Injury Involving the Entire Globe

Ferenc Kuhn, Robert Morris, C. Douglas Witherspoon

2.15.1 Introduction

Open globe injuries1 may cause substantial damage to the eye, making the situation akin to that of a polytraumatized person: the condition of one pathology influences the condition and treatment of another (Fig. 2.2.14). The most serious of the potential scenarios is when the retina requires major surgery urgently but the cornea has become opaque and interferes with visibility. Such an injury represents one of the most challenging indications for the ocular traumatologist, and the number of viable options is limited.

2.15.2 Evaluation

The cornea is so badly damaged that even the color of the iris may be impossible to determine at the slit lamp (Fig. 2.2.14). The condition of the cornea may be due to the presence of multiple wounds with excessive edema and/or blood staining. The lens, if present at all (Fig. 2.12.2), is rarely clear. The vitreous hemorrhage is usually very severe, and the retina is often incarcerated in the wound. Early retinal detachment and the development of PVR are frequent complications. The visual acuity is typically in the NLP to HM range. The treatment should not be based on whether the visual acuity is NLP or greater (see Chap. 1.8).

1 Occasionally, a contusion can also inflict such damage.

2.15.3 Management Options

The outcome of the injury is primarily determined by the condition of the postequatorial retina.2 The main question is to what extent the traumatized cornea interferes with posterior segment surgery. The following management options are available:

• No surgery. Abandoning the eye is equal to a death sentence: spontaneous improvement is unreasonable to expect. Early phthisis is likely.

• Delayed surgery. Vitrectomy is performed only when the cornea's interference with visibility is sufficiently reduced. Unfortunately, this is usually very late, and the prognosis of the injury is extremely poor.

• Timely but limited surgery. Vitrectomy is performed within the first 2 weeks, but it is not carried to completeness because the condition of the cornea does not permit it. The prognosis is very poor.

• Incremental surgeries. Posterior segment surgery is done in several surgical sessions. Even though performed early, each vitrectomy is incomplete, depending on the condition of the cornea. The disadvantages far outweigh the benefits; the prognosis is very poor.

• Endoscopy-assisted vitrectomy. The endoscopic approach has the advantage of bypassing the corneal interference (see Chap. 2.20). It also makes corneal transplantation potentially avoidable.3 Endoscopy-as-sisted vitrectomy has its own, significant technical difficulties, mainly that is performed without stereoscopy and surgery is not bimanual, and it requires considerable experience. Another factor to consider is the inability to postoperatively inspect the retina until the media opacity clears. Nevertheless, EAV is a viable option and should be high on the surgeon's consideration list. In summary, the main advantage of the endoscope over the TKP is that the patient is spared the risks associated with PK if the corneal opacity is temporary.

2 Presuming that the optic nerve is not injured, the tissue (other than the postequatorial retina) with decisive impact on the outcome is the ciliary body (see Chap. 2.8).

3 Not all eyes sustain irreversibly damage; with time some corneas recover.

O Cave

Use of the endoscope in an eye that has sustained major damage to both the anterior and posterior segments demands a surgeon who has great experience in both ocular traumatology and endoscopy (see Chap. 2.20).

• Temporary keratoprosthesis vitrectomy. Considering all options this is the most promising alternative. Most trauma specialists have sufficient experience in vitrectomy as well as in corneal grafting; if not, two specialists should operate in a joint procedure (see below). In summary, the main advantage of the TKP over the endoscope is that it provides early vision restoration to the patient and retinal inspection to the surgeon.

O Pearl

There is no justification for abandoning eyes with serious anterior- and posterior segment trauma. Both the endoscope and the TKP allow the surgeon to perform uncompromising vitrectomy in the subacute period.

2.15.3.1 TKP Vitrectomy

The TKP is an artificial, temporary graft, replacing the patient's nontransparent cornea for the duration of posterior segment surgery (Fig. 2.15.1). Independent of design and material (Table 2.15.1), the TKP provides a crystal-clear view during vitrectomy while providing for the necessary closed globe environment. Ideally, a standard PK is performed at the conclusion of vitrectomy, replacing the TKP with donor tissue (Fig. 2.15.2). If a donor tissue is unavailable, two temporary solutions4 are available: the TKP is left in the cornea or the patient's own damaged cornea is used as a graft.

4 Both are acceptable for a few days, and either of these solutions is preferred to delaying the vitrectomy.

Fig. 2.15.1 The temporary keratoprosthesis (TKP) device intraoperatively. As opposed to a completely nontransparent cornea (see Fig. 2.2.14), the Landers TKP provides unhindered viewing of the retina. Use of a wide-angle system or a contact lens for fine epiretinal work are both possible

Fig. 2.15.2 PK to complete the procedure. At the end of surgery, a corneal graft is placed. There is excellent red reflex and the retina is attached
Table 2.15.1 A comparison of two temporary keratoprosthesis designs

Variable

Eckardt[1]

Landers [10]

Diameter

7 or 8 mm

7.2 or 8.2 mma

Phakic version available

Yes

Yes

Suture placement

Up to surgeon

Predetermined holes

Reusable

Yesb

Yes

Material

Silicone

0 0

Post a comment