The Bulging Eye

History

Mia, a 9-year-old female spayed Longhair Chihuahua, presented to Iowa Veterinary Specialists due to a bulging left eye. This was an acute injury, as the owner came home after work to find Mia presenting with partial proptosis of the left eye. There was no known history of ocular disease or metabolic disease. As well as the owner did not see any signs of trauma or fighting with other dogs in the household. Mia is not on any medications per owner.

Physical Exam

Mia had a normal temperature, heart rate, respiration rate, capillary refill time, and pink mucous membranes. The right eye was unaffected, but the left eye was noted to have a partial proptosis. The menace and pupillary light response were intact in both eyes. As well as Mia was able to move the eyes readily. The pain score given was 2/4 and the body condition score was 4/5, she is a bit overweight/dental calculus present. No other significant abnormalities were found in the physical exam except the left eye.

Orbital Proptosis

• Definition
  • The globe being removed from the orbit by a blunt force trauma or in a
    brachycephalic dog a less intense situation.
• Brachycephalic dogs:
  • Types of breeds: Pugs, Chihuahuas (like Mia), Bulldog, etc.
  • Due to the shape of the skull the globe, has a higher likelihood of coming out of orbit. This could be by just jumping off the couch.
• Diagnosis:
  • If the globe is anterior to the orbit and eyelids.
  • The eyelids are posterior to the globe.
• Determining if the eye is still viable:
  • If these tests are passed:
    • Direct and Indirect Pupillary light response
    • Presence of vision
    • Visualization of the fundus
  • No extraocular muscle damage.
  • No intraocular hemorrhage.
  • No facial fractures due to trauma.
  • Not in mesocephalic and dolichocephalic breeds.
    • If in these types of dogs, it is likely a substantial skull trauma.
• If the eye is still viable, surgery by putting the globe back into the socket is a good choice.

Treatment Plans

Two treatment plans were provided to the owner. To start, a 12 cm e-collar and the application of sterile lube on the left eye. Next either…

1) Surgical intervention of replacing the globe into the socket and temporary tarsorrhaphy.
a. An explanation was given to the owner that future enucleation, glaucoma... may occur.
b. Due to the globe being viable, this was recommended.

2) Enucleation
a. This would be done if the owners did not want to chance the partial proptosis occurring again.

The owner opted for option 1.

Treatment

1. An IV catheter was placed, and Mia was given 0.3 mg/kg methadone and blood was obtained for pre-anesthetic bloodwork.
   1. Low amylase, high PCT, and high lipase were found. All other levels in the CBC/Chem were normal. 
      1. Amylase – An enzyme the pancreas and intestinal tract produce. The purpose is to break down sugar.
      2. PCT – This is plateletcrit, which is the volume percentage that platelets match on a total volume of blood.
      3. Lipase – An enzyme that breaks down fats.
   2. These were not significant enough findings that indicated sedation would affect her negatively.
      1. She had normal kidney and liver values.
2. Sedation by dexdomitor 5mcg/kg and ketamine 5 mg/kg IV
3. Induction – Propofol IV to effect
4. Maintenance – Intubation, Isoflurane and Oxygen
5. Surgical intervention occurs:
   1. Periocular tissues clipped and aseptically prepared.
   2. Sterile ophthalmic betadine is used to prepare the globe.
   3. Two horizontal mattress sutures were placed using 3-0 PDS.
      1. This prevents eyelid suture pressure and laceration.
   4. Gentle upward traction was placed on the sutures while applying gentle pressure
      to the globe.
      1. Putting it back where the eye belongs, into the socket.
      2. Globe was reduced! No longer protruding out!
   5. A temporary tarsorrhaphy was performed using interrupted horizontal mattress
      sutures, leaving the medial canthus open.
      1. The medial canthus staying open allowed owners to give the tobramycin
         medication in the eye during recovery.
         1. Tobramycin is an aminoglycoside, that acts against susceptible
            bacteria, hence it is an antibiotic for the eyes.
6. Sedation was reversed by Antisedan by intramuscular injection.
7. Uneventful recovery.
8. Medications sent home: carprofen, gabapentin, tobramycin (only left eye), and genteal
   tears (only left eye). Removal of sutures should occur in 14 days.

Conclusion of Treatment

Sutures started coming undone on day 13, therefore, the sutures were removed sooner than anticipated. However, everything was healed and there were no issues.