Ординатура / Офтальмология / Английские материалы / Strabismus Surgery and Its Complications_Coats, Olitsky_2007

Postoperative

Infection

22

Serious infections following strabismus surgery are uncommon. Most busy strabismus surgeons are unlikely to see more than one or two cases of endophthalmitis and/or orbital cellulitis during their entire career. Other important, but less serious infections, such as preseptal cellulitis and subconjunctival abscesses, are more common. Endophthalmitis is so rare after­ strabismus surgery that it is often initially misdiagnosed. Though it is uncommon, the visual outcome of endophthalmitis following strabismus surgery is often poor, and this could in part be compounded by a delay in diagnosis. Thus, surgeon awareness of risk factors, clinical presentation, and treatment remain important. A comprehensive review of ocular, periocular, and systemic infection as related to strabismus surgery is presented in this chapter.

22.1 Risk Factors

The most common source of viable organisms producing endophthalmitis after strabismus surgery is not known. Potential sources of infection include the normal bacterial flora in the region of the operative site, contaminated surgical material, postoperative periocular abscess, and transient endogenous bacteremia. There are many proven and suspected factors that predispose a patient to postoperative infection. Patients who are immunocompromised, such as those with poorly controlled diabetes, patients undergoing chemotherapy, and patients on corticosteroid therapy, are at increased risk for postoperative infection due to their lack of ability to mount a normal immune response to deal with the inevitable contamination of the operative site that occurs during the normal course of surgery.

Most of the available data on risk factors for surgical site contamination and for risk of endophthalmitis following ophthalmologic surgery relate to cataract surgery and other intraocular surgical procedures. Though uncomplicated strabismus surgery does not result in perforation of the sclera, the strabismus surgeon should still be aware of these reports. One study suggested that an ophthalmic surgeon’s speaking to a patient during surgery, especially if the patient was hard of hearing requiring the surgeon to shout to be understood, could increase the risk of bacterial contamination of the operative site [1].

Chapter

22

22.1.1 Glove Perforation

The surgeon’s hands are an important potential source of bacterial contamination during surgery and proper hand washing prior to surgery is important in reducing the risk of contamination of the operative site from this source. Glove perforation during surgery occurs more frequently than surgeons may realize and glove perforation not only exposes the patient to contaminants on the surgeon’s hands but also exposes the surgeon to potentially infected patient tissues and body fluids. Most ophthalmic surgeons erroneously believe that holes seldom develop in their own gloves during surgery [2]. One study of 2292 surgical procedures of all types identified glove tears in 249 (11%) gloves from surgeons, assistants, and/or nurses [3]. The mechanism of glove tears was identified in only a third of the cases, thus occult glove perforation is more common than recognized perforation. The rate of glove perforation in ophthalmologic surgery has been reported to be as high as 4% [4]. Perforation was most common with retina surgery and least common with strabismus surgery. Perforation of the surgeon’s left glove was more common than perforation of right gloves. The risk appeared highest for perforation of left gloves while handling suture needles. Sutures should be loaded onto the needle holder without ever touching the needle itself. Placement of a needle into a needle holder can be easily facilitated by holding the suture material close to the needle. Holding the needle in one’s hand while placing it into the needle holder or passing it off the operative field is a common, but very poor, practice. It exposes both the patient and operating room personnel to unnecessary risk.

22.1.2Operating Room Equipment and Supplies

Operating room equipment and supplies are generally sterile and are rarely the source of contamination that results in postoperative infection. However, bacterial contamination of solutions that are used during intraocular surgery have been reported as the source of organisms leading to the development of endophthalmitis [5]. Though we are not aware of any cases

of endophthalmitis due to contaminated solutions used during strabismus surgery and recognize that this mechanism of contamination is less likely to occur during strabismus surgery compared with intraocular surgery, serious infection through contaminated solutions is possible.

Instruments, implants, explants, and surgical supplies can become contaminated during any surgical procedure through several potential mechanisms. The ocular adnexa and conjunctiva of the patient are prime sources of potential contamination during ophthalmologic surgery. Doyle and coworkers [6] reported significant contamination of intraocular lenses that touched the bulbar conjunctiva of the patient during cataract surgery or that were left on the surgical drape near the operative site. Though most of the available data relate to intraocular surgery, similar mechanisms of contamination are possible during strabismus surgery. Olitsky and coworkers [7] studied the rate of needle contamination during strabismus surgery in patients who had received preoperative skin and conjunctival preparation with standard 5% povidone-iodine solution prior to surgery. They were able to demonstrate bacterial contamination on 16 (15.1%) of 106 needles and 15 (24.6%) of 61 cases of strabismus surgery. The organisms recovered closely resembled indigenous bacterial flora. They believed that needles used during strabismus surgery could be a source of bacteria that could lead to infection after strabismus surgery. Carothers and coworkers [8] reported on the level of bacterial contamination of both needles and sutures used during strabismus surgery. They cultured needles and sutures used on 56 eyes from 31 consecutive children undergoing strabismus surgery. The cases had received preoperative preparation with a standard solution of 5% povidone-iodine including instillation in the conjunctival fornices. Of the 31 cases, 17 (54.8%) produced at least one positive specimen. It was found that 19% of the needles and 25.2% of the sutures were culture positive. Most of the positive specimens (96.7% of needles, 91.3% of sutures) produced three or fewer colony forming units, corresponding to seven or fewer total viable organisms per needle or suture in accordance with the dilution scheme, and coagulase-negative staphylococci overwhelmingly predominated. While most of the contaminated needles and sutures were not heavily contaminated, some were sufficiently contaminated with enough colony forming units of bacteria that they were probably capable of producing endophthalmitis under the right circumstances. Wang and coworkers [9] have demonstrated that needles and sutures contaminated with a physiologic dose of bacteria can transmit live bacteria into an eye bank eye during eye wall perforation.

Given the fact that the sutures and needles used during surgery have a high potential to become contaminated with bacteria during routine strabismus surgery, steps to reduce the risk of exposure to contaminated needles and sutures should be considered. Isolation of the eyelids and lashes with an adhesive drape (>Fig. 22.1) may reduce the potential for contamination during ophthalmic surgery, though there is no evidence that this measure reduces the risk of infection related to strabismus surgery. If a scleral perforation is suspected or confirmed during surgery, the surgeon should consider halting passage of the needle and withdraw it immediately, before potentially con-

Chapter 22

Fig. 22.1. Isolation of the lashes for strabismus surgery to reduce the risk of contamination of instruments and supplies

taminated suture material is drawn through the perforation site. Likewise, if the needle has already been passed through the sclera, it may be prudent to cut the suture flush with the sclera and remove it, to avoid having to draw additional potentially contaminated needle and suture back through the suspected perforation site to remove it. Leaving a foreign body (suture) in a scleral perforation site has the potential to increase the risk of infection, and thus repositioning of the suture to another site should be considered mandatory.

22.2 Endophthalmitis

The estimated incidence of endophthalmitis following strabismus surgery ranges from 1 in 350,000 cases [10] suggested in 1962 to 1 in 18,500 cases [11] suggested in 1992. Numerous risk factors have been proposed. Scleral perforation is commonly believed to increase the risk of developing endophthalmitis following strabismus surgery, though clear evidence that this is the case is not available. Salamon and coworkers [12] treated two cases of endophthalmitis following strabismus surgery. Scleral perforation was recognized during surgery on one patient and was treated with cryopexy. Sclera perforation was suspected, but not confirmed, in the second case. Recchia and coworkers [13] reported six cases of endophthalmitis in children following strabismus surgery who were referred to them over a 5-year period. Scleral perforation was not suspected by the operating surgeon at the time of strabismus surgery in these six cases.

The cause of endophthalmitis after strabismus surgery is not known, and is probably variable. Several theories have been proposed. Rosenbaum [14] suggested the possibility that endophthalmitis following strabismus surgery could have an endogenous origin. Good and coworkers [15] suggested that partial obstruction of the nasolacrimal duct and upper airway infection could be a risk factor for development of postoperative endophthalmitis in children undergoing cataract surgery. There is no reason to doubt that these same factors might not

also increase the risk of endophthalmitis following strabismus surgery. Staphylococcus and Streptococcus have been the predominant organisms cultured in reported cases of endophthalmitis (>Table 22.1).

Abscess formation occurring around the muscle suture in the absence of sclera perforation was suspected in one reported case [14]. Kushner and Meyers [16] reported a case of endophthalmitis following strabismus surgery reoperation that was caused by Staphylococcus aureus. Perforation was not suspected at the time of surgery. The child went swimming 5 days after surgery and 2 days later complained of right eye discomfort and erythema of the conjunctiva was noted by the parents. These authors felt that swimming was the likely source of exposure to the infectious agent. Recchia and co-workers [13] noted that five of the six cases of the endophthalmitis they treated occurred following surgery on the left medial rectus muscle. They postulated that surgery by a right-handed surgeon in the tight surgical space afforded during medial rectus muscle surgery through a fornix incision could have played a role in increasing the risk of infection.

The insidious presentation of endophthalmitis following strabismus surgery and the tendency for children not to complain of unilateral vision loss both make this already rare condition even more difficult to accurately diagnose. An accurate diagnosis of endophthalmitis is often not made until several days after the onset of signs and/or symptoms (>Table 22.1). Reported signs and symptoms are numerous. The most common presenting complaints have been pain, eyelid swelling, and redness. Table 22.2 presents a comprehensive tabulation of the signs and symptoms reported in 22 cases of endophthalmitis. Onset of symptoms has been reported as early as 1 day after surgery to as long as 13 days after surgery (>Table 22.1). Diagnosis has been reported as early as 3 days after surgery and as late as 30 days following surgery. Thus, no reasonable follow-up schedule can ensure that the surgeon will be able to make an early diagnosis of endophthalmitis in all patients. The use of antibiotic drops following surgery is not necessarily protective either. In the largest series of reported cases, the six patients reported by Recchia and co-workers [13], postoperative management had included a combination antibiotic steroid drop in all cases.

The visual outcome following most reported cases of endophthalmitis following strabismus surgery has generally been poor, with rare exceptions. Among the 22 cases reviewed in Table 22.1, the outcome was light perception or worse in 12 cases with 6 eyes requiring enucleation and 3 eyes developing phthisis bulbi. Occasionally favorable outcomes have been reported. Uniat and coworkers [17] reported a successful outcome in a 78-year-old woman who developed endophthalmitis due to Staphylococcus epidermidis in association with a scleral perforation during surgery. The onset of symptoms and diagnosis occurred on the third postoperative day and the patient underwent vitrectomy with intravitreal antibiotics. Kushner and Meyers [16] also reported a patient who underwent strabismus surgery on an amblyopic eye and who was diagnosed with endophthalmitis due to Staphylococcus aureus 8 days after surgery. The patient underwent pars plana vitrectomy with intravitreal and subconjunctival antibiotic administration. This

child had hand motion vision at the time of diagnosis but ultimately recovered to 20/40, the level of vision present prior to strabismus surgery. Walton and Cohen [18] reported successful treatment of endophthalmitis due to Staphylococcus epider­ midis with intravitreal antibiotics and corticosteroids.

The Endophthalmitis Vitrectomy Study [19] provided guidelines regarding the use of intravitreal antibiotics and vitrectomy in patients with frank endophthalmitis following cataract surgery. Although translating these results to noncataract surgery-related cases of endophthalmitis may be controversial, the recommendations of the Endophthalmitis Vitrectomy Study probably have some application to endophthalmitis after strabismus surgery. The study demonstrated that if vision was light perception or worse, a pars plana vitrectomy with intravitreal administration of antibiotics was the treatment of choice. On the other hand, if vision was hand motion or better an intravitreal injection of antibiotics alone was appropriate. An intravitreal antibiotic regimen commonly used includes ceftazidime (2.25 µg/ml) and vancomycin (1 µg/ml) in an adult eye. While systemic treatment alone is insufficient, fourth generation fluoroquinolones may be an adjunct to maintain adequate intravitreal levels of antibiotics following intravitreal antibiotic administration.

Most strabismus surgery is performed on children, therefore special considerations for the treatment of endophthalmitis in children require clarification. First, assessment of vision in infants and young children may be impossible, rendering application of the Endophthalmitis Vitrectomy Study recommendations even more difficult. Second, the safety of systemic use of fourth generation fluoroquinolones in children is unclear. We will use these agents in children in consultation with an infectious disease specialist when indicated. It should be stressed that visual outcomes from endophthalmitis following strabismus surgery are often poor. Endophthalmitis after strabismus surgery is rare and there is a complete absence of clinical trials to provide evidence-based science on how to manage patients with this complication. Although the Endophthalmitis Vitrectomy Study may provide some useful guidelines, the population studied did not include patients with endophthalmitis following strabismus surgery.

Despite its infrequency, the poor visual outcome commonly associated with endophthalmitis after strabismus surgery justifies preventative measures. Prevention of all cases of endophthalmitis following strabismus surgery is probably not feasible. Rosenbaum [14] suggested that “minor” preoperative infections, which are often considered unimportant by operating surgeons, might need to be reevaluated. The frequency of upper respiratory tract infection or other minor infection in children at the time of strabismus surgery is high and it would be difficult, if not impossible, to demonstrate an association between ocular infection following surgery and the presence of such “minor” infection at the time of surgery. Concurrent systemic infection was not reported in the majority of cases of endophthalmitis reported in the literature.

The protective value of topical antibiotics following strabismus surgery is controversial. Kearns and Cullen [20] randomized 104 children undergoing strabismus surgery to one of 3 postoperative treatment regimens: (1) fucithalmic twice a day,

(2) chloramphenicol ointment twice a day, or (3) no treatment. The no treatment arm was discontinued early when three of the initial eight patients randomized to the nontreatment arm developed a “severe mucopurulent conjunctivitis and had to return to the hospital” for treatment. This occurred on the third postoperative day in each case and none of the patients developed endophthalmitis. Prompt improvement was noted upon initiation of topical antibiotic therapy in all three patients. Of 51 patients in the fucithalmic group, 1 (2%) returned 3 days after surgery because of marked conjunctivitis and grew Hemophilus influenza from the conjunctiva. Of 45 patients in the chloramphenicol group, 3 (7%) returned on the second or third postoperative day because of a “frank mucopurulent conjunctivitis,” while 1 patient still had discharge at 9 days that cleared after a change of the patient’s antibiotic regimen. These authors concluded that antibiotics should be used routinely in children following strabismus surgery. The frequency of significant mucopurulent discharge reported in this study in both the treated and placebo groups seems extraordinarily high in our experience, making application of the results of this study to routine practice difficult.

These findings are in contrast to the findings reported by other authors. Hagan and Dinning [21] randomized children to day surgery without medications or an overnight stay in the hospital with the use of postoperative oxyphenbutazone/chlor­ amphenicol ointment twice a day for 14 days. They found no difference in the level of inflammation or discomfort in either group. Wortham and co-workers [22] randomized each eye of 50 patients undergoing bilateral strabismus surgery to receive either a topical preparation of sulfacetamide-prednisolone solution or artificial tears. The patients were followed for 6 weeks after surgery for evidence of infection. No difference was found in the amount of lid swelling, corneal clarity, conjunctival injection, chemosis, or discharge among the treatment groups. These authors concluded that routine use of postoperative antibiotic drops as an adjunct to perioperative sterile preparation and prudent use of an antibiotic immediately at the culmination of surgery appeared to serve no benefit in otherwise uncomplicated strabismus surgery.

Probably more important is for the strabismus surgeon to be aware of the potential signs and symptoms of endophthalmitis and review these signs and symptoms with patients and families after surgery and ensure that patients have ready access to the surgeon or his/her covering physician in the days and weeks immediately following surgery in the event that a problem develops. In many if not most cases of endophthalmitis, there is a delay of several days from onset of signs and symptoms to diagnosis of endophthalmitis (>Table 22.1). Among the 18 reported cases of endophthalmitis summarized in Table 22.1 with both time of onset of symptoms and diagnosis reported, the range between onset of symptoms and diagnosis was zero to 9 days, with only four patients diagnosed on the day of onset of symptoms. Systemic signs and symptoms related to strabismus surgery are so uncommon and unexpected that children who experience systemic signs and symptoms of illness are often first seen by their pediatrician for evaluation of what is believed to be a viral syndrome. If the pediatrician does not recognize the presence of a serious intraocular

infection, treatment as a typical viral syndrome may be recommended. Only when signs and symptoms progress, or the child returns for his/her regularly scheduled postoperative office visit with the ophthalmologists will the correct diagnosis of endophthalmitis be made. Thus a discussion with patients and parents about the signs and symptoms of a serious infection and instructions on what to do if concern arises is important after surgery. Our experience with endophthalmitis following strabismus surgery in adults also suggests that intraocular infection following strabismus surgery may sometimes produce different signs and symptoms during the early course of the infection. Two adults who developed endophthalmitis initially complained of floaters and not pain. The vitreous showed clear evidence of infection but the anterior chambers was clear. The numerous signs and symptoms that have been reported are summarized in Table 22.2.

22.3Periocular Infection

(Orbital and Preseptal Cellulitis)

Orbital and preseptal cellulitis has been reported infrequently following strabismus surgery. Orbital cellulitis can be fulminant, presenting with the extreme proptosis, chemosis, eyelid swelling, and pain [23]. Prior to the discovery of antibiotics, the mortality rate from orbital cellulitis ranged from 20% to 50% and blindness occurred in 20% to 55% of survivors. The condition is rare enough following strabismus surgery that it may not be initially suspected and treatment may be delayed. Only a few cases reports about orbital cellulitis have populated the literature in the last few decades [24–27]. von Noorden has stated that the condition is either rare or that surgeons choose not to report it [25].

The validity of von Noorden’s statement may be underscored by the findings of the Periocular Infection Study Group [28], which surveyed members of the American Association for Pediatric Ophthalmology and Strabismus and identified 25 cases of cellulitis. Staphylococcus aureus was the cultured organism in the majority of cases. It has been suggested that cellulitis occurs following strabismus surgery in approximately 1 in 1100 cases [29].

Risk factors for development of cellulitis were not identified, but the authors raised the possibility that at least some of the infections might have been incidental. For example, one surgeon in the study group reported two patients who developed cellulitis after their strabismus surgery was cancelled because of the presence of an upper respiratory tract infection. Had surgery been performed, these infections would almost certainly have been characterized as a surgical complication. Another patient developed cellulitis in the unoperated eye associated with otitis media and bronchitis that was not recognized until after surgery.

Presenting signs and symptoms of cellulitis varied in this study, though marked swelling was noted in 24 (96%) of 25 patients and severe pain was reported by 17 (68%) of 25 patients. Other signs and symptoms that were reported are listed in Table 22.3. The patient and/or family typically became

Table 22.3. Ocular and systemic signs and symptoms of preseptal cellulitis after strabismus surgery [28] (Reproduced with permission from Kivlin JD and coworkers. Periocular infection after strabismus surgery. Journal of Pediatric Ophthalmology and Strabismus. Copyright © 1995, Slack, Inc.)

aware of unusual symptoms between 1 and 5 days following surgery. Fifty-six percent of the patients had experienced a routine postoperative course prior to the diagnosis of cellulitis. It has been our experience that the parent or patient who calls after surgery with a complaint of isolated lid swelling following strabismus surgery usually does not have cellulitis. On the other hand, the parent or patient who calls complaining of eyelid swelling and significant erythema almost always has cellulitis (>Fig. 22.2). Patients calling with concerns about lid swelling are therefore asked specifically about eyelid erythema.

Fig. 22.2. Preseptal cellulitis presenting 3 days following uncomplicated strabismus surgery

Possible predisposing factors that have been suggested include excessive eye rubbing, unsuspected sinusitis, unreliable family, and poor hygiene [28]. Two cases reported by the Periocular Infection Study Group [28] were initially managed by a primary care physician who did not appreciate the potential seriousness of the condition following ophthalmologic surgery. Thus, patients and parents should be advised to consult their ophthalmologist immediately if there is a concern about postoperative infection.

All cases of cellulitis in the Periocular Infection Study Group [28] report responded to antibiotic therapy, though only five were successfully treated with oral antibiotics alone, suggesting that hospitalization with intravenous antibiotics may be the preferred initial treatment option. This is in contrast to our experience with patients who present with postoperative preseptal cellulitis, who have generally responded favorably to oral antibiotics alone and hospitalization has rarely been necessary.

Good hygiene, hand washing, and avoidance of eye rubbing following surgery may have a beneficial prophylactic effect and should be encouraged. It is unclear if the presence of a concurrent minor infection adversely affects the rate of developing cellulitis. This is compounded by the fact that it is often difficult to diagnose an upper respiratory tract infection and/or

sinusitis preoperatively. Kivlin and co-workers [28] suggested that if an upper respiratory tract infection or infection elsewhere develops after strabismus surgery it is reasonable to consider prescribing oral antibiotics on the assumption that the infection could be bacterial, rather than to assume it is of viral origin, thus reducing the risk of developing an ocular or periocular infection.

22.4 Scleritis

Scleritis has been rarely reported following strabismus surgery. Because of its infrequency, it may be initially misdiagnosed and mismanaged. Hemady et al. [30] reported a case of scleritis in a 70-year-old man who began to complain of discomfort and ocular redness of his left eye following an inferior rectus muscle recession done to treat thyroid-related ophthalmopathy. His history was also notable for diabetes, hypertension, and atherosclerotic heart disease. He was initially treated for conjunctivitis and, when he failed to respond to treatment, he was referred for further evaluation 2 weeks later. B-scan ultrasonography revealed choroidal and scleral thickening, confirming a suspected diagnosis of posterior scleritis. Scleral

biopsy revealed neutrophil invasion of vessel walls and mononuclear perivasculitis. Proteus mirabilis was cultured from the sclera and the infection responded immediately to intravenous antibiotic administration. Sykes et al. [31] reported an 86-year- old women with scleritis due to Hemophilus influenza who had undergone strabismus surgery 10 years earlier.

22.5 Subconjunctival Abscess

Paakkala [32] reported 11 patients who developed a postoperative subconjunctival abscess at the operative site among 1467 muscles operated for strabismus. The problem was diagnosed an average of 7 days after surgery. Purulent material was noted near the suture while it was being removed in each case. Chromic gut suture had been used in six of the cases, plain gut suture in four cases, and Dacron suture in two cases. The presence of a subconjunctival abscess in association with endophthalmitis (and possibly casually related) has been reported [14]. Large subconjunctival abscesses can develop (>Fig. 22.3).

A subconjunctival abscess diagnosed following strabismus surgery should be surgically drained as soon as practical after it is recognized. Drainage can be done in the office or in the operating room, depending upon the severity and location of the abscess and cooperation of the patient. Oral antibiotics may be sufficient, but intravenous antibiotics may be considered in severe cases. Affected patients should undergo a dilated fundus examination and slit lamp examination to assess for intraocular infection and should be followed closely for development of endophthalmitis and/or orbital cellulitis. Affected patients should be advised of warning signs of these serious potential complications.

Fig. 22.3. Large subconjunctival abscess several days following strabismus surgery. (Courtesy of Richard A. Saunders, MD)

Chapter 22

22.6 Corneal Ulcer

Bedrossian [33] reported a 24-year-old healthy nurse who developed a corneal abscess due to Staphylococcus aureus 5 days following strabismus surgery. The patient developed a hypopyon 2 days later. She was treated with topical and oral antibiotics and had a favorable outcome. We are aware of one case of bilateral Pseudomonas corneal ulceration following corneal bridle suture placement to facilitate strabismus surgery. There are several reports of patients who developed neurotropic corneal ulceration following strabismus surgery, most with special susceptibility to the condition. Zehl and Snell [34] reported a 9-year-old boy with a fifth and seventh nerve palsy who underwent horizontal strabismus surgery. The child developed multifocal neurotropic corneal ulceration. He was treated with a contact lens and lubricating ointments and ultimately healed. These authors felt that operating on such an eye was associated with an increased risk of corneal ulceration, but they did not feel that the risk was unacceptable. Wintle et al. [35] reported a patient with Pendred syndrome who had a bilateral abducens nerve palsy. Two months following bilateral transposition surgery, the child developed corneal ulceration involving the inferior aspect of the left cornea. Marked reduction in corneal sensitivity was ultimately noted and the author suggested that corneal sensitivity should be evaluated prior to surgery in suspicious situations.

22.7 Concurrent Systemic Infections

The decision on whether to perform or postpone strabismus surgery on a patient with a concurrent systemic infection can be difficult. Certainly, a febrile patient or a patient with a known serious systemic infection should not undergo strabismus surgery. On the other hand, the presence of recently treated otitis media, mild ongoing sinusitis, and/or mild upper respiratory tract infection is quite common in the pediatric population, especially during the winter months. The infrequency of periocular and intraocular infection following strabismus surgery renders it difficult, if not impossible, to draw a clear association between the presence of such concurrent “minor” infections and the development of periocular and intraocular infection. The decision to operate should be made on a case-by-case basis after a discussion of the pros and cons of delaying surgery with the patient and/or parent.

In contrast, the presence of a periocular infection, such as severe blepharitis or a nasolacrimal duct obstruction, warrants serious consideration for postponing strabismus surgery until the condition has been resolved. Any condition that directly increases the level of bacterial exposure at the operative site has the potential to increase the risk of postoperative infection and thus strabismus surgery should be avoided in their presence. In a child with concurrent strabismus and nasolacrimal duct obstruction it is our practice to treat the nasolacrimal duct obstruction with a probing procedure and defer strabismus surgery until the lacrimal drainage system is functional, unless

such an obstruction is unilateral and the strabismus surgery can be performed on the nonobstructed eye.

22.8Subacute Bacterial Endocarditis Prophylaxis

Prophylactic antibiotic administration for patients who are susceptible to bacterial endocarditis is recommended for certain surgical procedures, such as surgery involving the respiratory tract, gastrointestinal tract, and the genitourinary tract. Prophylactic antibiotic administration is not required for strabismus surgery because of a low risk of bacteremia associated with strabismus surgery.

22.9 Concurrent Surgeries

Pediatricians and parents often wish to combine surgical procedures during a single operative setting to eliminate the need for a second trip to the operating room. The most common request we receive is to coordinate placement of myringotomy tubes and/or tonsillectomy and adenoidectomy. Is it safe to perform strabismus surgery in close association with one of these procedures? An answer to this question is not available through evidence-based medicine, and the decision should be made on a case-by-case basis. We base this decision on several factors including the general health of the child, the risk posed to the child by a second exposure to anesthesia, and the nature of the concurrent procedure that is proposed.

Not infrequently, the strabismus surgeon is asked to perform strabismus surgery on a child who is undergoing an adenoidectomy. Bacteremia has been reported in 14% of healthy children undergoing adenoidectomy [36] and up to 40% of healthy children undergoing tonsillectomy and adenoidectomy [37], although others have reported that the condition is rare [38]. Because the source of infection causing endophthalmitis following strabismus surgery is not known and because use of prophylactic antibiotics does not prevent bacteremia after adenoidectomy, some strabismus surgeons may feel uncomfortable recommending strabismus surgery in this setting and will recommend performing strabismus surgery on a separate day. Recognizing that the risk of endophthalmitis is very rare after strabismus surgery and that there is no hard evidence to support either position, it would be hard to disagree with either approach.

22.10 Special Situations

Monocular patients are at particular risk for life-altering consequences from vision loss in their sound eye. Strabismus surgery can be performed on a patient with severe unilateral visual impairment and sometimes is required on the sound eye in order to maximally correct the patient’s problem. Surgical prepa-

ration mandates a frank discussion with the patient about the associated risks and their potential consequences. Additional steps to reduce the risk of endophthalmitis may be considered such as utilizing techniques for strabismus surgery that do not require placement of sutures in the sclera (Chap. 21).

References

1.Schiff FS (1990) The shouting surgeon as a possible source of endophthalmitis. Ophthalmic Surg 21:438–440

2.Apt L, Miller KM (1992) Occult glove perforation during ophthalmic surgery. Trans Am Ophthalmol Soc 90:71–95

3.Wright JG, McGeer AJ, Chyatte D, Ransohoff DF (1991) Mechanisms of glove tears and sharp injuries among surgical personnel. J Am Med Assoc 266:1668–1671

4.Nakazawa M, Sato K, Mizuno K (1984) Incidence of perforations in rubber gloves during ophthalmic surgery. Ophthalmic Surg 15:236–240

5.Centers for Disease Control and Prevention (CDC) (1996) Outbreaks of postoperative bacterial endophthalmitis caused by intrinsically contaminated ophthalmic solutions – Thailand, 1992, and Canada, 1993. MMWR Morb Mortal Wkly Rep 45:491–494

6.Doyle A, Beigi B, Early A, Blake A, Eustace P, Hone R (1995) Adherence of bacteria to intraocular lenses: a prospective study. Br J Ophthalmol 79:347–349

7.Olitsky SE, Vilardo M, Awner S, Reynolds JD (1998) Needle sterility during strabismus surgery. J AAPOS 2:151–152

8.Carothers TS, Coats DK, McCreery KM et al (2003) Quantification of incidental needle and suture contamination during strabismus surgery. Binocul Vis Strabismus Q 18:75–79

9.Wang N, Coats DK, Paysse EA, Saunders RA, Wilson P, Rossman SN (2000) The significance of cryotherapy in reducing bacterial count during experimental scleral perforation. In: de Faber JT (ed) European Strabismological Association. Swets and Zeitlinger, Barcelona, pp 177–180

10.Knobloch R, Lorenz A (1962) [On serious complications after strabismus operations.] Klin Monatsbl Augenheilkd 141:348–353

11.Simon JW, Lininger LL, Scheraga JL (1992) Recognized scleral perforation during eye muscle surgery: incidence and sequelae. J Pediatr Ophthalmol Strabismus 29:273–275

12.Salamon SM, Friberg TR, Luxenberg MN (1982) Endophthalmitis after strabismus surgery. Am J Ophthalmol 93:39–41

13.Recchia FM, Baumal CR, Sivalingam A, Kleiner R, Duker JS, Vrabec TR (2000) Endophthalmitis after pediatric strabismus surgery. Arch Ophthalmol 118:939–944

14.Rosenbaum AL (2000) Endophthalmitis after strabismus surgery. Arch Ophthalmol 118:982–983

15.Good WV, Hing S, Irvine AR, Hoyt CS, Taylor DS (1990) Postoperative endophthalmitis in children following cataract surgery. J Pediatr Ophthalmol Strabismus 27:283–285

16.Kushner BJ, Meyers FL (1989) Good visual outcome after endophthalmitis in an eye previously treated successfully for amblyopia. J Pediatr Ophthalmol Strabismus 26:69–71

17.Uniat LM, Olk RJ, Kenneally CZ, Windsor CE (1988) Endophthalmitis after strabismus surgery with a good visual result. Ophthalmic Surg 19:42–43

18.Walton RC, Cohen AS (2004) Staphylococcus epidermidis endoph­ thalmitis following strabismus surgery. J AAPOS 8:592–593

19.Results of the Endophthalmitis Vitrectomy Study (1995) A randomized trial of immediate vitrectomy and of intravenous antibiotics for the treatment of postoperative bacterial endophthalmitis. Endophthalmitis Vitrectomy Study Group. Arch Ophthalmol 113:1479–1496

20.Kearns PP, Cullen JF (1992) Fucithalmic, chloramphenicol or no treatment after squint surgery in children. A single blind randomised study. Acta Ophthalmol (Copenh) 70:132–134

21.Hagan MC, Dinning WJ (1987) Day case strabismus surgery without post-operative ocular medication. A masked randomised study. Eye 1 (Pt 5):581–584

22.Wortham ET, Anandakrishnan I, Kraft SP, Smith D, Morin JD (1990) Are antibiotic-steroid drops necessary following strabismus surgery? A prospective, randomized, masked trial. J Pediatr Ophthalmol Strabismus 27:205–207

23.de Sa L, Hoyt CS, Good WV (1992) Complications of pediatric ophthalmic surgery. Int Ophthalmol Clin 32:31–39

24.Wilson ME, Paul TO (1987) Orbital cellulitis following strabismus surgery. Ophthalmic Surg 18:92–94

25.Von Noorden GK (1972) Orbital cellulitis following extraocular muscle surgery. Am J Ophthalmol 74:627–629

26.Weakley DR (1991) Orbital cellulitis complicating strabismus surgery: a case report and review of the literature. Ann Ophthalmol 23:454–457

27.Palamar M, Uretmen O, Kose S (2005) Orbital cellulitis after strabismus surgery. J AAPOS 9:602–603

28.Kivlin JD, Wilson ME Jr. (1995) Periocular infection after strabismus surgery. The Periocular Infection Study Group. J Pediatr Ophthalmol Strabismus 32:42–49

29.Locatcher-Khorazo D, Seegal BC, Gutierrez EH (1972) Postoperative infections of the eye. In: Locatcher-Khorazo D, Seegal BC (eds) Microbiology of the eye. CV Mosby, St Louis, Mo., pp 80–82

30.Hemady R, Sainz de la Maza M, Raizman MB, Foster CS (1992) Six cases of scleritis associated with systemic infection. Am J Ophthalmol 114:55–62

31.Sykes SO, Riemann C, Santos CI et al (1999) Haemophilus influ­ enzae associated scleritis. Br J Ophthalmol 83:410–413

32.Paakkala AM (1982) Surgical treatment of strabismus. A retrospective investigation of results of surgical treatment of horizontal strabismus. Acta Ophthalmol Suppl 156:1–107

33.Bedrossian EH (1966) Hypopyon keratitis: following muscle surgery. Am J Ophthalmol 61:1530–1532

34.Zehl DN, Snell AC (1977) Extraocular muscle surgery in the presence of complete paralysis of the fifth, sixth and seventh cranial nerves. J Pediatr Ophthalmol 14:76–78

35.Wintle RV, Choong YF, Laws DE (2003) Unilateral corneal anaesthesia and ulceration following squint surgery in a child with Pendred syndrome and bilateral sixth nerve palsy. Br J Ophthalmol 87:1192

36.Sanchez-Carrion S, Prim MP, De Diego JI, Sastre N, Pena-Garcia P (2005) Bacteremia following pediatric adenoidectomy. Int J Pediatr Otorhinolaryngol 69:1547–1550

37.Van Eyck M (1976) Bacteremia after tonsillectomy and adenectomy. Acta Otolaryngol 81:242–243

38.Okur E, Aral M, Yildirim I, Kilie MA, Ciragil P (2002) Bacteremia during adenoidectomy. Int J Pediatr Otorhinolaryngol 66:149–153

39.Havener WH, Kimball OP (1960) Scleral perforation during strabismus surgery. Am J Ophthalmol 50:807–808

40.Gottlieb F, Castro JL (1970) Perforation of the globe during strabismus surgery. Arch Ophthalmol 84:151–157

41.McNeer K (1975) Three complications of strabismus surgery. Ann Ophthalmol 7:441–446

42.Weinstein GS, Mondino BJ, Weinberg RJ, Biglan AW (1979) Endophthalmitis in a pediatric population. Ann Ophthalmol 11:935–943

43.Apple DJ, Jones GR, Reidy JJ, Loftfield K (1985) Ocular perforation and phthisis bulbi secondary to strabismus surgery. J Pediatr Ophthalmol Strabismus 22:184–187

44.Bialasiewicz AA, Ruprecht KW, Naumann GO (1990) [Staphylococcal endophthalmitis following squint surgery.] Klin Monatsbl Augenheilkd 196:86–88

45.Thomas JW, Hamill MB, Lambert HM (1993) Streptococcus pneumoniae endophthalmitis following strabismus surgery. Arch Ophthalmol 111:1170–1171

46.Thorne JE, Maguire AM (2000) Hemophilus aegyptius endophthalmitis following strabismus surgery. J Pediatr Ophthalmol Strabismus 37:52–53

47.Ruby A, Shaikh S, Khammar AJ, Trese M (2005) Suprachoroidal septic effusion leading to panophthalmitis following strabismus surgery. J Pediatr Ophthalmol Strabismus 42:250–252