Prevalence of ocular findings and their association with glycemia in dogs with diabetes mellitus: A 10-year clinical study (2009-2019).

Background: Although ocular findings in diabetic patients are well described, prevalence data for those is unknown. Aim: To describe the prevalence of ocular findings and their association with glycemia in dogs with diabetes mellitus. Methods: Medical records from diabetic dogs assessed by the ophthalmology and the internal medicine services at the Veterinary Teaching Hospital of the Autonomous University of Barcelona were reviewed (2009-2019). Results: Seventy-five dogs (150 eyes) of both genders (51/75 females; 68% and 24/75 males; 32%) and a mean age of 9.37 ± 2.43 years, were included. The most common ocular findings were cataracts (146/150; 97.3%), vitreous degeneration (45/98; 45.9%), anterior uveitis (47/150; 31.3%), aqueous deficiency dry eye (ADDE) (33/150; 22%), diffuse corneal edema (31/150; 20.7%), non-proliferative retinopathy (13/98; 13.3%), and lipid keratopathy (9/150; 6%). The most prevalent type of cataracts observed (78/146; 53.4%) was intumescent, which was commonly accompanied by non-proliferative retinopathy (p = 0.003). Among the diabetic dogs, blood glucose levels were statistically higher in dogs with non-proliferative retinopathy or anterior uveitis (p < 0.005). Conclusions: Ocular complications of diabetes mellitus in dogs are numerous, being the most frequent intumescent cataracts, vitreous degeneration, anterior uveitis, ADDE, diffuse corneal edema, and non-proliferative retinopathy. This high prevalence warrants a more detailed ophthalmic evaluation in diabetic dogs especially for those undergoing cataract surgery. Furthermore, a predisposition for anterior segment inflammation and non-proliferative retinopathy is suggested when fasting plasma glucose is higher than 600 mg/dl..

Safety and efficacy of unilateral topical application of rocuronium bromide in healthy scops owls (Otus scops).

OBJECTIVE: To evaluate the safety and efficacy of unilateral topical application of rocuronium bromide in scops owls. ANIMALS STUDIED: Ten healthy adult scops owls. PROCEDURES: Birds weighting between 82-111 g were enrolled. Complete physical and ophthalmic examinations were performed. Each animal received a single dose of 0.15 mg of rocuronium bromide (30 µL) in a randomly selected eye. Static pupillometric evaluations were performed before and after drug instillation at 0, 30, 60, 90, and 120 minutes, in a room with fixed light intensity. Physical and ophthalmic examinations were carried out to evaluate possible adverse effects. RESULTS: Median pupil (95% CI) size at t0 was 7.10 mm (5.51-7.41) for placebo eyes and 7.22 mm (6.93-7.48) for treated eyes, showing no statistical differences (P > .05). When compared to the placebo eye, significant mydriasis was achieved at t30 [8.18 mm (7.22-9.00)] (P = .014) and lasting until t90 [7.35 mm (6.20-9.52)] (P = .004). Maximal mydriasis was obtained at t60 [8.63 mm (7.72-9.81)] (P = .001). During this period, the treated eye no longer responded to direct light stimulation. Complete mydriasis was observed in 5/10 birds (mean weight 97.4 g). Pupil size at t90 and t120 did not differ from baseline (P > .05) in treated eyes. No adverse effects were seen during the study period. CONCLUSION: Single-dose topical rocuronium bromide (0.15 mg) is a safe and effective medium duration mydriatic agent in scops owls. Further studies are needed to evaluate bilateral topical application and standardize the mydriatic protocol.

Intracanalicular injection of N-acetylcysteine as adjunctive treatment for sialoceles in dogs: 25 cases (2000-2017).

OBJECTIVE: To describe intracanalicular injection of 10% N-acetylcysteine (IINAC) as adjunctive treatment for sialoceles in dogs. ANIMALS: 25 client-owned dogs. PROCEDURES: Hard copy medical records at 2 veterinary ophthalmology practices were searched to identify dogs that underwent IINAC for treatment of sialoceles from January 2000 to December 2017. Signalment, affected salivary gland, clinical signs, duration of signs, other treatments administered, diagnostic tests performed, anesthetic approach, N-acetylcysteine volume administered, complications, follow-up time, and recurrence of sialoceles were recorded. Descriptive statistics were reported. RESULTS: Boxers and mixed-breed dogs were most commonly represented. Subjectively decreased globe retropulsion and conjunctival or periorbital swelling (23/25 [92%] dogs each) were the most common clinical signs, with no vision deficits in any patient. The zygomatic gland was mainly affected (23/25 [92%] dogs), followed by parotid and mandibular glands (1 [4%] dog each). The condition was unilateral in 22 (88%) dogs. Ultrasonography (19/25 [76%] dogs), MRI (14 [56%]), fine-needle aspiration (20 [80%]), and biopsy (4 [16%]) were performed; however, the condition was deemed idiopathic in 22 (88%) dogs. Most IINACs were performed with local anesthesia (median volume, 5 mL/gland; range, 1.5 to 9 mL). No complications were identified. Other treatments included antimicrobials and anti-inflammatories. Mean follow-up time was 18.8 months. All recurrences (5/23 [22%] dogs) were controlled with medical management. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested noninvasive IINAC may be a useful adjunctive treatment for sialoceles in dogs. The procedure was easily and safely performed with local anesthesia (or general anesthesia with concurrent diagnostic imaging) in these dogs.

Effects of topical 1% cyclopentolate hydrochloride on quantitative pupillometry measurements, tear production and intraocular pressure in healthy horses.

OBJECTIVE: To evaluate the effect of topical cyclopentolate hydrochloride (CH) on quantitative pupillometric readings (PR), tear production (TP), and intraocular pressure (IOP) in healthy horses. ANIMALS STUDIED: Fourteen client-owned horses. PROCEDURES: In a two-phase design study, each animal received 1% CH ophthalmic solution in the left eye [treated] and 0.9% NaCl in the right eye [control] (0.2 mL each). In the first phase (n = 7), TP, IOP, and PR assessment was performed by Schirmer tear test I, rebound tonometry and static pupillometry, at 1, 8, 24, 48, 72, 96, 120, 148, 172, and 196-hours post-instillation. In the second phase (n = 7), plateau mydriasis was evaluated by assessing PR hourly for 8 hours post-instillation. For PR assessment, pupil area (PA), vertical diameter (VPD), and horizontal diameter (HPD) were recorded. All pupillometries were obtained in a room with fixed light intensity (45-60 lux). Statistical analysis was performed by generalized estimating equations method for the effect on parameters over time. RESULTS: After topical CH, significant differences in pupil dilation were seen from 1 to 172 hours for VPD and from 8 to 24 hours for PA, without significant differences on HPD over time. In the second phase, plateau PA and VPD were reached at 3 hours, while plateau HPD at 2 hours. No significant effects were detected on TP and IOP in both eyes at any time, nor on PR of the nontreated eyes. CONCLUSIONS: Topical 1% cyclopentolate hydrochloride could be considered an effective and safe option when a mydriatic/cycloplegic drug is needed in horses.

Corneoconjunctival transposition for the treatment of deep stromal to full-thickness corneal defects in dogs: A multicentric retrospective study of 100 cases (2012-2018).

OBJECTIVE: To describe and evaluate the use of corneoconjunctival transposition (CTT) as a surgical treatment for canine deep stromal ulcers, descemetoceles, and full-thickness corneal defects and to determine its efficacy in preserving corneal graft transparency and vision. ANIMALS STUDIED: One hundred client-owned dogs with deep stromal ulcers, descemetoceles, or full-thickness corneal defects. METHODS: Medical records of canine patients that underwent CCT, from 2012 to 2018, were reviewed. Only, patients with preoperative positive consensual pupillary light and dazzle reflexes were included. RESULTS: There were 59 males and 41 females, from 0.3 to 17 years. Brachycephalic breeds were overrepresented (65%). All patients were unilaterally affected, with 16 deep stromal ulcers, 33 descemetoceles, and 51 corneal perforations, of a median (range) size of 4 (2-8) mm. The central cornea was affected in the majority of cases (57%), and euryblepharon and keratoconjunctivitis sicca were the most common concurrent ocular diseases (42% and 40%, respectively). The graft was most frequently harvested from dorsal (67%), and 9/0 absorbable suture material was used. Intraoperative and postoperative complications were seen in 7 and 21 cases, respectively. Mean follow-up time was 107.8 days. Vision was preserved in 96% patients, with 62% showing faint to mild opacification. Among the statistically analyzed variables, euryblepharon and pigmentary keratitis were found to be significantly associated with greater corneal graft opacification (P = .040 and P = .028, respectively). CONCLUSIONS: Corneoconjunctival transposition is an effective surgical treatment for deep stromal, descemetocele, and full-thickness corneal defects in dogs, achieving a highly satisfactory degree of corneal graft transparency and preserving vision.

Effect of Cryopreserved Amniotic Membrane on the Mechanical Properties of Skeletal Muscle after Strabismus Surgery in Rabbits.

PURPOSE: To study the functional recovery of the superior rectus muscle (SRM) after its partial resection in a rabbit model with and without cryopreserved amniotic membrane (AM). MATERIAL AND METHODS: Resection of the right and left SRMs of 30 rabbits was performed. On the left eyes, a single sheet of equine cryopreserved AM was placed covering the muscle edge sutured. Active and passive mechanical properties of muscles operated with and without AM were monitored over time at 30 (n = 10), 60 (n = 10), and 90 (n = 10) days after surgery. Muscle samples were extracted and electrically stimulated to register the force exerted by the samples, characterizing its active behavior. They were, then, subjected to stretching test to obtain its resistance to deformation, known as passive behavior. Moreover, right and left eyes of a control group (n = 5) were equally subjected to active and passive tests to characterize the physiological behavior of SRM muscles. RESULTS: On active function examination, statistically significant differences were documented between the following: control vs AM and no AM at 30 days (p = 0.002 and p = 0.04, respectively). All other comparisons were insignificant (p > 0.05). On passive function analysis, significant differences were only found between control vs. no AM at 30 days (p = 0.004) and between AM vs. no AM at 30 days (p = 0.002). Indeed, muscle operated without AM did not recover a normal passive function until 60 days after surgery. CONCLUSION: Cryopreserved AM is effective in accelerating recovery of SRM passive function in rabbits. Nevertheless, AM produced no significant effect on recovery of SRM active function..

Why Non-contact Tonometry Tests Cannot Evaluate the Effects of Corneal Collagen Cross-linking.

PURPOSE: To assess the feasibility of characterizing and following up the mechanical behavior of the corneal tissue after corneal cross-linking (CXL) by using a combined mechanical (in vivo indentation and in vitro uniaxial tensile tests) and morphological (immunohisto-chemistry) experimental protocol. METHODS: CXL (3 mW/cm2; 370 nm) for 20 minutes (total dose 3.6 J/cm2) was performed on 12 New Zealand rabbits. The mechanical behavior of the cornea was characterized in small and large strain regimens using an in vivo indentation test with a laboratory device and an in vitro uniaxial tensile test, respectively. These tests and corneal immunohistochemistry were performed before (PreCXL) and on the 7th (PostCXL-7d) and 56th days (PostCXL-56d) after CXL. The intraocular pressure and corneal thickness were measured before each test. RESULTS: For the indentation tests, significant differences were found between PreCXL and PostCXL-7d and between PostCXL-7d and PostCXL-56d, but not between PreCXL and PostCXL-56d. On average, for the small strain regimen, PostCXL-7d corneas showed the most compliant behavior, with progressive recovery of the corneal stiffness over time. For the large strain regimen, significant differences in the maximum tangent modulus between PreCXL and PostCXL-7d and between PreCXL and PostCXL-56d were observed for the uniaxial tensile tests, with no significant differences between PostCXL-7d and PostCXL-56d. Immunohistochemistry showed a lack of cells in the anterior stroma at PostCXL-7d, but at PostCXL-56d the cell density and morphology were comparable to PreCXL. CONCLUSIONS: Indentation tests cannot characterize the changes in the corneal collagen scaffold caused by the CXL, but the uniaxial test can. However, indentation tests can assess the recovery of keratocyte density after CXL. [J Refract Surg. 2017;33(3):184-192.].

A Rabbit Model of Acanthamoeba Keratitis: Use of Infected Soft Contact Lenses After Corneal Epithelium Debridement With a Diamond Burr.

Purpose: To develop a rabbit model of Acanthamoeba keratitis (AK) as the best method to reproduce the natural course of this disease. Methods: To induce AK, infected contact lenses (1000 amoebae/mm2, 90% trophozoites) were placed over the previously debrided corneal surface, in combination with a temporary tarsorrhaphy. Environmental and clinical strains of Acanthamoeba spp. (genotype T4) were used. Three groups (1L, n = 32; 2L-21d, n = 5; 2L-3d, n = 23) were established according to the number of contact lenses used (1L, 1 lens; 2L-21d and 2L-3d, 2 lenses) and the placement day of these (1L, day 1; 2L-21d, days 1 and 21; 2L-3d, days 1 and 3). The infection was quantified by a clinical score system and confirmed using corneal cytology and culture, polymerase chain reaction and histopathologic analysis. Results: The infection rate obtained was high (1L, 87.5%; 2L-21d, 100%; 2L-3d, 82.6%), although no clinical signs were observed in the 50% of the infected animals in group 1L. Among groups, group 2L-3d showed more cases of moderate and severe infection. Among strains, no statistically significant differences were found in the infection rate. In the control eyes, cross infection was confirmed when a sterile contact lens was placed in the previously debrided corneas but not if the eye remained intact. Conclusions: The combination of two infected contact lenses after corneal debridement seems to be an alternative model, clinically and histopathologically similar to its human counterpart, to induce the different AK stages and reproduce the course of the disease in rabbits.