EyeWitness Fall 2010 - 6

FEATURE ARTICLE
Examining Your Patient for Multifocal GP Lenses
design they may have tried that did not work for them. If they are entirely new to contact lenses, this may Many factors go into success or failure not be a bad thing. Without a history of fitting multifocal GP lenses. These of expectations to meet or bad habits include the patient’s individual ocular to break, you may find this an easier findings, the lid position and tensituation to win than one with a long sion, and their expectations. No two history of doing things “their way.” people are exactly the same in how If after interviewing the patient, these factors come into play. Failure to Figure 6. Upper lid positioning above cornea you feel you have a good candidate makes lid attachment difficult. Opt instead consider all the factors will make the for translating design or centered design that for GP multifocals, you need to use fit process more difficult or even lead require no upper lid interaction. that information about their visual to an unsuccessful outcome. demands and marry it with their Assessing the individual patient eye and lid anatomy. Like with any occurs in many ways and can often go GP lens fit, consider the effect the on at different levels at the same time. prescription and corneal curvature While talking to the patient and diswill have on the fit. Trying to fit a covering what their needs are, observe patient with steep corneas and a high how they blink, where their lids are in plus Rx in a lens that requires some relation to their cornea, and whether degree of lid control may not be the they appear to have tight lids or loose best move. Consider instead a lens lids. It is important to discern what the Figure 7. Lower lid position below cornea makes with a design that is fit as centered patient’s visual demands are at distranslating design difficult to fit. Opt instead as possible, or perhaps a translating for a lens that utilizes some degree of upper lid tance, near, and intermediate. These design with or without truncation. interaction. can be determined with direct quesThe position of the lids in relations that address each aspect. How tion to the cornea may be the biggest much driving do you do and particularly, night driving? Do fit factor that you face. In general, lenses that require some you use a computer for extended periods on most days? degree of lid attachment cannot be fitted when the upHow much reading do you do? Do you have any hobbies per lid is positioned above the cornea (Figure 6). In this that require exceptional distance, intermediate, or near case, fit a lens that needs to center well to work properly vision? Any lens fitting, to be successful, must begin with a or fit a translating design. In cases where the lower lid is clear understanding of what the visual demands are for the positioned below the cornea or even well above the lower individual patient. limbus (Figure 7), a translating design is difficult to fit. Once it is clear what the visual requirements are, it Finally, consider the tension of the lids. In cases where lid may be a good idea to test the patient to see how demandtension is significant, the lenses may slip from the upper ing they will be. I like to pose scenerios and see how the lids but will easily rest on the lower lid, making translation patient reacts. Asking a patient if they would be happy with possible. When lid tension is lax, it may actually be easier lenses that allowed them to drive and work on a computer for the upper lids to hold a lens making an aspheric or comfortably, but might require occasional use of reading concentric design more appropriate. Don’t forget to look glasses over the lenses can help you determine how big at each eye as a separate entity, especially with increasing a task you are undertaking. Patients that seem willing to age. Lid asymmetry increases with age and a patient may work with you and compromise at times will be easier be better served with two different brands of lenses if their to please and reach a successful outcome than one that lids are of different postures. expects optimal vision at all distances and at all times. Never forget that as you begin the fit process for any Don’t forget to find out about the patient’s history patient, your local GP lab is an invaluable resource. With with contact lenses. For the patient that presents wearing the right information, your GP lab can recommend an GP lenses that they already love and are only looking for appropriate type of lens for the patient you are beginning improved reading, you may only need to assess their curto fit. Providing the basics, such as keratometric readings, rent lenses and find a multifocal that mimics them for fit. spectacle Rx, and add power is necessary to fabricate a If they have tried GP multifocals in the past and failed, try set of lenses. Including the upper and lower lid position, to determine why and whether the main reason for failure lid tension, any other ocular health findings, as well as the fell on the patient or their prior fitter, or what type of lens patient’s occupation, hobbies, and visual demands when
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EyeWitness Fall 2010

Table of Contents for the Digital Edition of EyeWitness Fall 2010