**6. Surgical techniques**

Although corneal transplantation for infections keratitis follows the basic surgical technique of penetrating keratoplasty, special attention must be given to certain details:

#### **6.1 Preoperative procedures**

We recommend general anesthesia .It is important to have a soft eye preoperatively so that problems related to positive vitreous pressure can be prevented.

Therapeutic Keratoplasty for Microbial Keratitis 23

thickness bites are not taken as they may form a conduit for passage of infection from the cornea into the anterior chamber. It is not uncommon to use greater number of sutures than

Table 2. Profile of infectious keratitis 2025 cases, during 10 years (2000-2010) in 14.65% cases with therapeutic keratoplasty in advanced process, dates of "Asociación Para Evitar la

Immediate postoperative treatment focuses on prevention of recurrence of infection and

Box 1. Guidelines for postoperative management of terapeutic keratoplasty

conventional technique of keratoplasty (16 Sutures).Table 2

Sex 68,7 % (♂)

Endophthalmitis 11,9 % Perforation 50,7 %

Age 50,90 ± 16,298 years old

Survival graft 10,08 ± 15,97 months Size of the donor 8,80 ± 0,19 mm. Size receiver 8,17 ± 0,13 mm.

Ceguera en México Hospital "Dr. Luis Sanchez Bulnes"

hastening the complete epithelization of the graft.

**7. Postoperative management** 

Type penetrating keratoplasty 98.5% QPP vs.1.5% Lamelar

Intravenous Manitol produces deturgescence of the vitreous and helps to minimize these problems.

At the time of therapeutic keratoplasty by placing the appropriate trephine over the cornea and creating an indentation in the epithelium.

#### **6.2 Exposure**

In general, we commonly use lid speculum and suture a Fleringa ring in place to provide scleral support, in cases of large ulcers that reach up to the limbus, peritomy is required and homeostasis is achieved by the use of wet-field cautery.

#### **6.3 Host preparation bed**

The goal of surgery is to excise all necrotic or infected tissue during trephination. It possible, a 1 mm rim of healthy corneal tissue should also be removed to leave a stable, no infected recipient bed.

Conjuntival peritomies should be done in cases requiring large or eccentric grafts.

The trephination of the recipient bed can be technically difficult. Careful partial-thickness trephination with a Sharp trephine is done in the absence of any perforation; in eyes with a perforation, support is obtained with cyanocrylate and viscoelastic protection and anterior chamber can be reformed and the host trephination can be performed under a more controlled environment, care should be taken to avoid exerting excessive pressure on the globe to prevent extrusion of the ocular contents a freehand dissection of the host bed may be done.

### **6.4 Clearing the anterior chamber of exudates**

Irrigation of the anterior chamber is done using a balanced salt solution. Elimination of all exudative material from the anterior chamber helps to prevent the recurrence of infection and reduces complications such as glaucoma.

The membranes over iris are dissected gently by the irrigating cannula and are removed with forceps. Any membrane covering the iris surface should be removed very gently, and every effort should be made to arrest bleeding from the iris surface.

Intracameral antibiotics or antifungals can be used whenever they are required.

Two large peripheral iridectomies are recommended .Removal of cataracts should be deferred because the lens forms an effective barrier that prevents the spread of infection into the vitreous. When vitreous involvement is diagnosed, open sky vitrectomy is indicated. The anterior chamber is reformed with a viscoelastic substance, and the margin of the recipient bed is trimmed.

#### **6.5 Preparation of the donor botton**

The donor button should be trephined after the size of the recipient opening is measured and preparation of the host bed, because necrotic tissue may require additional trimming which may alter the size of the graft.

The donor button is punched from the endothelial side and usually 0.5-1.0 mm larger than the selected host trephine.

#### **6.6 Suturing**

The donor-recipient junction was sewn by 10-0 monofilament Nylon interrupted sutures passing though at least 70% depth of the host cornea is the preferred technique. Full

Intravenous Manitol produces deturgescence of the vitreous and helps to minimize these

At the time of therapeutic keratoplasty by placing the appropriate trephine over the cornea

In general, we commonly use lid speculum and suture a Fleringa ring in place to provide scleral support, in cases of large ulcers that reach up to the limbus, peritomy is required and

The goal of surgery is to excise all necrotic or infected tissue during trephination. It possible, a 1 mm rim of healthy corneal tissue should also be removed to leave a stable, no infected

The trephination of the recipient bed can be technically difficult. Careful partial-thickness trephination with a Sharp trephine is done in the absence of any perforation; in eyes with a perforation, support is obtained with cyanocrylate and viscoelastic protection and anterior chamber can be reformed and the host trephination can be performed under a more controlled environment, care should be taken to avoid exerting excessive pressure on the globe to prevent

Irrigation of the anterior chamber is done using a balanced salt solution. Elimination of all exudative material from the anterior chamber helps to prevent the recurrence of infection

The membranes over iris are dissected gently by the irrigating cannula and are removed with forceps. Any membrane covering the iris surface should be removed very gently, and

Two large peripheral iridectomies are recommended .Removal of cataracts should be deferred because the lens forms an effective barrier that prevents the spread of infection into the vitreous. When vitreous involvement is diagnosed, open sky vitrectomy is indicated. The anterior chamber is reformed with a viscoelastic substance, and the margin of the

The donor button should be trephined after the size of the recipient opening is measured and preparation of the host bed, because necrotic tissue may require additional trimming

The donor button is punched from the endothelial side and usually 0.5-1.0 mm larger than

The donor-recipient junction was sewn by 10-0 monofilament Nylon interrupted sutures passing though at least 70% depth of the host cornea is the preferred technique. Full

Conjuntival peritomies should be done in cases requiring large or eccentric grafts.

extrusion of the ocular contents a freehand dissection of the host bed may be done.

Intracameral antibiotics or antifungals can be used whenever they are required.

every effort should be made to arrest bleeding from the iris surface.

problems.

**6.2 Exposure** 

recipient bed.

**6.3 Host preparation bed** 

recipient bed is trimmed.

the selected host trephine.

**6.6 Suturing** 

**6.5 Preparation of the donor botton** 

which may alter the size of the graft.

and creating an indentation in the epithelium.

homeostasis is achieved by the use of wet-field cautery.

**6.4 Clearing the anterior chamber of exudates** 

and reduces complications such as glaucoma.

thickness bites are not taken as they may form a conduit for passage of infection from the cornea into the anterior chamber. It is not uncommon to use greater number of sutures than conventional technique of keratoplasty (16 Sutures).Table 2


Table 2. Profile of infectious keratitis 2025 cases, during 10 years (2000-2010) in 14.65% cases with therapeutic keratoplasty in advanced process, dates of "Asociación Para Evitar la Ceguera en México Hospital "Dr. Luis Sanchez Bulnes"
