Abstract
Abstract: :
Purpose: Contact lens wear is known to pose a threat to the health of the ocular surface. Use of in vivo confocal microscopy (IVCM) to visualize leukocyte rolling and extravasation in inflammation was recently described by Kirveskari et al. (Nature Medicine 7;3;376-379; March 2001). We tested the hypothesis that contact lens wear was associated with measurable inflammation in superficial vessels. Methods: Leukocyte rolling and sticking, which are hallmarks of the inflammatory process, were recorded by IVCM (Advanced scanning limited). IVCM was performed on the conjunctival blood vessels 4-5 mm temporal to the limbus OU on 46 contact lens wearers (13 male, 36 female; 10 daily disposables, 27 extended wear disposables, and 9 rigid gas permeable) between the ages of 22 to 53 (average 32.7 years) and 21 non-contact lens wearers (8 male, 15 female) between the ages of 26 to 54 (average 36.4 years). Digital conversion was performed with Canopus Digital Storm Video imaging and Adobe Premiere software. We obtained information regarding demographics, past medical history, type of contact lens (daily soft, extended soft, and rigid gas permeable, Dk values[oxygen diffusion gradient]), and routine contact lens care (overnight disinfection, length of contact lens wear, and time prior to lens disposal). All patients had an anterior segment exam. White blood cells were graded based on density of cell adhesion within conjunctival vessels in a given ten second frame. Results: Although 67% of patients with contact lens wear exhibited measurable leukocyte sticking and rolling in the conjunctival vessels, similar leukocyte dynamics were found in the controls (56%). A subgroup analysis of soft contact lens wearers show leukocyte sticking and rolling in 75% (n=8) of those wearing lenses with a Dk value less than 10, 73% (n=26) of subjects wearing lenses with a Dk value between 15 and 32, and 0% (n=1) of those wearing lenses with a Dk >100. Subgroup analysis based on patient compliance in standard lens care reveals sticking and rolling in 77% (n=22) of noncompliant patients as compared to 58% (n=24) of compliant patients. Conclusion: IVCM is a novel, powerful technique to recognize a critical but subclinical component of inflammation. We speculate that overuse of contact lenses may place these patients at greater risk for complications from contact lens. In contrast to a prior report, we frequently detected leukocyte rolling or sticking within conjunctival vessels of normal eyes, possibly reflecting normal immune surveillance.
Keywords: conjunctiva • inflammation • contact lens