The use of contact lenses, not just for beauty

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SINGAPORE (JP): "Beauty is in the eyes of the beholder!" Among the fairer sex of this world...there is no doubt that each would vie for the acclaim of being the "fairest of them all"!

The commonest indication for using contact lenses has always been attributed to "beauty-consciousness" and certainly Dorothy Parker's famous quote, "Men seldom make passes at girls who wear glasses!" helps to justify a woman's desire to wear contacts.

The simplest reason for wearing contact lenses is of course to restore vision, without distorting or lessening the beauty of the wearer. The "bottle glass" appearance of thick myopic corrective lenses certainly does an injustice to many a fair maiden. Contacts restore nature's intended good looks to the wearer.

Other reasons for using contacts are for professionals like airline staff, actors or actresses and deep sea divers where spectacles would be cumbersome. Persons with high astigmatism or keratoconus certainly have much clearer vision with Rigid Gas Permeable (RGP) lenses.

There are other medical conditions like dry eyes with cornea problems wherein contacts are used as therapeutic bandage lenses.

The consideration of "sight" or "clear vision" with contact lenses certainly deserves a comparison of pros and cons and a review of history, indications, contraindications, advantages and disadvantages.

History

Persons with refractive errors like myopia (shortsightedness) hyperopia (farsightedness), astigmatism (defect of vision causing improper focusing) certainly have blurred and distorted vision.

It was Leonardo da Vinci who invented the corrective lenses for myopia. In the 1800's the first experimental glass contact lenses were tried, and with progress in technology, different materials were utilized.

Compositions have evolved from hard to softer materials for comfort and from low water content to high water contents as high as 85 percent, made from copolymer vinyl lenses.

However, they proved too fragile and new materials like silicon were tried. This material is certainly stronger and is extremely oxygen-permeable, but because of its hydrophobic properties it also has drawbacks. So, hard lenses with high gas- permeability evolved as a great challenge in contact lens wear.

The popularity of contact lenses resulted from the clear vision that was made possible with both hard and RGP contact lenses. Then when soft lenses improved the comfort and even more people started wearing them, but persons with astigmatism of more than -1.00 DS could only manage to get the desired clarity with Toric Soft lenses or RGP lenses.

Contraindication

But, there are some contraindications of wearing contact lenses. Eye disease, recurrent infections and eye allergies make wearing of contact lenses difficult or impossible for some. Intolerance of contact lenses has prevented others from being able to wear contacts, but this has become rarer with the development of superior types of lenses.

High water content lenses produced problems not only through their increased susceptibility for bacterial infection, but from users wearing them beyond the recommended wearing time because of increased comfort causing increased accumulation of lens deposits.

These lens deposits were usually mixed deposits of organic (muco-protein, lipoprotein) or mineral"jelly-bumps"( iron, calcium). With prolonged wear, and the mechanical microtrauma of the upper palpebral conjunctivae, the incidence of giant papillary conjunctivitis (GPC) became as high as 12.5 percent among contact lens wearers (Malaysian study, 1994).

Daily, Weekly, Bi-weekly and Monthly Soft Disposable lenses have decreased and almost totally eliminated GPC among contact- lens wearers. All these lenses however, have been worn with the precaution of daily removal and overnight soaking in "all in one sterile preserved solutions". Yet now "after a 10 year hiatus, soft contact lenses that can be worn for more than 24 hours and for up to four weeks, are being relaunched", according to John Dart of London's Moorfieid Eye Hospital.

Complication

Complications for contact lens wearers were numerous until materials, design and water content were improved. Among some of the former complications, which occasionally may still be seen are -- GPC, Contact Keratoconjunctivitis, Dry Eye Syndrome, Superficial Punctate Keratitis (SPK), Cornea Infiltrates and Vascularisation, Acute Occlusive and Overwearing Syndromes. (Ruben M a Khoo CY, Contact Lenses, Medical Aspects).

Extended wear contact lenses have a group of complications peculiar to them, because of relatively reduced oxygen availability, such as corneal infiltrates, microcysts and limbal neovascularization.

Acanthamoeba and fungal infections are a danger, but their incidence have been reduced with better patient education and better training for eye-professionals who fit contact lenses.

Are contact lenses safe for children? This is the most frequent question asked by my patients.

There are ongoing studies on the special usage RGP Contact Lenses in stabilization of Progressive Myopia in children.

It has also been the subject of world-wide studies to determine whether RGP lenses retard the progress of myopia, during its most rapid period of development from 10 to 13 years of age.

A three-year study reported by Singapore's Dr. Khoo Chong Yew in 1996, validated that progressive increases in myopia were reduced among wearers of RGP lenses compared with spectacle wearers.

Dr. Jenny P. Deva is a consultant ophthalmologist for Ophir Eye Clinic, Klang, Selangor; Visiting Consultant, Selangor Medical Center, Shah Alam; Honorary Lecturer, Department of Ophthalmology Medical Faculty University of Malaya, Kuala Lumpur, Malaysia.