Curative Corneal Procedures 5711 Penetrating Keratoplasty Fig 518a

Principle: This involves replacement of diseased corneal tissue with a full-thickness donor graft of corneal tissue of varying diameter. A clear, regularly refracting button of donor cornea is placed in an opacified or irregularly refracting cornea. The corneal button is sutured with a continuous single or double suture (Fig. 5.19) or with interrupted sutures. (For special considerations in corneal transplants, see also Morphology and healing.)

Penetrating keratoplasty can be performed as an elective procedure to improve visual acuity or as an emergency procedure (emergency keratoplasty). Emergency keratoplasty is indicated to treat a perforated or nonhealing corneal ulcer to remove the perforation site and save the eye (tectonickeratoplasty).

Indications: Corneal diseases that affect the full thickness of the corneal stroma (corneal scars, dystrophy, or degeneration) or protrusion anomalies such as keratoconus or keratoglobus with or without central corneal opacifi-cation.

Allograft Rejection (Complications): The body's immune system can respond with a chronic focal allograft rejection (Fig. 5.20) or a diffuse allograft rejection (Fig. 5.21). The graft will be become opacified.

— Penetrating keratoplasty. -

Fig. 5.19 The donor corneal button is sutured with a continuous double suture.

— Penetrating keratoplasty. -

— Chronic focal allograft rejection.

Fig. 5.20 a The reaction proceeds from vascular branches extending to the graft (arrows). The graft shows focal opacifica-tion (left image) and is thickened (right image) with a progressive frontal line (Khodadoust's line).

b The same eye after two weeks of topical and systemic steroid therapy. The graft is again clear and of normal thickness.

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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