Search Results - "Veterinary Ophthalmology Vol. 26, No. 2 ( 2023-03)"

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 155-160

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.

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1463-5216, 1463-5224

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Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 108-120

The aim of this study was to describe the placement of subpalpebral lavage (SPL) systems in 12 dogs (15 eyes) intolerant of topical ocular medications to assess the suitability, complications encountered and owner perception of use. Animals Studied Retrospective review of dogs that underwent SPL placement for treatment of ocular disease at the Ophthalmology Department, University of Bristol Small Animal Hospital between 2017 and 2021. Procedure(s) Data recorded included signalment, history, diagnosis, treatment, reason for SPL placement, uni‐ or bilateral placement, duration of placement, complications, and outcome. Owner perception was assessed using an online questionnaire. Statistical analysis included McNemar and Wilcoxon signed‐ranks tests. Results Twelve dogs (15 eyes) underwent SPL placement. Eleven owners completed the online questionnaire. Corneal ulceration was the most common disease requiring SPL placement ( n  = 13/15 eyes, 86.7%). Most cases received multimodal topical therapy ( n  = 9/15 eyes, 60.0%) via SPL. Owners administered medication 6.63 times daily via SPL (range 1–16 applications/day). All dogs requiring ongoing topical medication ( n  = 8/12, 66.7%) were trained to accept direct administration during SPL treatment. Statistically significant improvements in medication compliance, ease of application, and reduced perceived risk of iatrogenic ocular injury were reported by owners ( p ‐value = .001, .004, and .031 respectively). Minor complications were infrequently reported but an excellent outcome was achieved for all eyes. Conclusion Subpalpebral lavage placement provides a practical and safe solution for the provision of frequent multimodal ocular medication when treating patients with a challenging temperament.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03)

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 86-100

Equine recurrent uveitis (ERU) is an ocular inflammatory disease that can be difficult to manage clinically. As such, it is the leading cause of bilateral blindness for horses. ERU is suspected to have a complex autoimmune etiology with both environmental and genetic risk factors contributing to onset and disease progression in some or all cases. Work in recent years has aimed at unraveling the primary triggers, such as infectious agents and inherited breed‐specific risk factors, for disease onset, persistence, and progression. This review has aimed at encompassing those factors that have been associated, implicated, or substantiated as contributors to ERU, as well as identifying areas for which additional knowledge is needed to better understand risk for disease onset and progression. A greater understanding of the risk factors for ERU will enable earlier detection and better prognosis through prevention and new therapeutics.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 121-127

To describe the surgical technique and clinical outcomes of the glabellar flap and its modification for the reconstruction of the medial canthus following resection of tumors in three dogs and two cats. Methods Three dogs (7‐, 7‐, and 12.5‐year‐old mixed breeds) and two cats (10‐ and 14‐year‐old Domestic shorthair) presented with a 7–13 mm tumor affecting the eyelid and/or conjunctiva in the medial canthal region. Following en bloc mass excision, an inverted V‐shaped skin incision was made in the glabellar region (i.e., the area between the eyebrows in humans). The apex of the inverted V‐shaped flap was rotated in three cases, whereas a horizontal sliding movement was performed in the other two cases to better cover the surgical wound. The surgical flap was then trimmed to fit the surgical wound and sutured in place in two layers (subcutaneous and cutaneous). Results Tumors were diagnosed as mast cell tumors ( n  = 3), amelanotic conjunctival melanoma ( n  = 1), and apocrine ductal adenoma ( n  = 1). No recurrence was noted in a follow‐up time of 146 ± 84 days. Satisfactory cosmetic outcome with normal eyelids closure was achieved in all cases. Mild trichiasis was present in all patients and mild epiphora was noted in 2/5 patients, but there were no associated clinical signs such as discomfort or keratitis. Conclusions The glabellar flap was easy to perform and provided a good outcome in terms of cosmetic, eyelid function, and corneal health. Postoperative complications from trichiasis appear to be minimized by the presence of the third eyelid in this region.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 169-175

To describe blindness, initially presenting as a unilateral condition and diagnosed as sudden acquired retinal degeneration syndrome (SARDS). Animals Studied One Dachshund and four Maltese dogs presented with unilateral blindness, for which the results of general ophthalmic examinations were insufficient to explain the blindness. All dogs were spayed females. Results Intraocular pressures were normal, and the optical media of the eyes were clear. Fundus appearances of the initially blind eyes were within normal variations, with slightly attenuated retinal blood vessels in some cases when compared with the sighted contralateral eyes. Electroretinography (ERG) amplitudes of the affected eyes were flat and reduced in the contralateral‐sighted eyes in four dogs. One dog underwent ERG after the blindness progressed bilaterally 8 days after initial presentation (despite topical steroid medication). Two dogs had no recheck visits, but phone call follow‐ups reported bilateral blindness 3 months later in one dog. One dog received no medication and retained vision in the contralateral eye until the last follow‐up (94 days later). One dog received systemic cyclosporine and steroid medications and maintained vision in the contralateral eye; however, regular ERG rechecks showed a trend of declining amplitude (448 days). In this dog, optical coherence tomography (OCT) showed different stages of disorganized retinal layers as well as different retinal thickness between the eyes. Conclusions Despite normal‐looking fundi, ERG and OCT revealed different degrees of retinal changes between both eyes in this study. Eyes with vision might develop progressive blindness after a substantial amount of time in these presumed SARDS cases.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 176-179

An 8‐year‐old female pre‐metamorphic axolotl ( Ambystoma mexicanum ) was examined for a suspected anterior lens luxation. Slit‐lamp biomicroscopy revealed two lens‐like structures in the anterior chamber of the right eye (OD), each with cataractous change. Ultrasound biomicroscopy and optical coherence tomography (OCT) were performed without sedation, and revealed small lenticular structures each with distinct nuclei and cortices. Although a distinct connection of the two lenticular structures could not be definitively ruled out, the structures appeared separate. Each of the lenticular structures was closely associated with its respective iris leaflet. This report demonstrates application of advanced imaging for diagnostic use in axolotl ophthalmology, showing that imaging of the lens can be performed without sedation, topical anesthetic, nor contact gel with high diagnostic quality. Although two distinct lenses were diagnosed with no historical evidence of trauma, the small sizes of each lenticular structure, with no detectable connection between them, are suggestive of a possible regenerative abnormality. This report opens discussion for the regenerative capabilities of the pre‐metamorphic adult axolotl and possible implementations of their use in regenerative medicine research for the development of future therapies.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 101-107

To determine the prevalence of ocular disease in draft horses in the United States. Animals Draft horses of various breeds and ages. Procedure Nondilated ophthalmic examination was performed using slit lamp biomicroscopy and indirect ophthalmoscopy. Intraocular pressures were measured when possible. Results One hundred sixty‐five draft horses were examined. Age range: 10 days to 33 years (mean 10.8 years, median 10 years); 87 geldings (52.7%), 71 mares (43.0%), 7 stallions (4.2%); 64 Percherons (38.8%), 51 Belgians (30.9%), 29 Clydesdales (17.6%), 15 Shires (9%), and 6 other draft breed (3.6%). Intraocular pressure: mean 24.7 mmHg OD, range 13‐37 mmHg; mean 25.0 mmHg OS, range 11‐37 mmHg. Vision‐threatening disease was present in 9 horses (5.5%): complete cataracts 1, post‐traumatic optic nerve atrophy 1, uveitis and secondary glaucoma 1, retinal detachment 1, large chorioretinal scar 3, phthisis bulbi 2. Non‐vision‐threatening ocular disease was present in 56 horses (33.9%) involving one or more ocular structures: eyelid trauma/notch defect 14 (8.5%), SCC‐type adnexal lesions 12 (7.3%), corneal scars 16 (9.7%), keratitis 6 (3.6%), corpora nigra cyst 15 (9.1%), incipient/punctate cataract 50 (30.3%), vitreous degeneration 10 (6.1%), asteroid hyalosis 1, “bullethole” chorioretinal scars 3, RPE coloboma 1. Linear keratopathy was present in 28 horses (17%) with 2/28 having concurrent vision threatening ocular disease. Conclusions Ocular abnormalities, in particular minor cataracts, were relatively common in this population, but not typically vision‐threatening. Additionally, this survey demonstrated a greater prevalence of linear keratopathy in draft horses compared with reports in other breeds; however, it does not appear to be associated with concurrent ocular disease.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

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Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 161-168

This case report describes the successful correction of partial obstruction of the NL duct in a cat by means of a modified retrograde NL duct cannulation using a steerable angle‐tipped hydrophilic guidewire (AH guidewire) following a paranasal incision. Animal Studied A 2‐year‐old neutered male American domestic shorthair cat was referred to the Purdue University Veterinary Hospital (PUVH) for chronic epiphora suspected secondary to nasolacrimal (NL) system obstruction. Procedures At the first visit, the cat had epiphora OD and facial dermatitis but no other abnormalities on physical and ophthalmic examinations. Computed tomography (CT)‐dacryocystorhinography revealed partial obstruction of the NL duct secondary to stenosis near the distal root of the right maxillary third premolar (107). A digital three‐dimensional (3D) model of the right maxilla and NL duct was created for inspection and virtual cannulation of the NL. The model was 3D printed and cannulation of the NL duct was rehearsed with various stent materials. Retrograde NL stenting with the guidance of a steerable angle‐tipped hydrophilic guidewire was conducted following a paranasal incision. A urethral catheter was cannulated over the guidewire and maintained for 44 days. Results The epiphora resolved immediately after stenting. At 21 days post‐stenting, the cat developed acute bullous keratopathy secondary to self‐trauma which was treated with a third eyelid flap. On the final follow‐up communication with the owner at 210 days post‐stenting, no epiphora or any other concerns were reported. Conclusion To the authors' knowledge, this is the first report of successful NL stenting and resolution of epiphora in a cat with a partial NL system obstruction.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 83-85

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

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Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 145-154

Electroretinography (ERG) is used prior to cataract removal surgery to assess retinal function. We aimed to replicate and improve upon previous studies by performing a full ECVO protocol and by examining the retina post‐surgery in all patients. Animals studied One hundred twenty‐seven eyes from 67 dogs were included in the study. Procedures A full ECVO protocol electroretinography, which includes extensive rod and cone analysis, was performed on all dogs presenting for cataract surgery. Results Our main findings were that amplitudes, but not implicit times of rod responses decreased with advanced cataracts. Amplitudes of the single flash rod and rod flicker responses were significantly lower in eyes with mature cataracts, and the former also decreased in hypermature cataracts. Cone flicker amplitude responses were also significantly lower in eyes with mature and hypermature cataracts. However, mixed single flash rod‐cone and cone responses, with the exception of the mixed rod‐cone a‐wave amplitude in eyes with hypermature cataracts, were unaffected by cataract stage. The b‐wave amplitude of the scotopic, mixed rod‐cone, and photopic cone responses were affected by age and decreased by an average of 2.9, 7.5, and 1.5 μV/year, retrospectively ( p   〈  0.01). Conclusions Lower ERG amplitudes in canine cataract patients may result from aging or the presence of advanced cataracts and may not indicate the presence of retinal disease.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 128-134

The aims of this study were to compare the central corneal thickness (CCT) measured by an ultrasonic pachymeter (SP‐100, Tomey, Japão) versus the Galilei G6™ (Ziemer Ophthalmics System AG, Port, Switzerland) and to compare the simulated keratometry (SimK) measured by an autokeratometer (KM 500 Nidek) versus the Galilei G6™. Animal studied Eighteen mixed‐breed cats, 10 males, and eight females, aged between 18 and 48 months, were evaluated ( n  = 36 eyes). Procedure(S) The cats were manually restrained using a blanket. The operator held the autokeratometer close to the eye and measured the SimK. Next, one anesthetic eye drop was applied; the operator lightly touched the corneal using the ultrasound pachymeter and measured the CCT. At another moment, the cats were sedated using meperidine and xylazine and then evaluated using the Galilei. Student's t ‐test was employed to perform the statistical analyzes. Results Considering the CCT, the ultrasound pachymeter provided mean ± SD of 623.03 ± 48.17 μm and the Galilei 617.34 ± 53.38 μm. The autokeratometer produced a SimK of 38.20 ± 0.84D (8.84 ± 0.20 mm) and the Galilei 38.37 ± 0.83D (8.80 ± 0.19 mm). The CCT and SimK did not differ statistically regardless of the device used. Conclusion To the best of the authors' knowledge, this is the first work to compare the CCT measured by the Galilei versus the ultrasonic pachymeter and to compare the SimK measured by the Galilei versus the keratometer in cats. No statistical difference was found considering the CCT and the SimK measured by the different devices.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22

Veterinary Ophthalmology, Wiley, Vol. 26, No. 2 ( 2023-03), p. 135-144

There is limited knowledge regarding the safety and accuracy of ultrasound‐guided retrobulbar nerve blocks in horses. The aim of this study was to compare these parameters between blind and ultrasound‐guided injection techniques for the dorsal retrobulbar nerve block in horses. Methods Equine cadaver heads were used to inject the retrobulbar space with contrast medium (CM). Injections were performed either blindly based on anatomic landmarks (blind group, n  = 44) or under ultrasonographic guidance (US‐group, n  = 44), equally divided between an experienced and unexperienced operator. Needle position and distribution of CM were assessed with computed tomography imaging and evaluated by a board‐certified veterinary diagnostic imager blinded to the technique. Safety and accuracy of both techniques were compared. Results Ocular penetration was observed in two cases ( n  = 2/44) in the blind group but not in the US group ( n  = 0/44). No intrathecal, intraneural, or intravascular injections were seen in either group. Safety was significantly improved in the US group ( p  = .026). There was no statistically significant difference between the groups regarding the accuracy of the injection. Excellent accuracy was achieved more often with the ultrasound‐guided technique ( n  = 11/22) than with the blind technique ( n  = 7/22) when performed by the unexperienced operator, but this difference was not statistically significant. Conclusion To prevent globe‐threatening complications and improve the safety of the injection, we recommend using the ultrasound‐guided injection technique for the dorsal retrobulbar nerve block.

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1463-5216, 1463-5224

English

Wiley

2023

2011043-1

22