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Ananya Datta
Erin S. Tomiyama
Kathryn Richdale


Background and objective: The fitting of orthokeratology (ortho-k) and multifocal soft contact lenses (SCL) is becoming increasingly popular worldwide for reducing the rate of myopia progression. However, overnight wear use of lenses and microbial contamination of contact lenses and storage vials has been shown to increase the risk of corneal inflammatory and infiltrative events (CIEs). Therefore, we conducted a pilot study to compare the rate, level, and type of microbial contamination of contact lenses and storage vials
when participants wear ortho-k and SCL in combination with a hydrogen-peroxide disinfecting system.

Material and Methods: A prospective, single-centre, randomized, crossover study was conducted to evalu-ate the rate and level of contact lens and storage vials contamination during the use of ortho-k and SCL along with a hydrogen-peroxide disinfecting solution over two 10 day wearing periods. Ocular signs and symptoms were assessed during lens wear at baseline and after each wearing period. In addition, contact lens and storage vials were collected, and the type and amount of microbial contamination were evaluated using viable culture and standard identification methods.
Results: Twenty-five adults were enrolled, and 21 completed the study. One (5%) ortho-k lens, five (24%) ortho-k storage vials, one (5%) SCL and one (5%) SCL storage vial were contaminated (P > 0.05), predominantly with Gram-positive bacteria. None of the participants had contamination with both ortho-k and SCL. No significant differences were found between the ocular signs, including conjunctival redness and roughness, or conjunctival or corneal staining (all P > 0.05), irrespective of using ortho-k or SCL.

Conclusion: This study provides the first data that directly compares microbial contamination of ortho-K versus SCL in patients using a hydrogen-peroxide disinfection system. However, the overall microbial contamination rate of contact lens storage vials was much lower (30%) than the previously reported study with ortho-k lens wear. The results support conducting a larger clinical trial designed to understand differences in microbial contamination with different lens materials and modalities.


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How to Cite
Datta A, Tomiyama ES, Richdale K. MICROBIAL BIOBURDEN OF ORTHOKERATOLOGY AND HYDROGEL CONTACT LENSES AND STORAGE CASES USING A HYDROGEN-PEROXIDE DISINFECTING SYSTEM: A PILOT STUDY. JCLRS [Internet]. 2021Oct.26 [cited 2021Dec.4];5(1):e19-e31. Available from: http://jclrs.org/index.php/JCLRS/article/view/43
Original Article
Author Biographies

Ananya Datta, University of Houston

University of Houston College of Optometry, Texas, USA

Erin S. Tomiyama, University of Houston

University of Houston College of Optometry, Texas, USA

Kathryn Richdale, University of Houston

University of Houston College of Optometry, Texas, USA


1. Pucker AD, Tichenor AA. A Review of Contact Lens Dropout. Clin Optom. 2020;12:85-94. doi:10.2147/OPTO.S198637
2. Cope JR, Collier SA, Nethercut H, Jones JM, Yates K, Yoder JS. Risk Behaviors for Contact Lens–Related Eye Infections Among Adults and Adolescents — United States, 2016. MMWR Morb Mortal Wkly Rep. 2017;66(32):841. doi:10.15585/MMWR.MM6632A2
3. Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Investig Opthalmology Vis Sci. 2013;54(10):6510.
4. Cho P, Cheung S-W. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Investig Opthalmology Vis Sci. 2012;53(11):7077.
5. Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Investig Opthalmology Vis Sci. 2011;52(5):2170.
6. Cho P, Cheung W, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Glob Orthokeratology Symp. 2005;30:71-80.
7. 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.
8. Watt KG, Swarbrick HA. Trends in microbial keratitis associated with orthokeratology. Eye Contact Lens Sci Clin Pract. 2007;33(Supplement):373-377.
9. Hsiao C-H, Lin H-C, Chen Y-F, et al. Infectious keratitis related to overnight orthokeratology. Cornea. 2005;24(7):783-788.
10. Goodlaw E. Risk of infection from sleeping with contact lenses on: causes of risk. Optom Vis Sci. 1996;73(3):156-158.
11. Chan TCY, Li EYM, Wong VWY, Jhanji V. Orthokeratology-associated infectious keratitis in a tertiary care eye hospital in Hong Kong. Am J Ophthalmol. 2014;158(6):1130-1135.e2.
12. Wu Y, Willcox M, Zhu H, Stapleton F. Contact lens hygiene compliance and lens case contamination: A review. Contact Lens Anterior Eye. 2015;38(5):307-316.
13. Sankaridurg PR, Sweeney DF, Sharma S, et al. Adverse events with extended wear of disposable hydrogels: Results for the first 13 months of lens wear. Ophthalmology. 1999;106(9):1671-1680. doi:10.1016/S0161-6420(99)90346-9
14. Young AL, Leung ATS, Cheng LL, Law RWK, Wong AKK, Lam DSC. Orthokeratology Lens-Related corneal ulcers in children: A case series. Ophthalmology. 2004;111(3):590-595. doi:10.1016/J.OPHTHA.2003.06.003
15. Willcox MD, Holden BA. Contact lens related corneal infections. Biosci Rep. 2001;21(4):445-461.
16. Stapleton F, Keay L, Edwards K, et al. The incidence of contact lens-related microbial keratitis in Australia. Ophthalmology. 2008;115(10):1655-1662.
17. Wihelmus K. Review of clinical exeperience with microbial keratitis associated with contact lenses. CLAO. 1987;13:211-214.
18. Watt K, Swarbrick HA. Microbial keratitis in overnight orthokeratology: review of the first 50 cases. Eye Contact Lens. 2005;31(5):201-208.
19. Szczotka-Flynn L, Lass JH, Sethi A, et al. Risk factors for corneal infiltrative events during continuous wear of silicone hydrogel contact lenses. Invest Ophthalmol Vis Sci. 2010;51(11):5421-5430.
20. Sweeney DF, Jalbert I, Covey M, et al. Clinical characterization of corneal infiltrative events observed with soft contact lens wear. Cornea. 2003;22(5):435-442.
21. Nilsson SE. Seven-day extended wear and 30-day continuous wear of high oxygen transmissibility soft silicone hydrogel contact lenses: a randomized 1-year study of 504 patients. CLAO. 2001;27(3):125-136.
22. Sankaridurg PR, Sharma S, Willcox M, et al. Bacterial colonization of disposable soft contact lenses is greater during corneal infiltrative events than during asymptomatic extended lens wear. J Clin Microbiol. 2000;38(12):4420-4424.
23. Sankaridurg PR, Willcox MDP, Sharma S, et al. Haemophilus influenzae adherent to contact lenses associated with production of acute ocular inflammation. J Clin Microbiol. 1996;34(10):2426-2431.
24. Szczotka-Flynn L, Chalmers R. Incidence and epidemiologic associations of corneal infiltrates with silicone hydrogel contact lenses. Eye Contact Lens. 2013;39(1):48-52.
25. Donzis P, Mondino P, Weissman B, Bruckner D. Microbial contamination of contact lens care systems. Am J Ophthalmol. 1987;104:325-333.
26. Wilson LA, Sawant AD, Simmons RB, Ahearn DG. Microbial contamination of contact lens storage cases and solutions. Am J Ophthalmol. 1990;110(2):193-198.
27. Stapleton F, Keay L, Sanfilippo P, Katiyar S, Edwards K, Naduvilath T. Relationship between climate, disease severity and causative organism for contact lens–associated microbial keratitis in Australia. Am J Ophthalmol. 2007;144(5):690-698.e1.
28. Galentine PG, Cohen EJ, Laibson PR, Adams CP, Michaud R, Arentsen JJ. Corneal ulcers associated with contact lens wear. Arch Ophthalmol. 1984;102(6):891-894.
29. Bennett HGB, Hay J, Kirkness CM, Seal D V, Devonshire P. Antimicrobial management of presumed microbial keratitis: guidelines for treatment of central and peripheral ulcers. Br J Ophthalmol. 1998;82(2):137-145.
30. Cheng KH, Leung SL, Hoekman HW, et al. Incidence of contact-lens-associated microbial keratitis and its related morbidity. Lancet. 1999;354(9174):181-185.
31. Mubareka S, Alfa M, Harding GK, Booton G, Ekins M, Vancaeseele P. Acanthamoeba species keratitis in a soft contact lens wearer molecularly linked to well water. Can J Infect Dis Med Microbiol. 2006;17(2):120-122.
32. Wilhelmus K, Robinson N, Font R, Hamill M, Jones D. Fungal keratitis in contact lens wearers. Am J Ophthalmol. 1988;106(6):708-714.
33. McLaughlin-Borlace L, Stapleton F, Matheson M, Dart JK. Bacterial biofilm on contact lenses and lens storage cases in wearers with microbial keratitis. J Appl Microbiol. 1998;84(5):827-838.
34. Devonshire P, Munro FA, Abernethy C, Clark BJ. Microbial contamination of contact lens cases in the west of Scotland. Br J Ophthalmol. 1993;77(1):41-45.
35. Gopinathan U, Stapleton F, Sharma S, et al. Microbial contamination of hydrogel contact lenses. J Appl Microbiol. 1997;82(5):653-658.
36. Wu Y, Zhu H, Harmis N, Iskandar S, Willcox M, Stapleton F. Profile and frequency of microbial contamination of contact lens cases. Optom Vis Sci. 2010;87(3):152-158.
37. Willcox MDP, Carnt N, Diec J, et al. Contact lens case contamination during daily wear of silicone hydrogels. Optom Vis Sci. 2010;87(7):456-464.
38. Szczotka-Flynn LB, Pearlman E, Ghannoum M. Microbial contamination of contact lenses, lens care solutions, and their accessories: a literature review. Eye Contact Lens. 2010;36(2):116-129.
39. Tomiyama ES, Hu C, Marsack JD, Richdale K. Greater higher order aberrations induced by toric orthokeratology versus soft toric multifocal contact lens wear. Ophthalmic Physiol Opt. 2021;41(4):726-735. doi:10.1111/OPO.12839
40. Dantam J, Zhu H, Willcox M, et al. In vivo assessment of antimicrobial efficacy of silver-impregnated contact lens storage cases. Invest Ophthalmol Vis Sci. 2012;53(3):1641-1648.
41. Kanpolat A, Kalayci D, Arman D, Drunk K. Contamination in contact lens care system. CLAO. 1992;18(2):104-107.
42. Midelfart J, Midelfart A, Bevanger L. Microbial contamination of contact lens cases among mediacal students. CLAO. 1996;22(1):21-24.
43. Datta A, Willcox MDP, Stapleton F. In vivo efficacy of silver-impregnated barrel contact lens storage cases. Contact Lens Anterior Eye. 2021;44(4):101357. doi:10.1016/J.CLAE.2020.08.001
44. Yung AMS, Boost M V, Cho P, Yap M. The effect of a compliance enhancement strategy (self-review) on the level of lens care compliance and contamination of contact lenses and lens care accessories. Clin Exp Optom. 2007;90(3):190-202.
45. Boost M V, Cho P, Hong T, Polytechnic K, Special HK. Microbial flora of tears of orthokeratology patients, and microbial contamination of contact lenses and contact lens accessories. Optom Vis Sci. 2005;82(6):451-458.
46. Pens CJ, Costa M da, Fadanelli C, Caumo K, Rott M. Acanthamoeba spp. and bacterial contamination in contact lens storage cases and the relationship to user profiles. Parasitol Res. 2008;103(6):1241-1245.
47. Gray TB, Cursons RT, Sherwan JF, Rose PR. Acanthamoeba, bacterial, and fungal contamination of contact lens storage cases. Br J Ophthalmol. 1995;79(6):601-605.
48. Paragon Vision Sciences Inc. Professional fitting Paragon CRT ® Paragon CRT ® 100 Contact lens corneal refractive therapy. 2015:1-16.
49. Diec J, Naduvilath T, Tilia D, Papas EB, Lazon de la Jara P. Discrimination of subjective responses between contact lenses with a novel questionnaire. Contact Lens Anterior Eye. 2017;40(6):367-381.
50. Lo J, Kuo M-T, Chien C-C, Tseng S-L, Lai Y-H, Fang P-C. Microbial bioburden of orthokeratology contact lens care system. Eye Contact Lens Sci Clin Pract. 2016;42(1):61-67.
51. Wanga J, Liua L, Boostb M, Yapb M, Cho P. Risk factors associated with contamination of orthokeratology lens cases. Contact Lens Anterior Eye. 2020;43:178-184.
52. Gabriel MM, McAnally C, Bartell J, et al. Biocidal Efficacy of a Hydrogen Peroxide Lens Care Solution Incorporating a Novel Wetting Agent. Eye Contact Lens. 2019;45(3):164-170.
53. Willcox M. Hydrogen peroxide versus multipurpose disinfecting solutions – what are the differences? Ocul Surf Charact Asian Eye. 2008.
54. Papas E, Carnt N, Willcox M, Holden B. Complications associated with care product use during silicone daily wear of hydrogel contact lens. Eye Contact Lens. 2008;33(6):392-393.
55. Hovding G. The conjunctival and contact lens bacterial flora during lens wear. Acta Ophthalmol. 1981;59(3):387-401. doi:10.1111/j.1755-3768.1981.tb03004.x
56. Lakkis C, Fleiszig SMJ. Resistance of Pseudomonas aeruginosa isolates to hydrogel contact lens disinfection correlates with cytotoxic activity. J Clin Microbiol. 2001;39(4):1477-1486.
57. Gabriel MM, McAnally C, Chen H, Srinivasan S, Manoj V, Garofalo R. Hydrogen Peroxide Disinfecting Solution for Gas Permeable Contact Lenses: A Review of the Antimicrobial Efficacy, Compatibility, and Safety Performance of a One-Step Lens Care System. Clin Optom. 2021;13:7. doi:10.2147/OPTO.S280046
58. MM G, C M, J B, et al. Biocidal Efficacy of a Hydrogen Peroxide Lens Care Solution Incorporating a Novel Wetting Agent. Eye Contact Lens. 2019;45(3):164-170. doi:10.1097/ICL.0000000000000549
59. Bourcier T, Thomas F, Borderie V, Chaumeil C, Laroche L. Bacterial keratitis: predisposing factors, clinical and microbiological review of 300 cases. Br J Ophthalmol. 2003;87(7):834-839.
60. Willcox MDP. Characterization of the normal microbiota of the ocular surface. Exp Eye Res. 2013;117:99-105. doi:10.1016/J.EXER.2013.06.003
61. Ramachandran L, Sharma S, Sankaridurg PR, et al. Examination of the conjunctival microbiota after 8 hours of eye closure. CLAO J. 1995;21(3):195-199.
62. Zhang H, Zhao F, Hutchinson DS, et al. Conjunctival Microbiome Changes Associated With Soft Contact Lens and Orthokeratology Lens Wearing. Invest Ophthalmol Vis Sci. 2017;58(1):128-136. doi:10.1167/IOVS.16-20231
63. Szczotka-Flynn LB, Bajaksouzian S, Jacobs MR, Rimm A. Risk Factors for contact lens bacterial contamination during continuous wear. Optom Vis Sci. 2009;86(11):1216-1226.
64. Üstüntürk M, Zeybek Z. Microbial contamination of contact lens storage cases and domestic tap water of contact lens wearers. Wien Klin Wochenschr. 2012;124(S3):17-22.
65. Thakur D V, Gaikwad UN. Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users. Indian J Med Res. 2014;140(2):307-309.
66. Panthi S, Paudel P, Chaudhary M, Sapkota K, Shah DN. Microbial contamination of contact lens care accessories and compliance with care regimens in Nepal. Contact Lens Anterior Eye. 2014;37(1):2-10.
67. Szczotka-Flynn L, Jiang Y, Raghupathy S, et al. Corneal inflammatory events with daily silicone hydrogel lens wear. Optom Vis Sci. 2014;91(1):3-12.
68. Cho P, Boost M, Cheng R. Non-compliance and microbial contamination in orthokeratology. Optom Vis Sci. 2009;86(11):1227-1234.
69. Lo J, Fang P, Chien C, Hsiao C, Tseng S, Lai Y. PCR analysis for assessment of bacterial bioburden in orthokeratology lens cases. 2016;(August 2015):1-8.
70. Fang PC, Lo J, Chang TC, et al. Bacterial bioburden decrease in orthokeratology lens storage cases after forewarning: Assessment by the DNA Dot Hybridization Assay. Eye Contact Lens. 2017;43(3):174-180. doi:10.1097/ICL.0000000000000252