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. 2021 Mar 1;98(3):182-198.
doi: 10.1097/OPX.0000000000001664.

American Academy of Optometry Microbial Keratitis Think Tank

Loretta B Szczotka-Flynn, Joseph P Shovlin  1 , Cristina M Schnider  2 , Barbara E Caffery  3 , Eduardo C Alfonso  4 , Nicole A Carnt  5 , Robin L Chalmers  6 , Sarah Collier  7 , Deborah S Jacobs  8 , Charlotte E Joslin  9 , Abby R Kroken  10 , Carol Lakkis, Eric Pearlman  11 , Oliver D Schein  12 , Fiona Stapleton  5 , Elmer Tu  13 , Mark D P Willcox  5
Affiliations

American Academy of Optometry Microbial Keratitis Think Tank

Loretta B Szczotka-Flynn et al. Optom Vis Sci. .

Abstract

Significance: Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies.

Purpose: The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting.

Methods: Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives.

Results: The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed.

Conclusions: The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.

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Conflict of interest statement

Conflict of Interest Disclosure: All participants were paid by the American Academy of Optometry to participate. The following authors report financial interests, but none of these sponsors provided financial or other support and had no involvement in this report: ECA, Alcon Laboratories, Alcon Research Institute, and Salvat Laboratories; CL, Johnson & Johnson Vision Care, Source One Technical Solutions, Scigofer, and CooperVision; NAC, Alcon, Johnson & Johnson, CooperVision, Specsavers, and Luxottica; DSJ, TECLens, Inc., and Simple Contacts; CEJ, Johnson & Johnson Vision Care, Inc.; CMS, Johnson & Johnson Vision Care; JPS, AbbVie, Aerie Pharmaceuticals, Dompe, LensTech, and Novartis; FS, Alcon Laboratories, Azura Ophthalmics, Nthalmic, Menicon, Novartis, and Sequirus; LBS-F, Johnson & Johnson Vision Care, Alcon, and LensTech; and MDPW, Johnson & Johnson Medical Pty Ltd., Johnson & Johnson Vision Care Inc., CooperVision, Allergan, Alcon Laboratories, and Ophtecs Corp.

Figures

Figure 1.
Figure 1.
Unadjusted incidence of microbial keratitis reported by lens type and mode of wear. Incidence per 10,000 wearers with 95% confidence intervals. RGP = rigid gas permeable (corneal); HG = hydrogel; SiH = silicone hydrogel; Mixed = mixed hydrogel and silicone hydrogel; DD = daily disposable; DW = daily wear; O/N = overnight wear; EW = extended wear; OK = Orthokeratology. Data based on findings from these studies: Stapleton et al 2008, Chalmers et al 2011, Bullimore et al 2013, Bullimore 2017.
Figure 2.
Figure 2.
Incidence of severe microbial keratitis reported by lens type and mode of wear. Incidence per 10,000 wearers with 95% confidence intervals. RGP = rigid gas permeable (corneal); HG = hydrogel; SiH = silicone hydrogel; DD = daily disposable; DW = daily wear; O/N = overnight wear; EW = extended wear; Occ = occasional. Data based on findings from Stapleton et al 2008.
Figure 3.
Figure 3.
Model of mechanism of infection of cornea by Pseudomonas aeruginosa.
Figure 3.
Figure 3.
Model of mechanism of infection of cornea by Pseudomonas aeruginosa.
Figure 3.
Figure 3.
Model of mechanism of infection of cornea by Pseudomonas aeruginosa.
Figure 4.
Figure 4.
Confocal Microscopy of Filamentous Elements in a Patient with Fungal Keratitis
Figure 5.
Figure 5.
Biogeography of the ocular microbiome (Courtesy of Dr Jerome Ozkan, School of Optometry and Vision Science, University of New South Wales). Conjunctiva_tissue = limbal conjunctiva removed from fellow eye of patients undergoing pterygium surgery; Conjunctiva_surface = swabs of the bulbar conjunctiva of humans; Lid_margin = swabs of the lid margin of humans; skin = swabs of the skin on the upper eyelid of humans. MDS = multidimensional scaling which is used to display the positions of the OTUs in two dimensions; this gives information regarding the similarities of OTUs between and within mammalian species.
See this image and copyright information in PMC

References

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