Tuesday, January 29, 2013

1266. Enucleation of the eye in a dwarf and a Syrian hamster

TOA PAYOH VETS
toapayohvets.com

Date:   30 January, 2013  
 
Focus: Small animals - dogs, cats, hamsters, guinea pigs & rabbits
Veterinary Surgery: Enucleation of the eye in 2 hamsters 
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
First written: 22 January, 2013
Date:   30 January, 2013  
toapayohvets.com 
Be Kind To Pets
Veterinary Education
Project 2010-0129

CASE 1. A DWARF HAMSTER HAS A POPPED OUT EYEBALL
 
Jan 22, 2013

"She is going to die," the young lady wiped her tears as her 2-year-old female dwarf hamster was sleepy unlike others. The hamster just would not move when held on the palm of her hands. She took her out several times and this would stress out the sleepy hamster which had not eaten and drunk water in the past 2 days and was in great pain.

"Two days ago, the right eyeball just popped out," she said. "Before that there was a white spot in her right eye. I thought it was a cataract."

The hamster's shoulder skin stood up when pulled indicating severe dehydration. The protruded eyeball must be very painful as the hamster can't talk. She just sat still most of the time. The owner was quoted $400 by another vet to do surgery. "I don't have that much money," the student said. "Normally I charge $100-$250" for hamster surgery depending on how complicated it is and the time it takes.
 
Eyeball prolapse 2 weeks after observation of "white" corneal ulcer Painful eye.
Continuous rubbing of the right eye
Lethargy & dehydrated. Subcutaneous injection of dextrose saline
   
Anaesthesia - isoflurane gas in a small
container
as required
Illustration of Surgery to educate owner & for medical records Right eyelids snipped off and stitched. Excellent and fast recovery (video) 48 hours after eyeball removal. Owner's e-mail image of a bleeding wound to the left of the surgery area. "This could be due to self-inflicted rubbing before or after surgery as it is not possible to put on an e-collar for hamsters, unlike in the dog," I explained. "Bring the hamster down for examination." No further complaint from the owner as at Jan 30, 2013. 
PRE-OP DEXTROSE SALINE
"What are you injecting?" Dr Daniel saw me preparing a small injection of 0.05 ml in a 1-ml syringe and thought I was overdosing this hamster. "It is dextrose saline as he is so lethargic and weak."

ANAESTHESIA
"This is a very sick hamster," I said to Dr Daniel when we discussed anaesthesia. He proposed 1 drop of Zoletil IM. "The safest is just isoflurane gas," I said. "The vet needs to be very observant as it is hard to tell when the hamster is fully anaesthesized.

We put the hamster inside a plastic container infused with 5% isoflurane gas. "Count up to 10 and take out. Repeat," I said. Dr Daniel did say 1,2,3...10!" once. The dosage was not enough. He tried again. "Use the mask," I said. But the mask was not effective as it was too big.

SURGERY

Basically the surgery of enucleation of the eyeball is similar to that for the dog. I incised a 4-mm area on the lateral canthus to enlarge the orbital area. Then I clamped the base of the right eyeball with curved forceps. The normal left eyeball suddenly popped out and the hamster squeaked.

I ceased the procedure and gave the hamster more anaesthetic fas. I scrutinised the hamster inside the plastic container. Once she could not move, I quickly took her out within a second. I clamped the eyeball again and excised the base with scalpel.

Unlike the dog, it was not possible to ligate the optic stalk and blood vessels as there was insufficient exposure in the dwarf hamster. Without ligation, profuse bleeding ensued. I swabbed off the blood and quickly cut off the upper and lower eyelids with scissors. Now, there would be two skin wounds which would heal well when I sutured with 6/0 sutures. The hamster was under gas anaesthesia which was just sufficient but would be short in duration. So, the hamster wriggled as she was waking up. I stitched the eyelids fast using 3 interrupted sutures.

"Hold on to his front paws, the scruff of his neck," I said to Dr Daniel. The dwarf hamster is so small that there is no space for both of us with 4 hands manipulating the dwarf. Finally, I sutured the eyelids.

The intern was trying to focus her camera to document the surgery. It was too cramped for the intern to take a video of the surgery. "The surgery needs to be very fast as the hamster's chances of survival on the operating table are good. Therefore, you can't video as this will delay the process." The intern left the operation room.

However she videoed 30 minutes post op and the hamster was busy cleaning himself. This video would be shown in the production of the video.

Surprisingly, the hamster became much more energetic after removal of the eyeball. It would be attributed to removal of pain and the dextrose saline. This was one of those cases which I think that the hamster would die on the operating table as he was not active and severely dehydrated.  So, the owner and I were glad to see him much alive. She took him home in the afternoon and was given medication.

FOLLOW UP:  1 DAY AFTER SURGERY
On Tuesday, Jan 22, 2013,  I phoned the young lady. She was most happy. "The hamster drinks a lot," she said. "She is much more alive." It was good news.

PHONE CALL FROM OWNER 2 DAYS AFTER SURGERY
Yesterday, Wednesday, Jan 23, 2013, the owner phoned me to say that there is a big hole. "Is it normal for hamster in such operations to have a big hole in the eye? What should I do? Can I send you the images of the eye by iPhone?" I said it was difficult to know what she meant and it is best to examine it as she thought there was a stitch breakdown exposing the eye wound.

She brought the hamster to the surgery in the afternoon. I was out and some driver had suddenly swerved into my parked car opposite the church and public library, damaging the right fore lamp area. So Dr Daniel examined this hamster.

"What happened?" I asked Dr Daniel.
"The swelling was due to the bleeding after removal of the eyeball. It has become a clot. The owner did not give the pain killer and the hamster scratches the eye area. But the hamster is normal, very active, eating and running. Is it possible that you did not snip off the eyelids but had just stitched up the eyelids?"

Dr Daniel was assisting me in this surgery to remove the eyeball but he was on the other side of the op table holding on to the hamster while I stitched up the "eyelids". As the hamster was a dwarf, he could not see me using a pair of scissors to snip off the upper and lower eyelids, as per standard operating procedure in eyeball removal surgery. In fact, it would be professionally incompetent not to do.

SNIPPING OFF THE UPPER AND LOWER EYELIDS
His palm is 4X in area compared to this dwarf and unlike the surgery in the dog or cat, he could not see much. He saw me using the scissors to cut off the 6/0 sutures after stitching the "eyelids". Actually, I had trimmed off the eyelids before putting in 3 stitches to close the eye. "I had cut off the eyelids, otherwise the eye would not seal off when the stitches dissolve," I said to him patiently.

 

CASE 2. A SYRIAN HAMSTER HAS A BLIND SHRUNKEN EYEBALL
Sep 20, 2010
 
The same surgical procedure of eyeball enucleation is illustrated in a Syrian hamster below.  The 3rd eyelid is not so prominent in the hamster unlike in the dog but is should be removed if it can be seen.
 
syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore  
Shrunken blind eye Illustration of surgical process to educate the hamster owner and for medical record Isoflurane gas
anaesthesia given by mask
Eyeball has been taken out. Eyelids snipped and the new wounds are stitched with fine sutures  
syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore syrian eye injured prolapsed luxated fight with other hamster enucleation toa payoh vets singapore    
Hamster wakes up fast when given gas anaesthesia Post-operation Stitches are absorbable. No need to return for stitch removal. No further visits or complaints from the owner since the surgery.  
ADVICES & TIPS:

1.  Eye Injuries Are Emergencies in Hamsters. Consult Your Vet Immediately

2.  The vet must deliver a hamster alive at the end of surgery.
Therefore, the vet must know what to do and complete the procedure of enucleation in less than 1 minute in order to deliver a good outcome. Sick hamsters can't survive long anaesthesia and surgery (>2 minutes usually).   

3. EYEBALL REMOVAL SURGERY IN HAMSTERS  COMPARED TO THE DOG AND CATS

The anaesthesia and surgery to remove the eyeball in the hamster can be completed in less than 5 minutes unlike in the dog or cat owing to the small size of the eyeball. The same principles of surgery apply to the hamster as to the dog and cat, only that the operation is on a miniature scale and the anaesthetic risk of death from isoflurane gas is 10x higher as it is difficult to monitor the depths of anaesthesia.   

4. SAVING THE EYE USING TARSORRHAPHY

This hamster had a "white spot" in the right eye earlier. The owner thought it was a cataract. This would be a corneal ulcer which tend to be painful and itchy. The hamster would have scratched so hard that her right eyeball popped out permanently and caused great pain.

In the dog and cat, it is possible to "save the eye" if it is not badly damaged or infect. This is done by doing lateral canthotomy (which I did in this hamster) to enlarge the ocular space, push back the eyeball, give antibiotics and anti-inflammatory, stitch up the upper and lower eyelids (tarsorrhaphy) to protect the eyeball and keeping it moist. In 14-21 days review the eyeball and remove the stitches. In tarsorrhaphy, the eyelids are not snipped off. An e-collar is then worn. All these are not possible for the hamster esp. the post-op care as the hamster hates the e-collar and will get rid of it in no time. The hamster may not eat or survive after such a drastic surgery. So, removing the popped out eyeball is the practical option.  
 

This webpage is:
http://kongyuensing.com/folder7/201301123hamster_eyeball_enucleation_toapayohvets.htm
 
 
More info at: Dogs or Cats
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