Regional Veterinary Surgery

HYDROPHTHALMOS

Hydrophthalmos

• It is an enlargement of the eyeball associated with increase in the quantity of aqueous humour. When hydrophthalmos is congenital it is called megaophthalmos or megaophthalmos congenitus.
• Hydrophthalmos is usually the result of interference with the drainage of aqueous humour and may be due to the adhesion of iris to the cornea at the filtration angle.
• The tunics of the eyeball, espically the sclera and cornea become thin and weak. This condition is common in cats.

Symptoms

• Due to the general increase in the fluid contents the eyeball bulges forward causing exophthalmos and lagophthalmos. This causes drying or dessication and interference with the nourishment of the cornea.
• The cornea becomes opaque, due to pannus. The lens is detached and usually floats in the aqueous humour and may become adherent to the cornea or vitreous humour.
• Keratoglobus (protrusion of cornea into a globular enlargement) or keratoconus (conical enlargement of the cornea) may be observed.

Prognosis

• Guarded

Treatment

• Anterior chamber centesis is performed to decompress the anterior chamber 
• If hydrophthalmos is due to adhesion of the iris to the cornea or other structural deformities, treatment is confined to removal of diseased eyeball.

Technique

• Method  Enucleation of eye
  • The conjunctiva is held by forceps and is divided around the eyeball exposing the scleral insertions of the muscles of eyeball. These are divided one by one so that it will be possible to turn the eyeball and severe the rest of the attachments.
  • The eyeball is removed and the orbit is packed with sterile gauze to arrest haemorrhage. If tarsorrhaphy is to be performed, the edges of the lid are trimmed and sutured.
• Method  Extirpation of eye (Eviseration of orbit)
  • The palpebral borders of the eyelids are temporarily sutured together. An eplliptical cutaneous incision enclosing this suture line is made without opening into the conjunctival sac.
  • Retracting the skin edges, the eyeball along with its muscles is detached from the bony orbit by blunt dissection between the tenon’s capsule and bony orbit.
  • After division of the attachments close to the base of the orbit and removal of the eyeball the orbital cavity is packed with sterile gauze to control bleeding.
  • The skin edges are united by apposition sutures leaving a small gap at the inner canthus for removal of the gauze packing for subsequent dressings .