Clinical Comparison of Two Blinded Retrobulbar Block Techniques in Dogs Undergoing Enucleation: a Randomized Superiority Study

The University of Florida College of Veterinary Medicine is currently recruiting dogs undergoing enucleation.

Enrollment Status: Currently Enrolling

Inclusion criteria: Dogs undergoing unilateral enucleation at the University of Florida Veterinary Hospital are eligible to be enrolled. To participate, the dog must be healthy and weighing more than 5kg (11lb). There is no restriction related to breed or sex.

Exclusion criteria: Dogs undergoing enucleation because of a retrobulbar neoplasia or abscess.

Treatment: All dogs enrolled in this study will undergo enucleation according to our standard operating procedures, but they will be randomly allocated to one of the following groups:

– Group ITP: a preoperative retrobulbar anesthesia will be performed using the inferior-temporal-palpebral approach.

– Group ST: a preoperative retrobulbar anesthesia will be performed using the supratemporal approach.

During surgery, your dog will be thoroughly monitored as we normally do according to our standard operating procedures, despite the group allocation. Throughout hospitalization, the level of pain of your dog will be regularly evaluated and analgesic drugs administered as necessary to keep him/her comfortable. 

Cost: There are no additional expenses for participating in this study. Clients will be responsible for all clinic costs and drug treatments as appropriate. An estimate of costs for which you will be responsible will be prepared for you at the time of admission.

Contacts: You can contact our Small Animal Hospital at (352) 392-2235, or complete the Study Interest Form to see if your dog qualifies.

Study Investigators: Dr Enzo Vettorato, Dr Caryn Plummer, Dr Paoul Martinez.

Background: Eye surgeries in dogs can be painful, which can cause distress and lead to complications like the dog scratching or damaging the surgical site. To help manage this pain, veterinarians often use a special technique called retrobulbar anesthesia, which involves injecting local anesthetic behind the eye to block pain signals during and after surgery. One commonly used method, called inferior-temporal-palpebral (ITP) approach, has shown inconsistent results in how well the anesthetic spreads to the right area behind the eye. A newer method, called the supratemporal (ST) approach, has shown more consistent results in laboratory tests, but has not yet been fully studied in real-life veterinary patients. This study was designed to compare the two techniques (ITP and ST) in dogs undergoing eye removal surgery (enucleation). The researchers want to find out whether the newer ST approach provides better pain control during surgery, while keeping postoperative pain relief and other side effects—like need for extra pain medication and eating habits—similar between the two methods.