISA. RESULTS: The corneal re-epithelialization rate did not differ between groups (p = .26), being 0.48 ± 0.05 mm2 /h in the CG and 0.41 ± 0.03 mm2 /h in the TG. Similarly, the average time to achieve corneal wound healing did not differ between groups (p = .25) and was 61.50 ± 3.54 h in the CG and 70.50 ± 6.71 h in the TG. The dimensions of the ulcerated areas also did not differ at any time point between the groups (p > .05). In both groups, corneas healed without scarring, pigmentation, or vascularization. The expression of MMP-9 in the tears was similar in both groups at 24 h post-keratectomy, with a slight decrease at 48 h (p > .05). CONCLUSIONS: The instillation of a commercial AME (EyeQ®) is safe, but it did not decrease the corneal re-epithelialization time or the early expression of MMP-9 in the tears of cats with experimentally induced superficial ulcerative keratitis in this study.

Pyogenic granuloma of the cornea in a pony: Uncommon complication of corneal wound healing.

A 6-year-old miniature Shetland pony mare was referred for evaluation of a left corneal mass, which developed from the healing tissue of a corneal traumatic ulceration that had occurred 4 weeks previously. On gross examination, a spherical, smooth-surfaced, and pink-colored lesion of about 1 cm in diameter was protruding from the left palpebral fissure. Ophthalmic examination revealed that it was attached to the scar tissue of the cornea, and that one corpora nigra was adherent to the posterior face of corneal wounded area, without sign of uveitis. The remainder of the ophthalmic examination was unremarkable. The mass was excised, and cryotherapy was used as an adjunctive therapy. Histopathology of the resected mass was consistent with a pyogenic granuloma on the basis of radially oriented proliferating capillaries, embedded in immature granulation tissue containing an infiltrate of neutrophils, plasma cells and eosinophils. There were no histological features of malignancy. 2 months after surgery, the ventral part of the fibrotic corneal scar was slightly raised by a pink tissue, suggesting possible recurrence of the initial lesion. A second cryotherapy was performed over the leukoma area. No recurrence has been noted for a follow-up period of more than 25 months. Pyogenic granuloma is a benign proliferative fibrovascular response that typically develops after trauma or surgery. Corneal involvement is rare in humans, and to the authors' knowledge has never been documented in veterinary ophthalmology.

Long-term outcome of autologous fascia lata grafting with conjunctival flap overlay in horses with ulcerative keratitis and keratomalacia.

OBJECTIVES: To describe the technique, postoperative complications, and outcome after autologous fascia lata grafting with conjunctival flap overlay in horses with ulcerative keratitis and keratomalacia. STUDY DESIGN: Retrospective case series. ANIMALS: Eleven horses with ulcerative keratitis and keratomalacia. METHODS: Horses included had undergone fascia lata grafting with conjunctival flap overlay due to impending or recent corneal perforation. Preceding therapy, lesion characteristics, postoperative complications, and short- and long-term outcomes were recorded. RESULTS: Postoperative complications included complete (1/11) or partial (2/11) dehiscence of the conjunctival flap and fascia lata graft, postoperative pneumonia (1/11), intermittent hypercreatinemia (2/11) and mild uveitis after trimming of the conjunctival flap (9/10). The donor sites healed without complications (11/11). A satisfactory short-term outcome (at cessation of medical therapy) was achieved in all horses (11/11). Long-term follow-up (median 29 months, range 7-127 months) was available for 10/11 horses. A comfortable eye with functional vision was achieved in 9/10 horses with long-term follow-up, including 3/4 horses with prior corneal perforation and 1/11 horses in which the fascia lata graft completely dehisced 15 days after surgery. Enucleation was required in a single horse (1/10) after phthisis bulbi developed 7 months postoperatively. CONCLUSION: Fascia lata grafting with conjunctival flap overlay appears to be a viable solution for globe preservation in horses with ulcerative keratitis and keratomalacia. Long-term ocular comfort with functional visual outcomes can be achieved in most cases with limited concerns for donor site morbidity while bypassing acquisition, storage or lesion-size limitations related to other biomaterials.

Eyes Instead of Ears: Eye Injuries Following Ocular Exposure to Otic Medications.

To determine the epidemiology of ocular exposures and toxicoses in dogs and cats from otic products, 79 dog and cat cases with an ocular exposure to a topical otic medication were retrieved from the American Society for the Prevention of Cruelty to Animals Animal Poison Control Center database. Prescription products were involved in 75/79 (95%) of cases, and over-the-counter products in 4 (5%). Clinical signs included conjunctivitis, blepharospasm, epiphora, ocular discharge, and corneal ulceration. Medication error, specifically involving mistaken identification (i.e., an otic product confused with an ophthalmic product), occurred in 68/79 (86%) of cases. In 4 of these 68 cases, an otic instead of an ophthalmic medication was mistakenly dispensed to the pet owner. Unintentional delivery (i.e., accidental ocular exposure in the course of an otic application) occurred in 9/79 (11%) of cases, and 2 (3%) cases involved intentional delivery of otic products to the eyes. Because mistaken identification was the most common cause of ocular toxicoses from otic products, separate storage and/or distinctive packaging for ophthalmic versus otic products could reduce medication errors. Animal poison control center epidemiological data can be used as a source of information regarding veterinary medication errors.

Evaluation of corneal ulcer type, skull conformation, and other risk factors in dogs: A retrospective study of 347 cases.

Objective: To investigate the incidence of corneal ulceration (CU) and establish risk factors for dogs referred to an academic referral hospital in Ontario, Canada. Animals: Dogs (N = 1101). Procedure: Type of CU, number of CU diagnoses, breed, skull conformation, weight, sex, neuter status, age, and comorbidities were analyzed for simple CU, spontaneous chronic corneal epithelial defects (SCCEDs), and complex CU. Complex ulcers were subdivided into deep, presence of keratomalacia, descemetoceles, and corneal lacerations and foreign bodies (CLFB). Results: The inclusion criteria were met by 347 dogs and 754 served as a control population of non-corneal ulceration (NCU) cases. Complex ulcers predominated (n = 134; 38.5%), including deep (n = 41; 11.8%), with keratomalacia (n = 20; 5.7%), descemetocele (n = 59; 17.0%), and CLFB (n = 14; 4.0%). Shih tzus were most predominant for every ulcer type, except for boxers for SCCEDs. Brachycephalic breeds have 2.757 greater odds (P < 0.0001) of presenting for CU, and 2.695 greater odds (P < 0.0001) of having a complex CU. Each 1 kg decrease in body weight increased odds of CU diagnosis by 1.3%. Yearly increase in age augmented the odds of CU diagnosis by 8.9% (P < 0.0001); older dogs were more likely to have SCCEDs (P = 0.0040) and keratomalacia (P = 0.0257). Comorbidities increased odds of repeat CU diagnosis (P = 0.0024). Dogs with diabetes mellitus (P = 0.0318) had higher odds of SCCEDs. Conclusion: Skull conformation, age, body weight, and comorbidities were identified risk factors for CU. Clinical relevance: Knowledge of risk factors will help veterinarians triage at risk demographics.

Évaluation du type d'ulcère cornéen, de la conformation du crâne et autres facteurs de risque chez le chien : une étude rétrospective de 347 cas. Objectif: Étudier l'incidence d'ulcération de la cornée (UC) et établir les facteurs de risque pour les chiens référés à un hôpital universitaire de référence en Ontario, Canada. Animaux: Chiens (N = 1101). Procédure: Le type d'UC, le nombre de diagnostics d'UC, la race, la conformation du crâne, le poids, le sexe, le statut de stérilisation, l'âge et les comorbidités ont été analysés pour les UC simples, les défauts épithéliaux cornéens chroniques spontanés (SCCEDs) et les UC complexes. Les ulcères complexes ont été subdivisés en profonds, présence de kératomalacie, descémétocèles et lacérations cornéennes et corps étrangers (CLFB). Résultats: Les critères d'inclusion ont été remplis par 347 chiens et 754 ont servi de population témoin de cas d'ulcération non-cornéenne (UNC). Les ulcères complexes prédominaient (n = 134; 38,5 %), y compris profonds (n = 41; 11,8 %), avec kératomalacie (n = 20; 5,7 %), descémétocèles (n = 59; 17,0 %) et CLFB (n = 14; 4,0 %). Les shih tzus étaient les plus prédominants pour chaque type d'ulcère, à l'exception des boxers pour les SCCEDs. Les races brachycéphales ont 2,757 chances plus élevées (P < 0,0001) de présenter un UC et 2,695 chances plus élevées (P < 0,0001) d'avoir un UC complexe. Chaque diminution de 1 kg du poids corporel augmentait les risques de diagnostic de UC de 1,3 %. L'augmentation annuelle de l'âge augmentait les chances de diagnostic d'UC de 8,9 % (P < 0,0001); les chiens plus âgés étaient plus susceptibles d'avoir des SCCEDs (P = 0,0040) et une kératomalacie (P = 0,0257). Les comorbidités ont augmenté les chances de répéter le diagnostic d'UC (P = 0,0024). Les chiens atteints de diabète mellitus (P = 0,0318) avaient un risque plus élevé de SCCEDs. Conclusion: La conformation du crâne, l'âge, le poids corporel et les comorbidités ont été identifiés comme facteurs de risque d'UC. Pertinence clinique: La connaissance des facteurs de risque aidera les vétérinaires à trier les cas à risque selon les données démographiques.(Traduit par Dr Serge Messier).

Efficacious cellular therapy of descemetocele in a dog.

The cornea is comprised of 4 layers; the outermost layer is the epithelium, followed by the stroma, Descemet's membrane, and endothelium. Corneal descemetocele is a serious consequence of progressive corneal ulceration, characterized by a herniation of the Descemet membrane through an overlying stromal defect. It requires urgent intervention due to the risk of perforation. Although there are several treatments available for this type of corneal ulcer, conservative approaches may be inadequate due to the typical severity of this injury. Surgical interventions, including conjunctival autograft transplantation and corneoscleral transposition, are commonly used. Mesenchymal stem cells (MSCs) have been used to effectively treat corneal ulcers, but there are limited reports regarding its use for descemetocele. A 7-year-old female shih tzu was diagnosed with descemetocele. In this dog, 2 × 106 MSCs, provided by CellTech - Stem Cell Technologies, were injected bilaterally into the conjunctiva, with an additional 5 × 105 MSCs applied topically to each eye. The ulcer achieved complete remission with an absence of corneal opacity after 75 d, supporting the claim that MSCs are an effective and safe option for the treatment of descemetocele. Key clinical message: The dog's descemetocele healed completely after a single application of MSCs after 30 d, with scars and leukoma completely absent after 75 d. No surgical intervention was required.

Thérapie cellulaire efficace de la descemétocèle chez un chien. La cornée est composée de quatre couches; la couche la plus externe est l'épithélium, suivi du stroma, de la membrane de Descemet et de l'endothélium. La descémétocèle cornéenne est une conséquence grave de l'ulcération cornéenne progressive, caractérisée par une hernie de la membrane de Descemet à travers un défaut stromal sus-jacent. Elle nécessite une intervention urgente en raison du risque de perforation. Bien qu'il existe plusieurs traitements disponibles pour ce type d'ulcère cornéen, les approches conservatrices peuvent être inadéquates en raison de la gravité typique de cette blessure. Les interventions chirurgicales, y compris une autogreffe conjonctivale et la transposition cornéosclérale, sont couramment utilisées. Les cellules souches mésenchymateuses (MSCs) ont été utilisées pour traiter efficacement les ulcères cornéens, mais il existe peu de rapports concernant leur utilisation pour la descemétocèle. Une femelle shih tzu de 7 ans a été diagnostiquée avec descemetocele. Chez ce chien, 2 × 106 MSCs, fournies par CellTech ­ Stem Cell Technologies, ont été injectées bilatéralement dans la conjonctive, avec 5 × 105 MSCs supplémentaires appliquées localement sur chaque oeil. L'ulcère a obtenu une rémission complète avec une absence d'opacité cornéenne après 75 jours, soutenant l'affirmation selon laquelle les MSCs sont une option efficace et sûre pour le traitement de la descemétocèle.Message clinique clé:La descemétocèle de ce chien a complètement guéri après une seule application de MSCs après 30 jours, avec des cicatrices et un leucome complètement absents après 75 jours. Aucune intervention chirurgicale n'a été nécessaire.(Traduit par Dr Serge Messier).

IN VIVO CONFOCAL MICROSCOPY FOR CHARACTERIZATION OF MYCOTIC KERATITIS IN OWLS (BUBO SCANDIACUS, STRIX VARIA) AND A WOODCOCK (SCOLOPAX MINOR): THREE CASES.

This case series describes the use of in vivo confocal microscopy in the diagnosis and treatment of mycotic keratitis in two owls (one Bubo scandiacus, one Strix varia) and one woodcock (Scolopax minor). Each bird was at increased risk of fungal infection due to recent injury or stress. Ophthalmic findings in all birds included blepharospasm, ocular discharge, ulcerative keratitis, white or yellow corneal plaques, and anterior uveitis. Fungal hyphae were identified in corneal samples from all three eyes examined cytologically and in all three eyes by using in vivo confocal microscopy. Aspergillus fumigatus was isolated from a corneal culture in one bird. Despite medical treatment, progressive ocular disease prompted enucleation in two birds. Fungal hyphae were detected by histopathology in one of the two enucleated eyes. In vivo confocal microscopy aided the diagnosis of fungal keratitis in all birds and was the only diagnostic method that allowed immediate, real-time quantification of the extent (area and depth) and severity of mycotic keratitis.

Clinical and microbiological analysis of fungal keratitis in Toronto, Canada: A 20-year study.

Fungal keratitis is a devastating and difficult-to-treat ocular infection with high morbidity. Understanding geographic microbiological and clinical trends helps to guide rapid and effective treatment. We therefore report the characteristics and outcomes of fungal keratitis in Toronto,ON Canada, over a 20-year period. An electronic search of microbiology records at University Health Network, Toronto, ON, Canada identified all patients with positive corneal fungal culture over a 20-year period seen at our tertiary referral cornea practice. Review of corresponding patient charts identified demographic and microbiological details, clinical course, treatment regimen, and final outcomes associated with each episode of culture-positive fungal keratitis. A total of 46 patients with 51 discrete fungal keratitis episodes were included. Five patients experienced recurrent fungal keratitis. Candida species accounted for 60.8% of positive fungal cultures, followed by Filamentous species at 35.3%. Preferred initial anti-fungal treatment was topical amphotericin at 36.7% followed by topical voriconazole at 32.6%. Surgical intervention was required in 48.9% with therapeutic penetrating keratoplasty being the most common procedure (22.4%). Final visual acuity (VA) of <20/200 was attributed to 58% of patients in this study. Risk factors for poor outcomes included poor VA, topical steroid use at presentation, Candida involvement, history of ocular surface disease, organic ocular trauma, or prior corneal transplantation. Candida is the most frequent keratomycotic pathogen in Toronto. Risk factors for poor visual outcome include prior corneal transplantation, ocular surface disease/trauma, or pre-existing topical steroid use. Early suspicion, diagnosis and treatment are paramount for best clinical outcomes. LAY SUMMARY: Fungal keratitis can cause severe vision loss without effective treatment. In Toronto, Candida had been the most common species over a 20-year period. Poor clinical outcome was associated with low presenting visual acuity, previous corneal transplant, topical steroid use, trauma, and Candida involvement.

Medical management and resolution of perinatal bilateral exophthalmia and secondary corneal ulcers in an Antillean manatee (Trichechus manatus manatus) neonate from Puerto Rico.

OBJECTIVE: To present a novel case of perinatal bilateral exophthalmos and corneal ulcers in a neonate Antillean manatee and describe the medical treatment that led to the resolution of the observed clinical signs and vision restoration. ANIMAL STUDIED: A manatee stranded alone in Puerto Rico on July 5, 2020. RESULTS: The manatee was found in critical condition with pronounced exophthalmos, lagophthalmos, and corneal opacification of both eyes (OU). Vision impairment was evident due to the lack of ocular menace reflex and bumping into the tank's walls. Biomicroscopy revealed conjunctival hyperemia and chemosis, limited third eyelid movement, but had viscous tears present OU. Dense, full-thickness, white to cream-colored cellular infiltrates affected 70% of the cornea with peripheral active vascularization OU. Rubeosis iridis was also present OU. Treatment consisted of supportive medical management, including nutritional support and topical treatment for ulcerative keratitis. Resolution of the corneal ulcers and functional vision were achieved after 6 weeks of therapy. Currently, bilateral, mild, intermittent exophthalmos is observed with no adverse clinical signs, and the calf is in good health. CONCLUSIONS: The extent of bilateral corneal disease on a neonatal calf may be a result of an intrauterine infection or possible trauma at or right after birth. While the latter may have led to exophthalmia and consequent corneal disease, the exact cause could not be determined. Supportive therapy and medical management of infectious keratitis were successful and led to vision recovery. This is the first report of ocular pathology in a neonatal manatee.

Ectopic cilia in 112 dogs: A multicenter retrospective study.

OBJECTIVE: The aim of this retrospective study was to review the clinical data and outcomes of patients that suffered ectopic cilium (EC). ANIMALS STUDIED: One hundred and twelve dogs from multiple private practices in France, with a clinical diagnosis of EC were included in the study. RESULTS: The mean age of affected dogs was 2.3 years. There were 64 females and 48 males. The most represented breeds were the Shi Tzu, the French Bulldog, the English Bulldog and the Chihuahua. Eleven dogs were affected bilaterally. The upper eyelid was implicated in 93.5% of the cases, with the median portion being the most affected. No statistical difference was observed between the right and the left eye. EC were associated with distichiasis in 50% of the cases. Pigmentation of the conjunctiva at the point of exit of the EC was present in 58% of the cases. EC were short in 75% and long in 25% of the cases. Corneal complications were statistically associated with short EC. The corneal lesions associated with EC were keratitis (94%), corneal granuloma (0.8%), corneal fibrosis (2.7%), corneal degeneration (0.8%), superficial corneal ulcer (68.7%), deep corneal ulcer (8%) and perforating corneal ulcer (0.8%). The surgeries which consisted of the removal of the hair follicle was successful in 88.4% of the cases. CONCLUSION: EC is a rare condition which can be treated successfully by the removal of the hair follicles. It must be suspected in cases of corneal lesions unresponsive to medical treatment.

Concentrations of tissue inhibitor of matrix metalloproteinase-1 and hyaluronic acid in canine amniotic membranes cryopreserved for different time points and its effects in dogs with complicated corneal ulcers.

OBJECTIVES: To determine the concentrations of total protein (TP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and hyaluronic acid (HA) in amniotic membranes (AMs) harvested from placentas of bitches of different ages and cryopreserved for different time points. The outcomes of complicated corneal defects of dogs repaired with AMs stored for the same time points were also evaluated. PROCEDURES: Ten cryopreserved canine AMs were stored for short term (2-50 days), middle term (92-210 days), or long term (256-357 days). TP was quantified by Bradford's test, whereas TIMP-1 and HA were quantified by ELISA. Twenty-one dogs that had an AM transplantation to restore deep or perforating corneal wounds were selected. RESULTS: TIMP-1 levels were lower in AMs cryopreserved for middle term (p = .02) and long term (p = .0009), when compared to AMs stored for short term. TP (p = .39) and HA (p = .18) concentrations in AMs did not differ among the storage time. TIMP-1 concentration in AMs correlated with storage time (R = -.65, p < .0001), while TP (R = -.33, p = .07) and HA concentrations did not (R = -.15, p = .41). The age of donors did not correlate with the components evaluated in the AMs. Corneal defects repaired with AMs stored for short term healed sooner than the ones repaired with AMs stored for middle (p < .01) and long term (p = .02). Additionally, TIMP-1 levels in AMs correlated negatively with the epithelization time (R = -.62, p = .002). Graft opacity was severe in 55% of cases. However, the HA levels in AMs correlated negatively with the opacification score (R = -.47, p = .03). Vision was observed in more patients who presented deep ulcers and descemetoceles, than in the ones with perforations (p = .004). CONCLUSIONS: TIMP-1 concentration in canine AMs significantly decreased over a year storage time, while TP and HA concentrations did not change during the same period. The age of donors did not correlate with the components evaluated in the AMs. Complicated corneal defects repaired with AMs cryopreserved for short term healed sooner and tended to be less opaque; however, satisfactory to optimal outcomes were achieved even in the eyes repaired with AMs stored for up to a year.

Corneal diamond burr debridement for superficial non-healing corneal ulcers in cats.

OBJECTIVE: To describe the clinical outcomes and efficacy of diamond burr debridement (DBD) treatment for corneal ulceration in cats. PROCEDURE(S): Medical records of cats that received DBD at two private practices between 2015 and 2021 were retrospectively reviewed. DBD was performed using a battery-powered, handheld motorized burr and a bandage contact lens was placed in 18/21 eyes. Corneal ulceration was considered resolved if the cornea was fluorescein negative with a stable epithelial surface. Recurrence was defined as return of corneal ulceration. Descriptive statistics and a Fisher's exact test were conducted on the study population. RESULTS: Twenty-one eyes from 20 cats with superficial corneal ulcers refractory to medical treatment underwent DBD. Domestic and Burmese were the most commonly encountered breeds and the median age of affected cats was 8.83 years (range 0.5-20 years). Corneal ulceration was present for a median of 14 days prior to DBD. Healing was achieved in 81% of eyes; with four eyes failing to heal and requiring further intervention. Corneal sequestrum was reported in one case that failed to heal. Of the healed cases, three cases recurred (17.6%) at a mean of 116.3 days (range 79-135 days). Burmese were overrepresented (p < .001) in cases that failed to heal or recurred (6/7 eyes; 85.7%). The median postoperative follow-up time was 93 days (range 6-1613 days). CONCLUSIONS: Diamond burr debridement is a safe, non-invasive treatment for corneal ulceration in cats but, compared with published results, it had a lower success rate than superficial lamellar keratectomy.