402 |
45 Endophthalmitis |
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a |
b |
Fig. 45.2 Cleaning the AC in an eye with traumatic endophthalmitis. (a) In this patient with a 3-day-old traumatic endophthalmitis, the corneal wound has not been sutured since the patient did not seek help after the injury. The AC filled is with nontransparent material; it is not possible to determine how much the cornea would interfere with visibility during vitrectomy. (b) The corneal wound was closed with full-thickness sutures, the epithelium scraped, and an AC maintainer placed. The fibrinous membrane is being removed with forceps, the iris is now visible, and only a few minutes have elapsed since the taking of the picture seen on (a)
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b |
Fig. 45.3 The posterior pole in an eye with advanced endophthalmitis. (a) “Macular hypopyon”: accumulation of pure pus overlying the deepest point of the eye in a patient who has been lying in bed for several days. (b) The posterior vitreous is still not detached, even though the injury is 3 weeks old. Without creating the PVD the surface of the posterior retina cannot be cleansed. The PVD, and the vacuuming of the bacterial colonies seen as white dots on the image, are technically difficult procedures at such a late stage, and the prognosis is very poor
45.2Surgical Technique
CEVE is what I call the ideal solution. The goal is to remove as much of the purulent material as possible, consistent with safety, and do it basically as soon as the diagnosis has been made.
Table 45.3 provides details about the surgical procedure, which is the same irrespective of whether it is performed early or late. Surgery, however, is easy in the early and very difficult in the advances cases; either way, but especially in advanced cases, the surgeon must proceed in a step-by-step fashion from anterior to posterior. Skipping a step makes surgery even more difficult and risky.
45.2 Surgical Technique |
403 |
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Table 45.3 Surgical steps in PPV for endophthalmitis |
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Step |
Comment |
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Preparation |
Have the diagnostic equipment (for culturing) readya |
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Place the pars plana infusion cannula but do not open it unless you can |
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definitely confirm/see that the tip is in the vitreous cavity; use an AC |
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maintainer until (see below) |
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Cornea |
Scrape the endothelium.b It is always edematous and greatly interferes with |
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visualization |
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If the stroma is also edematous, press a dry sponge against it or use |
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high-concentration glucose topically (see Sect. 25.1.4) |
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If folds are present in Descemet’s membrane, clean the AC and then try to |
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fill the AC tightly with cohesive visco (see below) |
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AC |
It always has cells and a fibrinous membrane, even if true hypopyon is not |
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visiblec |
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Prepare 2 paracenteses: |
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The first one inferotemporally – insert an AC maintainer here |
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The second one is superotemporal; this is used to aspirate all cellular elements |
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Following the irrigation, insert a forceps or the probe, and grab or aspirate the |
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fibrinous membrane. The membrane is adherent to tissues and requires some |
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force to separate, but it is also elastic so it usually comes off in one piece |
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Cave: the iris is “hot” and can easily bleed |
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Make sure you remove the membrane from the angle |
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Especially in children, the purulent material and the membrane may recur |
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during surgery, and repeated removal may become necessary |
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Pupil |
Make sure it is as wide as possible; you can try adrenaline, visco, or iris |
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retractors (see Sect. 25.2.2) |
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Lens |
It is rare that the crystalline lens that otherwise would be left in place needs |
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to be removed so as to complete the PPV; however, the lens must be |
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sacrificed if it in any way interferes with surgical success |
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IOL |
It is rare that the IOL needs to be removed; it is done as a “routine” only in |
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the eyes with chronic endophthalmitis |
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Thoroughly clean both surfaces of the IOL (see Sect. 25.2.3.2) |
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Posterior capsule |
Make a large capsulectomy and irrigate the capsular bag |
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Vitreous cavity if |
Proceed as in a normal case (P-A PPV). Make sure that you create a PVD, |
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the retina is |
and vacuum the macular surface with the flute needle |
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now visible |
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Vitreous cavity if |
Proceed first in an anteroposterior order; reverse it only if a PVD has been |
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the retina is |
created |
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not or only |
Clean the area behind the lens first and then the central vitreous, and do the |
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barely visible |
creation of this “well” on the nasal side. The retina may be detached and |
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necrotic: it would not necessarily bleed even if bitten into (see Sect. 62.3) |
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Create a PVD,d vacuum the macular surface (see Sect. 25.2.7.2). The retina |
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is very fragile and can easily be damaged. If some of the vitreous is |
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extremely adherent to the surface, do not force its detachment |
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Vacuum the macular surface as described above |
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Once most of the vitreous cavity has been cleaned, continue with the vitrectomy |
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in the periphery. Here you need to proceed with extreme caution. Usually |
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there is a white, nontransparent ring of purulent vitreous there, which is best |
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seen by scleral indentation, but it is not possible to see the retina behind it. |
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This vitreous is best reduced in thickness but then left behind |
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aThe best is to discuss beforehand the details with the lab where the samples will be sent. bEven if the patient is diabetic – something that is unadvisable otherwise.
cIf a small (1–2 mm) hypopyon was seen at the slit lamp, it may become invisible once the patient lies down.
dNever assume that the posterior hyaloid face has spontaneously detached.
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45 Endophthalmitis |
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Pearl
The real fear in endophthalmitis must concern the organism and the toxic, purulent material bathing the retina, not the risk of causing an RD.
If a retinal break is found or suspected, or RD is present, the completion of the surgery is different.
•Inject antibiotics and steroid into the infusion bottle. The dose is calculated so that the concentration in the bottle13 is the same as the intravitreal injection’s concentration would be.
•Complete the vitrectomy using this infusion fluid so that it irrigates the vitreous cavity to a sufficient extent and duration.
•Fill the vitreous cavity with silicone oil.
•Inject antibiotics and steroid into the oil, 1/3 of the usual dose.
45.3Posttraumatic Endophthalmitis
Most of what is important has been described above; below is a list of some of the unique features of a trauma-related infection.
•The diagnosis may be much more difficult as the signs and symptoms of the endophthalmitis can be masked by those of the injury.
•The organism is often very virulent; the time to intervention should be kept to the minimum possible.
•The default intervention option is CEVE.
–Compromise may be acceptable regarding certain elements of the surgery itself,14 but no delay is acceptable: posttraumatic endophthalmitis is an absolute emergency.
•The full armamentarium of antimicrobial therapy has to be employed, and unless the organism is fungal, intravitreal steroid should also be injected.
13The drugs are expensive. A small amount of infusion fluid (say 50 ml) will suffice since most of the operation has been done by now.
14I.e., foregoing complete removal of the adherent vitreous from a necrotic retinal surface.