Contact Lenses: The Frenemies.

Abstract

The Eye & Contact Lens team is pleased to present this special issue featuring articles from invited speakers who participated in the Eye and Contact Lens Association/Japan Contact Lens Society Joint Symposium held on April 29, 2021, during the seventh Asia Cornea Society Biennial Scientific Meeting. This symposium covered important contact lens–related topics including contact lens use in keratoconus, ocular surface diseases, and myopia control. In addition, contact lens–related complications and the use of contact lenses as drug delivery devices were also discussed. Traditionally used for visual rehabilitation, contact lenses have found a niche for therapeutic indications. Orthokeratology is the use of specially designed contact lenses to temporarily reshape the cornea to improve vision.1 The orthokeratology lenses have also been shown to have an inhibitory effect on axial elongation for 2 years as compared with single-vision spectacles and contact lenses, helping to control myopia. Myopia is a global epidemic on the rise, garnering increased attention, particularly in therapeutics and prevention, and the field of myopia control. The current management options for myopia in the United States include contact lenses, spectacles, atropine, and environmental and behavioral modifications.2 The new treatments include combined therapy with low-dose atropine eye drops and orthokeratology lenses. Modifications in environmental factors, especially the time spent outdoors, have been shown to slow the progression of myopia. These policies have already been adopted in countries with a high prevalence of myopia in schoolchildren, particularly in Asia. In addition to myopia control and treatment, contact lenses play an important role in visual and ocular surface rehabilitation. Corneal rigid gas-permeable contact lenses are commonly used for visual rehabilitation in keratoconus. The two fitting strategies, apical touch fitting with spherical lenses and parallel fitting with multicurve lenses, have different success rates depending on the type and severity of keratoconus.3 Contact lens designs have evolved immensely over the past few decades. Medically necessary contact lens fitting has reduced the need for corneal transplantation in patients with corneal ectasias and complex ocular surface diseases. Therapeutic contact lenses are also used in the management of patients with complex ocular surface disease.4 These include bandage soft contact lenses, scleral lenses, and customized prosthetic devices in the management of recurrent corneal erosion and ocular graft-vs-host disease. The prosthetic replacement of the ocular surface ecosystem (PROSE) treatment for Stevens–Johnson syndrome has been shown to improve visual acuity and help in closure of corneal epithelial defects. Because many of these therapeutic contact lenses are required to be worn for an extended period, antibiotic prophylaxis is of paramount importance at the time of fitting. Contact lenses have also been used for drug delivery to the ocular surface. The proximity of contact lens to the ocular surface makes it a perfect candidate for extended drug delivery. In addition, pharmacologic agents may be copolymerized with hydrogels allowing controlled drug diffusion through contact lenses.5 Use of contact lenses for drug delivery reduces waste through nasolacrimal drainage and frequency of dosage while allowing sustained release of the drug. Despite all its attributes, complications can occur, and contact lens wear is a common predisposing factor for microbial keratitis.6 It shares the blame with ocular trauma for being one of the two preventable risk factors for corneal infection. Pseudomonas aeruginosa remains the commonest cause of contact lens–related corneal infection likely because of its virulent characteristics and ability to survive in the contact lens/storage case/ocular environment.7 Contact lens case contamination has been reported in most contact lens wearers. The formation of bacterial biofilm on the contact lens surface and storage cases plays a role in the pathogenesis of microbial keratitis. Bacterial cells within a biofilm show increased resistance to antimicrobial agents. The use of newer techniques such as metabolomics, gene expression, and characterization of ocular microbiome is helping us improve our understanding of contact lens–related keratitis. Advances in contact lens technology have significantly enhanced our ability to care for patients with various ocular conditions, leading to better patient outcomes and satisfaction. However, it is important to keep in mind that serious complications can occur from contact lens use, and therefore, we must be vigilant that, in addition to being our friend, the lenses can be our enemy as well.