Veterinary ophthalmology最新文献

Objective: The aim of the study was to investigate clinical features of lamellar keratectomy for presumed calcific corneal degeneration in a population of geriatric dogs using blunt scissors dissection under topical anesthesia.

Animals studied and procedures: Retrospective analysis of dogs with clinically diagnosed calcific degeneration treated by keratectomy under topical anesthesia between 2015 and 2021 at two veterinary ophthalmology practices was performed. Descriptive data regarding signalment, concurrent systemic and ocular disease, complications, healing time, and recurrence were collected. Kaplan-Meier survival analysis was performed to calculate 1-year recurrence probability.

Results: Sixty-five eyes in 57 dogs met inclusion criteria. All 54 eyes with follow-up healed within a median of 14 days (7-74), including 17 with complicating factors of infection or deep stromal ulceration. Globe rupture occurred intraoperatively in three eyes (4.6%), for which subsequent conjunctival graft was performed. Calculated 1-year recurrence probability from 47 eyes followed long term was 25%. Multivariate Cox proportional hazard modeling showed a significant association between documented systemic disease and time to recurrence (p = .035), irrespective of topical EDTA use (p = .432). Median follow-up time available for all cases was 249 days.

Conclusions: Blunt lamellar dissection with corneal scissors can be performed in dogs under topical anesthesia, yielding healing times and recurrence comparable to previously reported treatments for calcific corneal degeneration. Globe rupture is an inherent risk of both the disease and procedure and occurred in 4.6% of treated eyes. This approach expands non-anesthetic treatment options for affected patients but should only be performed with advanced microsurgical training and client counseling on individual risk and benefit.

Objective: To determine if the area of the canine optic nerve head (ONH) is related to the peripapillary retinal nerve fiber layer (RNFL) thickness.

Animals studied: A total of 44 eyes of 22 adult normal laboratory Beagles.

Procedures: In this retrospective study, confocal scanning laser ophthalmoscopy (cSLO) and spectral domain optical coherence tomography (SD-OCT) images were evaluated. The sum of eight RNFL thickness measurements along the 12° circular OCT b-scan around the ONH was used to represent the total number of retinal ganglion cell (RGC) axons. The area of the ONH was measured by tracing the outer edges of the ONH in the cSLO images and adjusted for axial globe length. Descriptive and Pearson correlation statistics were used to describe the distribution of the ONH sizes and the relationship between total RNFL thickness and ONH area.

Results: The ONH area distribution for all eyes combined was approximately symmetric with an overall mean (± standard deviation) of 129 ± 35 degrees². The ONH areas between right and left eyes showed a strong, significant linear correlation (r = 0.83, p = 0.00). The mean sum of the eight RNFL thicknesses measured along the 12° circular OCT b-scan around the ONH was 448 ± 50 μm. There was a moderate, significant positive linear correlation between peripapillary RNFL thickness and ONH area (r = 0.43, p = 0.004).

Conclusions: In laboratory Beagles, the ONH area is partly affected by the peripapillary RNFL thickness, representing the total RGC axon number forming the optic nerve.

Objective: Chromatic (colorimetric) pupillary light reflexes (cPLR) are reportedly useful in canine neuro-ophthalmology to differentiate sudden acquired retinal degeneration syndrome (SARDS) from optic pathway disease (neurological disorders) causing acute blindness. We report two canine cases with cPLR test results reported to be consistent with primary retinal disease that were subsequently diagnosed with optic pathway (CNS) disease.

Animals studied: A 7-year-old Dachshund and a 7-year-old Weimaraner were presented for acute blindness.

Procedures and results: Both dogs failed obstacle tests, showed absent menace responses, bilateral mydriasis, and absent PLRs with white light in both eyes. The cPLRs were tested using a BPI-50 Precision Illuminator (Retinographics Inc., USA). Both dogs exhibited no PLR with red light (660 nm), and brisk though incomplete pupillary constriction with blue light (465 nm) at 200 kcd/m². Electroretinograms (ERG) of both eyes were normal in both dogs. Magnetic resonance imaging (MRI) of the brain revealed a left-sided cystic extra-axial mass (suspected meningioma) in the rostral cranial fossa in the Dachshund and a lesion affecting the rostral bones of the skull base and optic nerves in the Weimaraner (confirmed lymphoma).

Conclusions: These are the first two reported canine cases with acute, bilateral amaurosis due to optic pathway disease with present blue light-cPLR.

Objective: Determine if feeding two teaspoons per ten pounds of body weight per day of Saco powdered buttermilk (SPB) for 8 weeks affects salivary pH (SpH), magnesium (Mg), phosphorus (Phos), calcium (Ca), or total protein (TP) in dogs.

Animals: Eighteen dogs were enrolled following owner consent. Dogs with severe dental disease or that had been administered antibiotics in the past 3 months were excluded.

Procedures: Fasted saliva samples were collected using Salivette tubes within the same hour on Days 0, 1, 30, 31, 60, 61, 90, and 91. pH was measured immediately upon collection, samples were then mailed for laboratory analysis. SPB was administered at a dose of two teaspoons per ten pounds of body weight per day on Days 1-60. Baseline complete blood counts and serum chemistries were run before saliva collection on Day 1.

Results: Sixteen dogs completed the study. Side effects included flatulence (2) and loose stool (1). Salivette cotton swab ingestion occurred twice prior to change in method of securing swab during collection. Weight remained stable. There was no significant change in SpH, TP, Ca, or Phos during the study. There was a statistically significant, linear increase in Mg (p = 0.0065).

Conclusions: Feeding two teaspoons per ten pounds of body weight per day for 8 weeks did not significantly affect salivary pH, total protein, calcium, or phosphorus. There was a small linear increase in salivary magnesium concentration over the study period that did not return to baseline within 30 days of discontinuation of buttermilk supplementation, significance of which is unknown.

Objective: To describe calvarial hyperostosis syndrome (CHS) as a potential and unusual cause of exophthalmos or epiphora in young dogs.

Animals studied: A nine-month-old female intact (case 1) and a two-year-old male intact Labrador Retriever (case 2).

Procedures: Patient history, including previous treatments, was documented. Both cases underwent physical and ophthalmological examinations, computed Tomography (CT), and histopathological analysis. Additional dacryocystorhinography (DCR) was performed in case 2.

Results: Lateral exophthalmos of the left eye was the primary clinical sign in case 1. In case 2, serous lacrimal discharge was observed without other signs of ocular irritation. A slightly thickened and firm area distal to the medial canthus of the right eye was also noted. In this case, Jones 1 test on the right side was negative, whereas Jones test 2 revealed increased resistance when flushing the nasolacrimal system. CT imaging in both cases identified solid, smoothly marginated new bone formation. In case 1, this involved the left frontal bone, occipital bone, parietal bone, and temporal bone. In case 2, the new bone formation affected the right lacrimal bone and frontal process of the maxillary bone, leading to encasement and narrowing of the nasolacrimal duct (NLD). Histopathological analysis revealed active bone remodeling with osteoblasts in case 1, while case 2 demonstrated regularly differentiated trabecular lamellar bone with intertrabecular spaces. No evidence of neoplasia or osteomyelitis was observed in either case. Taken together, these findings strongly support a diagnosis of CHS in both cases.

Conclusions: CHS involving flat bones can present as exophthalmos or epiphora and should be considered in the differential diagnoses of these conditions, particularly in young dogs.

Objective: To measure the eyelid margin thickness (LMT) in dogs with meibomian gland dysfunction (MGD) and evaluate its correlation with meibomian gland (MG) morphology.

Animals studied: Fifty-nine client-owned dogs.

Procedure: The LMT was measured on slit lamp biomicroscopy images and divided into groups of 1 to 4, from the thinnest to thickest, based on quartiles. MG morphology, including distortion, thickening, shortening, and dropout, was evaluated using noninvasive infrared meibography. The LMT and meibography results were compared between the MGD and normal groups. Statistical analysis was performed to determine the correlation between LMT and MG morphology.

Results: The mean LMT was significantly greater in the MGD group (1.18 ± 0.19 mm) than the normal group (1.00 ± 0.13 mm) and was positively correlated with MG loss (p < 0.01). The LMT was thicker in dogs over 12 years (1.25 ± 0.20 mm). The LMT group 4 (≥ 1.26 mm) had the highest percentage of abnormal MG (95.7%) and MG loss area (37%). The total abnormal MG ratio and thickened MG ratio were significantly higher in the LMT group 4. LMT ≥ 1.20 mm was identified as a potential indicator for MG loss area of more than one-third.

Conclusions: Eyelids with thick LMT had more abnormal MG morphology, including thickening and dropout. An LMT ≥ 1.20 mm could be a criterion to suspect MGD. Thus, the LMT could be a simple screening tool to predict MG loss and might aid in the diagnosis and early management of MGD with a sensitivity of 0.645 and a specificity of 0.768.

Objective: To evaluate the evolution of corneal sensitivity in healthy beagle puppies during the first weeks of life, compare these results with adult corneal sensitivity, and determine the age at which adult corneal sensitivity levels are reached.

Animals studied: Twelve puppies and five adult females.

Procedures: Corneal sensitivity was assessed in puppies weekly from 2 to 7 weeks of age and in their mothers by measuring the corneal touch threshold (CTT) in the central cornea using a Cochet-Bonnet esthesiometer. Hygrometric and temperature measurements were recorded throughout the study period.

Results: In puppies, esthesiometry indicated a progressive decrease in corneal sensitivity with age. Sensitivity was higher between 2 and 4 weeks, which stabilized between 5 and 7 weeks, with a median CTT values of 0.5, 0.5, 0.8, 1.4, 1.2, and 1.4 g/mm² at 2, 3, 4, 5, 6, and 7 weeks, respectively. The median CTT in puppies reached the adult median value (1.4 g/mm²) at 5 weeks. The median CTT at 2 weeks was significantly different from the median CTT at 7 weeks (0.5 vs. 1.4 g/mm²). Humidity and temperature were not significantly associated with corneal sensitivity in adults.

Conclusions: In this study, corneal sensitivity in beagle puppies was higher during the first 3 weeks of life compared to 7 weeks. During this early period, puppies exhibited corneal sensitivity levels exceeding those of adults, which subsequently decreased to adult-equivalent values between 5 and 7 weeks of age.

Objective: To investigate the level of pro-inflammatory cytokines in aqueous humor from ADAMTS10-mutant research Beagles at an early stage of open-angle glaucoma (OAG).

Animals studied: Twenty-four research Beagles were enrolled into this case-controlled study. Three groups of ADAMTS10-mutant research Beagles were enrolled in this study: (1) Intraocular pressure (IOP) 15-25 mmHg (normotensive IOP), (2) IOP 25-30 mmHg, and (3) IOP 30-36 mmHg. An unaffected control group of Beagles that were either ADAMTS10-wildtype (WT) or heterozygote-carrier with normotensive IOPs were also enrolled.

Procedures: Aqueous humor samples were collected and analyzed for 16 pro-inflammatory cytokines using the Canine Cytokine SpikeMix and target mass spectrometry via multiple reaction monitoring (MRM-MS). Statistical differences between the four groups' pro-inflammatory cytokines, as well as correlations between pro-inflammatory cytokines and IOPs, were analyzed using Kruskal-Wallis tests and Spearman's rho (ρ) correlations, respectively.

Results: IOP 15-25 mmHg (n = 8); IOP 25-30 mmHg (n = 6); IOP 30-36 mmHg (n = 5); and Control (WT n = 3, carrier n = 2, total n = 5). There were no differences between pro-inflammatory cytokines across the four groups (all p-values > 0.05). IL-13 had a moderate positive correlation with IOP, but was non-significant (ρ = 0.373, p = 0.073); IL-1β had a moderate negative correlation with IOP but was also non-significant (ρ = -0.344, p = 0.100). All other pro-inflammatory cytokines had only mild correlation with IOPs (|ρ| < 0.229, p > 0.05).

Conclusions: There were no significant changes in the investigated pro-inflammatory cytokines with elevated IOP in canine ADAMTS10-OAG.

Objective: To evaluate the effect of intravenous mannitol and hypertonic saline (HS) on intraocular pressure (IOP) and biometry parameters of horses with elevated intracranial pressure (ICP).

Procedures: Seven horses with normal ophthalmic exams were anesthetized and placed in lateral recumbency. A subarachnoid transducer was placed, and the head was lowered until ICP measured 40 mmHg +/- 2 mmHg. Five intravenous boluses of mannitol 20% (0.4 g/kg) or HS 7.2% (1 mL/kg) were administered, each 15 min apart. A 2-day washout period ensued, and the procedure was repeated with the other hyperosmotic agent. IOP via a TonoVet, axial length and vitreous chamber depth via biometry, and ICP via the subarachnoid transducer were monitored.

Results: No significant correlation between ICP and IOP was identified. Estimated marginal mean (EMM) reduction in IOP (comparing values 5 min post bolus to values at bolus administration) following mannitol and HS was 2.4 mmHg and 0.4 mmHg, respectively. Mean axial length EMM decreased by and increased by 0.1 mm following mannitol and HS, respectively. Mean vitreous chamber depth EMM was unchanged and increased by 0.1 mm following mannitol and HS, respectively. The EMM of the second HS bolus demonstrated an increase of 0.8 mm (95% confidence interval 0.01-1.5 mm) in axial length (p < 0.048), though the remaining individual bolus assessments were not statistically significant.

Conclusions: Intravenous mannitol and HS did not cause a significant change in IOP, axial length, or vitreous chamber depth in healthy, anesthetized, laterally recumbent horses in this experimental model of increased ICP.