Ophthalmic Surgery

Eye surgery

Surgery is indicated in many conditions in a range of species including dogs, cats, horses, birds, reptiles and even fish!. Eye surgery can be classified into different categories by the location of the involved tissues and by the type of surgical techniques employed, i.e.:

• Structures external to the eye
• The surface structures of the eye
• The internal structures of the eye

or:

• Conventional surgery
• Microsurgery
• Electrosurgery
• Laser surgery

As the suructure of eyes and their surounding tissues are small and delicate, use of magnification is essential. AMCRS has special operating microscopes for these, and other microsurgery, procedures.

Eyelids

The eyelids may require surgery for repair of injuries or developmental abnormalities. Eyelids can curl inwards or outwards, be too tight or too loose, each variation causing a different degree of problem, most of which can be corrected surgically.

Extra eyelashes, a very common problem, may be treated by electrolysis, cryotherapy or surgical excision to prevent their regrowth. Each case has to be carefully assessed to determine which technique is most appropriate and least likely to result in inappropriate scarring.

An orbital abscess has pushed the third eyelid forward

The cornea

Corneal injuries are common. Lacerations and wounds from embedded foreign bodies (left) require surgical closure (as do surgical wounds used to access deeper structures within the eye). Deep ulcers are a serious problem as they can penetrate into the anterior chamber of the eye allowing entry of infection and foreign matyerial. When caught early enougn the proces can usually be arrested medically, but many deep ulcers need help to permit healing.

A varuiety of conjunctival flaps and grafts can be used to replace the missing surface layers. These often look unpleasant at first as in the image to the right, but the redness disappears once healing is complete, leaving an area of translucent to transparent scar tissue that in most cases permits reasonable sight.

Lack of sufficient tear secretion can often be treated medically, but when this proves inadequate and there are persistent corneal problems a parotid duct transpositioning procesdure can often be done to divert some of the copious saliva production most dogs have onto the eye. This does ahve a minor disadvantage as the secretion rate when food is around increases dramatically causing marked tear overflow.

The lens

Lens dislocation is a problem in a number of dog breeds. Here the lens can be seen in the anterior chamber of a Jack russell terrier's eye. The lens damages the cornea when this happens so it is necessary to either displace the lens caudallu behind the iris or to remove it surgically.

Cataracts prevent affected individuals from seeing detail. If teh retina is functioning OK, as tested by electroretinography, then it is worth considering surgery to remove the cataract. Gross surgery for lens removal has disadvantages and teh risks of complications is high. The use of phaecoemulsification techniques greatly reduces teh risk of complications so this is often the recommended technique ro treatment of cataracts. The necessary equipment and the sets of sterile disposable accessories are expensive, this being represented in the cost of treatment

The retina

Retinal damage is serious and difficult to treat. Laser surgery is used to help prevent spread of retinal detacment and in some cases can be used to reattach a detached retina like that shown below.