Considerations in Contact Lens Use Under Adverse Conditions Proceedings of a Symposium (1991) / Chapter Skim
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Endothelial Effects From Contact Lens Wear
Endothelial Effects From Contact Lens Wear
Pages 84-94
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From page 84... ...
If there is a perceived advantage in the wearing of contact lenses versus spectacles when piloting an aircraft because of the "freedom" afforded the pilot in terms of not having spectacles "hanging on the face," I guarantee that it will result in better performance directly measurable or not. Nevertheless, just as in the civilian community, military personnel about to be fitted with contact lenses must be apprised of the immediate and longterm risks of contact lens wear, so that wearers will not return saying: "I didn't know contact lenses might cause corneal ulcers" or "You didn't tell me about 'Agent Contact Lens'." With this in mind, let me tell you about one long-term effect of contact lens wear.
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From page 85... ...
Subjects vary markedly in the number of blebs produced. The appearance of corneal endothelial blebs has been noted not only with contact lens wear but also with lid closure, nitrogen goggles, and carbon dioxide environment.
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From page 87... ...
FIGURE 2 Mean endothelial cell area versus subject age. SOURCE: Schoessler (1988)
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From page 88... ...
Endothelial cell polymegethism is characterized by the development of many cells that are smaller than normal and by the development of cells much larger than normal. Corneal endothelial cell area distributions for long-term contact lens wearers differ from those of nonusers of contact lenses.
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From page 89... ...
. 8 9 10 11 3 4 CELL AREA FIGURE 5 Endothelial cell area distributions for contact lens wearers and age- and sexmatched controls.
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From page 90... ...
Such extreme changes in cell morphology have generally not been described for the normally aging patient. Endothelial cell photographs from contact lens wearers may also reveal cells that appear thick or "swollen." These cells seem to project out of the mosaic pattern and are mostly noted in persons who have worn PMMA contact lenses for long periods of time.
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From page 91... ...
The implication is that contact lens wear may alter endothelial cells sufficiently to impair their ability to allow the cornea to regain normal deturgescence following severe corneal stress, such as that from IOL surgery. This conclusion reemphasizes the need for development of contact lens materials with high oxygen permeability.
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From page 92... ...
For the majority of the present contact-lens-wearing population, this may mean an increased risk of corneal swelling complications or other problems following high corneal stress such as corneal surgery. One must be concerned not only with the reported results of cataract/IOL surgery but also with potential long-term problems associated with radial keratomy procedures on corneas with polymegethous endothelial cells.
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From page 93... ...
Holden 1977 Transient endothelial changes soon after wearing soft contact lenses. American Journal of Optometry and Physiological Optics 54: 856-858.
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