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Orthokeratology-Associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong
Accepted Manuscript Orthokeratology-associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong Tommy CY. Chan, Emmy YM. Li, Victoria WY. Wong, Vishal Jhanji PII:
S0002-9394(14)00528-5
DOI:
10.1016/j.ajo.2014.08.026
Reference:
AJOPHT 9039
To appear in:
American Journal of Ophthalmology
Received Date: 14 July 2014 Revised Date:
19 August 2014
Accepted Date: 19 August 2014
Please cite this article as: Chan TC, Li EY, Wong VW, Jhanji V, Orthokeratology-associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong, American Journal of Ophthalmology (2014), doi: 10.1016/j.ajo.2014.08.026. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Orthokeratology-associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong
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1,2 Tommy CY Chan 1,2 Emmy YM Li 1,2 Victoria WY Wong
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1 Hong Kong Eye Hospital, Hong Kong SAR, China
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1,2 Vishal Jhanji
2 Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
Short title: Orthokeratology-associated Keratitis in Hong Kong
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Financial support / Conflict of interest: Nil Financial disclosures: None
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Keywords: Orthokeratology, Infectious Keratitis, Treatment; Complications
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Corresponding author: Vishal Jhanji, MD Department of Ophthalmology and Visual Sciences The Chinese University of Hong Kong Hong Kong Tel: +852 39435807 Fax: +852 27159490 E-mail: [email protected]
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Abstract Purpose: To analyze cases of orthokeratology-associated infectious keratitis managed in a tertiary care eye hospital in Hong Kong between 2003 and 2013. Design: Retrospective study Methods: Case records of patients with infectious keratitis due to orthokeratology contact lenses were analyzed. Data analyzed included clinical features, microbiological evaluation, and treatment outcomes. Results: A total of 23 patients were included (16 females, 7 males, mean age, 15.0 ± 4.2 years; range: 9 to 23 years). All patients were using overnight orthokeratology for an average of 2.7 ± 2.8 years (range: 3 months to 10 years) before the onset of infection. Clinical features included corneal infiltrate (n=14, 60.86%), and corneal perineuritis (n=12, 52.17%). Fifteen eyes (65.2%) had a positive microbiological culture obtained from corneal scrapings. The most commonly isolated organism was Pseudomonas aeruginosa (n=6) followed by coagulase-negative Staphylococcus (n=5) and Acanthamoeba (n=3). Five cases of Pseudomonas aeruginosa and 5 cases of Acanthamoeba were identified from contact lenses or contact lens solution. The mean duration from disease onset to remission was 31.9 ± 34.9 days (range: 6 to 131 days). All patients responded to medical treatment, and no emergency surgical intervention was needed. The best-corrected logMAR visual acuity improved significantly from 0.62 ± 0.51 (20/83 Snellen) to 0.15 ± 0.20 (20/28 Snellen) (Wilcoxon signed rank test, p < 0.001). Conclusions: Orthokeratology-associated infectious keratitis continues to be a serious problem especially in regions with high prevalence of myopia. Early clinical and microbiological diagnosis and intensive treatment can improve final visual outcomes.
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Introduction
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Orthokeratology is a non-surgical method for myopia reduction. It aims to improve unaided visual acuity by the application of rigid contact lenses.1 Reverse-geometry gas-permeable contact lenses that have a base curve flatter than the central corneal curvature and a secondary curve steeper than the base curve radius, induce central corneal flattening for correction of myopia.2 With availability of lens materials with higher oxygen transmissibility, overnight orthokeratology allows patient to achieve an improved unaided vision during daytime. Hong Kong has one of the highest prevalence rates of myopia with 61.5% myopic children by the age of 12 years.3 Consequently, orthokeratology is an appealing option for parents in this part of the world. However, orthokeratology has been reported to be associated with adverse effects, which range from variability in visual acuity and decrease in quality of vision to sight-threatening infective keratitis.4-5 Over 100 cases of orthokeratology-related infective keratitis have been reported since 2001 in the literature, mainly from East Asia, including China, Taiwan and Hong Kong.4 In a review of all reported cases of orthokeratology-related keratitis between 2001 and 2007, the peak year for occurrence was in the early years, followed by a decreasing trend afterwards.5
We analyzed the clinical and microbiological characteristics and clinical outcomes of orthokeratology-related keratitis, which were treated at the Hong Kong Eye Hospital between 2003 and 2013.
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Methods
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A retrospective chart review was conducted for all patients with orthokeratology-associated infectious keratitis admitted to the Hong Kong Eye Hospital between January 2003 and December 2013. Cases were identified using the diagnostic codes “Corneal disorder due to contact lens” and “Keratitis” from the Clinical Data Analysis and Reporting System of the Hong Kong Hospital Authority. Exclusion criteria included non-orthokeratology cases and cases treated on an outpatient basis. Medical records were traced, and clinical information was retrieved for analysis. Patients were diagnosed to have infectious keratitis clinically under slit-lamp examination by the presence of an epithelial defect, stromal infiltrate or specific signs such as perineuritis. Corneal scrapings were performed in all cases for microbiological investigations including Gram’s stain. Microbiological samples were inoculated on to blood agar, chocolate agar, Sabouraud’s Dextrose Agar, and non-nutrient agar culture plates. Contact lenses and storage solution were also obtained for microbiological cultures. All patients received intensive empirical broad-spectrum antimicrobial or amoebicidal therapy. The treatment was modified according to culture and sensitivity results as well as the clinical response after admission. The study was approved by the Institutional Review Board of the hospital and adhered to the tenets of the Declaration of Helsinki. Statistical
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analysis was performed using PASW software version 18.0 (SPSS/IBM, Inc., Chicago, IL). P values of 0.05 or less were considered to be statistically significant.
Results
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Overall, 23 patients were included in this study (Table 1). The mean age of patients was 15.0 ± 4.2 years (range: 9 to 23 years) (16 females, 7 males). All patients had unilateral ocular involvement (14 right eyes, 9 left eyes). Patients were using overnight orthokeratology for an average of 2.7 ± 2.8 years (range: 3 months to 10 years) before the onset of infection. There were no other associated risk factors. All patients claimed to have good contact lens hygiene and did not recall any prior ocular injury. Moreover, none of them suffered from ocular surface diseases or systemic illness. Fourteen patients had received previous treatment from other ophthalmologists in the form of amoebicidal eye drops, topical fluoroquinolones, aminoglycosides, and anti-herpetic eye ointment. The mean duration from onset of disease to hospital admission was 16.5 ± 30.2 days (range: 1 to 122 days). All patients presented with painful red eyes and reduced visual acuity. The best-corrected logMAR visual acuity at presentation was 0.62 ± 0.51 (20/83 Snellen). Clinical features and microbiological profile of all patients is summarized in Table 1. A central or paracentral corneal infiltrate was noted in 14 (60.86%) eyes with an average size of 2.7 ± 1.7 mm (range: 0.5 to 6.0 mm). There was an associated hypopyon in 3 (13.0%) eyes. Corneal perineuritis suggestive of Acanthamoeba keratitis was noted in 12 (52.2%) eyes.
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Fifteen (65.2%) eyes had a positive microbiological culture obtained from corneal scrapings (Table 2). One pathogen was identified in 12 cases, while 3 cases had polymicrobial infection. The most commonly isolated organism was Pseudomonas aeruginosa (n=6) followed by coagulasenegative Staphylococcus (CNS) (n=5) and Acanthamoeba (n=3). Staphylococcus aureus, Serratia marcescens, Micrococcus luteus and Flavobacterium species each accounted for a single case. Orthokeratology lenses or lens storage solution were available for microbiological investigations in all cases. There were 5 cases of Pseudomonas aeruginosa and 5 cases of Acanthamoeba identified from contact lenses or solution. When the results of corneal scraping, contact lenses and storage media were combined, the culture-positive rate was 78.2% (n=18), and the most common pathogens were Pseudomonas aeruginosa (n=8), Acanthamoeba (n=6) and CNS (n=5). No fungal organisms were isolated in any of the cases although 1 case responded well to combined anti-bacterial and anti-fungal treatments. At the time of presentation, empirical treatment was started in the form of hourly levofloxacin 0.5% or moxifloxacin 0.5% eye drops and once daily ofloxacin 0.3% ointment. For ulcers involving the visual axis and stromal infiltrates larger than 2 mm, fortified vancomycin (50mg/ml) and fortified tobramycin or gentamicin (14mg/ml) were administered hourly. Polyhexamethylene biguanide 0.02% and propamidine isethionate 0.1% were
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started in cases suspected to have Acanthamoeba keratitis. Overall, 12 eyes, which presented with corneal perineuritis, were treated empirically with amoebicidal drugs. The mean duration of hospitalization was 15.3 ± 9.8 days (range: 5 to 31 days).
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All patients responded to medical treatment. The mean duration from disease onset to remission was 31.9 ± 34.9 days (range: 6 to 131 days). Residual central or paracentral corneal scarring was observed in all cases. The final best-corrected logMAR visual acuity was 0.15 ± 0.20 (20/28 Snellen), which was significantly better than the visual acuity at presentation (Wilcoxon signed rank test, p < 0.001).
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Considering the 2 most common pathogens in our series, the duration from symptom onset to hospitalization was 2.9 ± 2.6 days (range: 1 to 8 days) and 15.7 ± 12.4 days (range: 2 to 31 days) in cases with Pseudomonas aeruginosa and Acanthamoeba, respectively (Mann Whitney U test, p = 0.008). The disease duration in cases with Pseudomonas aeruginosa and Acanthamoeba was 13.0 ± 7.7 days (range: 6 to 28 days) and 35.3 ± 16.1 days (range: 19 to 62 days), respectively (Mann Whitney U test, p = 0.005). The amoebicidal drugs were continued in all 12 patients with perineuritis for up to 6 months after the initial diagnosis.
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Overall, during the study period 393 cases with infectious keratitis and 121 cases with contact lens-related keratitis were admitted to the hospital for management. The proportion of orthokeratology-related keratitis cases was 5.9 % and 19% respectively during this time period (Table 1). Interestingly, of the 32 cases with contact lens-related Acanthamoeba keratitis over the 10year period, 12 (37.5%) were due to orthokeratology lenses (Table 1). Discussion
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Overnight orthokeratology is considered a viable option for temporary reduction of myopia.6,7 The increasing popularity of orthokeratology in communities with high prevalence of myopia increases the stakes for infectious keratitis in these regions. Reduced oxygen transmission through contact lens, together with the lack of eye movement to disrupt microbial glycocalyx and the absence of blinking to spread lysozyme over corneal surface, are some of the postulated factors associated with keratitis in nocturnal contact lens wearers.8-10 The reverse-geometry design was hypothesized to further compromise the epithelial surface secondary to its compressive effect exerted on the cornea thereby making it more susceptible to infection.11 The fact that users of orthokeratology lenses are predominantly adolescents, who are less likely to practice good contact lens hygiene, further increases the risk for acquiring infectious keratitis. Previous reports have shown an association between orthokeratology and infectious keratitis with predominance of patients from East Asia.12-18 In a review of 123 cases of orthokeratology-associated infectious keratitis, Pseudomonas aeruginosa accounted for 37% of the cases and Acanthamoeba was implicated in 33% of the cases.5 We observed a similar
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trend in the present study with Pseudomonas aeruginosa and Acanthamoeba isolated in 34.8% and 26.1% of the cases respectively. Pseudomonas aeruginosa has been the most commonly reported organism associated with contact lens wear.19 It can progress rapidly to corneal melting or perforation without prompt treatment. Fortunately, most cases in our series received appropriate treatment within few days of onset of symptoms. Surgical intervention in the form of emergency keratoplasty was not needed in any of the cases.
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Acanthamoeba has also been notoriously associated with contact lens use. The diagnosis as well as the treatment of Acanthamoeba keratitis is challenging in most cases.20 The clinical features of Acanthamoeba keratitis are variable and may resemble those of herpetic eye infection further delaying the commencement of appropriate treatment.21 This could explain relatively longer disease duration of Acanthamoeba keratits in the current study. Moreover, half of the cases presented with perineuritis were culture negative in microbial investigations. Despite the difficulty and delay in making diagnosis, all cases in our study responded well to amoebicidal treatment.
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The microbiological yield was high in our case series. Although corneal scrapings did not show a positive culture result in 8 out of 23 patients, possibly attributed to the use of broad-spectrum antibiotics prior to presentation, additional microbiological information was obtained from culturing the contact lens and storage solution. An association between microbiological cultures of contact lens and corneal scrapings in contact lensrelated keratitis has been reported previously, demonstrating that 40% of negative corneal scraping cases were positive on contact lens culture.22 We observed a similar proportion of cases (37.5%) in the current study.
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A previous study showed that 18% of pediatric keratitis treated in our hospital was related to orthokeratology.17 Another single-center study in our locality also demonstrated that 38.8% of infective keratitis in patients less than 18 years was associated with orthokeratology lenses.18 The 2 studies described above included both cases treated as inpatient and outpatient. In a review of orthokeratology-associated infectious keratitis between 2001 and 2007, the peak year for occurrence was 2001 followed by a decreasing trend afterwards.5 It was hypothesized that the initial high incidence of corneal infection was due to the unregulated use of orthokeratology. The decreasing number of cases in the following years was a likely result of tightened regulation and standardized clinical practice.4,23 In our study, the observed number of orthokeratology-associated microbial keratitis was quite constant within the study period, ranging from 1 to 3 cases annually, except for a surge in the recent 2 years. A recently published study in Taiwan showed that 19.1% of pediatric microbial keratitis was associated with orthokeratology, which increased significantly from 9.9% in 10 years.24 There is currently no registry for orthokeratology lenses in Hong Kong. Most orthokeratology practitioners are optometrists, while ophthalmologists mostly see complications related to the use of this modality. The American Academy of Ophthalmology Technology Assessment Report states that since the total population using overnight orthokeratology is unknown, it is difficult to assess
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the overall prevalence and incidence of orthokeratology-associated complications.4 A retrospective study relying on corneal infection reported by orthokeratology practitioners estimated that the incidence of orthokeratologyassociated microbial keratitis was 7.7 cases in 10,000 patient-years.25 The rate was similar to that of other overnight contact lens wear, but higher compared with daily contact lens wear, which was 1.2 per 10,000 wearers,26 although orthokeratology lenses are not worn for most of the waking hours. The authors recommend that the practitioners and parents should be aware of this risk because it is an important part of the risk-benefit ratio. The trend observed in our study may simply reflect a renewed interest in orthokeratology or an increased awareness of contact lens related problems amongst the general population. In addition, the viability of these lenses for the control of myopia progression may have increased this proportion in recent years.27,28 Although the current study is a single-center study, and we only included hospitalized patients suffering from corneal infection, this may have underestimated the true number of cases, however, it is noteworthy that majority of the cases with orthokeratology-related infectious keratitis are admitted for investigations and treatment in our hospital. The results of this study serve to reiterate the issue of potential risk of infectious keratitis associated with orthokeratology. It is essential for eye care practitioners to fully explain such risks to the patients and the parents, and to provide regular monitoring and counseling in order to warn about the signs and symptoms of keratitis so that the patients can seek medical attention promptly.
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In conclusion, despite an improved standardization of orthokeratology services we continue to see cases with orthokeratology associated infectious keratitis. Parents and children should be fully informed and consented on the potential risk of developing corneal infection and associated visual loss before prescribing the service. Fortunately, with increased vigilance, early diagnosis and intensive treatment results in a good visual outcome. A co-sharing model of orthokeratology service provided by both optometrists and ophthalmologists should be most beneficial to our patients.
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Acknowledgments section:
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A. Funding/support: None B. Financial disclosures: None C. Contribution of authors: Concept and design: TC, VJ; Analysis and interpretation: TC, EL, VJ; Writing the article: TC, EL, VW, VJ; Critical revision of the article: TC, EL, VW, VJ; Final approval of the article: TC, EL, VW, VJ; Data collection: TC, EL; Provision of materials, patients or resources: VW, VJ; Statistical expertise: TC, EL; Obtaining funding: VJ; Literature search: TC, EL,; Administrative, technical or logistic support: VW, VJ D. Other acknowledgements: None
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References 1. Wilson DR, Keeney AH. Corrective measures for myopia. Surv Ophthalmol 1990;34(4):294-304. 2. Nichols JJ, Marsich MM, Nguyen M, Barr JT, Bullimore MA. Overnight orthokeratology. Optom Vis Sci 2000;77(5):252-259. 3. Lam CS, Lam CH, Cheng SC, Chan LY. Prevalence of myopia among Hong Kong Chinese schoolchildren: changes over two decades. Ophthalmic Physiol Opt 2012;32(1):17-24. 4. Van Meter WS, Musch DC, Jacobs DS, et al. Safety of overnight orthokeratology for myopia: a report by the American Academy of Ophthalmology. Ophthalmology 2008;115(12):2301-2313 e2301. 5. Watt KG, Swarbrick HA. Trends in microbial keratitis associated with orthokeratology. Eye Contact Lens 2007;33(6 Pt 2):373-377; discussion 382. 6. Swarbrick HA. Orthokeratology review and update. Clin Exp Optom 2006;89(3):124-143. 7. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res 2005;30(1):71-80. 8. Miller MJ, Wilson LA, Ahearn DG. Adherence of Pseudomonas aeruginosa to rigid gas-permeable contact lenses. Arch Ophthalmol 1991;109(10):1447-1448. 9. Ren DH, Petroll WM, Jester JV, Ho-Fan J, Cavanagh HD. The relationship between contact lens oxygen permeability and binding of Pseudomonas aeruginosa to human corneal epithelial cells after overnight and extended wear. CLAO J 1999;25(2):80-100. 10. Lin MC, Graham AD, Fusaro RE, Polse KA. Impact of rigid gaspermeable contact lens extended wear on corneal epithelial barrier function. Invest Ophthalmol Vis Sci 2002;43(4):1019-1024. 11. Watt K, Swarbrick HA. Microbial keratitis in overnight orthokeratology: review of the first 50 cases. Eye Contact Lens 2005;31(5):201-208. 12. Xuguang S, Lin C, Yan Z, et al. Acanthamoeba keratitis as a complication of orthokeratology. Am J Ophthalmol 2003;136(6):11591161. 13. Young AL, Leung AT, Cheng LL, Law RW, Wong AK, Lam DS. Orthokeratology lens-related corneal ulcers in children: a case series. Ophthalmology 2004;111(3):590-595. 14. Hsiao CH, Lin HC, Chen YF, et al. Infectious keratitis related to overnight orthokeratology. Cornea 2005;24(7):783-788. 15. Tseng CH, Fong CF, Chen WL, Hou YC, Wang IJ, Hu FR. Overnight orthokeratology-associated microbial keratitis. Cornea 2005;24(7):778782. 16. Sun X, Zhao H, Deng S, et al. Infectious keratitis related to orthokeratology. Ophthalmic Physiol Opt 2006;26(2):133-136. 17. Wong VW, Lai TY, Chi SC, Lam DS. Pediatric ocular surface infections: a 5-year review of demographics, clinical features, risk factors, microbiological results, and treatment. Cornea 2011;30(9):9951002. 18. Young AL, Leung KS, Tsim N, Hui M, Jhanji V. Risk factors, microbiological profile, and treatment outcomes of pediatric microbial
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23. 24.
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26.
27.
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keratitis in a tertiary care hospital in Hong Kong. Am J Ophthalmol 2013;156(5):1040-1044 e1042. Lam DS, Houang E, Fan DS, et al. Incidence and risk factors for microbial keratitis in Hong Kong: comparison with Europe and North America. Eye (Lond) 2002;16(5):608-618. Robertson DM, McCulley JP, Cavanagh HD. Severe acanthamoeba keratitis after overnight orthokeratology. Eye Contact Lens 2007;33(3):121-123. Greenwell TH, Loh RS, Chehade M, Mills RA. Misdiagnosis of orthokeratology-related Acanthamoeba keratitis as herpes simplex virus keratitis. Clin Experment Ophthalmol 2013;41(4):418-420. Das S, Sheorey H, Taylor HR, Vajpayee RB. Association between cultures of contact lens and corneal scraping in contact lens related microbial keratitis. Arch Ophthalmology 2007;125(9):1182-1185. DeWoolfson BH. Orthokeratology lens--related ulcers in children. Ophthalmology 2005;112(1):167; author reply 167. Lee YS, Tan HY, Yeh LK, et al. Pediatric microbial keratitis in Taiwan: clinical and microbiological profiles, 1998-2002 versus 2008-2012. Am J Ophthalmol 2014;157(5):1090-1096. Bullimore MA, Sinnott LT, Jones-Jordan LA. The risk of microbial keratitis with overnight corneal reshaping lenses. Optom Vis Sci 2013;90(9):937-944. Stapleton F, Keay L, Edwards K, et al. The incidence of contact lensrelated microbial keratitis in Australia. Ophthalmology 2008;115(10):1655-1662. Cho P, Cheung SW. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci 2012;53(11):7077-7085. Kwok LS, Pierscionek BK, Bullimore M, Swarbrick HA, Mountford J, Sutton G. Orthokeratology for myopic children: wolf in sheep's clothing? Clin Experiment Ophthalmol 2005;33(4):343-347.
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Year
2004
2005
2006
2007
2008
OrthoKa keratitis (Case)
2
3
1
1
1
3
CLb keratitis (Case)
6
11
18
20
Overall keratitis (Case)
37
33
46
62
Proportion of OrthoKa keratitis in CLb keratitis (%)
33.3
27.3
5.6
5.0
Proportion of OrthoKa keratitis in total microbial keratitis (%)
25
50
7.7
OrthoKa Acanthamoeba (Case)
0
2
a b
OrthoK: Orthokeratology-associated CL: Contact lens-associated
2
3
2010
2011
2012
2013
Total
1
1
1
4
5
23
M AN U 7
5
10
10
9
15
121
32
24
22
33
37
39
28
393
10.0
42.9
20.0
10.0
10.0
44.4
33.3
19.0
5.6
25.0
60.0
25.0
25.0
12.5
44.4
41.7
5.9
0
1
1
2
0
0
0
3
3
12
5
5
3
5
2
1
0
4
2
32
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CLb Acanthamoeba (Case)
2009
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2003
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Table 1: Year-wise trend for orthokeratology-related cases with keratitis in comparison to contact lens-related keratitis cases and overall keratitis cases admitted to Hong Kong Eye Hospital between 2003 and 2013
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Microbiological Culture
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Table 2: Clinical features, microbiological profiles and visual outcomes of orthokeratology-associated microbial keratitis admitted to Hong Kong Eye Hospital between 2003 and 2013
a
Storage Solution
Final LogMAR BCVA (Snellen)
Pseudomonas aeruginosa
No growth
0.10 (20/25)
No growth
No growth
0.05 (20/22)
Pseudomonas aeruginosa
Pseudomonas aeruginosa
0.10 (20/25)
No growth
No growth
0.05 (20/22)
No growth
No growth
0.70 (20/100)
Pseudomonas aeruginosa
No growth
0.10 (20/25)
No growth
Pseudomonas aeruginosa
0.00 (20/20)
No growth
Acanthamoeba
No growth
0.00 (20/20)
Paracentral ulcer
Pseudomonas aeruginosa Flavobacterium species
Pseudomonas aeruginosa Flavobacterium species
No growth
0.10 (20/25)
11/F
Central infiltrate, perineuritis
No growth
No growth
No growth
0.10 (20/25)
17/F
Paracentral ulcer, perineuritis
Acanthamoeba
Acanthamoeba
No growth
0.16 (20/28)
13/M
Central ulcer
Coagulase-negative Staphylococcus
No growth
No growth
0.16 (20/28)
18/F
Central ulcer, hypopyon
No growth
No growth
No growth
0.16 (20/28)
Clinical Features
Corneal Scraping
Contact Lens
14/F
Central ulcer, hypopyon
Pseudomonas aeruginosa
10/F
Diffuse infiltrate
No growth
23/F
Central ulcer
No growth
18/M
Diffuse infiltrate, perineuritis
Acanthamoeba
19/M
Central ulcer, perineuritis
No growth
19/M
Paracentral ulcer
18/F
Diffuse infiltrate, perineuritis
15/F
Paracentral infiltrate, perineuritis
14/M
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Pseudomonas aeruginosa Staphylococcus aureus Coagulase-negative Staphylococcus
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Central ulcer
Coagulase-negative Staphylococcus
No growth
16/F
Central infiltrate, perineuritis
No growth
Acanthamoeba
15/M
Central infiltrate, perineuritis
Acanthamoeba
Acanthamoeba
20/F
Diffuse infiltrate, perineuritis
Coagulase-negative Staphylococcus
Acanthamoeba
22/F
Central ulcer
Pseudomonas aeruginosa
9/F
Paracentral ulcer, perineuritis
No growth
10/F
Central ulcer, hypopyon, perineuritis
Pseudomonas aeruginosa Serratia marcescens
9/F
Paracentral ulcer
Micrococcus luteus
9/F
Paracentral ulcer
Pseudomonas aeruginosa
14/M
Diffuse infiltrate, perineuritis
Coagulase-negative Staphylococcus
0.22 (20/33)
No growth
0.10 (20/25)
No growth
0.10 (20/25)
Acanthamoeba
0.16 (20/33)
No growth
No growth
0.16 (20/33)
No growth
No growth
0.00 (20/20)
No growth
No growth
0.70 (20/100)
No growth
No growth
0.10 (20/25)
No growth
No growth
0.00 (20/20)
No growth
No growth
0.00 (20/20)
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No growth
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BCVA: Best-corrected visual acuity
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a
13/F
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Tommy C Chan is a Resident in Hong Kong Eye Hospital. He is also the Honorary Clinical Tutor of Department of Ophthalmology and Visual Sciences of the Chinese University of Hong Kong.
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Vishal Jhanji is an Assistant Professor of Ophthalmology at The Chinese University of Hong Kong. He specializes in corneal and external eye diseases. He has published his research work in prominent peer-reviewed journals. He can be reached at [email protected].
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S0002-9394(14)00528-5
DOI:
10.1016/j.ajo.2014.08.026
Reference:
AJOPHT 9039
To appear in:
American Journal of Ophthalmology
Received Date: 14 July 2014 Revised Date:
19 August 2014
Accepted Date: 19 August 2014
Please cite this article as: Chan TC, Li EY, Wong VW, Jhanji V, Orthokeratology-associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong, American Journal of Ophthalmology (2014), doi: 10.1016/j.ajo.2014.08.026. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Orthokeratology-associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong
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1,2 Tommy CY Chan 1,2 Emmy YM Li 1,2 Victoria WY Wong
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1 Hong Kong Eye Hospital, Hong Kong SAR, China
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1,2 Vishal Jhanji
2 Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
Short title: Orthokeratology-associated Keratitis in Hong Kong
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Financial support / Conflict of interest: Nil Financial disclosures: None
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Keywords: Orthokeratology, Infectious Keratitis, Treatment; Complications
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Corresponding author: Vishal Jhanji, MD Department of Ophthalmology and Visual Sciences The Chinese University of Hong Kong Hong Kong Tel: +852 39435807 Fax: +852 27159490 E-mail: [email protected]
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Abstract Purpose: To analyze cases of orthokeratology-associated infectious keratitis managed in a tertiary care eye hospital in Hong Kong between 2003 and 2013. Design: Retrospective study Methods: Case records of patients with infectious keratitis due to orthokeratology contact lenses were analyzed. Data analyzed included clinical features, microbiological evaluation, and treatment outcomes. Results: A total of 23 patients were included (16 females, 7 males, mean age, 15.0 ± 4.2 years; range: 9 to 23 years). All patients were using overnight orthokeratology for an average of 2.7 ± 2.8 years (range: 3 months to 10 years) before the onset of infection. Clinical features included corneal infiltrate (n=14, 60.86%), and corneal perineuritis (n=12, 52.17%). Fifteen eyes (65.2%) had a positive microbiological culture obtained from corneal scrapings. The most commonly isolated organism was Pseudomonas aeruginosa (n=6) followed by coagulase-negative Staphylococcus (n=5) and Acanthamoeba (n=3). Five cases of Pseudomonas aeruginosa and 5 cases of Acanthamoeba were identified from contact lenses or contact lens solution. The mean duration from disease onset to remission was 31.9 ± 34.9 days (range: 6 to 131 days). All patients responded to medical treatment, and no emergency surgical intervention was needed. The best-corrected logMAR visual acuity improved significantly from 0.62 ± 0.51 (20/83 Snellen) to 0.15 ± 0.20 (20/28 Snellen) (Wilcoxon signed rank test, p < 0.001). Conclusions: Orthokeratology-associated infectious keratitis continues to be a serious problem especially in regions with high prevalence of myopia. Early clinical and microbiological diagnosis and intensive treatment can improve final visual outcomes.
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Introduction
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Orthokeratology is a non-surgical method for myopia reduction. It aims to improve unaided visual acuity by the application of rigid contact lenses.1 Reverse-geometry gas-permeable contact lenses that have a base curve flatter than the central corneal curvature and a secondary curve steeper than the base curve radius, induce central corneal flattening for correction of myopia.2 With availability of lens materials with higher oxygen transmissibility, overnight orthokeratology allows patient to achieve an improved unaided vision during daytime. Hong Kong has one of the highest prevalence rates of myopia with 61.5% myopic children by the age of 12 years.3 Consequently, orthokeratology is an appealing option for parents in this part of the world. However, orthokeratology has been reported to be associated with adverse effects, which range from variability in visual acuity and decrease in quality of vision to sight-threatening infective keratitis.4-5 Over 100 cases of orthokeratology-related infective keratitis have been reported since 2001 in the literature, mainly from East Asia, including China, Taiwan and Hong Kong.4 In a review of all reported cases of orthokeratology-related keratitis between 2001 and 2007, the peak year for occurrence was in the early years, followed by a decreasing trend afterwards.5
We analyzed the clinical and microbiological characteristics and clinical outcomes of orthokeratology-related keratitis, which were treated at the Hong Kong Eye Hospital between 2003 and 2013.
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Methods
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A retrospective chart review was conducted for all patients with orthokeratology-associated infectious keratitis admitted to the Hong Kong Eye Hospital between January 2003 and December 2013. Cases were identified using the diagnostic codes “Corneal disorder due to contact lens” and “Keratitis” from the Clinical Data Analysis and Reporting System of the Hong Kong Hospital Authority. Exclusion criteria included non-orthokeratology cases and cases treated on an outpatient basis. Medical records were traced, and clinical information was retrieved for analysis. Patients were diagnosed to have infectious keratitis clinically under slit-lamp examination by the presence of an epithelial defect, stromal infiltrate or specific signs such as perineuritis. Corneal scrapings were performed in all cases for microbiological investigations including Gram’s stain. Microbiological samples were inoculated on to blood agar, chocolate agar, Sabouraud’s Dextrose Agar, and non-nutrient agar culture plates. Contact lenses and storage solution were also obtained for microbiological cultures. All patients received intensive empirical broad-spectrum antimicrobial or amoebicidal therapy. The treatment was modified according to culture and sensitivity results as well as the clinical response after admission. The study was approved by the Institutional Review Board of the hospital and adhered to the tenets of the Declaration of Helsinki. Statistical
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analysis was performed using PASW software version 18.0 (SPSS/IBM, Inc., Chicago, IL). P values of 0.05 or less were considered to be statistically significant.
Results
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Overall, 23 patients were included in this study (Table 1). The mean age of patients was 15.0 ± 4.2 years (range: 9 to 23 years) (16 females, 7 males). All patients had unilateral ocular involvement (14 right eyes, 9 left eyes). Patients were using overnight orthokeratology for an average of 2.7 ± 2.8 years (range: 3 months to 10 years) before the onset of infection. There were no other associated risk factors. All patients claimed to have good contact lens hygiene and did not recall any prior ocular injury. Moreover, none of them suffered from ocular surface diseases or systemic illness. Fourteen patients had received previous treatment from other ophthalmologists in the form of amoebicidal eye drops, topical fluoroquinolones, aminoglycosides, and anti-herpetic eye ointment. The mean duration from onset of disease to hospital admission was 16.5 ± 30.2 days (range: 1 to 122 days). All patients presented with painful red eyes and reduced visual acuity. The best-corrected logMAR visual acuity at presentation was 0.62 ± 0.51 (20/83 Snellen). Clinical features and microbiological profile of all patients is summarized in Table 1. A central or paracentral corneal infiltrate was noted in 14 (60.86%) eyes with an average size of 2.7 ± 1.7 mm (range: 0.5 to 6.0 mm). There was an associated hypopyon in 3 (13.0%) eyes. Corneal perineuritis suggestive of Acanthamoeba keratitis was noted in 12 (52.2%) eyes.
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Fifteen (65.2%) eyes had a positive microbiological culture obtained from corneal scrapings (Table 2). One pathogen was identified in 12 cases, while 3 cases had polymicrobial infection. The most commonly isolated organism was Pseudomonas aeruginosa (n=6) followed by coagulasenegative Staphylococcus (CNS) (n=5) and Acanthamoeba (n=3). Staphylococcus aureus, Serratia marcescens, Micrococcus luteus and Flavobacterium species each accounted for a single case. Orthokeratology lenses or lens storage solution were available for microbiological investigations in all cases. There were 5 cases of Pseudomonas aeruginosa and 5 cases of Acanthamoeba identified from contact lenses or solution. When the results of corneal scraping, contact lenses and storage media were combined, the culture-positive rate was 78.2% (n=18), and the most common pathogens were Pseudomonas aeruginosa (n=8), Acanthamoeba (n=6) and CNS (n=5). No fungal organisms were isolated in any of the cases although 1 case responded well to combined anti-bacterial and anti-fungal treatments. At the time of presentation, empirical treatment was started in the form of hourly levofloxacin 0.5% or moxifloxacin 0.5% eye drops and once daily ofloxacin 0.3% ointment. For ulcers involving the visual axis and stromal infiltrates larger than 2 mm, fortified vancomycin (50mg/ml) and fortified tobramycin or gentamicin (14mg/ml) were administered hourly. Polyhexamethylene biguanide 0.02% and propamidine isethionate 0.1% were
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started in cases suspected to have Acanthamoeba keratitis. Overall, 12 eyes, which presented with corneal perineuritis, were treated empirically with amoebicidal drugs. The mean duration of hospitalization was 15.3 ± 9.8 days (range: 5 to 31 days).
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All patients responded to medical treatment. The mean duration from disease onset to remission was 31.9 ± 34.9 days (range: 6 to 131 days). Residual central or paracentral corneal scarring was observed in all cases. The final best-corrected logMAR visual acuity was 0.15 ± 0.20 (20/28 Snellen), which was significantly better than the visual acuity at presentation (Wilcoxon signed rank test, p < 0.001).
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Considering the 2 most common pathogens in our series, the duration from symptom onset to hospitalization was 2.9 ± 2.6 days (range: 1 to 8 days) and 15.7 ± 12.4 days (range: 2 to 31 days) in cases with Pseudomonas aeruginosa and Acanthamoeba, respectively (Mann Whitney U test, p = 0.008). The disease duration in cases with Pseudomonas aeruginosa and Acanthamoeba was 13.0 ± 7.7 days (range: 6 to 28 days) and 35.3 ± 16.1 days (range: 19 to 62 days), respectively (Mann Whitney U test, p = 0.005). The amoebicidal drugs were continued in all 12 patients with perineuritis for up to 6 months after the initial diagnosis.
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Overall, during the study period 393 cases with infectious keratitis and 121 cases with contact lens-related keratitis were admitted to the hospital for management. The proportion of orthokeratology-related keratitis cases was 5.9 % and 19% respectively during this time period (Table 1). Interestingly, of the 32 cases with contact lens-related Acanthamoeba keratitis over the 10year period, 12 (37.5%) were due to orthokeratology lenses (Table 1). Discussion
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Overnight orthokeratology is considered a viable option for temporary reduction of myopia.6,7 The increasing popularity of orthokeratology in communities with high prevalence of myopia increases the stakes for infectious keratitis in these regions. Reduced oxygen transmission through contact lens, together with the lack of eye movement to disrupt microbial glycocalyx and the absence of blinking to spread lysozyme over corneal surface, are some of the postulated factors associated with keratitis in nocturnal contact lens wearers.8-10 The reverse-geometry design was hypothesized to further compromise the epithelial surface secondary to its compressive effect exerted on the cornea thereby making it more susceptible to infection.11 The fact that users of orthokeratology lenses are predominantly adolescents, who are less likely to practice good contact lens hygiene, further increases the risk for acquiring infectious keratitis. Previous reports have shown an association between orthokeratology and infectious keratitis with predominance of patients from East Asia.12-18 In a review of 123 cases of orthokeratology-associated infectious keratitis, Pseudomonas aeruginosa accounted for 37% of the cases and Acanthamoeba was implicated in 33% of the cases.5 We observed a similar
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trend in the present study with Pseudomonas aeruginosa and Acanthamoeba isolated in 34.8% and 26.1% of the cases respectively. Pseudomonas aeruginosa has been the most commonly reported organism associated with contact lens wear.19 It can progress rapidly to corneal melting or perforation without prompt treatment. Fortunately, most cases in our series received appropriate treatment within few days of onset of symptoms. Surgical intervention in the form of emergency keratoplasty was not needed in any of the cases.
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Acanthamoeba has also been notoriously associated with contact lens use. The diagnosis as well as the treatment of Acanthamoeba keratitis is challenging in most cases.20 The clinical features of Acanthamoeba keratitis are variable and may resemble those of herpetic eye infection further delaying the commencement of appropriate treatment.21 This could explain relatively longer disease duration of Acanthamoeba keratits in the current study. Moreover, half of the cases presented with perineuritis were culture negative in microbial investigations. Despite the difficulty and delay in making diagnosis, all cases in our study responded well to amoebicidal treatment.
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The microbiological yield was high in our case series. Although corneal scrapings did not show a positive culture result in 8 out of 23 patients, possibly attributed to the use of broad-spectrum antibiotics prior to presentation, additional microbiological information was obtained from culturing the contact lens and storage solution. An association between microbiological cultures of contact lens and corneal scrapings in contact lensrelated keratitis has been reported previously, demonstrating that 40% of negative corneal scraping cases were positive on contact lens culture.22 We observed a similar proportion of cases (37.5%) in the current study.
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A previous study showed that 18% of pediatric keratitis treated in our hospital was related to orthokeratology.17 Another single-center study in our locality also demonstrated that 38.8% of infective keratitis in patients less than 18 years was associated with orthokeratology lenses.18 The 2 studies described above included both cases treated as inpatient and outpatient. In a review of orthokeratology-associated infectious keratitis between 2001 and 2007, the peak year for occurrence was 2001 followed by a decreasing trend afterwards.5 It was hypothesized that the initial high incidence of corneal infection was due to the unregulated use of orthokeratology. The decreasing number of cases in the following years was a likely result of tightened regulation and standardized clinical practice.4,23 In our study, the observed number of orthokeratology-associated microbial keratitis was quite constant within the study period, ranging from 1 to 3 cases annually, except for a surge in the recent 2 years. A recently published study in Taiwan showed that 19.1% of pediatric microbial keratitis was associated with orthokeratology, which increased significantly from 9.9% in 10 years.24 There is currently no registry for orthokeratology lenses in Hong Kong. Most orthokeratology practitioners are optometrists, while ophthalmologists mostly see complications related to the use of this modality. The American Academy of Ophthalmology Technology Assessment Report states that since the total population using overnight orthokeratology is unknown, it is difficult to assess
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the overall prevalence and incidence of orthokeratology-associated complications.4 A retrospective study relying on corneal infection reported by orthokeratology practitioners estimated that the incidence of orthokeratologyassociated microbial keratitis was 7.7 cases in 10,000 patient-years.25 The rate was similar to that of other overnight contact lens wear, but higher compared with daily contact lens wear, which was 1.2 per 10,000 wearers,26 although orthokeratology lenses are not worn for most of the waking hours. The authors recommend that the practitioners and parents should be aware of this risk because it is an important part of the risk-benefit ratio. The trend observed in our study may simply reflect a renewed interest in orthokeratology or an increased awareness of contact lens related problems amongst the general population. In addition, the viability of these lenses for the control of myopia progression may have increased this proportion in recent years.27,28 Although the current study is a single-center study, and we only included hospitalized patients suffering from corneal infection, this may have underestimated the true number of cases, however, it is noteworthy that majority of the cases with orthokeratology-related infectious keratitis are admitted for investigations and treatment in our hospital. The results of this study serve to reiterate the issue of potential risk of infectious keratitis associated with orthokeratology. It is essential for eye care practitioners to fully explain such risks to the patients and the parents, and to provide regular monitoring and counseling in order to warn about the signs and symptoms of keratitis so that the patients can seek medical attention promptly.
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In conclusion, despite an improved standardization of orthokeratology services we continue to see cases with orthokeratology associated infectious keratitis. Parents and children should be fully informed and consented on the potential risk of developing corneal infection and associated visual loss before prescribing the service. Fortunately, with increased vigilance, early diagnosis and intensive treatment results in a good visual outcome. A co-sharing model of orthokeratology service provided by both optometrists and ophthalmologists should be most beneficial to our patients.
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Acknowledgments section:
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A. Funding/support: None B. Financial disclosures: None C. Contribution of authors: Concept and design: TC, VJ; Analysis and interpretation: TC, EL, VJ; Writing the article: TC, EL, VW, VJ; Critical revision of the article: TC, EL, VW, VJ; Final approval of the article: TC, EL, VW, VJ; Data collection: TC, EL; Provision of materials, patients or resources: VW, VJ; Statistical expertise: TC, EL; Obtaining funding: VJ; Literature search: TC, EL,; Administrative, technical or logistic support: VW, VJ D. Other acknowledgements: None
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References 1. Wilson DR, Keeney AH. Corrective measures for myopia. Surv Ophthalmol 1990;34(4):294-304. 2. Nichols JJ, Marsich MM, Nguyen M, Barr JT, Bullimore MA. Overnight orthokeratology. Optom Vis Sci 2000;77(5):252-259. 3. Lam CS, Lam CH, Cheng SC, Chan LY. Prevalence of myopia among Hong Kong Chinese schoolchildren: changes over two decades. Ophthalmic Physiol Opt 2012;32(1):17-24. 4. Van Meter WS, Musch DC, Jacobs DS, et al. Safety of overnight orthokeratology for myopia: a report by the American Academy of Ophthalmology. Ophthalmology 2008;115(12):2301-2313 e2301. 5. Watt KG, Swarbrick HA. Trends in microbial keratitis associated with orthokeratology. Eye Contact Lens 2007;33(6 Pt 2):373-377; discussion 382. 6. Swarbrick HA. Orthokeratology review and update. Clin Exp Optom 2006;89(3):124-143. 7. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res 2005;30(1):71-80. 8. Miller MJ, Wilson LA, Ahearn DG. Adherence of Pseudomonas aeruginosa to rigid gas-permeable contact lenses. Arch Ophthalmol 1991;109(10):1447-1448. 9. Ren DH, Petroll WM, Jester JV, Ho-Fan J, Cavanagh HD. The relationship between contact lens oxygen permeability and binding of Pseudomonas aeruginosa to human corneal epithelial cells after overnight and extended wear. CLAO J 1999;25(2):80-100. 10. Lin MC, Graham AD, Fusaro RE, Polse KA. Impact of rigid gaspermeable contact lens extended wear on corneal epithelial barrier function. Invest Ophthalmol Vis Sci 2002;43(4):1019-1024. 11. Watt K, Swarbrick HA. Microbial keratitis in overnight orthokeratology: review of the first 50 cases. Eye Contact Lens 2005;31(5):201-208. 12. Xuguang S, Lin C, Yan Z, et al. Acanthamoeba keratitis as a complication of orthokeratology. Am J Ophthalmol 2003;136(6):11591161. 13. Young AL, Leung AT, Cheng LL, Law RW, Wong AK, Lam DS. Orthokeratology lens-related corneal ulcers in children: a case series. Ophthalmology 2004;111(3):590-595. 14. Hsiao CH, Lin HC, Chen YF, et al. Infectious keratitis related to overnight orthokeratology. Cornea 2005;24(7):783-788. 15. Tseng CH, Fong CF, Chen WL, Hou YC, Wang IJ, Hu FR. Overnight orthokeratology-associated microbial keratitis. Cornea 2005;24(7):778782. 16. Sun X, Zhao H, Deng S, et al. Infectious keratitis related to orthokeratology. Ophthalmic Physiol Opt 2006;26(2):133-136. 17. Wong VW, Lai TY, Chi SC, Lam DS. Pediatric ocular surface infections: a 5-year review of demographics, clinical features, risk factors, microbiological results, and treatment. Cornea 2011;30(9):9951002. 18. Young AL, Leung KS, Tsim N, Hui M, Jhanji V. Risk factors, microbiological profile, and treatment outcomes of pediatric microbial
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23. 24.
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keratitis in a tertiary care hospital in Hong Kong. Am J Ophthalmol 2013;156(5):1040-1044 e1042. Lam DS, Houang E, Fan DS, et al. Incidence and risk factors for microbial keratitis in Hong Kong: comparison with Europe and North America. Eye (Lond) 2002;16(5):608-618. Robertson DM, McCulley JP, Cavanagh HD. Severe acanthamoeba keratitis after overnight orthokeratology. Eye Contact Lens 2007;33(3):121-123. Greenwell TH, Loh RS, Chehade M, Mills RA. Misdiagnosis of orthokeratology-related Acanthamoeba keratitis as herpes simplex virus keratitis. Clin Experment Ophthalmol 2013;41(4):418-420. Das S, Sheorey H, Taylor HR, Vajpayee RB. Association between cultures of contact lens and corneal scraping in contact lens related microbial keratitis. Arch Ophthalmology 2007;125(9):1182-1185. DeWoolfson BH. Orthokeratology lens--related ulcers in children. Ophthalmology 2005;112(1):167; author reply 167. Lee YS, Tan HY, Yeh LK, et al. Pediatric microbial keratitis in Taiwan: clinical and microbiological profiles, 1998-2002 versus 2008-2012. Am J Ophthalmol 2014;157(5):1090-1096. Bullimore MA, Sinnott LT, Jones-Jordan LA. The risk of microbial keratitis with overnight corneal reshaping lenses. Optom Vis Sci 2013;90(9):937-944. Stapleton F, Keay L, Edwards K, et al. The incidence of contact lensrelated microbial keratitis in Australia. Ophthalmology 2008;115(10):1655-1662. Cho P, Cheung SW. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci 2012;53(11):7077-7085. Kwok LS, Pierscionek BK, Bullimore M, Swarbrick HA, Mountford J, Sutton G. Orthokeratology for myopic children: wolf in sheep's clothing? Clin Experiment Ophthalmol 2005;33(4):343-347.
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Year
2004
2005
2006
2007
2008
OrthoKa keratitis (Case)
2
3
1
1
1
3
CLb keratitis (Case)
6
11
18
20
Overall keratitis (Case)
37
33
46
62
Proportion of OrthoKa keratitis in CLb keratitis (%)
33.3
27.3
5.6
5.0
Proportion of OrthoKa keratitis in total microbial keratitis (%)
25
50
7.7
OrthoKa Acanthamoeba (Case)
0
2
a b
OrthoK: Orthokeratology-associated CL: Contact lens-associated
2
3
2010
2011
2012
2013
Total
1
1
1
4
5
23
M AN U 7
5
10
10
9
15
121
32
24
22
33
37
39
28
393
10.0
42.9
20.0
10.0
10.0
44.4
33.3
19.0
5.6
25.0
60.0
25.0
25.0
12.5
44.4
41.7
5.9
0
1
1
2
0
0
0
3
3
12
5
5
3
5
2
1
0
4
2
32
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CLb Acanthamoeba (Case)
2009
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2003
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Table 1: Year-wise trend for orthokeratology-related cases with keratitis in comparison to contact lens-related keratitis cases and overall keratitis cases admitted to Hong Kong Eye Hospital between 2003 and 2013
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Microbiological Culture
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Table 2: Clinical features, microbiological profiles and visual outcomes of orthokeratology-associated microbial keratitis admitted to Hong Kong Eye Hospital between 2003 and 2013
a
Storage Solution
Final LogMAR BCVA (Snellen)
Pseudomonas aeruginosa
No growth
0.10 (20/25)
No growth
No growth
0.05 (20/22)
Pseudomonas aeruginosa
Pseudomonas aeruginosa
0.10 (20/25)
No growth
No growth
0.05 (20/22)
No growth
No growth
0.70 (20/100)
Pseudomonas aeruginosa
No growth
0.10 (20/25)
No growth
Pseudomonas aeruginosa
0.00 (20/20)
No growth
Acanthamoeba
No growth
0.00 (20/20)
Paracentral ulcer
Pseudomonas aeruginosa Flavobacterium species
Pseudomonas aeruginosa Flavobacterium species
No growth
0.10 (20/25)
11/F
Central infiltrate, perineuritis
No growth
No growth
No growth
0.10 (20/25)
17/F
Paracentral ulcer, perineuritis
Acanthamoeba
Acanthamoeba
No growth
0.16 (20/28)
13/M
Central ulcer
Coagulase-negative Staphylococcus
No growth
No growth
0.16 (20/28)
18/F
Central ulcer, hypopyon
No growth
No growth
No growth
0.16 (20/28)
Clinical Features
Corneal Scraping
Contact Lens
14/F
Central ulcer, hypopyon
Pseudomonas aeruginosa
10/F
Diffuse infiltrate
No growth
23/F
Central ulcer
No growth
18/M
Diffuse infiltrate, perineuritis
Acanthamoeba
19/M
Central ulcer, perineuritis
No growth
19/M
Paracentral ulcer
18/F
Diffuse infiltrate, perineuritis
15/F
Paracentral infiltrate, perineuritis
14/M
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Pseudomonas aeruginosa Staphylococcus aureus Coagulase-negative Staphylococcus
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Central ulcer
Coagulase-negative Staphylococcus
No growth
16/F
Central infiltrate, perineuritis
No growth
Acanthamoeba
15/M
Central infiltrate, perineuritis
Acanthamoeba
Acanthamoeba
20/F
Diffuse infiltrate, perineuritis
Coagulase-negative Staphylococcus
Acanthamoeba
22/F
Central ulcer
Pseudomonas aeruginosa
9/F
Paracentral ulcer, perineuritis
No growth
10/F
Central ulcer, hypopyon, perineuritis
Pseudomonas aeruginosa Serratia marcescens
9/F
Paracentral ulcer
Micrococcus luteus
9/F
Paracentral ulcer
Pseudomonas aeruginosa
14/M
Diffuse infiltrate, perineuritis
Coagulase-negative Staphylococcus
0.22 (20/33)
No growth
0.10 (20/25)
No growth
0.10 (20/25)
Acanthamoeba
0.16 (20/33)
No growth
No growth
0.16 (20/33)
No growth
No growth
0.00 (20/20)
No growth
No growth
0.70 (20/100)
No growth
No growth
0.10 (20/25)
No growth
No growth
0.00 (20/20)
No growth
No growth
0.00 (20/20)
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No growth
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BCVA: Best-corrected visual acuity
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13/F
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Tommy C Chan is a Resident in Hong Kong Eye Hospital. He is also the Honorary Clinical Tutor of Department of Ophthalmology and Visual Sciences of the Chinese University of Hong Kong.
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Vishal Jhanji is an Assistant Professor of Ophthalmology at The Chinese University of Hong Kong. He specializes in corneal and external eye diseases. He has published his research work in prominent peer-reviewed journals. He can be reached at [email protected].
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