Cécile Maissa is the Research Manager at OTG Research & Consultancy and Visiting Research Fellow in the School of Life & Health Sciences at Aston University, UK.
Despite constant improvement in contact lens materials and designs available, the leading cause of discontinuation from contact lens wear is discomfort. Comfort during contact lens wear is not easily predicted by clinical signs and is thought to be related to a number of factors, including the lens’ effect on the tear film layer and its mechanical interaction with the ocular surfaces. The following editorial describes the presentation, location and presumed mechanical causes of lid wiper epitheliopathy, lid parallel conjunctival folds, conjunctival epithelial flap and conjunctival staining and their possible effect on comfort based upon a number of recent clinical presentations related to the mechanical effects of contact lenses.
Lid wiper epitheliopathy
Lid wiper epitheliopathy (LWE) is an alteration of the advancing lid margin in the area of contact between the upper eyelid and ocular surfaces (the lid wiper), caused by friction during lid movements. It was described as “lid wiper epitheliopathy” initially by Korb et al.1,2.
LWE is assumed to be related to the mechanical forces that occur during blinking and the repeated rubbing of the lid margin epithelium against the cornea or contact lens surface3,4. In the presence of a contact lens, the tear film is known to be thinner or less stable and therefore less able to maintain adequate lubrication between the two moving surfaces to minimize friction during the blink. The repeated “wiping” action of the upper eyelid over the contact lens surface can lead to mechanical trauma of the lid margin and epithelial cells, visualized clinically as increased staining along the upper lid margin.
LWE has been suggested as an early indicator of dry eye disease5 and has been identified as a clinical sign more prevalent and more severe during contact lens wear and in symptomatic contact lens wearers than asymptomatic wearers6,7,8,9,10. LWE has also been observed on the lower eyelid but without any significant difference between contact lens wearers with and without dry eye symptoms11,12.
Recently, a study explored the relationship between comfort and LWE in contact lens wearers. The assessment after ten days of wear of lotrafilcon A or comfilcon A showed that LWE of the upper lid increased during contact lens wear; however, the study failed to demonstrate an association between LWE and comfort13.
Lid parallel conjunctival folds
Lid parallel conjunctival folds (LIPCOF) are located in the lateral lower quadrant of the bulbar conjunctiva, parallel to the lower lid margin14; these subclinical conjunctival folds are not associated with aging and, to distinguish them from conjunctivochalasis, were initially described in dry eye subjects as LIPCOF by Hoh (1995).
Similar to LWE, LIPCOF has been reported to increase significantly in symptomatic contact lens wearers15,16 and may be a predictor of contact lens-induced dry eye symptoms17.
Conjunctival epithelial flap
Conjunctival epithelial flaps (CEF) are lesions of the bulbar conjunctiva, usually bilateral and only observed in the superior or inferior quadrants; they are thought to be composed of vital epithelial and goblet cells18,19,20. Conjunctival epithelial flaps were first reported in overnight extended wear of silicone hydrogels by Lofstrom and Kruse in 2005; since then CEFs have also been observed with daily wear of silicone hydrogels21,22,23,24. They are believed to result from the repeated interaction of the lens periphery and the ocular surface, initially observed by clinicians as contact lens-induced conjunctival staining. Lofstrom and Kruse further hypothesised that CEFs were linked to contact lens fit, edge design, base curve and material modulus, with higher modulus materials with non-round edge designs more likely to produce CEFs. The occurrence of CEF is generally asymptomatic and is not related to any discomfort. Initial reports of CEF showed no direct impact on lens wearing satisfaction or comfort25,26; however, the long term effect of this condition on discomfort is unknown.
Conjunctival staining
Limbal staining, also referred to as circumlimbal staining or contact lens-induced conjunctival staining (CLICS), is produced by direct contact between the lens periphery and the ocular surface; its severity is dependent upon both the lens design (edge profile) and material rigidity (modulus)27,28,29,30, with the least staining produced by “rounded” edge contact lenses with the apex away from the ocular surface and the greatest staining by “knife-point” edge design in close apposition with the ocular surface. Several studies have shown that increased circumlimbal staining, indicative of mechanical disturbance, was not a significant factor associated with decreased comfort; in fact recent data from our group and others31,32,33,34,35,36 showed that the rounded edge contact lenses, which created the least circumlimbal staining, produced the worst comfort and the knife-point edge contact lenses with the worst staining and tighter fit achieved the best comfort.
Bulbar staining away from the limbus, outside of the area covered by the contact lens, is believed to be more an exposure-type staining resulting from the poor stability of the tear film spreading over the whole ocular surface in the presence of a contact lens and subsequent increased evaporation. Bulbar staining has been associated with an increase in dry eye symptomatology in contact lens wearers37,38,39. More recently, the presence of staining in the bulbar region of the conjunctiva was associated with a significant decrease in comfort for contact lenses with knife-point edge design40.
The above findings suggest that the primary factor controlling comfort is the lens edge design, its potential interaction with the eyelids and its effect on fit, and that ocular tissue dehydration is an important secondary factor41. Limbal staining does not appear to influence immediate contact lens acceptance; however the long term effect of limbal staining is unknown. Comparative studies looking at the effect of LWE and LIPCOF with contact lens materials that have different surface characteristics (surface wettability, friction) and with different comfort responses are needed to investigate any association with comfort.
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- Korb DR, Greiner JV, et al.. Lid-wiper epitheliopathy and dry-eye symptoms in contact lens wearers. CLAO J 2002;28(4):211-6.
- Korb DR, Herman JP, et al.. Lid wiper epitheliopathy and dry eye symptoms. Eye Contact Lens 2005;31(1):2-8.
- Korb DR, Herman JP, et al.. Prevalence of lid wiper epitheliopathy in subjects with dry eye signs and symptoms. Cornea 2010;29(4):377-83.
- Pult H, Purslow C, et al.. Clinical tests for successful contact lens wear: relationship and predictive potential. Optom Vis Sci 2008;85(10):E924-9.
- Korb DR, Herman JP, et al.. Lid wiper epitheliopathy and dry eye symptoms. Eye Contact Lens 2005;31(1):2-8.
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- Shiraishi A, Yamanishi S, et al.. Lid-wiper epitheliopathy in patients with dry eye symptoms. Nihon Ganka Gakkai Zasshi 2009;113:596-600.
- Varikooty J, Srinivasan S, Jones L. Atypical manifestation of upper lid margin staining in silicone hydrogel lens wearers with symptoms of dry eye. Cont Lens Anterior Eye 2008;31(1):44-6. Epub 2007 Aug 24.
- Pult H, Purslow C, et al.. Clinical tests for successful contact lens wear: relationship and predictive potential. Optom Vis Sci 2008;85(10):E924-9.
- Berry M, Pult H, et al.. Mucins and ocular signs in symptomatic and asymptomatic contact lens wear. Optom Vis Sci 2008;85:930–8.
- Shiraishi A, Yamanishi S, et al.. Lid-wiper epitheliopathy in patients with dry eye symptoms. Nihon Ganka Gakkai Zasshi 2009;113:596-600.
- Berry M, Pult H, Purslow C, Murphy PJ. Mucins and ocular signs in symptomatic and asymptomatic contact lens wear. Optom Vis Sci 2008;85:930–8.
- Stahl UG, Delaveris A, et al.. Lid wiper epitheliopathy: exploring the links to comfort and osmolality in contact lens wear. Cont Lens Anterior Eye 2011;34(Supplement 1) S1-S43:518.
- Sickenberg W, Pult H, Sickenberg B. LIPCOF and contact lens wearers – A new tool to forecast subjective dryness and degree of comfort of contact lens wearers. Contactologia 2000;22:74-9.
- Pult H, Purslow C, et al.. Clinical tests for successful contact lens wear: relationship and predictive potential. Optom Vis Sci 2008;85(10):E924-9.
- Berry M, Pult H, Purslow C, Murphy PJ. Mucins and ocular signs in symptomatic and asymptomatic contact lens wear. Optom Vis Sci 2008;85:930–8.
- Pult H, Murphy PJ, Purslow C. A novel method to predict the dry eye symptoms in new contact lens wearers. Optom Vis Sci 2009;86:1042–50.
- Lofstrom T, Kruse A. A conjunctival response to silicone hydrogel lens wear: a new finding reveals how silicone hydrogel lenses may affect the conjunctival epithelium. CL Spectrum, September 2005;42-4. http://www.clspectrum.com/ article.aspx ?article=12869
- Thota S, Perrigin J, et al.. Conjunctival flaps in silicone hydrogel lens wearers. Invest Ophthalmol Vis Sci 2006;47: E-Abstract 82.
- Markoulli M, Carnt N, et al.. Resolution and clinical characteristics of conjunctival “flaps”. Invest Ophthalmol Vis Sci 2007;48: E-Abstract 5391.
- Lin M, Truong T, et al.. Conjunctival epithelial flaps with silicone hydrogel lenses worn for daily wear. Optom Vis Sci 2005;82:E-abstract 050078.
- Lakkis C, Weidemann K. Clinical evaluation of a new non surface treated silicone hydrogel lens during continuous wear. Invest Ophthalmol Vis Sci 2006; 47 E-abstract 2395
- Santodomingo-Rubido J, Wolffsohn J, Gilmartin B. Conjunctival epithelial flaps with 18 months of silicone hydrogel contact lens wear. Eye Contact Lens 2008;34(1):35-8.
- Graham AD, Truong TN, Lin MC. Conjunctival epithelial flap in continuous contact lens wear. Optom Vis Sci 2009;86(4):e324-31.
- Lofstrom T, Kruse A. A conjunctival response to silicone hydrogel lens wear: a new finding reveals how silicone hydrogel lenses may affect the conjunctival epithelium. CL Spectrum, September 2005;42-4. http://www.clspectrum.com/ article.aspx ?article=12869
- Markoulli M, Carnt N, et al.. Resolution and clinical characteristics of conjunctival “flaps”. Invest Ophthalmol Vis Sci 2007;48: E-Abstract 5391.
- Maïssa C, Guillon M, Garofalo RJ. Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis. Eye Contact Lens 2012;38(1):16-26.
- Brennan NA, Coles ML, Ang JH. An evaluation of silicone-hydrogel lenses worn on a daily wear basis. Clin Exp Optom 2006;89(1):18-25.
- Brennan NA, Coles ML, et al.. A 12-month prospective clinical trial of comfilcon A silicone-hydrogel contact lenses worn on a 30-day continuous wear basis. Cont Lens Anterior Eye 2007 May;30(2):108-18. Epub 2007 Apr 8.
- Hübner T. Edge profiles of hydrogel contact lenses and their effect on fitting and wearing characteristics. Wöhlk contactlinsen www.woehlk.com January 10, 2010. Available at: http://www.woehlk.com.hr/pdf/woehlk-wissen-02-en.pdf. Accessed July 21st, 2011.
- Ozkan J, Ehrmann K, et al.. Lens parameter changes under in vitro and ex vivo conditions and their effect on the conjunctiva. Cont Lens Anterior Eye 2013 Feb 7. pii: S1367-0484(13)00005-2. doi: 10.1016/j.clae.2013.01.004. Epub ahead of print
- Maïssa C, Guillon M, Garofalo RJ. Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis. Eye Contact Lens 2012;38(1):16-26.
- Morgan PB, Chamberlain P, et al.. Ocular physiology and comfort in neophyte subjects fitted with daily disposable silicone hydrogel contact lenses. Cont Lens Anterior Eye 2012;Dec 29. pii: S1367-0484(12)00331-1. doi: 10.1016/j.clae.2012.12.001. Epub ahead of print
- Hübner T. Edge profiles of hydrogel contact lenses and their effect on fitting and wearing characteristics. Wöhlk contactlinsen www.woehlk.com. January 10, 2010. Available at: http://www.woehlk.com.hr/pdf/woehlk-wissen-02-en.pdf. Accessed July 21st, 2011.
- Brennan NA, Coles ML, Ang JH. An evaluation of silicone-hydrogel lenses worn on a daily wear basis. Clin Exp Optom 2006;89(1):18-25.
- Brennan NA, Coles ML, et al.. A 12-month prospective clinical trial of comfilcon A silicone-hydrogel contact lenses worn on a 30-day continuous wear basis. Cont Lens Anterior Eye 2007;30(2):108-18. Epub 2007 Apr 8.
- Guillon M, Maïssa C. Bulbar conjunctival staining in contact lens wearers and non-lens wearers and its association with symptomatology. Cont Lens Anterior Eye 2005;28(2):67-73. Epub 2005 Apr 26.
- Lakkis C, Brennan NA. Bulbar conjunctival fluorescein staining in hydrogel contact lens wearers. CLAO J 1996;22(3):189-94.
- Maïssa C, Guillon M. Tear film and ocular surface characteristics associated with dry eye symptomatology. Optom Vis Sci 2011;88: E-abstract 115948.
- Maïssa C, Guillon M, Garofalo RJ. Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis. Eye Contact Lens 2012;38(1):16-26.
- Maïssa C, Guillon M, Garofalo RJ. Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis. Eye Contact Lens 2012;38(1):16-26.