Lack of effect of a topical regenerative agent on re-epithelialization rate of canine spontaneous chronic corneal epithelial defects: A randomized, double-masked, placebo-controlled study

Breed distribution of spontaneous chronic corneal epithelial defects in UK dogs

BACKGROUND

This study aimed to assess the risk of bilateral disease in dogs affected by spontaneous chronic corneal epithelial defects (SCCEDs) and identify any recent changes in the distribution of breeds affected.

METHODS

Medical records of dogs assessed at a single ophthalmic centre for the management of SCCEDs between 2007 and 2020 were reviewed, and clinical data were extracted.

RESULTS

Three hundred and seven dogs met the inclusion criteria. Boxers (129 dogs), Staffordshire Bull Terriers (37 dogs) and French Bulldogs (20 dogs) were most frequently affected. Overall, the median age at presentation was 8 years (range 1-15 years), but French Bulldogs had a younger median age of 6 years. Boxers, French Bulldogs and Staffordshire Bull Terriers showed higher odds of bilateral ulceration (odds ratio 1.79, 1.65 and 1.64, respectively) compared to the overall study population. The median time between presentations when both eyes were affected was 4 months (range 0-42 months). There was a statistically significant increase in French Bulldogs, a reduction in Boxers and a stable number of Staffordshire Bull Terriers treated for this condition. However, as the effective sample size from each individual breed was small, further studies would be beneficial to confirm these findings.

CONCLUSION

The results from this study suggest a shift in breed distribution. The risk of bilateral disease is higher in the three breeds reported here, and owners should be counselled appropriately at the initial examination.

Use of autologous serum or Vizoovet to improve healing rates of spontaneous chronic corneal epithelial defects after diamond burr debridement in dogs

PURPOSE

To determine whether the use of autologous serum or Vizoovet® improved healing rates of spontaneous chronic corneal epithelial defects (SCCEDs) after diamond burr debridement (DBD) in dogs.

STUDY DESIGN

Two parallel group randomized prospective study with a historical control group.

MATERIALS AND METHODS

Canine patients having undergone DBD for treatment of SCCEDs were included. Data for the control group (ofloxacin only) were gathered from patient records. Patients were randomly assigned to treatment groups for post-procedural medical treatments of ofloxacin and autologous serum (group 1) or ofloxacin and Vizoovet®, an all-natural eyed drop containing propolis, aloe vera, and chamomile (group 2). Each dog was examined between 2 and 3 weeks until the cornea was fluorescein stain negative. Data points collected included age, sex, breed, type of medications used, retention of bandage contact lens (BCL), time to healing, and number of DBD performed.

RESULTS

A total of 120 dogs, each contributing one eye to the study, underwent DBD for SCCEDs. Mean (± standard deviation) days until healed were 20.1 ± 11.1 days, 16.3 ± 4.5 days, and 16.0 ± 3.7 days for the control group, group 1, and group 2, respectively. There was a marginally significant difference in days until healed between groups (p = .0515). SCCEDs healed significantly faster in group 2 (p = .03) and marginally faster in group 1 (p = .06) compared with the control group. Days until healing between group 1 and 2 were not significantly different (p = .76).

CONCLUSIONS

As compared to the control group, use of Vizoovet® as adjunctive medical treatment resulted in shorter corneal healing time after DBD.

Bacterial isolates of indolent ulcers in 43 dogs

PURPOSE

To determine whether bacteria are isolated from canine indolent ulcers and evaluate their influence on clinical outcomes.

METHODS

Swabs for anaerobic and aerobic culture were collected from indolent ulcers of 43 client-owned dogs presenting to the University of Saskatchewan Veterinary Medical Centre. Outcomes were compared between ulcers with bacterial isolates and those without. Medical therapy was reviewed.

RESULTS

Bacteria were isolated in 8/43 ulcers: Three cultured two isolates and five cultured single isolates. Staphylococcus was the most common genus isolated and was present in six ulcers: Species included unspecified [2], pseudintermedius [2], schleiferi [1], and hominis [1]. Streptococcus was the second most common isolate present in two ulcers: Species included canis and agalactiae. Tobramycin was the most common antibiotic used in ulcers with bacterial isolates prior to referral (n = 3). One case did not have conclusive follow-up data from the referring veterinarian and was therefore excluded from further analysis. All seven culture-positive ulcers were recorded as healed without complication: six healing after one procedure and one healing after two procedures. Thirty-five ulcers were culture-negative. There was no difference in outcome between indolent ulcers with bacterial isolates and those with negative cultures (P = .7475).

CONCLUSIONS

Bacteria were isolated from 19% of indolent ulcers, and Staphylococcus was the most common isolate. Bacterial isolation did not influence outcome.

Equine non-healing corneal ulcers: a retrospective evaluation of 57 cases (2001-2017)

BACKGROUND AND OBJECTIVES

Non-healing corneal ulcers (NHCU) are a common problem in equine practice and several treatment options are available with different success and healing times. The aim of this retrospective study was to evaluate and to compare treatment protocols, clinical courses, corneal healing time and outcomes of NHCU.

METHODS

From December 2001 to December 2017, a total of 57 horses with NHCU were presented at the Vetmeduni Vienna. Recorded data included affected eye, signalment, clinical symptoms, season of diagnosis, treatment protocols, complications and corneal healing rate.

RESULTS

Sixty-three eyes were diagnosed with a NHCU. Follow-up information was available for 48/63 eyes. For those treated medically mean corneal healing time was 15.7 days (± SD 12.0). Medical treatment included topical antibiotics, antimycotics, cycloplegics, and systemic anti-inflammatory drugs. Twelve eyes received treatment with a poly-carboxymethylglucose-sulfate regenerating agent (Cacicol^®; Thea Pharma GmbH, Wien, Austria). Other common additional treatments included debridement with an iodine drenched cotton tip (48 eyes; 76.2 %) and diamond burr debridement (30 eyes; 47.6 %). A bandage contact lens (BCL) was used for 10 eyes. Each eye received at least one additional treatment, although none of them led to a statistically significant alteration in healing time. Only usage of a BCL significantly increased healing time when compared to not using a BCL (p = 0.035). When all treatments failed, superficial keratectomy with placement of a conjunctival flap was performed. Secondary complications included stromal cellular infiltration, keratomycosis, keratomalacia, and corneal abscess formation.

CONCLUSIONS

Results correlated with those previously described and thus demonstrated the difficulty and complexity of this disease. Further research is needed to determine an optimal treatment protocol for non-healing ulcers in horses.

CLINICAL RELEVANCE

Since NHCUs are a commonly encountered problem in equine practice a reliable treatment protocol is required. This study reflects the problems with those ulcers and provides several protocols for possible treatments.

Case Reports for Topical Treatment of Corneal Ulcers with a New Matrix Therapy Agent or RGTA® in Dogs

Superficial corneal ulcers that fail to heal within a normal time period and are refractory to conventional therapy in dogs are common in veterinary practice. Different etiologies can lead to this result, including spontaneous chronic corneal epithelial defects (SCCEDs) and ulcerative keratitis associated with bullous keratopathy. Thus, there is an urgent need to find new therapeutic approaches such as matrix therapy replacement. To determine the efficacy of a new ophthalmic treatment (Clerapliq^®) for SCCEDs and ulcerative keratitis associated with bullous keratopathy, a total of 11 dogs referred to the clinic because of nonhealing erosive ulcers after a classic primary treatment were enrolled to get this new treatment. Dogs underwent ophthalmic exams and 7 dogs (10 eyes) were diagnosed with superficial ulceration and 4 dogs (5 eyes) with bullous keratopathy due to endothelial dystrophy/degeneration. They received eye drops of Clerapliq^® every 3 days until recovery. The results showed that the corneas with recurrences of the ulcers were resolved predominantly by using Clerapliq^® every 3 days in 83.3% of the cases during a period of treatment ranging between 6 to 35 days. Therefore, this new approach using matrix therapy regenerating technology in treating superficial ulcers and bullous keratopathy in dogs can be successfully considered as an adjunctive therapy.

CNN-based diagnosis models for canine ulcerative keratitis

The purpose of this methodological study was to develop a convolutional neural network (CNN), which is a recently developed deep-learning-based image recognition method, to determine corneal ulcer severity in dogs. The CNN model was trained with images for which corneal ulcer severity (normal, superficial, and deep) were previously classified by veterinary ophthalmologists' diagnostic evaluations of corneal photographs from patients who visited the Veterinary Medical Teaching Hospital (VMTH) at Konkuk University and 3 different veterinary ophthalmology specialty hospitals in Korea. The original images (depicting normal corneas (36) and corneas with superficial (47) ulcers, deep (47) ulcers), flipped images (total 520), rotated images (total 520), and both flipped and rotated images (total 1,040) were labeled, learned and evaluated with GoogLeNet, ResNet, and VGGNet models, and the severity of each corneal ulcer image was determined. To accomplish this task, models based on TensorFlow, an open-source software library developed by Google, were used, and the labeled images were converted into TensorFlow record (TFRecord) format. The models were fine-tuned using a CNN model trained on the ImageNet dataset and then used to predict severity. Most of the models achieved accuracies of over 90% when classifying superficial and deep corneal ulcers, and ResNet and VGGNet achieved accuracies over 90% for classifying normal corneas, corneas with superficial ulcers, and corneas with deep ulcers. This study proposes a method to effectively determine corneal ulcer severity in dogs by using a CNN and concludes that multiple image classification models can be used in the veterinary field.