SUBRETINAL ABSCESS AFTER STRABISMUS SURGERY: CASE REPORT AND LITERATURE REVIEW Chirag C. Patel, MD,* David T. Goldenberg, MD,† Michael T. Trese, MD,*† Mark K. Walsh, MD, PhD,† Edward R. O’Malley, MD‡
Purpose: The purpose of this study is to describe the first reported case of a subretinal abscess after strabismus surgery and the successful treatment with vitrectomy, intravitreal antibiotics, and cryotherapy. Methods: This is a retrospective case report and literature review. Results: A 4-year-old boy underwent uncomplicated bilateral medial rectus muscle recession. Within 9 days after surgery, he developed unilateral endophthalmitis with a subretinal abscess at the approximate location of the medial rectus muscle insertion. The rectus muscle-scleral suture was removed, and transscleral cryotherapy was applied to the abscess site. Vitrectomy with injection of intravitreal antibiotics was performed. A bacterial culture of the removed suture was positive for Staphylococcus aureus and sensitive to his antibiotics. By 1 month, the abscess and vitritis had resolved completely. Conclusion: This is the first reported case of endophthalmitis with a subretinal abscess occurring after strabismus surgery. In general, endophthalmitis after strabismus surgery has a poor visual prognosis. Early diagnosis and intervention with intravitreal antibiotics and possible vitrectomy may be advantageous for patients with a subretinal abscess. RETINAL CASES & BRIEF REPORTS 5:6–9, 2011
inability to verbalize their symptoms often results in a delay in their diagnosis.2 Herein, we describe a child with endophthalmitis and a subretinal abscess after strabismus surgery that was successfully treated with vitrectomy, antibiotics, and adjunctive cryotherapy.
From the *Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan; †Associated Retinal Consultants, Royal Oak, Michigan; and ‡Henry Ford Grosse Pointe Ophthalmology, Grosse Pointe Park, Michigan.
E
ndophthalmitis after strabismus surgery is extremely rare, with an estimated incidence as low as 1 in 185,000 cases.1 The development of a subretinal abscess after strabismus surgery is presumed to be even less common, and to our knowledge, it has not been reported in the English language literature. Treatment options for such patients have traditionally included antibiotics (topical, intravitreal, and systemic), topical corticosteroids, and vitrectomy. Despite appropriate and prompt treatment, the visual prognosis for these patients is generally very poor.2,3 This especially holds true for children because the
Case Report A previously healthy 4-year-old boy with a history of esotropia underwent uncomplicated bilateral medial rectus muscle recession. During the operation, all sutures were passed without evidence of scleral perforation. Nine days later, the child had difficulty in opening his left eye, and his mother noted increased conjunctival redness for several days. Visual acuity was unavailable because of poor patient cooperation. External examination demonstrated photophobia, a serous ocular discharge, and periocular tissues that were tender to palpation. The conjunctiva of the left eye exhibited significant injection (Figure 1). A dilated funduscopic examination under anesthesia showed moderate vitritis and inflammatory debris in the left eye. A shallow, white subretinal lesion consistent with a subretinal abscess was visible in the nasal periphery at the approximate location of the medial rectus muscle insertion (Figure 2). The findings of an examination of the right eye were within normal limits.
None of the authors has any financial interest in this manuscript. Reprint requests: David T. Goldenberg, MD, Associated Retinal Consultants, 3535 West 13 Mile Road, Ste. #344, Royal Oak, MI 48073; e-mail: [email protected]
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performed, and a sample of vitreous fluid was sent for culture. All sclerotomies were sutured closed, and vancomycin 1.0 mg and ceftazidime 2.25 mg were injected into the vitreous cavity. Oral levofloxacin antibiotics were initiated, and on postoperative Day 1, topical prednisolone acetate, atropine sulfate, and gentamicin eye drops were started. On postoperative Day 3, the suture culture was positive for Staphylococcus aureus with sensitivity to vancomycin and levofloxacin. The vitreous fluid culture did not yield any organisms. An examination under anesthesia was performed on postoperative Day 4, which showed decreased vitreous haze. Mild retinal edema from the cryotherapy surrounded the subretinal abscess. There was a persistent vitreous opacity overlying the abscess, and vancomycin 1.0 mg and ceftazidime 2.25 mg were again injected into the midvitreous cavity. A repeat examination under anesthesia on postoperative Day 8 demonstrated significant clearing of the vitritis. The child continued to improve, and, at 1 month postoperatively, there was a complete resolution of the vitreous inflammation with clear media (Figure 3A) and a residual chorioretinal scar at the cryotherapy site (Figure 3B). He was able to fix and follow with each eye.
Discussion
Fig. 1. External photograph of the left eye exhibiting a marked conjunctival injection.
A nasal peritomy was performed to expose the insertion of the medial rectus muscle of the left eye. The rectus muscle-scleral suture was identified and found to be free of purulent material. The suture was removed and sent for culture. The area was irrigated with vancomycin, and transcleral cryotherapy was applied to the entire subretinal abscess, using a freeze-thaw technique to 280°C under direct visualization. A core vitrectomy was
Fig. 2. Fundus photograph of the left eye demonstrating moderate vitritis and a white subretinal abscess in the nasal periphery.
Subretinal abscess formation is a very rare ophthalmic finding.4 It has most often been reported as an uncommon presentation of endogenous bacterial endophthalmitis, especially in immunocompromised patients.4 The only reported case of a subretinal abscess caused by an exogenous source occurred after a scleral buckling procedure.5 Through our search of Medline, we found no other reports in the English language literature of subretinal abscess formation after ophthalmic surgery. To our knowledge, we described the first case of a subretinal abscess occurring after strabismus surgery. The etiology of subretinal abscess formation after strabismus surgery is unclear. It is commonly assumed that bacteria may gain access to the choroid and subretinal space through a scleral perforation during a suture pass. Scleral perforation during strabismus surgery is rare and is estimated to occur in 0.13%1 to 1.8%6 of cases. Nevertheless, endophthalmitis can develop after strabismus surgery without scleral perforation. In the largest case series to date, Recchia et al2 reported six cases of endophthalmitis after pediatric strabismus surgery without scleral perforation. The authors suggested a small abscess may form in the thinnest part of the sclera posterior to the muscle insertion, which may progress to intraocular infection.2 Furthermore, Olitsky et al7 have shown that needles used during strabismus surgery may be a source of bacterial contamination in 15% to 24% of cases. Therefore, bacteria may be deposited intrasclerally without actual scleral perforation. Although scleral perforation did not occur in our
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RETINAL CASES & BRIEF REPORTS´ 2011 VOLUME 5 NUMBER 1
Fig. 3. A, Fundus photo-graph of the left eye showing resolution of the vitritis and mild pigmentary changes 1 month after treatment. B, Fundus photograph of the nasal periphery showing resolution of the subretinal abscess with a residual chorioretinal scar.
patient, his subretinal abscess was likely caused by suture contamination, given the positive bacterial growth from the suture culture. In further support of this theory is the observation that the suture was located adjacent to the abscess. Our patient’s vitreous culture was negative, and it is possible that the infection was contained in the subretinal space with a secondary sterile vitritis, although a negative vitreous sample does not necessarily rule out infectious endophthalmitis. Even though endophthalmitis after strabismus surgery is rare, the visual prognosis is usually very poor despite appropriate treatment.2 Through our search of Medline, we found fewer than 20 cases of endophthalmitis after strabismus surgery, approximately two thirds of them resulting in no light perception vision. In contrast to these generally poor outcomes, our patient’s improvement can be attributed to the early diagnosis of his subretinal abscess by his pediatric ophthalmologist and our aggressive
intervention with antibiotics (topical, intravitreal, and systemic), vitrectomy, removal of the contaminated suture, and adjunctive cryotherapy to the abscess site. Our patient likely benefited from all aspects of our multitiered therapy, including the initial cryotherapy application to the abscess. Sipperley and Shore8 described a case in which cryotherapy was applied after external drainage of a septic retinal cyst from endogenous endophthalmitis. To our knowledge, this is the first reported case of cryotherapy used in the management of a subretinal abscess. Intravitreal antibiotics, alone or in combination with systemic antibiotics, may fail to sterilize an abscess located in the subretinal space. In other areas of the body, abscesses are routinely incised because systemic antibiotics often fail to penetrate the abscess wall. During cryotherapy, intracellular ice crystal forms, thereby causing mechanical damage and eventual dissolution of cellular membranes.9 The extreme temperatures from the freeze-thaw cycle may also have an immediate bactericidal effect. In addition, cryotherapy may irritate the wall of an abscess and potentially improve antibiotic penetration into the nidus of infection. The technique also has the advantage of avoiding more complicated surgical maneuvers such as external drainage or retinotomies to access the subretinal abscess, which can lead to further complications including retinal detachment, proliferative vitreoretinopathy, and the need for additional surgery. However, it is impossible to determine what benefit, if any, cryotherapy offered in this isolated case, given the use of multiple treatment modalities. Furthermore, the sclera in areas of muscle insertions and in areas of suture abscesses may be thin, and aggressive scleral depression or excessive cryotherapy may cause scleral perforation. Because children are less likely to verbalize their symptoms, physicians should have a low threshold for repeating an examination after pediatric ophthalmic surgery. Patients with a subretinal abscess or endophthalmitis after pediatric strabismus surgery may benefit from a combination of treatments, including vitrectomy and antibiotic administration. Cryotherapy may add to a surgeon’s armamentarium in the management of a subretinal abscess. Key words: cryotherapy, endophthalmitis, intravitreal antibiotics, strabismus surgery, subretinal abscess. References 1. Simon JW, Lininger LL, Scheraga JL. Recognized scleral perforation during eye muscle surgery: incidence and sequelae. J Pediatr Ophthalmol Strabismus 1992;29:273–275.
SUBRETINAL ABSCESS AFTER STRABISMUS SURGERY 2. Recchia FM, Baurmal CR, Sivalingam A, et al. Endophthalmitis after pediatric strabismus surgery. Arch Ophthalmol 2000;118:939–944. 3. Ruby A, Shaikh S, Khammar AJ, Trese M. Suprachoroidal septic effusion leading to panophthalmitis following strabismus surgery. J Pediatr Ophthalmol Strabismus 2005;42:250–252 4. Harris EW, D’Amico DJ, Bhisitkul R, et al. Bacterial subretinal abscess: a case report and review of the literature. Am J Ophthalmol 2000;129:778–785. 5. Tay E, Bainbridge J, da Cruz L. Subretinal abscess after scleral buckling surgery: a rare risk of retinal surgery. Can J Ophthalmol 2007;42:141–142.
9 6. Noel LP, Bloom JN, Clarke WN, Bawazeer A. Retinal perforation in strabismus surgery. J Pediatr Ophthalmol Strabismus 1997;34:115–117. 7. Olitsky SE, Vilardo M, Awner S, Reynolds JP. Needle sterility during strabismus surgery. J AAPOS 1998;2: 151–152. 8. Sipperley JO, Shore JW. Septic retinal cyst in endogenous klebsiella endophthalmitis. Am J Ophthalmol 1982;94: 124–125. 9. Wilkinson CP, Rice TA. Michels Retinal Detachment. 2nd ed. St. Louis, MO: Mosby; 1997:391–395.
Purpose: The purpose of this study is to describe the first reported case of a subretinal abscess after strabismus surgery and the successful treatment with vitrectomy, intravitreal antibiotics, and cryotherapy. Methods: This is a retrospective case report and literature review. Results: A 4-year-old boy underwent uncomplicated bilateral medial rectus muscle recession. Within 9 days after surgery, he developed unilateral endophthalmitis with a subretinal abscess at the approximate location of the medial rectus muscle insertion. The rectus muscle-scleral suture was removed, and transscleral cryotherapy was applied to the abscess site. Vitrectomy with injection of intravitreal antibiotics was performed. A bacterial culture of the removed suture was positive for Staphylococcus aureus and sensitive to his antibiotics. By 1 month, the abscess and vitritis had resolved completely. Conclusion: This is the first reported case of endophthalmitis with a subretinal abscess occurring after strabismus surgery. In general, endophthalmitis after strabismus surgery has a poor visual prognosis. Early diagnosis and intervention with intravitreal antibiotics and possible vitrectomy may be advantageous for patients with a subretinal abscess. RETINAL CASES & BRIEF REPORTS 5:6–9, 2011
inability to verbalize their symptoms often results in a delay in their diagnosis.2 Herein, we describe a child with endophthalmitis and a subretinal abscess after strabismus surgery that was successfully treated with vitrectomy, antibiotics, and adjunctive cryotherapy.
From the *Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan; †Associated Retinal Consultants, Royal Oak, Michigan; and ‡Henry Ford Grosse Pointe Ophthalmology, Grosse Pointe Park, Michigan.
E
ndophthalmitis after strabismus surgery is extremely rare, with an estimated incidence as low as 1 in 185,000 cases.1 The development of a subretinal abscess after strabismus surgery is presumed to be even less common, and to our knowledge, it has not been reported in the English language literature. Treatment options for such patients have traditionally included antibiotics (topical, intravitreal, and systemic), topical corticosteroids, and vitrectomy. Despite appropriate and prompt treatment, the visual prognosis for these patients is generally very poor.2,3 This especially holds true for children because the
Case Report A previously healthy 4-year-old boy with a history of esotropia underwent uncomplicated bilateral medial rectus muscle recession. During the operation, all sutures were passed without evidence of scleral perforation. Nine days later, the child had difficulty in opening his left eye, and his mother noted increased conjunctival redness for several days. Visual acuity was unavailable because of poor patient cooperation. External examination demonstrated photophobia, a serous ocular discharge, and periocular tissues that were tender to palpation. The conjunctiva of the left eye exhibited significant injection (Figure 1). A dilated funduscopic examination under anesthesia showed moderate vitritis and inflammatory debris in the left eye. A shallow, white subretinal lesion consistent with a subretinal abscess was visible in the nasal periphery at the approximate location of the medial rectus muscle insertion (Figure 2). The findings of an examination of the right eye were within normal limits.
None of the authors has any financial interest in this manuscript. Reprint requests: David T. Goldenberg, MD, Associated Retinal Consultants, 3535 West 13 Mile Road, Ste. #344, Royal Oak, MI 48073; e-mail: [email protected]
6
7
SUBRETINAL ABSCESS AFTER STRABISMUS SURGERY
performed, and a sample of vitreous fluid was sent for culture. All sclerotomies were sutured closed, and vancomycin 1.0 mg and ceftazidime 2.25 mg were injected into the vitreous cavity. Oral levofloxacin antibiotics were initiated, and on postoperative Day 1, topical prednisolone acetate, atropine sulfate, and gentamicin eye drops were started. On postoperative Day 3, the suture culture was positive for Staphylococcus aureus with sensitivity to vancomycin and levofloxacin. The vitreous fluid culture did not yield any organisms. An examination under anesthesia was performed on postoperative Day 4, which showed decreased vitreous haze. Mild retinal edema from the cryotherapy surrounded the subretinal abscess. There was a persistent vitreous opacity overlying the abscess, and vancomycin 1.0 mg and ceftazidime 2.25 mg were again injected into the midvitreous cavity. A repeat examination under anesthesia on postoperative Day 8 demonstrated significant clearing of the vitritis. The child continued to improve, and, at 1 month postoperatively, there was a complete resolution of the vitreous inflammation with clear media (Figure 3A) and a residual chorioretinal scar at the cryotherapy site (Figure 3B). He was able to fix and follow with each eye.
Discussion
Fig. 1. External photograph of the left eye exhibiting a marked conjunctival injection.
A nasal peritomy was performed to expose the insertion of the medial rectus muscle of the left eye. The rectus muscle-scleral suture was identified and found to be free of purulent material. The suture was removed and sent for culture. The area was irrigated with vancomycin, and transcleral cryotherapy was applied to the entire subretinal abscess, using a freeze-thaw technique to 280°C under direct visualization. A core vitrectomy was
Fig. 2. Fundus photograph of the left eye demonstrating moderate vitritis and a white subretinal abscess in the nasal periphery.
Subretinal abscess formation is a very rare ophthalmic finding.4 It has most often been reported as an uncommon presentation of endogenous bacterial endophthalmitis, especially in immunocompromised patients.4 The only reported case of a subretinal abscess caused by an exogenous source occurred after a scleral buckling procedure.5 Through our search of Medline, we found no other reports in the English language literature of subretinal abscess formation after ophthalmic surgery. To our knowledge, we described the first case of a subretinal abscess occurring after strabismus surgery. The etiology of subretinal abscess formation after strabismus surgery is unclear. It is commonly assumed that bacteria may gain access to the choroid and subretinal space through a scleral perforation during a suture pass. Scleral perforation during strabismus surgery is rare and is estimated to occur in 0.13%1 to 1.8%6 of cases. Nevertheless, endophthalmitis can develop after strabismus surgery without scleral perforation. In the largest case series to date, Recchia et al2 reported six cases of endophthalmitis after pediatric strabismus surgery without scleral perforation. The authors suggested a small abscess may form in the thinnest part of the sclera posterior to the muscle insertion, which may progress to intraocular infection.2 Furthermore, Olitsky et al7 have shown that needles used during strabismus surgery may be a source of bacterial contamination in 15% to 24% of cases. Therefore, bacteria may be deposited intrasclerally without actual scleral perforation. Although scleral perforation did not occur in our
8
RETINAL CASES & BRIEF REPORTS´ 2011 VOLUME 5 NUMBER 1
Fig. 3. A, Fundus photo-graph of the left eye showing resolution of the vitritis and mild pigmentary changes 1 month after treatment. B, Fundus photograph of the nasal periphery showing resolution of the subretinal abscess with a residual chorioretinal scar.
patient, his subretinal abscess was likely caused by suture contamination, given the positive bacterial growth from the suture culture. In further support of this theory is the observation that the suture was located adjacent to the abscess. Our patient’s vitreous culture was negative, and it is possible that the infection was contained in the subretinal space with a secondary sterile vitritis, although a negative vitreous sample does not necessarily rule out infectious endophthalmitis. Even though endophthalmitis after strabismus surgery is rare, the visual prognosis is usually very poor despite appropriate treatment.2 Through our search of Medline, we found fewer than 20 cases of endophthalmitis after strabismus surgery, approximately two thirds of them resulting in no light perception vision. In contrast to these generally poor outcomes, our patient’s improvement can be attributed to the early diagnosis of his subretinal abscess by his pediatric ophthalmologist and our aggressive
intervention with antibiotics (topical, intravitreal, and systemic), vitrectomy, removal of the contaminated suture, and adjunctive cryotherapy to the abscess site. Our patient likely benefited from all aspects of our multitiered therapy, including the initial cryotherapy application to the abscess. Sipperley and Shore8 described a case in which cryotherapy was applied after external drainage of a septic retinal cyst from endogenous endophthalmitis. To our knowledge, this is the first reported case of cryotherapy used in the management of a subretinal abscess. Intravitreal antibiotics, alone or in combination with systemic antibiotics, may fail to sterilize an abscess located in the subretinal space. In other areas of the body, abscesses are routinely incised because systemic antibiotics often fail to penetrate the abscess wall. During cryotherapy, intracellular ice crystal forms, thereby causing mechanical damage and eventual dissolution of cellular membranes.9 The extreme temperatures from the freeze-thaw cycle may also have an immediate bactericidal effect. In addition, cryotherapy may irritate the wall of an abscess and potentially improve antibiotic penetration into the nidus of infection. The technique also has the advantage of avoiding more complicated surgical maneuvers such as external drainage or retinotomies to access the subretinal abscess, which can lead to further complications including retinal detachment, proliferative vitreoretinopathy, and the need for additional surgery. However, it is impossible to determine what benefit, if any, cryotherapy offered in this isolated case, given the use of multiple treatment modalities. Furthermore, the sclera in areas of muscle insertions and in areas of suture abscesses may be thin, and aggressive scleral depression or excessive cryotherapy may cause scleral perforation. Because children are less likely to verbalize their symptoms, physicians should have a low threshold for repeating an examination after pediatric ophthalmic surgery. Patients with a subretinal abscess or endophthalmitis after pediatric strabismus surgery may benefit from a combination of treatments, including vitrectomy and antibiotic administration. Cryotherapy may add to a surgeon’s armamentarium in the management of a subretinal abscess. Key words: cryotherapy, endophthalmitis, intravitreal antibiotics, strabismus surgery, subretinal abscess. References 1. Simon JW, Lininger LL, Scheraga JL. Recognized scleral perforation during eye muscle surgery: incidence and sequelae. J Pediatr Ophthalmol Strabismus 1992;29:273–275.
SUBRETINAL ABSCESS AFTER STRABISMUS SURGERY 2. Recchia FM, Baurmal CR, Sivalingam A, et al. Endophthalmitis after pediatric strabismus surgery. Arch Ophthalmol 2000;118:939–944. 3. Ruby A, Shaikh S, Khammar AJ, Trese M. Suprachoroidal septic effusion leading to panophthalmitis following strabismus surgery. J Pediatr Ophthalmol Strabismus 2005;42:250–252 4. Harris EW, D’Amico DJ, Bhisitkul R, et al. Bacterial subretinal abscess: a case report and review of the literature. Am J Ophthalmol 2000;129:778–785. 5. Tay E, Bainbridge J, da Cruz L. Subretinal abscess after scleral buckling surgery: a rare risk of retinal surgery. Can J Ophthalmol 2007;42:141–142.
9 6. Noel LP, Bloom JN, Clarke WN, Bawazeer A. Retinal perforation in strabismus surgery. J Pediatr Ophthalmol Strabismus 1997;34:115–117. 7. Olitsky SE, Vilardo M, Awner S, Reynolds JP. Needle sterility during strabismus surgery. J AAPOS 1998;2: 151–152. 8. Sipperley JO, Shore JW. Septic retinal cyst in endogenous klebsiella endophthalmitis. Am J Ophthalmol 1982;94: 124–125. 9. Wilkinson CP, Rice TA. Michels Retinal Detachment. 2nd ed. St. Louis, MO: Mosby; 1997:391–395.
