Gonioscopy in Dogs: Unraveling the Key to Canine Glaucoma Management

Gonioscopy is a specialized ophthalmic diagnostic technique that holds immense importance in canine eye health, particularly when dealing with glaucoma. As one of the leading causes of blindness in dogs, glaucoma requires early detection and precise management to preserve vision. In this comprehensive article, we delve into the significance of gonioscopy in relation to dogs, understanding how this procedure aids in assessing the iridocorneal angle, diagnosing glaucoma, and guiding treatment decisions.

Understanding Gonioscopy

Gonioscopy is a diagnostic procedure used by veterinarians to visualize the iridocorneal angle, which is the junction between the iris and the cornea of a dog’s eye. The iridocorneal angle plays a crucial role in the regulation of intraocular pressure (IOP). It allows the aqueous humor, a fluid within the eye, to drain properly. If the drainage angle is obstructed or compromised, it can lead to an increase in IOP, resulting in glaucoma.

The Importance of Gonioscopy in Canine Glaucoma Management

  1. Early Detection of Glaucoma: Gonioscopy is a key tool in the early detection of glaucoma in dogs. By examining the iridocorneal angle, veterinarians can identify any abnormalities or blockages that may impede proper aqueous humor drainage. Early detection is crucial in preventing irreversible damage to the optic nerve and preserving vision.
  2. Differentiating between Types of Glaucoma: There are various types of glaucoma in dogs, including primary, secondary, and congenital glaucoma. Each type requires a different approach to management. Gonioscopy helps differentiate between these types by revealing the underlying causes of increased IOP.
  3. Assessing Treatment Options: Glaucoma management in dogs involves multiple treatment options, such as topical medications, laser therapy, and surgical procedures. Gonioscopy aids in determining the most appropriate treatment plan for each dog, considering the severity of the condition and the potential for surgical intervention.
  4. Monitoring Progression and Response to Treatment: After initiating treatment, regular gonioscopic examinations are essential for monitoring the dog’s response and the progression of the disease. Changes in the iridocorneal angle can indicate the success or failure of the treatment and guide veterinarians in making necessary adjustments.

Conducting Gonioscopy in Dogs

  1. Sedation or Anesthesia: Similar to ophthalmoscopy, gonioscopy may require sedation or anesthesia to ensure the dog remains still and comfortable during the procedure.
  2. Gonioscope and Mirrors: A specialized goniolens or gonioscope is used for the examination. The lens helps to visualize the iridocorneal angle while mirrors are used to direct light onto the area of interest.
  3. Application of Ocular Gel: Ocular gel is applied to the cornea to create a smooth surface and facilitate the contact between the gonioscope and the eye.
  4. Assessment of the Angle: The veterinarian will carefully place the gonioscope on the cornea, gently pressing to view the iridocorneal angle. The angle’s configuration, pigmentation, and visibility of structures are noted and recorded.
  5. Photography and Documentation: As with ophthalmoscopy, capturing images or videos during gonioscopy is valuable for documentation and future reference.


Gonioscopy is a fundamental procedure in canine eye health, particularly when managing glaucoma. By assessing the iridocorneal angle, veterinarians can detect early signs of glaucoma, differentiate between types, guide treatment decisions, and monitor the progress of the disease. For dog owners, understanding the significance of gonioscopy in maintaining their furry friends’ vision underscores the importance of regular veterinary eye examinations. With early detection and precise management, glaucoma can be effectively controlled, allowing dogs to enjoy a high quality of life for years to come.