The Right Lens for Every Patient
Base your contact lens recommendations on patient population and subjective visual, lifestyle and comfort needs.
By Alan Glazier, OD, FAAO, Rockville, Md.
IF YOU WANT TO be a step ahead when it comes to fitting contact lenses, you'll have to master the science of fitting as well as the art. To master the art, you must customize the fit to the patient. Coupling science with art enables you to select the right lens for each patient. In this article, I'll discuss specific groups of contact lens wearers and the lenses that I believe best suit their needs.
Children, Tweens and Teens
Over the years, gas-permeable (GP) lenses have been recommended for children ages 8 to 11, because it was believed soft contact lenses contributed to myopia progression.1 In addition, some studies indicated GP lenses were effective in slowing myopia progression.2,3 In fact, many eyecare practitioners, including myself, recommend orthokeratology (made of GP materials) for children whose parents inquire about potential ways to control myopia. Our recommendations are based on studies that demonstrate a statistically significant corrective and preventive/control effect in childhood myopia.4-6 In addition, children often find GP lenses easier to insert and remove because the lenses are small and don't require patients to touch their eyes to remove them.
Recently, however, many practitioners have begun offering soft lenses to children. The Adolescent and Child Health Initiative to Encourage Vision Empowerment study, presented at the Association for Research in Vision and Ophthalmology in 2008, revealed that soft lens wear wasn't shown to increase the rate of myopia progression in children during the 3-year study period.
If a patient's ocular health and lifestyle indicate he's a good candidate for soft lenses, and he's able to insert and remove the lens, I often recommend a single-use soft lens, because a sterile, fresh lens every day is least likely to compromise the cornea, which is important when fitting a still-developing eye.
Tweens (ages 10 to 12) and teens usually are able to insert and remove soft lenses, so I begin offering single-use, 1-week or 1-month daily wear lenses to appropriate candidates in this population. I've discovered that patients using the 2-week modalities generally over-wear their lenses, putting themselves at risk for eye infections. As a result, I offer the 2-week modality with a 1-week wearing schedule. I present this lens wear regimen as "new week, new lens," which I've discovered fosters compliance. An example of a viable candidate would be an avid athlete. GP lenses trap dirt and debris more readily than soft lenses due to a gap that exists between the lens and the eye. This can cause ocular discomfort in individuals who spend a great deal of time outdoors.
I offer the 2-week (on a 1-week wear schedule) and 1-month modalities to viable candidates who are mature enough to adhere to the necessary lens care regimen. If responsibility is an issue, I recommend a single-use soft lens, because this modality doesn't require lens care and thus reduces infection risk.
College/workforce Through Incipient Presbyopia
I offer 30-day extended-wear (overnight) and single-use lenses to college students, members of the workforce and incipient presbyopic patients, because they have enough accommodative ability to see clearly through a single-vision lens at many ranges with relative comfort. They also appreciate modalities that save them time and effort, because their lifestyles (studying, working long hours, raising children and so on) require more time, energy and memory.
Single-use lenses are excellent for alleviating and/or solving discomfort issues that can stem from the environment. For example, computer users often have reduced blinking frequency, because they've become conditioned to stare at their monitors for prolonged periods of time. This can lead to ocular dryness, sometimes making lens wear particularly uncomfortable for those wearing 2-week or 1-month daily wear lenses. With each day of wear, the lens surface material, in contact with the palpebral conjunctiva, breaks down and/or accumulates debris. A fresh lens every day can provide increased comfort for these patients.
Finding the perfect lens for presbyopic patients requires a great deal of trial and error, because often they aren't willing to compromise their distance vision by wearing simultaneous vision presbyopic lens options. My philosophy in fitting this patient population is "underpromise, overdeliver."
I begin with the initial consult. First, I determine which visual ranges are important to the patient by asking him about the activities that comprise his weekdays and weekends. Then, I educate the patient about his vision and the available options. Finally, I explain that there's a possibility I'll have to prescribe spectacle lenses to wear "over" the contact lenses in order to correct whatever distance or near residual refractive error remains after maximized fitting.
I offer incipient to moderate presbyopic patients simultaneous vision aspheric GP, aspheric soft or multifocal toric designs and, in some cases, translating GP designs. The best candidates sustain mid-range vision most of the day (eg, computer users).
Dry Eye Patients
In 2007, the International Dry Eye Workshop Definition and Classification Subcommittee determined that dry eye can be divided into two classes: evaporative and aqueous-tear deficient. Regardless of which form your patient has, you must treat the underlying cause of dry eye before fitting the patient with contact lenses.
In the case of evaporative dry eye, I don't lean toward a specific lens material, because patients can achieve successful wear with multiple materials, as long as the dry eye treatment was successful in mitigating the lid disease and restoring the lipid layer of the tear film.
I tend to offer my aqueous-tear deficient dry eye patients a low-water content silicone hydrogel lens that has a non-ionic surface. In theory, and sometimes in practice, the lens allows a greater portion of the available aqueous tear to come in contact with the eye, which provides resistance to protein deposits, and thus provides a more comfortable experience.
Although it's impossible to know for certain how the aforementioned patient groups will perceive their lenses through full days of wear, by coupling the science with the art of fitting, you provide them with an excellent chance of achieving successful wear from the start. I also recommend that you make yourself available to patients via follow-up visits, e-mail or text messaging, especially if they experience less-than-optimum results or simply have questions or concerns. Having access to you lets the patient know you're invested in his lens wear experience, and this adds to the patient's perception of a successful fit. nOD
- Walline JJ, Jones LA, Sinnott L, et al. A randomized trial of the effect of soft contact lenses on myopia progression in children. Invest Ophthalmol Vis Sci. 2008;49:4702-4706.
- Khoo CY, Chong J, Rajan U. A 3-year study on the effect of RGP contact lenses on myopic children. Singapore Med J. 1999;40:230-237.
- Walline JJ, Mutti DO, Jones LA, et al. The contact lens and myopia progression (CLAMP) study: design and baseline data. Optom Vis Sci. 2001;78:223-233.
- Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005;30:71-80.
- Mika R, Morgan B, Cron M, Lotoczky J, Pole J. Safety and efficacy of overnight orthokeratology in myopic children. Optometry. 2007;78:225-231.
- Walline JJ, Rah MJ, Jones LA. The Children's Overnight Orthokeratology Investigation (COOKI) pilot study. Optom Vis Sci. 2004;81:407-413.
|Dr. Glazier is owner and founder of Shady Grove Eye & Vision Care in Rockville, Md. He is the founder and CEO of Vision Solutions Technologies and is the inventor of several core technology patents. You can reach him at firstname.lastname@example.org.|