Ophthalmology

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Below, please find links to all of the clinical trials involving ophthalmology. The studies include a multitude of information, including (but not limited to) the study’s purpose, benefits for participating, and financial incentive information. If you have any questions, please contact the individual outlined at the end of each trial summary.

Please visit the Ophthalmology service webpage at the Veterinary Medical Teaching Hospital (VMTH) if you would like to learn more about the amazing things that our veterinarians can do for you and your animal.

Horses & Ponies

Equine Recurrent Uveitis: Understanding the Genetics in Horses

Title: Genomic investigation of Equine Recurrent Uveitis in Multiple Horse Breeds

Purpose: Equine recurrent uveitis (ERU) is the leading cause of blindness in horses, marked by repeated episodes of inflammation of the uveal tract of the eye. Appaloosa horses, known best for their white coat spotting patterns (termed leopard complex or LP), are eight times more likely than any other breed to develop this disease and four times more likely to go blind, suggesting genetics plays a major contributing role. However, little is known about the specific genetic factors involved. The objective of this study is to determine the genetic factors contributing to ERU in multiple horse breeds.

Contact: Drs. Mary Lassaline (lasutter@ucdavis.edu or 530-752-0290) or Rebecca Bellone (rbellone@ucdavis.edu or 530-752-9299) 

Participation Requirements: Horses with known pedigrees

Initial Evaluation for Participation: None.

Procedures: 

  • Examination of the horse’s eyes by a veterinary ophthalmologist
  • Photography of the horse to document coat color and any abnormalities found in the eyes
  • Collection of hair samples from the horse’s mane and/or a blood sample to analyze the DNA
  • Discussion of the horse’s medical history
  • Follow up phone calls or emails may be necessary if any questions about the horse’s medical history arise after the examination.
  • If any horse objects to having their eyes examined, to having mane hair pulled, or blood drawn, these procedures would not be performed.

Benefits: The results of this work may help to lower the incidence of this ocular disease in Appaloosas and other affected breeds, help breeders to make informed mating decisions, and be utilized by veterinarians to predict risk of developing disease for earlier diagnosis and treatment.

Owner Responsibilities: We expect that participation in this clinical trial will last for about 15 minutes but may take as long as one hour. If you allow your horse to participate in this study, you will be responsible for covering any injury sustained while participating and further diagnostics or therapy associated with the diagnosis of ERU if a presumptive diagnosis of ERU is made for your horse.

Printable Flyer (PDF)

Bilateral Corneal Stromal Loss: Understanding the Genetics in Friesian Horses

Title: Genetic investigation of bilateral corneal stromal loss in Friesian horses

Purpose: Bilateral corneal stromal loss (BCSL) is a potentially progressive ocular disease that can be associated with pain, vision loss and even loss of the eye. The objective of this study is to determine the role genetics plays in BCSL in Friesian horses. This study is designed to determine the incidence of BCSL in the breed, to determine the mode of inheritance if a single gene is involved, and identify candidate genes for further investigation.

Contact: Drs. Mary Lassaline (lasutter@ucdavis.edu or 530-752-0290) or Rebecca Bellone (rbellone@ucdavis.edu or 530-752-9299) 

Participation Requirements: Friesian horses with and without a diagnosis of bilateral corneal stromal loss (BCSL)

Initial Evaluation for Participation: Any Friesian horse is invited to participate. Please contact Drs. Mary Lassaline (lasutter@ucdavis.edu or 530-752-0290) or Rebecca Bellone (rbellone@ucdavis.edu or 530-752-9299) for more information.

Procedures: 

  • Participation in this study would involve up to one hour of time per horse included in the study. This time may involve examination of the horse’s eyes by a veterinary ophthalmologist, photography of the horse to document coat color and any abnormalities found in the eyes, collection of hair samples from the horse’s mane, and discussion of the horse’s medical history.
  • For some horses, hair samples may be collected from the mane to examine DNA for genes that may be involved in the development of BCSL.
  • If any horse objects to having their eyes examined, or to having mane hair pulled, these procedures would not be performed.

Benefits: All costs associated with the study will be paid by the sponsor/department. However, if a presumptive diagnosis of BCSL is made for your horse, any further diagnostics or therapy associated with the diagnosis of BCSL will be your responsibility. Copies of any biopsy reports from horses that have been affected with BCSL may be requested.

We cannot promise any benefits to your horse or other animals from your taking part in this clinical trial; however, possible benefits include lowering the incidence of this ocular disease in Friesians and other affected breeds, helping breeders to make informed mating decisions, and better prediction of the risk of developing disease for earlier diagnosis and treatment.

Owner Responsibilities: If you allow your horse to participate in this study, you will not be responsible for anything other than allowing us access to examine your horse and pull hairs from the mane.

Printable Flyer (PDF)

Ocular Squamous Cell Carcinoma: Understanding the Genetics in Horses

Title: Genetic Investigation of Ocular Squamous Cell Carcinoma in Horses

Purpose: Squamous cell carcinoma (SCC) is one of the most common forms of cancer to affect the eye in horses, frequently occurring at the limbus, where the clear cornea meets the white of the eye, or on the nictitating membrane, also known as the third eyelid.  This type of eye cancer affects some breeds more than others (e.g., Haflingers) so the objective of this study is to determine the role genetics plays in ocular squamous cell carcinoma in multiple breeds.  This study is designed to determine the incidence of SCC, to determine the modes of inheritance and identify DNA variants that put horses at risk for this cancer. 

Contact: Drs. Mary Lassaline (lasutter@ucdavis.edu or 530-752-0290), Rebecca Bellone (rbellone@ucdavis.edu or 530-752-9299), or Kelly Knickelbein (kknickelbein@ucdavis.edu or 530-718-8359)

Participation Requirements: Horses with confirmed ocular SCC (confirmed by pathology), or horses that have not been diagnosed with ocular SCC that are at least 13 years old.  Horses that are suspicious for ocular SCC are invited to participate, but confirmation would be required prior to inclusion in the study.

Initial Evaluation for Participation: Any horse with confirmed ocular SCC does not need to be evaluated in person to participate.  Participation for horses with confirmed ocular SCC involves providing (1) a copy of a pathology report confirming ocular SCC, (2) the horse’s registered name for pedigree analysis, and (3) a blood or hair sample.  Horses that have not had ocular SCC and are at least 13 years old will need to be examined by a boarded veterinary ophthalmologist to confirm that they do not have ocular SCC.  This may be done at UC-Davis VMTH or elsewhere.  

Procedures:

  • Participation in this clinical trial, which could last between 15 minutes to one hour, will include discussion of the horse’s medical history, documentation on known pedigree information, examination of the horse’s eyes by a veterinary ophthalmologist, photography of the horse to document coat color and any abnormalities found in the eyes, and collection of hair samples from the horse’s mane. 
  • Examination of a horse’s eyes is similar to examination of a person’s eyes, with lights and magnifying lenses shone into the eyes to see if they are normal, or if any signs suspicious for ocular SCC are present. 
  • For some horses, a blood sample may be collected from the jugular vein, and hair samples may be collected from the mane. This is similar to pulling the mane for show but only pulling a very small sample of about 50 hairs. This blood and hair would be used to isolate DNA for genetic studies to help understand which genes may be involved in the development of ocular SCC. 
  • Follow up phone calls or emails may be necessary if any questions about the horse’s medical history arise after the examination. 
  • If any horse objects to having their eyes examined or to having blood taken or mane hair pulled, these procedures would not be performed.

Benefits: If you are selected to participate in the study, the study will cover the costs associated with eye examination, blood collection, and mane pulling; however, if a presumptive diagnosis of SCC is made for your horse, any further diagnostics or therapy associated with the diagnosis of SCC will be your responsibility.

We cannot promise any benefits to your horse or other animals from your taking part in this clinical trial; however, possible benefits include lowering the incidence of this common eye cancer, helping breeders to make informed mating decisions, and better prediction of the risk of developing disease for earlier diagnosis and treatment.  

Owner Responsibilities: Financially, you will be responsible for covering any costs associated with injuries sustained while participating in this trial and any costs associated with follow up of your animal at VMTH for assessment.

Printable Flyer (PDF)

News Article
NOW AVAILABLE! Ocular Squamous Cell Carcinoma Genetic Test

Dogs

NEW! Retinal Degeneration: Understanding the Disease in Greyhounds

Title: Investigation of the progression, mechanics and genomics of Retinal Degeneration in Greyhound Dogs

Purpose of Study: This trial is being conducted to better characterize retinal degeneration syndrome in greyhounds with hopes of identifying the genetic components of this disease.

Contact: Dr. Sara Thomasy at smthomasy@ucdavis.edu or 530-752-6967

Participation Requirements: Greyhounds diagnosed with retinal degeneration

Initial Evaluation for Participation: None.

Procedures: If your dog is determined to be eligible and you choose to enroll him/her, then the following will be performed (some of the imaging may be performed under sedation if needed):

  • A routine opthalmic examination
    • Dilation of the eyes to examine the backs of the eyes Staining of the eye withfluorescin to look for corneal ulcers
  • Advanced diagnostic ocular imaging including spectral domain optical coherence tomography (non-contact imaging) and fundus photography
  • Blood collection for DNA analysis
  • Electroretinogram (ERG) to measure retinal function

Benefits: The study will cover all costs associated with the study and may pay up to $200 for medical treatment of adverse events incurred because of participation in this trial.

Your pet will benefit from the thorough ocular examination included in this trial. Results from this study will hopefully help us identify a gene associated with this disease in greyhounds.

Owner Responsibilities: If you choose to enroll your dog in the trial, you will be responsible for Comitting to at least one appointment, fasting your dog for procedures that may require sedation, keeping all scheduled appointments, monitoring the well-being of your dog at home, and reporting any changes or side effects.

Printable Flyer (PDF)

Corneal Endothelial Dystrophy: Evaluating a New Surgical Technique and Drug Combination

Title: A new surgery, Descemetorhexis Without Endothelial Keratoplasty, and Topical Ripasudil for Corneal Endothelial Dystrophy in Dogs

Purpose of Study: Corneal endothelial dystrophy (CED) is a devastating disease that causes blindness and discomfort. The purpose of this study is to evaluate the efficacy of a new surgical technique – Descemetorhexis Without Endothelial Keratoplasty (DWEK) – in combination with a new regenerative drug (ripasudil) to treat corneal endothelial dystrophy in dogs.

Contact: Monica Motta at mjmotta@ucdavis.edu or 530-752-6967

Participation Requirements: 

  • Dogs diagnosed with acute corneal endothelial dystrophy with focal edema
  • Ineligible: Dogs with severe cardiopulmonary or neurologic disease

Initial Evaluation for Participation: Prior to enrollment, a complete physical examination will be performed. A complete ophthalmic examination will be performed including a Schirmer Tear Test (STT) to assess tear production, Ultrasound pachymetry (USP) to measure corneal thickness and tonometry to measure intraocular pressure. Dogs may be sedated for the imaging procedures. Imaging parameters to follow sedation may be; external photography, digital slit lamp photography, Fourier-domain optical coherence tomography (FD-OCT), and in vivo confocal biomicroscopy (IVCM) scans of the anterior segment may be performed. Eyes will be dilated with topical tropicamide to examine the back of the eye, then the patient’s eyes will be stained with fluorescein to ensure no corneal ulcers developed following imaging and examination.

Procedures: If the exams, tests, and procedures show that your pet can take part in the study, and you choose to enroll them, then the following will be performed prior to and at 1, 3 and 6 weeks, and then 3, 6 and 12 months after surgery as part of the study:

  • A full ophthalmic examination including digital slit lamp photography, tear production measurement, eye pressure tests, eye dilation followed by ultrasonic pachymetry, fluorescein staining and digitally photography
  • Advanced ocular imaging while under sedation, including digital slit lamp biomicroscopy, spectral domain optical coherence tomography and confocal biomicroscopy
  • Blood collection and analysis
  • Corneal surgery in one eye while under anesthesia
  • Administration of topical ripasudil administration 4 times a day to both eyes for 1 year after surgery
  • Client questionnaires
  • Monitoring for any side effects for 6 months following discontinuation of ripasudil

Benefits: The study will cover the cost of the ophthalmic examination, ocular diagnostic testing, sedation, advanced ophthalmic imaging, blood collection, and medications, and offer to pay for medical treatment for injuries up to $1000 as long as the care is performed at UC Davis. In addition, you will receive a $1000 credit towards your dog’s pre-operative bloodwork, general anesthesia, corneal surgery, and hospitalization.

It is expected that this corneal surgery and the topical ripasudil will decrease the thickness of your dog’s cornea, improve vision and decrease the frequency of corneal ulcers that your dog has.

Owner Responsibilities: If you choose to enroll your dog in the trial, you will be responsible for:

  • Bringing your dog in for scheduled appointments
  • Covering costs of the diagnosis and anything beyond of the two above mentioned $1000 credits
  • Filling out questionnaires
  • Keeping a log book of when the medication was given
  • Giving multiple eye and oral medications several times a day for several weeks after surgery for 1 year
  • Monitoring the well-being of your dog at home and reporting any changes or side effects to us

You can choose to continue administering topical ripasudil after your dog completes the study but you will be responsible for the cost after the study ends.

Printable Flyer (PDF)

Primary Glaucoma: Understanding the Genetics in American Cocker Spaniels

Title: Proteomics and genomics of primary glaucoma in the dog

Purpose of Study: Glaucoma is a disease that is a common cause of blindness worldwide in human and canine patients. We are interested in characterizing this disease better with hopes of identifying protein biomarkers or the genetic components of this disease.

Contact: Monica Motta at mjmotta@ucdavis.edu or 530-752-6967

Participation Requirements: 

  • Healthy American Cocker Spaniels that are at least 10 years old with normal eyes
  • American Cocker Spaniels diagnosed with primary glaucoma

Initial Evaluation for Participation: None.

Procedures:

  • Limited Diagnostic Testing
    • A full ophthalmic examination
    • An eye pressure test prior to and after dilation
    • Dilation of the eyes to examine the back of the eyes
    • Corneal thickness measurements via ultrasonic pachymetry
    • Fluorescein staining to assess for corneal ulcers
    • Digital photographs of the eye
    • Gonioscopy to assess the drainage angles in the eye
    • Non-invasive A-Scan/B-Scan to determine the length of the ocular globe
    • Blood collection for genetic analysis
  • Advanced Diagnostic Imaging
    • If required, advanced ocular imaging, including digital slit lamp photography, spectral domain optical coherence tomography (non-contact imaging), ultrasound biomicroscopy and fundus photography to image the retina
    • Sedation may be required for some of the advanced diagnostic testing procedures.

Benefits: The study will cover cost associated with the ophthalmic examination, ocular diagnostic testing, sedation, advanced ophthalmic imaging and blood collection. In addition, the study will cover costs of any complications from the ophthalmic examination, diagnostic testing, gonioscopy, sedation, or blood sampling will be covered by the study up to $200.

Results from this study may lead to our improved ability to better predict the onset and progression of this disease. If a gene or effect through diagnostics that causes this disease is found, then we may be able to develop a genetic test or future diagnostic tests to know identify which dogs have or do not have this disease.

Owner Responsibilities: Although we expect to gain the majority of information from your dog in a single visit, we may want to do additional tests if your dog has a glaucomatous attack. We anticipate a maximum of 4 visits over a 2-year period for your dog. You will be responsible for filling out a questionnaire and survey regarding your dog’s history, monitoring the well-being of your dog at home and report any changes or side effects to us, and withhold food from your dog the morning prior to the appointment so that your dog can be sedated for advanced ocular examination. You will also be responsible for covering any costs (beyond $200) related to complications, diagnostic testing, gonioscopy, sedation or blood sampling.

Printable Flyer (PDF)

Article (HTML)

Sudden Acquired Retinal Degeneration Syndrome (SARDS): Understanding the Disease

Title: Proteomics and genomics of canine sudden acquired retinal degeneration syndrome

Purpose of Study: Sudden acquired retinal degeneration syndrome (SARDS) is a common cause of permanent blindness in dogs. Dogs usually present with rapid onset of blindness with no obvious abnormalities in the retina; however, the underlying cause for SARDS is unknown and no treatment exists. We are interested in characterizing this disease better with hopes of identifying protein biomarkers and/or the genetic components of this disease.

Contact: Monica Motta at mjmotta@ucdavis.edu or 530-752-6967

Participation Requirements:

  • Dogs diagnosed with Sudden Acquired Retinal Degeneration Syndrome (SARDS)
  • Dogs with healthy retinas

Initial Evaluation for Participation: None.

Procedures:

  • Routine ophthalmic examination
    • Dilation of the eyes to examine the back of the eyes
    • Staining of the eye with fluorescein to assess for corneal ulcers
  • Digital photography of the eye (fundus photography)
  • Blood collection for DNA analysis and serum storage
  • Electroretinogram (ERG) to measure retinal function

Benefits: Costs of any complications from the ophthalmic examination, diagnostic testing, ERG, sedation, or blood sampling will be covered by the study up to $200.

Results from this study will hopefully lead to a better ability to predict the onset and progression of this disease. If a gene that causes this disease is found, then we may be able to develop a genetic test to know which dogs have or do not have this disease.

Owner Responsibilities: You will be responsible for the cost of the ophthalmic exam and all diagnostic tests performed.

For most dogs, we expect that participation in this clinical trial will last for one visit for the ophthalmic exam, diagnostic testing and blood collection. However, we may ask you to come back for repeated blood sampling. We will also ask you to fill out a questionnaire regarding your dog’s history.

Printable Flyer (PDF)

Corneal Endothelial Dystrophy: Understanding the Disease in Boston Terriers, German Shorthaired Pointers, and German Wirehaired Pointers

Title: Phenotype and Genotype of Corneal Endothelial Dystrophy in Boston Terriers, German Shorthaired Pointers, and German Wirehaired Pointers

Purpose of Study: Corneal endothelial dystrophy (CED) is a devastating disease in dogs that can result in blindness and severe ocular pain from secondary complications. The endothelial cells comprise the most inner aspect of the cornea and are responsible for maintaining a proper fluid balance. This function is critical to ensuring that the cornea remains transparent for vision. In many animals, including dogs, corneal endothelial cells have a very limited capacity to regenerate following injury. In canine patients with CED, the endothelial cells degenerate until the cells still remaining can no longer function properly. This results in swelling of the cornea (edema) which results in decreased vision as well as formation of small fluid-filled blisters (bullae) on the cornea which can rupture and cause ocular discomfort. There are palliative treatments such as hypertonic saline to decrease corneal bullae formation but the only definitive treatment for this condition is a corneal transplant (penetrating keratoplasty). Unfortunately, corneal transplants are rarely performed in canine patients with CED due to the expense of the surgery and follow-up care, relatively high risk of complications, and lack of appropriate donor tissue.

Several dog breeds, including Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers, are seen more commonly for CED in comparison to other breeds. This observation suggests that this disease may have a genetic component. A similar condition called Fuch’s endothelial corneal dystrophy (FECD) exists in humans and several genes associated with FECD have been identified. We propose to identify the region of the dog genome associated with CED in Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers. In order to do this, we will perform thorough eye examinations and use non-invasive advanced imaging techniques to examine Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers with CED and age-matched control dogs. We will collect blood from these dogs to obtain DNA. The entire canine genome will be evaluated for an association with CED. This work will be used to identify the gene(s) responsible for this condition in Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers. The ultimate goal will be to develop a genetic test for CED in Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers and possibly other breeds, such as Chihuahuas and Dachshunds, with an increased risk of CED.

Contact: Monica Motta at mjmotta@ucdavis.edu or 530-752-6967

Participation Requirements:

  • Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers with Corneal Endothelial Dystrophy
  • Healthy Boston Terriers, German Shorthaired Pointers and German Wirehaired Pointers (>7 years of age)

Initial Evaluation for Participation: Dogs must receive a diagnosis by a veterinary ophthalmologist for corneal endothelial dystrophy.

Procedures:

  • Blood collection for DNA analysis
  • Ophthalmic examination, including digital slit lamp biomicroscopy, Schirmer tear test followed by dilation and staining of the eye wtih fluroescein and digital photography
  • Noninvasive advanced corneal imaging with ultrasonic pachymetry, confocal biomicroscopy and spectral domain-optical coherence tomography (all of which will require sedation)

Benefits: Benefits include an ophthalmic examination at no cost with thorough characterization of disease to aid in monitoring for progression.

Owner Responsibilities: No ophthalmic medications can be administered 48 h prior to examination. Food cannot be given in the morning in preparation for sedation.

Printable Flyer for Boston Terriers (PDF)
Printable Flyer for German Shorthaired and Wirehaired Pointers (PDF)

Publications:

  • Shull, O.R., Reilly, C.M., Davis, L.B., Murphy, C.J., and Thomasy, S.M. (2017). Phenotypic Characterization of Corneal Endothelial Dystrophy in German Shorthaired and Wirehaired Pointers Using In Vivo Advanced Corneal Imaging and Histopathology. Cornea, 2017 Oct 25 (DOI: 10.1097/ICO.0000000000001431)
  • Thomasy, S.M., Cortes, D.E., Hoehn, A.L., Calderon, A.C., Li, J.Y., & Murphy, C.J. (2016). In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy. Investigative Ophthalmology and Visual Science, 57(9): 495-503. (DOI:10.1167/iovs.15-18885)

 

Dry Eye Syndrome (Keratoconjunctivitis sicca): Understanding the Genetics in West Highland White Terriers

Title: The Genetics of Keratoconjunctivitis Sicca in West Highland White Terriers

Purpose of Study: Keratoconjunctivitis sicca (KCS) or dry eye is a devastating disease that causes ocular pain and potentially blindness. It is seen more frequently in West Highland White Terriers in comparison to many other breeds. We are interested identifying the genetic components of this disease as well as characterizing this disease better with examination and testing of the tear film and ocular surface and in select patients using advanced imaging techniques.

Contact: Monica Motta at mjmotta@ucdavis.edu or 530-752-6967

Participation Requirements:

  • West Highland White Terriers with Dry Eye Syndrome (affected); or,
  • West Highland White Terriers >7 years of age with no ocular abnormalities (control)

Initial Evaluation for Participation: Affected patients must receive a diagnosis by a veterinary ophthalmologist for dry eye. Dogs without ocular disease (controls) require no prior initial examination.

Procedures:

  • Routine ophthalmic examination and tear film tests
  • Blood collection for DNA analysis
  • Tears will be collected from the conjunctival sac using a blunt-tip needle attached to a syringe from both eyes. Tear collection will be performed at a separate time from the initial ophthalmic examination and tests.
  • Conjunctival biopsy: Two (2) minutes after regional anesthesia is applied, a small (approximately 5 mm x 2 mm) piece of conjunctiva will be removed from inside the lower eyelid.
  • Select patients only:
    • Advanced imaging: Spectral domain optical coherence tomography (non-contact imaging) and confocal biomicroscopy (imaging in which a gel on the instrument contacts the cornea) will also be performed to carefully image the cornea along with digital slit lamp photography.
    • Sedation for advanced imaging: In order to keep dogs relaxed and comfortable but awake for the advanced imaging, your dog will be given a mild sedative. The sedation chosen for your pet will depend on your dog’s age and health status.

Benefits: There will be no cost to you for your participation in this study and your dog will receive a very thorough eye examination at no charge. If a corneal ulcer occurs at the time of evaluation, the cost of medications, recheck examinations, and procedures (e.g., cotton-tipped applicator or Diamond burr debridement, grid keratotomy) will be performed at no cost to you if they are performed at UC Davis. If a surgical procedure is required, you will receive $200 of compensation towards the procedure if it is performed at UC Davis. If your dog has KCS, you will be compensated for taking part in this study with 2 months worth of immunosuppressive medication (e.g., cyclosporine/tacrolimulus) ointment or drops. The study will also cover the costs of any complications from the sedation, blood sampling or imaging up to $200.

Results from this study will allow us to better predict the onset and progression of this disease. If a gene that causes this disease is found, then we may be able to develop a genetic test to know which dogs have or do not have this disease.

Owner Responsibilities: Although there is no cost to participate in the study, you will need to cover any costs due to complications from sedation, blood sampling, or examination (including corneal ulceration) beyond $200. Additionally, please do not administer any medications to treat your dog’s dry eye for one week prior to the appointment other than the lubricant provided to you. If your dog is participating in the advanced imaging, please do not feed your dog the morning of the appointment (water is fine), as the sedation administered can cause vomiting.

Printable Flyer (PDF)

Nasolacrimal Apparatus Blockage: A multidisciplinary, minimally invasive treatment

Title: Canine Nasolacrimal Apparatus Stenting for Treatment of Obstruction

Purpose of Study: Tears from the ocular surface are drained from the eye through several important structures collectively known as the nasolacrimal apparatus (NLA). This frequently becomes blocked and sometimes infected leading to discomfort, tear staining, eye discharge, and skin inflammation, all of which are associated with a decreased quality of life. Clinically, NLA obstructions can be very frustrating to treat and can often lead to permanent obstruction.

We have established a team at the UC Davis Veterinary Medical Teaching Hospital consisting of specialists with expertise in Ophthalmology, Internal Medicine, Endoscopy, Diagnostic Imaging, and Interventional Radiology and have utilized fluoroscopy to successfully treat NLA obstruction in dogs. We have utilized fluoroscopy, CT, and endoscopy and capitalized on improvements in instrumentation and minimally invasive techniques developed for catheterization of other challenging locations such as the ureters to successfully treat NLA obstruction.

Based upon the success of this initial pilot study, we have initiated a clinical trial to recruit and treat more cases and to evaluate more objective outcome measures.

Contact: Please call 530-752-3937 to schedule your initial visit to the UC Davis Veterinary Ophthalmology Service.

Participation Requirements: Dogs demonstrating signs of nasolacrimal apparatus (NLA) blockage

Initial Evaluation for Participation: None

Procedures: After an initial examination at the UCD VMTH to ensure the patient meets study entry criteria, you will provide informed consent and complete a questionnaire concerning their dog’s signs. Patients will then undergo initial testing including CT scanning of the NLA, and NLA stenting using endoscopy and fluoroscopy. The stent will be left in position for at least 6 weeks. After stent removal, similar testing including CT scanning will again be performed, and you will repeat the same questionnaire. Diagnostic test results from before and after stenting will be compared. Some financial subsidization of case management costs is available through the clinical trial.

Benefits: The study will subsidize costs associated with the second CT scan. Based upon results from the 6 patients in the pilot study, it is possible but not assured that your pet will have reduction or resolution of signs associated with NLA obstruction. Information acquired during this study will allow us to advance the treatment for NLA blockage for veterinary patients worldwide.

Owner Responsibilities: You will be responsible for all costs except those associated with the repeat CT scan following stent removal. Additionally, you will need to bring your dog to the VMTH for all scheduled appointments including a follow-up visit at least 6-8 weeks after the procedure. Lastly, you will be required to complete questionnaires prior to and after the NLA stenting procedure.

Printable Flyer (PDF)

If you cannot find what you are looking for, please email us or call (530) 752-5366.