Seminars in Ophthalmology
ISSN: 0882-0538 (Print) 1744-5205 (Online) Journal homepage: http://www.tandfonline.com/loi/isio20
Management of Corneal Bee Sting Injuries Ruju R. Rai, Luis A. Gonzalez-Gonzalez, Thanos D. Papakostas, Donna Siracuse-Lee, Robert Dunphy, Lisa Fanciullo, Tulay Cakiner-Egilmez & Mary K. Daly To cite this article: Ruju R. Rai, Luis A. Gonzalez-Gonzalez, Thanos D. Papakostas, Donna Siracuse-Lee, Robert Dunphy, Lisa Fanciullo, Tulay Cakiner-Egilmez & Mary K. Daly (2017) Management of Corneal Bee Sting Injuries, Seminars in Ophthalmology, 32:2, 177-181, DOI: 10.3109/08820538.2015.1045301 To link to this article: http://dx.doi.org/10.3109/08820538.2015.1045301
Published online: 02 Feb 2017.
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Date: 08 February 2017, At: 08:08
Seminars in Ophthalmology, 2017; 32(2 ): 1 77 –1 81 © Taylor & Francis ISSN: 0882-0538 print / 1744-5205 online DOI: 10.3109/08820538.2015.1045301
ORIGINAL ARTICLE
Management of Corneal Bee Sting Injuries Ruju R. Rai1,2,3,4, Luis A. Gonzalez-Gonzalez1,3,4, Thanos D. Papakostas1,3,4, Donna Siracuse-Lee1,2, Robert Dunphy1, Lisa Fanciullo1, Tulay Cakiner-Egilmez1, and Mary K. Daly1,2,3 1
Veterans Affairs Boston Healthcare System, Boston, MA, USA, 2Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA, 3Department of Ophthalmology, Harvard Medical School, Boston, MA, USA, and 4Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
ABSTRACT Purpose: To review the management of keratitis after corneal bee stings and to report a case of deep stromal corneal infiltrate secondary to a retained bee stinger managed conservatively in a patient who presented three days after unsanitary manipulation of the stinger apparatus. Methods: Case report and review of literature. Results: A 57-year-old male beekeeper was evaluated for pain, blurry vision, and photosensitivity after a corneal bee sting. Of note, the venom sac had been removed with dirty tweezers three days prior to his visit. On exam, a focal infiltrate with diffuse edema was seen surrounding a retained bee stinger in the peripheral cornea. Trace cells in the anterior chamber were also noted. Based on a high suspicion for infectious keratitis, a conservative treatment strategy was elected. Administration of broad-spectrum topical antibiotics with concomitant abstention of corticosteroids led to rapid resolution of the symptoms. Over 16 months of follow-up, the stinger has remained in situ without migration and the patient has maintained 20/20 visual acuity without complications. There is debate on the preferred method for the management of corneal injury secondary to bee stings, especially when it is associated with a retained stinger. We herein present our findings in our appraisal of reported cases. Conclusion: In the aftermath of an ocular bee sting, close surveillance for inflammation and infection is essential. Individual manifestations of these injuries vary in timing, type, and severity; therefore, the accessibility of the stinger and the evolving clinical picture should guide therapeutic decisions. Keywords: Bee sting, cornea, endothelial cell, hymenoptera, keratitis, specular microscopy, stinger removal, trauma, venom
INTRODUCTION
The substantial variation in clinical presentation and outcomes from case to case has made it difficult to establish a therapeutic algorithm for corneal bee stings. Among 50 articles on the topic since the earliest case report in 1955,9 there is no consensus regarding whether to treat conservatively or aggressively, especially when a retained stinger is involved. At a minimum, appropriate care typically requires expeditious ophthalmologic evaluation, tetanus prophylaxis, and conventional agents for pain relief and antibiotic coverage.10 However, beyond these steps, decisions about removal of the stinger and the use of corticosteroids are a matter of debate.
Corneal bee stings are an infrequent form of eye trauma characterized by penetrating, infectious, toxic, and immunologic complications. The ocular response to this injury spans a spectrum from mild, local reactions in the conjunctiva and cornea to severe, extensive reactions involving other structures like the lens, optic nerve, or extraocular muscles.1–6 The considerable compositional differences in poison gland secretions among different bee species are thought to be a contributory factor to the wide range in the degree of response.7,8
Received 21 March 2014; revised 30 December 2014; accepted 12 April 2015; published online 10 July 2015 Correspondence: Mary K. Daly, M.D., Veterans Affairs Boston Healthcare System, Department of Ophthalmology, 150 S Huntington Ave., 8C-29, Jamaica Plain, MA 02130, USA. E-mail: [email protected] Color versions of one or more figures in the article can be found online at www.tandfonline.com/isio.
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This uncertainty is fueled by the nonspecific nature of acute inflammation, which in the case of bee stings can simultaneously be a reaction to microbial pathogens, the foreign material, and/or chemical/ mechanical damage. We herein describe a case of corneal infiltrate and edema associated with a retained bee stinger fragment after attempted extraction in unsterile conditions. Management was based on the presumption of an infectious keratitis given the history, signs, and symptoms. With this specific case as our launch pad, the purpose of this paper is to review the current therapeutic approaches of corneal bee sting injuries to add to the body of knowledge in the management of corneal trauma from bee stings, with a focus on infection in the differential diagnosis.
CLINICAL SUMMARY A 57-year-old male with past ocular history of herpes simplex keratitis of the left eye was working outdoors when he was stung by a bee in his right eye. Using unwashed hands and a pair of unclean forceps, his son immediately detached the portion of the stinger coupled to the venom sac. The patient developed symptoms of blurry vision, throbbing pain, and photosensitivity; he visited a local emergency department and was started on topical moxifloxacin and sublingual diphenhydramine.
Three days later, the patient presented to our clinic with persistent symptoms. Best-corrected visual acuity in the right eye was 20/25. On examination with the unaided eye, the right upper and lower eyelids were slightly edematous, the conjunctiva was injected, and the cornea was hazy with diffuse edema (Figure 1A). On slit-lamp examination, a dense, focal, 1 by 1 millimeter anterior-to-mid stromal infiltrate was observed in the temporal peripheral cornea; adjacent to the infiltrate, inferonasally, there was an area of reverse fluorescein staining consistent with the stinger entry point; directly posterior to the infiltrate a 1.5-millimeter angled stinger was embedded in the mid-stroma (Figure 1A–C). The anterior chamber was deep with trace cells. Anterior segment optical coherence tomography (AS-OCT) reaffirmed the slit-lamp findings and showed that the stinger was confined to the cornea (Figure 1D). Corneal pachymetry (CCT) revealed a central corneal thickness of 669 mm. Specular microscopy was inconclusive due to corneal edema. The dilated fundus exam was unremarkable. Both infectious and inflammatory etiologies were considered. However, in the context of significant risk factors, including microbe-carrying honey bees, the environmental setting of a farm, contact with nonsterile hands and instruments, and the duration of onset for the infiltrate, there was sufficient concern to treat for an infectious process and to defer the use of corticosteroids. Taking into account the deep stromal location of the infiltrate, we refrained from procuring
FIGURE 1. Clinical findings OD on day 1 post-trauma. (A) Mild diffuse conjunctival hyperemia and chemosis. At the 9 o’clock position (arrow), medial to the limbus, a 1.5 mm stinger with surrounding focal area of a dense white infiltrate can be visualized. (B) Close-up view of the stinger surrounded by a thick infiltrate. (C) In optical cross-section, the infiltrate can be localized in the anterior stroma. (D) Anterior segment ocular coherence tomography confirms location of the infiltrate and additionally shows that it overlies the retained stinger. The stinger is embedded in the anterior to mid-stroma and does not penetrate into the anterior chamber. Seminars in Ophthalmology
Management of Corneal Bee Sting Injuries specimens for culture and PCR analysis to safeguard against the risk of corneal perforation during the procedure. An empirical regimen of topical broadspectrum antimicrobials (vancomycin 31 mg/ml, tobramycin 14 mg/ml, and moxifloxacin 5 mg/ml), a topical antihistamine/mast cell stabilizer (ketotifen 0.25 mg/ml), a cycloplegic (cyclopentolate 10 mg/ml), and an oral antihistamine (loratidine 10 mg tab) was initiated. A decision was made not to pursue surgical management, given the location of the stinger and high suspicion of active infection. Five days later, visual acuity had recovered to 20/20 and the CCT had decreased to 582 mm. The conjunctival injection, corneal edema, and Descemet’s folds had significantly decreased. The anterior chamber was deep and quiet. At one week, the corneal edema had resolved, and the infiltrate had begun to clear (Figure 2A–D). Antibiotic coverage was narrowed to moxifloxacin only and the antihistamine was tapered off.
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Over the next several weeks, the CCT normalized to 542 mm, the endothelial cell count was 3054 mm, and the corneal infiltrate resolved completely, leaving behind a corneal scar (Figure 2E–F). All drops were stopped and the patient was followed at monthly intervals to monitor for late-onset sequelae. As of 16 months post-injury, there has been no evidence of complications.
DISCUSSION AND LITERATURE REVIEW There is debate on the preferred approach for the management of corneal injuries secondary to bee stings, especially when associated with a retained stinger.11 Venom from retained stingers is known to engender a spectrum of complications, including keratoconjunctivitis, endothelial degeneration, glaucoma, hyphema, cataract formation, lens subluxation,
FIGURE 2. Clinical findings OD: One (A–D) and five (E–F) weeks post-trauma follow-up visits. (A) Slit-lamp photograph showing a significant reduction of the infiltrate and edema one week post-injury. (B–D) In optical cross-section and ASOCT, there is a marked improvement in the clarity of the cornea and more defined margins of the infiltrate. (E–F) At five weeks post-injury, the eye is quiet and tolerating the foreign body. Note that there is a residual anterior stromal scar.
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uveitis, vitritis, optic neuritis, and chorioretinopathy.1–6,8,10,12–26 The most widely accepted method for the management of insect foreign bodies is to remove the exogenous material after ruling out intraocular involvement, followed by a treatment protocol analogous to that used for corneal abrasions.27 Accordingly, some have advocated extraction of the stinger in patients with corneal infiltrate and/or edema of any location or severity, under the rationale that the absence of the offending agent would lead to a rapid regression in the inflammatory response, thereby reducing the risk of complications and avoiding the necessity for chronic corticosteroid use. Previous reports of the complications from the failure to withdraw the stinger promptly lend validity to this approach, including a recent case in which a retained stinger induced chronic, recurrent keratouveitis unresponsive to topical steroids, ultimately requiring surgical removal for resolution of the inflammatory symptoms.24 Alternatively, a more conservative strategy has been suggested based on the premise that as long as the venom has been abolished or neutralized (e.g., venom sac removed), the chitinous exoskeleton is inert and can reside in the cornea without triggering inflammation of the surrounding tissue.1,2,18,28 There have been reported cases in which the stinger had resorbed or remained in place asymptomatically for many years.1,8,15,29,30 For example, Gilboa et al. described a patient who presented with decreased visual acuity and was found to have a retained, intralenticular wasp stinger for 28 years without inflammatory insult.1 Moreover, there is also concern that the manual pressure inevitably exerted via manipulation of the retained stinger apparatus during extraction attempts may not only disperse the venom to unexposed tissue, but may also cause mechanical damage due to shearing tractional forces from the barbed lancet configuration.1,8,18,30 Patients who had had partial removal of the stinger have been reported to experience severe chronic complications in the aftermath of the failed procedure (e.g., endothelial cell loss, iris atrophy, uveitis, corneal decompensation, cataract, and optic atrophy).15,21 Weighing these risks, many authors suggest treating medically before resorting to surgical intervention. The discourse on stinger removal within the literature can be roughly delineated into the aforementioned two schools of thought, but because the published evidence on the subject is largely restricted to case reports, individual opinions vary widely. In our appraisal of 26 cases of ocular bee sting with retained stinger over the last 28 years, the convention of extracting the foreign body was adhered to 77% of the time.2,4–6,8,10,15,18–21,23–26,29–32 An array of techniques, including forceps, needles, endoillumination guidance, and various types of keratectomy, have been attempted to extract bee stingers with mixed
success.2,4–6,10,15,18–21,23–26,29,31,32 We most closely agree with the recommendations of Razmjoo et al.10 In their two-stage management scheme, they suggest immediately pulling out the stinger if it is readily accessible or there is a dramatic primary reaction involving the visual axis. Eyes which do not fall into this category may be treated medically and monitored closely. Goddard et al. depicted an intermediate scenario in which this more nuanced scheme would have been instructive.29 Manual stinger removal was aborted when the delicate stinger could not easily be grasped with forceps. With the stinger in situ, the reaction took approximately one month to settle and the stinger migrated posteriorly with associated dense inferior corneal scarring below the visual axis. The eye eventually regained 6/6 vision, but had the infiltrate been slightly more central or had the inflammation continued to progress, the provider may have had to reattempt stinger extraction. The numerous risk factors for infectious keratitis in our patient’s history confounded whether the inflammatory reaction surrounding the retained stinger fragment was an infectious response to invading microorganisms, a toxic response to the venom, or an allergic response to the foreign body. In addition, the stinger’s position in the deep stroma would have made its retrieval technically difficult. Therefore, after confirming with ancillary tests that there was no ocular penetration, we chose to leave the stinger in situ and to closely monitor.8,29,30 Had the location of the stinger and infiltrate affected the visual axis, we might have considered a more aggressive surgical approach; in this case, however, the central cornea was clear apart from reactive edema. Irrespective of whether surgical intervention is pursued, the subtleties of medical management add another layer of complexity to the treatment course for corneal bee sting injuries. Because the predominant process responsible for the damage (i.e., penetrating, infectious, toxic, and immunologic) fluctuates from case to case, it can be difficult to decide the composition, dose, and duration of the regimen. Corticosteroids were used in roughly 79% of the existing case reports on ocular bee stings to suppress inflammation,1–6,8,10,13,15–17,20,21,23–27,30,31,33 likely because the majority of complications are caused by reactions to chemical mediators of the injected venom.10,23 Nonetheless, bacteria grow in 14% of corneal foreign body cultures;34 stingers, which are organic foreign bodies, have been associated with infectious complications (e.g., mucopurulent keratoconjunctivitis, hypopyon, infectious uveitis).10,18 In our case, we believed that the early removal of the venom sac may have reduced the burden of venom toxicity, while at the same time subjecting the patient to a higher risk of infectious inoculation, since it was performed without adequate antiseptic measures. Seminars in Ophthalmology
Management of Corneal Bee Sting Injuries The succeeding progression of infiltrate over the next three days without the presence of the venom sac furthered our concerns for infectious keratitis and convinced us to defer the use of corticosteroids. Keeping in mind that both coagulase-negative staphylococcus and pseudomonas have been formerly implicated with infection after corneal bee sting,18,34,35 we prescribed broad-spectrum antimicrobial agents, also adding coverage for atypical organisms in light of the agricultural setting. The quick reduction of the infiltrate following empirical antibiotic therapy suggests that, although there may have been a minor inflammatory component contributing, the predominant underlying process was infectious. Finally, because bee sting injuries have been associated with endothelial damage even six months to a year post-trauma, we included serial analysis of cell density, size, and shape with specular microscopy as part of our long-term surveillance. Several other authors have used this convenient office technique as an adjunct to slit-lamp biomicroscopy for tracking the progress of therapy and determining the optimal duration and intervals for follow-up.15,23,25,26 In conclusion, a thorough clinical history and detailed examination dictate the management of corneal bee stings, particularly with respect to stinger removal and the choice of medications. Regardless of the treatment route, all patients must be monitored closely for long-term complications.
DECLARATION OF INTEREST The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.
REFERENCES 1. Gilboa M, Gdal-On M, Zonis S. Bee and wasp stings of the eye: Retained intralenticular wasp sting: A case report. Br J Ophthalmol 1977;61(10):662–664. 2. Smolin G, Wong I. Bee sting of the cornea: Case report. Ann Ophthalmol (Skokie) 1982;14(4):342–343. 3. Singh G. Bee sting of the cornea. Ann Ophthalmol (Skokie) 1984;16(4):320–322. 4. Chen CJ, Richardson CD. Bee sting-induced ocular changes. Ann Ophthalmol (Skokie) 1986;18(10):285–286. 5. Yildirim N, Erol N, Basmak H. Bee sting of the cornea: A case report. Cornea 1998;17(3):333–334. 6. Lin PH, Wang NK, Hwang YS, et al. Bee sting of the cornea and conjunctiva: Management and outcomes. Cornea 2011; 30(4):392–394. 7. Schmidt JO, Blum MS, Overal WL. Comparative enzymology of venoms from stinging Hymenoptera. Toxicon 1986; 24(9):907–921. 8. Arcieri ES, Franca ET, de Oliveria HB, et al. Ocular lesions arising after stings by hymenopteran insects. Cornea 2002; 21(3):328–330. 9. Krannig HD. Scleral injury caused by bee sting, with posterior cortical cataract. Klin Monbl Augenheilkd Augenarztl Fortbild 1955;126(6):750–753.
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10. Razmjoo H, Abtahi MA, Roomizadeh P, et al. Management of corneal bee sting. Clin Ophthalmol 2011;5: 1697–1700. 11. Roomizadeh P, Razmjoo H, Abtahi MA, Abtahi SH. Management of corneal bee sting: Is surgical removal of a retained stinger always indicated? Int Ophthalmol 2013; 33(1):1–2. 12. Goldstein NP, Rucker CW, Klass DW. Encephalopathy and papilledema after bee sting. JAMA 1964;188:1083–1084. 13. Song HS, Wray SH. Bee sting optic neuritis: A case report with visual evoked potentials. J Clin Neuroophthalmol 1991; 11(1):45–49. 14. Kitagawa K, Hayasaka S, Setogawa T. Wasp sting-induced retinal damage. Ann Ophthalmol 1993;25(4):157–158. 15. Chuah G, Law E, Chan WK, Ang CL. Case reports and mini review of bee stings of the cornea. Singapore Med J 1996;37(4):389–391. 16. Choi MY, Cho SH. Optic neuritis after bee sting. Korean J Ophthalmol 2000;14(1):49–52. 17. Maltzman JS, Lee AG, Miller NR. Optic neuropathy occurring after bee and wasp sting. Ophthalmology 2000; 107(1):193–195. 18. Smith DG, Roberge RJ. Corneal bee sting with retained stinger. J Emerg Med 2001;20(2):125–128. 19. Al-Towerki AE. Corneal honeybee sting. Cornea 2003; 22(7):672–674. 20. Pal N, Azad RV, Sharma YR, et al. Bee stinginduced ciliochoroidal detachment. Eye (Lond) 2005; 19(9):1025–1026. 21. Teoh SC, Lee JJ, Fam HB. Corneal honeybee sting. Can J Ophthalmol 2005;40(4):469–471. 22. Chinwattanakul S, Prabhasawat P, Kongsap P. Corneal injury by bee sting with retained stinger: A case report. J Med Assoc Thai 2006;89(10):1766–1769. 23. Gurlu VP, Erda N. Corneal bee sting-induced endothelial changes. Cornea 2006;25(8):981–983. 24. Jain V, Shome D, Natarajan S. Corneal bee sting misdiagnosed as viral keratitis. Cornea 2007;26(10):1277–1278. 25. Hammel N, Bahar I. Descemet-stripping automated endothelial keratoplasty after bee sting of the cornea. J Cataract Refract Surg 2011;37(9):1726–1728. 26. Chauhan D. Corneal honey bee sting: Endoilluminatorassisted removal of retained stinger. Int Ophthalmol 2012; 32(3):285–288. 27. Hamill MB. Mechanical injury. In: Krachmer JH, Mannis MJ, Holland EJ, eds., Cornea, Vol 1, pp. 1169–1185. Maryland Heights, MO: Mosby/Elsevier, 2010. 28. Tuft SJ, Crompton DO, Coster DJ. Insect sting in a cornea. American Journal of Ophthalmology 1985;99(6):727–728. 29. Goddard SJ. Bee sting through the cornea. Med J Aust 1959; 46(16):530–531. 30. Yuen KS, Lai JS, Law RW, Lam DS. Confocal microscopy in bee sting corneal injury. Eye (Lond) 2003; 17(7):845–847. 31. Hasanee K, Carlsson A, ten Hove MW. Corneal bee sting: Full-thickness penetration in a patient wearing a contact lens. Can J Ophthalmol 2004;39(5):548–551. 32. Chaurasia S, Muralidhar R. Retained bee stinger in the tarsal plate. Int Ophthalmol 2011;31(2):111–112. 33. Berrios RR, Serrano LA. Bilateral optic neuritis after a bee sting. American Journal of Ophthalmology 1994; 117(5):677–678. 34. DeBroff BM, Donahue SP, Caputo BJ, et al. Clinical characteristics of corneal foreign bodies and their associated culture results. Clao J 1994;20(2):128–130. 35. Babushkin AE, Gimranov RM. Injury of the cornea by a bee sting complicated by Pseudomonas aeruginosa and herpesvirus infections. Vestn Oftalmol 1990;106(5):65.
ISSN: 0882-0538 (Print) 1744-5205 (Online) Journal homepage: http://www.tandfonline.com/loi/isio20
Management of Corneal Bee Sting Injuries Ruju R. Rai, Luis A. Gonzalez-Gonzalez, Thanos D. Papakostas, Donna Siracuse-Lee, Robert Dunphy, Lisa Fanciullo, Tulay Cakiner-Egilmez & Mary K. Daly To cite this article: Ruju R. Rai, Luis A. Gonzalez-Gonzalez, Thanos D. Papakostas, Donna Siracuse-Lee, Robert Dunphy, Lisa Fanciullo, Tulay Cakiner-Egilmez & Mary K. Daly (2017) Management of Corneal Bee Sting Injuries, Seminars in Ophthalmology, 32:2, 177-181, DOI: 10.3109/08820538.2015.1045301 To link to this article: http://dx.doi.org/10.3109/08820538.2015.1045301
Published online: 02 Feb 2017.
Submit your article to this journal
Article views: 5
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=isio20 Download by: [The UC San Diego Library]
Date: 08 February 2017, At: 08:08
Seminars in Ophthalmology, 2017; 32(2 ): 1 77 –1 81 © Taylor & Francis ISSN: 0882-0538 print / 1744-5205 online DOI: 10.3109/08820538.2015.1045301
ORIGINAL ARTICLE
Management of Corneal Bee Sting Injuries Ruju R. Rai1,2,3,4, Luis A. Gonzalez-Gonzalez1,3,4, Thanos D. Papakostas1,3,4, Donna Siracuse-Lee1,2, Robert Dunphy1, Lisa Fanciullo1, Tulay Cakiner-Egilmez1, and Mary K. Daly1,2,3 1
Veterans Affairs Boston Healthcare System, Boston, MA, USA, 2Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA, 3Department of Ophthalmology, Harvard Medical School, Boston, MA, USA, and 4Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
ABSTRACT Purpose: To review the management of keratitis after corneal bee stings and to report a case of deep stromal corneal infiltrate secondary to a retained bee stinger managed conservatively in a patient who presented three days after unsanitary manipulation of the stinger apparatus. Methods: Case report and review of literature. Results: A 57-year-old male beekeeper was evaluated for pain, blurry vision, and photosensitivity after a corneal bee sting. Of note, the venom sac had been removed with dirty tweezers three days prior to his visit. On exam, a focal infiltrate with diffuse edema was seen surrounding a retained bee stinger in the peripheral cornea. Trace cells in the anterior chamber were also noted. Based on a high suspicion for infectious keratitis, a conservative treatment strategy was elected. Administration of broad-spectrum topical antibiotics with concomitant abstention of corticosteroids led to rapid resolution of the symptoms. Over 16 months of follow-up, the stinger has remained in situ without migration and the patient has maintained 20/20 visual acuity without complications. There is debate on the preferred method for the management of corneal injury secondary to bee stings, especially when it is associated with a retained stinger. We herein present our findings in our appraisal of reported cases. Conclusion: In the aftermath of an ocular bee sting, close surveillance for inflammation and infection is essential. Individual manifestations of these injuries vary in timing, type, and severity; therefore, the accessibility of the stinger and the evolving clinical picture should guide therapeutic decisions. Keywords: Bee sting, cornea, endothelial cell, hymenoptera, keratitis, specular microscopy, stinger removal, trauma, venom
INTRODUCTION
The substantial variation in clinical presentation and outcomes from case to case has made it difficult to establish a therapeutic algorithm for corneal bee stings. Among 50 articles on the topic since the earliest case report in 1955,9 there is no consensus regarding whether to treat conservatively or aggressively, especially when a retained stinger is involved. At a minimum, appropriate care typically requires expeditious ophthalmologic evaluation, tetanus prophylaxis, and conventional agents for pain relief and antibiotic coverage.10 However, beyond these steps, decisions about removal of the stinger and the use of corticosteroids are a matter of debate.
Corneal bee stings are an infrequent form of eye trauma characterized by penetrating, infectious, toxic, and immunologic complications. The ocular response to this injury spans a spectrum from mild, local reactions in the conjunctiva and cornea to severe, extensive reactions involving other structures like the lens, optic nerve, or extraocular muscles.1–6 The considerable compositional differences in poison gland secretions among different bee species are thought to be a contributory factor to the wide range in the degree of response.7,8
Received 21 March 2014; revised 30 December 2014; accepted 12 April 2015; published online 10 July 2015 Correspondence: Mary K. Daly, M.D., Veterans Affairs Boston Healthcare System, Department of Ophthalmology, 150 S Huntington Ave., 8C-29, Jamaica Plain, MA 02130, USA. E-mail: [email protected] Color versions of one or more figures in the article can be found online at www.tandfonline.com/isio.
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This uncertainty is fueled by the nonspecific nature of acute inflammation, which in the case of bee stings can simultaneously be a reaction to microbial pathogens, the foreign material, and/or chemical/ mechanical damage. We herein describe a case of corneal infiltrate and edema associated with a retained bee stinger fragment after attempted extraction in unsterile conditions. Management was based on the presumption of an infectious keratitis given the history, signs, and symptoms. With this specific case as our launch pad, the purpose of this paper is to review the current therapeutic approaches of corneal bee sting injuries to add to the body of knowledge in the management of corneal trauma from bee stings, with a focus on infection in the differential diagnosis.
CLINICAL SUMMARY A 57-year-old male with past ocular history of herpes simplex keratitis of the left eye was working outdoors when he was stung by a bee in his right eye. Using unwashed hands and a pair of unclean forceps, his son immediately detached the portion of the stinger coupled to the venom sac. The patient developed symptoms of blurry vision, throbbing pain, and photosensitivity; he visited a local emergency department and was started on topical moxifloxacin and sublingual diphenhydramine.
Three days later, the patient presented to our clinic with persistent symptoms. Best-corrected visual acuity in the right eye was 20/25. On examination with the unaided eye, the right upper and lower eyelids were slightly edematous, the conjunctiva was injected, and the cornea was hazy with diffuse edema (Figure 1A). On slit-lamp examination, a dense, focal, 1 by 1 millimeter anterior-to-mid stromal infiltrate was observed in the temporal peripheral cornea; adjacent to the infiltrate, inferonasally, there was an area of reverse fluorescein staining consistent with the stinger entry point; directly posterior to the infiltrate a 1.5-millimeter angled stinger was embedded in the mid-stroma (Figure 1A–C). The anterior chamber was deep with trace cells. Anterior segment optical coherence tomography (AS-OCT) reaffirmed the slit-lamp findings and showed that the stinger was confined to the cornea (Figure 1D). Corneal pachymetry (CCT) revealed a central corneal thickness of 669 mm. Specular microscopy was inconclusive due to corneal edema. The dilated fundus exam was unremarkable. Both infectious and inflammatory etiologies were considered. However, in the context of significant risk factors, including microbe-carrying honey bees, the environmental setting of a farm, contact with nonsterile hands and instruments, and the duration of onset for the infiltrate, there was sufficient concern to treat for an infectious process and to defer the use of corticosteroids. Taking into account the deep stromal location of the infiltrate, we refrained from procuring
FIGURE 1. Clinical findings OD on day 1 post-trauma. (A) Mild diffuse conjunctival hyperemia and chemosis. At the 9 o’clock position (arrow), medial to the limbus, a 1.5 mm stinger with surrounding focal area of a dense white infiltrate can be visualized. (B) Close-up view of the stinger surrounded by a thick infiltrate. (C) In optical cross-section, the infiltrate can be localized in the anterior stroma. (D) Anterior segment ocular coherence tomography confirms location of the infiltrate and additionally shows that it overlies the retained stinger. The stinger is embedded in the anterior to mid-stroma and does not penetrate into the anterior chamber. Seminars in Ophthalmology
Management of Corneal Bee Sting Injuries specimens for culture and PCR analysis to safeguard against the risk of corneal perforation during the procedure. An empirical regimen of topical broadspectrum antimicrobials (vancomycin 31 mg/ml, tobramycin 14 mg/ml, and moxifloxacin 5 mg/ml), a topical antihistamine/mast cell stabilizer (ketotifen 0.25 mg/ml), a cycloplegic (cyclopentolate 10 mg/ml), and an oral antihistamine (loratidine 10 mg tab) was initiated. A decision was made not to pursue surgical management, given the location of the stinger and high suspicion of active infection. Five days later, visual acuity had recovered to 20/20 and the CCT had decreased to 582 mm. The conjunctival injection, corneal edema, and Descemet’s folds had significantly decreased. The anterior chamber was deep and quiet. At one week, the corneal edema had resolved, and the infiltrate had begun to clear (Figure 2A–D). Antibiotic coverage was narrowed to moxifloxacin only and the antihistamine was tapered off.
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Over the next several weeks, the CCT normalized to 542 mm, the endothelial cell count was 3054 mm, and the corneal infiltrate resolved completely, leaving behind a corneal scar (Figure 2E–F). All drops were stopped and the patient was followed at monthly intervals to monitor for late-onset sequelae. As of 16 months post-injury, there has been no evidence of complications.
DISCUSSION AND LITERATURE REVIEW There is debate on the preferred approach for the management of corneal injuries secondary to bee stings, especially when associated with a retained stinger.11 Venom from retained stingers is known to engender a spectrum of complications, including keratoconjunctivitis, endothelial degeneration, glaucoma, hyphema, cataract formation, lens subluxation,
FIGURE 2. Clinical findings OD: One (A–D) and five (E–F) weeks post-trauma follow-up visits. (A) Slit-lamp photograph showing a significant reduction of the infiltrate and edema one week post-injury. (B–D) In optical cross-section and ASOCT, there is a marked improvement in the clarity of the cornea and more defined margins of the infiltrate. (E–F) At five weeks post-injury, the eye is quiet and tolerating the foreign body. Note that there is a residual anterior stromal scar.
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uveitis, vitritis, optic neuritis, and chorioretinopathy.1–6,8,10,12–26 The most widely accepted method for the management of insect foreign bodies is to remove the exogenous material after ruling out intraocular involvement, followed by a treatment protocol analogous to that used for corneal abrasions.27 Accordingly, some have advocated extraction of the stinger in patients with corneal infiltrate and/or edema of any location or severity, under the rationale that the absence of the offending agent would lead to a rapid regression in the inflammatory response, thereby reducing the risk of complications and avoiding the necessity for chronic corticosteroid use. Previous reports of the complications from the failure to withdraw the stinger promptly lend validity to this approach, including a recent case in which a retained stinger induced chronic, recurrent keratouveitis unresponsive to topical steroids, ultimately requiring surgical removal for resolution of the inflammatory symptoms.24 Alternatively, a more conservative strategy has been suggested based on the premise that as long as the venom has been abolished or neutralized (e.g., venom sac removed), the chitinous exoskeleton is inert and can reside in the cornea without triggering inflammation of the surrounding tissue.1,2,18,28 There have been reported cases in which the stinger had resorbed or remained in place asymptomatically for many years.1,8,15,29,30 For example, Gilboa et al. described a patient who presented with decreased visual acuity and was found to have a retained, intralenticular wasp stinger for 28 years without inflammatory insult.1 Moreover, there is also concern that the manual pressure inevitably exerted via manipulation of the retained stinger apparatus during extraction attempts may not only disperse the venom to unexposed tissue, but may also cause mechanical damage due to shearing tractional forces from the barbed lancet configuration.1,8,18,30 Patients who had had partial removal of the stinger have been reported to experience severe chronic complications in the aftermath of the failed procedure (e.g., endothelial cell loss, iris atrophy, uveitis, corneal decompensation, cataract, and optic atrophy).15,21 Weighing these risks, many authors suggest treating medically before resorting to surgical intervention. The discourse on stinger removal within the literature can be roughly delineated into the aforementioned two schools of thought, but because the published evidence on the subject is largely restricted to case reports, individual opinions vary widely. In our appraisal of 26 cases of ocular bee sting with retained stinger over the last 28 years, the convention of extracting the foreign body was adhered to 77% of the time.2,4–6,8,10,15,18–21,23–26,29–32 An array of techniques, including forceps, needles, endoillumination guidance, and various types of keratectomy, have been attempted to extract bee stingers with mixed
success.2,4–6,10,15,18–21,23–26,29,31,32 We most closely agree with the recommendations of Razmjoo et al.10 In their two-stage management scheme, they suggest immediately pulling out the stinger if it is readily accessible or there is a dramatic primary reaction involving the visual axis. Eyes which do not fall into this category may be treated medically and monitored closely. Goddard et al. depicted an intermediate scenario in which this more nuanced scheme would have been instructive.29 Manual stinger removal was aborted when the delicate stinger could not easily be grasped with forceps. With the stinger in situ, the reaction took approximately one month to settle and the stinger migrated posteriorly with associated dense inferior corneal scarring below the visual axis. The eye eventually regained 6/6 vision, but had the infiltrate been slightly more central or had the inflammation continued to progress, the provider may have had to reattempt stinger extraction. The numerous risk factors for infectious keratitis in our patient’s history confounded whether the inflammatory reaction surrounding the retained stinger fragment was an infectious response to invading microorganisms, a toxic response to the venom, or an allergic response to the foreign body. In addition, the stinger’s position in the deep stroma would have made its retrieval technically difficult. Therefore, after confirming with ancillary tests that there was no ocular penetration, we chose to leave the stinger in situ and to closely monitor.8,29,30 Had the location of the stinger and infiltrate affected the visual axis, we might have considered a more aggressive surgical approach; in this case, however, the central cornea was clear apart from reactive edema. Irrespective of whether surgical intervention is pursued, the subtleties of medical management add another layer of complexity to the treatment course for corneal bee sting injuries. Because the predominant process responsible for the damage (i.e., penetrating, infectious, toxic, and immunologic) fluctuates from case to case, it can be difficult to decide the composition, dose, and duration of the regimen. Corticosteroids were used in roughly 79% of the existing case reports on ocular bee stings to suppress inflammation,1–6,8,10,13,15–17,20,21,23–27,30,31,33 likely because the majority of complications are caused by reactions to chemical mediators of the injected venom.10,23 Nonetheless, bacteria grow in 14% of corneal foreign body cultures;34 stingers, which are organic foreign bodies, have been associated with infectious complications (e.g., mucopurulent keratoconjunctivitis, hypopyon, infectious uveitis).10,18 In our case, we believed that the early removal of the venom sac may have reduced the burden of venom toxicity, while at the same time subjecting the patient to a higher risk of infectious inoculation, since it was performed without adequate antiseptic measures. Seminars in Ophthalmology
Management of Corneal Bee Sting Injuries The succeeding progression of infiltrate over the next three days without the presence of the venom sac furthered our concerns for infectious keratitis and convinced us to defer the use of corticosteroids. Keeping in mind that both coagulase-negative staphylococcus and pseudomonas have been formerly implicated with infection after corneal bee sting,18,34,35 we prescribed broad-spectrum antimicrobial agents, also adding coverage for atypical organisms in light of the agricultural setting. The quick reduction of the infiltrate following empirical antibiotic therapy suggests that, although there may have been a minor inflammatory component contributing, the predominant underlying process was infectious. Finally, because bee sting injuries have been associated with endothelial damage even six months to a year post-trauma, we included serial analysis of cell density, size, and shape with specular microscopy as part of our long-term surveillance. Several other authors have used this convenient office technique as an adjunct to slit-lamp biomicroscopy for tracking the progress of therapy and determining the optimal duration and intervals for follow-up.15,23,25,26 In conclusion, a thorough clinical history and detailed examination dictate the management of corneal bee stings, particularly with respect to stinger removal and the choice of medications. Regardless of the treatment route, all patients must be monitored closely for long-term complications.
DECLARATION OF INTEREST The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.
REFERENCES 1. Gilboa M, Gdal-On M, Zonis S. Bee and wasp stings of the eye: Retained intralenticular wasp sting: A case report. Br J Ophthalmol 1977;61(10):662–664. 2. Smolin G, Wong I. Bee sting of the cornea: Case report. Ann Ophthalmol (Skokie) 1982;14(4):342–343. 3. Singh G. Bee sting of the cornea. Ann Ophthalmol (Skokie) 1984;16(4):320–322. 4. Chen CJ, Richardson CD. Bee sting-induced ocular changes. Ann Ophthalmol (Skokie) 1986;18(10):285–286. 5. Yildirim N, Erol N, Basmak H. Bee sting of the cornea: A case report. Cornea 1998;17(3):333–334. 6. Lin PH, Wang NK, Hwang YS, et al. Bee sting of the cornea and conjunctiva: Management and outcomes. Cornea 2011; 30(4):392–394. 7. Schmidt JO, Blum MS, Overal WL. Comparative enzymology of venoms from stinging Hymenoptera. Toxicon 1986; 24(9):907–921. 8. Arcieri ES, Franca ET, de Oliveria HB, et al. Ocular lesions arising after stings by hymenopteran insects. Cornea 2002; 21(3):328–330. 9. Krannig HD. Scleral injury caused by bee sting, with posterior cortical cataract. Klin Monbl Augenheilkd Augenarztl Fortbild 1955;126(6):750–753.
© 2017 Taylor & Francis
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10. Razmjoo H, Abtahi MA, Roomizadeh P, et al. Management of corneal bee sting. Clin Ophthalmol 2011;5: 1697–1700. 11. Roomizadeh P, Razmjoo H, Abtahi MA, Abtahi SH. Management of corneal bee sting: Is surgical removal of a retained stinger always indicated? Int Ophthalmol 2013; 33(1):1–2. 12. Goldstein NP, Rucker CW, Klass DW. Encephalopathy and papilledema after bee sting. JAMA 1964;188:1083–1084. 13. Song HS, Wray SH. Bee sting optic neuritis: A case report with visual evoked potentials. J Clin Neuroophthalmol 1991; 11(1):45–49. 14. Kitagawa K, Hayasaka S, Setogawa T. Wasp sting-induced retinal damage. Ann Ophthalmol 1993;25(4):157–158. 15. Chuah G, Law E, Chan WK, Ang CL. Case reports and mini review of bee stings of the cornea. Singapore Med J 1996;37(4):389–391. 16. Choi MY, Cho SH. Optic neuritis after bee sting. Korean J Ophthalmol 2000;14(1):49–52. 17. Maltzman JS, Lee AG, Miller NR. Optic neuropathy occurring after bee and wasp sting. Ophthalmology 2000; 107(1):193–195. 18. Smith DG, Roberge RJ. Corneal bee sting with retained stinger. J Emerg Med 2001;20(2):125–128. 19. Al-Towerki AE. Corneal honeybee sting. Cornea 2003; 22(7):672–674. 20. Pal N, Azad RV, Sharma YR, et al. Bee stinginduced ciliochoroidal detachment. Eye (Lond) 2005; 19(9):1025–1026. 21. Teoh SC, Lee JJ, Fam HB. Corneal honeybee sting. Can J Ophthalmol 2005;40(4):469–471. 22. Chinwattanakul S, Prabhasawat P, Kongsap P. Corneal injury by bee sting with retained stinger: A case report. J Med Assoc Thai 2006;89(10):1766–1769. 23. Gurlu VP, Erda N. Corneal bee sting-induced endothelial changes. Cornea 2006;25(8):981–983. 24. Jain V, Shome D, Natarajan S. Corneal bee sting misdiagnosed as viral keratitis. Cornea 2007;26(10):1277–1278. 25. Hammel N, Bahar I. Descemet-stripping automated endothelial keratoplasty after bee sting of the cornea. J Cataract Refract Surg 2011;37(9):1726–1728. 26. Chauhan D. Corneal honey bee sting: Endoilluminatorassisted removal of retained stinger. Int Ophthalmol 2012; 32(3):285–288. 27. Hamill MB. Mechanical injury. In: Krachmer JH, Mannis MJ, Holland EJ, eds., Cornea, Vol 1, pp. 1169–1185. Maryland Heights, MO: Mosby/Elsevier, 2010. 28. Tuft SJ, Crompton DO, Coster DJ. Insect sting in a cornea. American Journal of Ophthalmology 1985;99(6):727–728. 29. Goddard SJ. Bee sting through the cornea. Med J Aust 1959; 46(16):530–531. 30. Yuen KS, Lai JS, Law RW, Lam DS. Confocal microscopy in bee sting corneal injury. Eye (Lond) 2003; 17(7):845–847. 31. Hasanee K, Carlsson A, ten Hove MW. Corneal bee sting: Full-thickness penetration in a patient wearing a contact lens. Can J Ophthalmol 2004;39(5):548–551. 32. Chaurasia S, Muralidhar R. Retained bee stinger in the tarsal plate. Int Ophthalmol 2011;31(2):111–112. 33. Berrios RR, Serrano LA. Bilateral optic neuritis after a bee sting. American Journal of Ophthalmology 1994; 117(5):677–678. 34. DeBroff BM, Donahue SP, Caputo BJ, et al. Clinical characteristics of corneal foreign bodies and their associated culture results. Clao J 1994;20(2):128–130. 35. Babushkin AE, Gimranov RM. Injury of the cornea by a bee sting complicated by Pseudomonas aeruginosa and herpesvirus infections. Vestn Oftalmol 1990;106(5):65.
