Congenital Glaucoma in Dogs (Inherited Glaucoma)
- Synonyms: Congenital Glaucoma, Primary Glaucoma in Newborns, Trabeculodysgenesis, Goniodysgenesis
- Occurrence: very rare
- Location of disease: Head/Neck
When to visit the vet?
Urgent see a veterinarian within 24 hours
If the condition worsens / symptoms persist, consult a veterinarian.
Definition
Congenital glaucoma, also known as congenital increased intraocular pressure, is a condition that occurs in dogs from birth or shortly after birth and is characterized by increased pressure inside the eye. As a result, damage to the optic nerve can occur, ultimately leading to vision loss or blindness.
The most important facts at a glance
Congenital glaucoma is a genetically determined malformation of the iridocorneal angle apparatus, which leads to pathologically increased intraocular pressure in dogs. The disease usually occurs early and bilaterally and can lead to pain and blindness if left untreated. Diagnosis is based on tonometry and gonioscopy, and therapy is medical and surgical. Lifelong monitoring is necessary. The prognosis depends on the time of diagnosis and the responsiveness to therapeutic measures.
Causes
Glaucoma is one of the most common causes of Blindness in dogs. This condition refers to a group of eye diseases caused by a pathologically increased intraocular pressure (IOP). The IOP rises when the balance between the production and drainage of the aqueous humor, a fluid in the eye, is disturbed. This leads to a pressure increase that can damage the optic nerve.
Normal intraocular pressure in dogs is between 15 and 25 mmHg. With glaucoma, this pressure can rise significantly, often exceeding 30 mmHg, which can damage the optic nerve and the retina. The optic nerve is responsible for transmitting visual information from the eye to the brain. Increased pressure can cause irreparable damage to this nerve, leading to vision loss or total blindness.
Congenital glaucoma occurs when the normal drainage pathways for the aqueous humor are defective from birth or do not develop properly. This is known as primary glaucoma and is often linked to genetics. Some dog breeds are predisposed, including Basset Hounds, Beagles, and Cocker Spaniels. There are also secondary forms of glaucoma that can be caused by other conditions such as inflammatory conditions, tumors, or eye injuries, but these are not congenital.
Symptoms
The symptoms of congenital glaucoma can be subtle and develop gradually. Therefore, early detection is crucial. Common symptoms include tearing, redness of the eye, increased intraocular pressure, enlarged or protruding eyes (exophthalmos), and corneal opacity. Dogs with glaucoma may also experience pain, which can manifest as frequent blinking, rubbing the affected eye, or general restlessness.
Another symptom is vision loss, which can be noticed through uncertainty / disorientation when walking, bumping into objects, or difficulty orienting in the environment. In advanced cases, complete blindness can occur.
The key sign is the combination of a “large, cloudy, red, and painful eye” with pupillary rigidity and rapidly progressing vision impairment. Any suspicion of glaucoma in a puppy or young dog is an emergency.
Therapy
The treatment of congenital glaucoma aims to lower intraocular pressure and prevent further damage to the optic nerve. Therapy can be medical or surgical. Medical treatments include eye drops or systemic medications that lower IOP by either reducing the production of aqueous humor or improving its drainage.
In severe cases or if medical therapy is insufficient, surgery may be necessary. Surgical procedures can include creating new drainage pathways for the aqueous humor or removing part of the ciliary body, which is responsible for aqueous humor production.
Prognosis and follow-up care
The prognosis for dogs with congenital glaucoma depends on various factors, including the severity of the condition, the timing of diagnosis, and the response to treatment. With early diagnosis and appropriate treatment, the progression of the disease can be slowed, and some dogs may retain part of their vision.
However, in cases where diagnosis is made late or treatment is ineffective, complete vision loss can occur. Regular check-ups and close collaboration with a veterinarian are crucial to monitor the course of the disease and adjust treatment.
Prevention
Since congenital glaucoma is often genetically determined, breeding plays an important role in prevention. Responsible breeding practices, including genetic testing for predisposing genes, can help minimize the risk of this condition in offspring. Breeders should ensure that they only use dogs free from glaucoma and other hereditary eye diseases.
Regular eye examinations in predisposed breeds can help detect early signs of glaucoma early, so that treatment can be initiated quickly. Early intervention can slow the progression of the disease and improve the quality of life of the affected dog.
Outlook on current research
Research into congenital glaucoma in dogs is an active field, as the disease has serious implications for the quality of life of affected animals. Scientists are investigating genetic predispositions, as some dog breeds are more susceptible to this condition. Breeds such as the Basset Hound, Beagle, and Cocker Spaniel are particularly in focus. Researchers use genetic analyses to identify specific genes associated with an increased risk. These findings could help develop breeding programs in the future that reduce the incidence of glaucoma.
Another research approach involves improving diagnostic methods. Currently, great emphasis is placed on developing non-invasive techniques that enable early detection of the disease. Technological advances in imaging, such as optical coherence tomography (OCT), offer potential for more precise and faster diagnoses. This is crucial, as early detection and treatment offer the best chances of preserving vision.
In therapeutic research, new medications and treatment approaches are being tested to lower intraocular pressure. Researchers are investigating the effectiveness of various drugs used in humans with glaucoma for their applicability in dogs. Additionally, stem cell therapies are being explored to regenerate damaged tissue and thus slow or stop the progression of the disease.
Alternative therapies and their effectiveness are also being researched, such as acupuncture or herbal treatments, which may have supportive effects. However, these studies are still in an early stage and require further research to confirm safety and effectiveness.
In summary, research into congenital glaucoma in dogs is diverse and promising. Through the interplay of genetic, diagnostic, and therapeutic research, scientists hope to develop more effective prevention and treatment strategies in the future to significantly improve the lives of affected dogs.
Frequently Asked Questions (FAQs)
1. What is congenital glaucoma in dogs?
2. Which breeds are particularly affected?
3. What are the symptoms of congenital glaucoma?
4. How is the disease diagnosed?
5. Can congenital glaucoma be cured?
6. How is the disease treated?
7. Can a dog with congenital glaucoma be helped to see better?
8. Are there preventive measures that can be taken?
9. How often should a dog be examined for this disease?
10. What role does genetics play in congenital glaucoma?
Literature
- Bedos, L., Grahn, B. H., & Wood, R. D. (2024). Prevalence of pre-iridal monocellular and fibrovascular membranes in canine globes affected with congenital glaucoma associated with anterior segment dysgenesis, primary glaucoma associated with goniodysgenesis, and secondary glaucoma. Frontiers in Veterinary Science, 11, Article 1289283. https://doi.org/10.3389/fvets.2024.1289283
- Leis, M. L., & Grahn, B. H. (2023). Glaucoma associated with anterior segment dysgenesis in dogs and cats. Veterinary Clinics of North America: Small Animal Practice, 53(2), 423–437. https://doi.org/10.1016/j.cvsm.2022.11.003
- Sandmeyer, L. (2023). The clinical approach to canine glaucoma. Veterinary Clinics of North America: Small Animal Practice, 53(2), 389–421. https://doi.org/10.1016/j.cvsm.2022.10.005
- Xia, Q., Cross, S., Smith, J., & Cebrian, C. (2022). Animal model contributions to primary congenital glaucoma. Genes, 13(6), Article 1044. https://doi.org/10.3390/genes13061044
- Strøm, A. R., Hässig, M., Iburg, T. M., & Spiess, B. M. (2011). Epidemiology of canine glaucoma presented to University of Zurich from 1995 to 2009. Part 1: Congenital and primary glaucoma (4 and 123 cases). Veterinary Ophthalmology, 14(2), 121–126. https://doi.org/10.1111/j.1463-5224.2010.00855.x
- Jerndal, T. (1983). Congenital glaucoma due to dominant goniodysgenesis. A new concept of the hereditary glaucoma. Acta Ophthalmologica, 61(4), 656–672. https://doi.org/10.1111/j.1755-3768.1983.tb01463.x
- Miller, P. E., & Bentley, E. (2015). Clinical signs and diagnosis of the canine primary glaucomas. Veterinary Clinics of North America: Small Animal Practice, 45(6), 1183–1212. https://doi.org/10.1016/j.cvsm.2015.06.006
- Komáromy, A. M., Petersen-Jones, S. M., & Ofri, R. (2015). Genetics of canine primary glaucomas. Veterinary Clinics of North America: Small Animal Practice, 45(6), 1159–1182. https://doi.org/10.1016/j.cvsm.2015.06.005
- Bedos, L., Grahn, B. H., & Wood, R. D. (2024). Prevalence of pre-iridal monocellular and fibrovascular membranes in canine globes affected with congenital glaucoma associated with anterior segment dysgenesis, primary glaucoma associated with goniodysgenesis, and secondary glaucoma. Frontiers in Veterinary Science, 11, Article 1289283. https://doi.org/10.3389/fvets.2024.1289283
- Leis, M. L., & Grahn, B. H. (2023). Glaucoma associated with anterior segment dysgenesis in dogs and cats. Veterinary Clinics of North America: Small Animal Practice, 53(2), 423–437. https://doi.org/10.1016/j.cvsm.2022.11.003
- Sandmeyer, L. (2023). The clinical approach to canine glaucoma. Veterinary Clinics of North America: Small Animal Practice, 53(2), 389–421. https://doi.org/10.1016/j.cvsm.2022.10.005
- Xia, Q., Cross, S., Smith, J., & Cebrian, C. (2022). Animal model contributions to primary congenital glaucoma. Genes, 13(6), Article 1044. https://doi.org/10.3390/genes13061044
- Strøm, A. R., Hässig, M., Iburg, T. M., & Spiess, B. M. (2011). Epidemiology of canine glaucoma presented to University of Zurich from 1995 to 2009. Part 1: Congenital and primary glaucoma (4 and 123 cases). Veterinary Ophthalmology, 14(2), 121–126. https://doi.org/10.1111/j.1463-5224.2010.00855.x
- Jerndal, T. (1983). Congenital glaucoma due to dominant goniodysgenesis. A new concept of the hereditary glaucoma. Acta Ophthalmologica, 61(4), 656–672. https://doi.org/10.1111/j.1755-3768.1983.tb01463.x
- Miller, P. E., & Bentley, E. (2015). Clinical signs and diagnosis of the canine primary glaucomas. Veterinary Clinics of North America: Small Animal Practice, 45(6), 1183–1212. https://doi.org/10.1016/j.cvsm.2015.06.006
- Komáromy, A. M., Petersen-Jones, S. M., & Ofri, R. (2015). Genetics of canine primary glaucomas. Veterinary Clinics of North America: Small Animal Practice, 45(6), 1159–1182. https://doi.org/10.1016/j.cvsm.2015.06.005