EyeWitness

Winter 2017

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CLSA EyeWitness Winter 2017 24 versation with a new potential contact lens patient prior to choosing a contact lens. Ask open ended questions like, "Why are you interested in wearing contact lenses?" and "What do you do for work?" Popular responses are: "I hate my glasses," "I want to wear them for sports," or "I want to wear them for special occasions." Remember to ask questions re- garding their ocular and physical health including questions about dry eyes, medical conditions, medications that may cause dry eyes, diabetes, sea- sonal allergies, and previous ocular in- fections or trauma. When a patient answers yes to hav- ing dry eyes, allergies, or any ocular in- fection that leaves the cornea a mess, consider starting a conversation about daily disposable contact lenses. Daily disposable contact lenses have the best patient compliance and are the health- iest choice. Putting in a fresh pair of contact lenses with the lens wettability completely intact and without previous of the lenses immediately after swimming. A third consideration when fitting soft contacts is knowing your preferred contact lenses. Determine your preferred daily disposables in sphere, toric, and mul- tifocal and do the same for monthly and two-week lenses. On the other hand, nev- er be afraid to experiment with new lens- es coming onto the market because there will always be something innovative about the new lens design. While some lenses are marketed to patients for extended wear, it is advisable that patients never sleep in their contact lenses due to the increased risk of infec- tion. However, if there is a gut feeling that a patient will be abusing and sleeping in their contact lenses, consider fitting them into FDA-approved extended wear lens- es to ensure that their cornea is at least receiving the amount of oxygen it needs during those periods of eyelid closure. Assessing a Soft Lens Fit Soft contact lenses are very forgiving and do not require as much precision as GP pletely centered on the cornea; however, it is okay for a lens to be decentered as long as it maintains full limbal coverage. When first learning how to assess lens movement quantitatively, utilize a known 1mm spot beam of light on the slit lamp. The spot beam of light is placed at the inferior edge of the contact lens (as close to the 6 o'clock position as possible without the eyelid interfering) and the patient is asked to blink nor- mally. If the contact lens moves half the width of the 1mm spot beam, the lens moved 0.50mm. The ideal range of blink movement is between 0.25 to 1.00mm of vertical excursion. If no movement is seen in primary gaze, ask the patient to then look up to see if the contact lens moves on up-gaze. If there is no movement in primary gaze or on up-gaze, have the patient look straight and then perform the push-up test. To perform the push-up test, place a finger against the patient's lower lid. Then push the lens upward (but not in- ward). If the contact lens is "free float- ing" and moves back quickly, this is con- sidered acceptable although not ideal. If the contact lens moves slowly or jerkily back into its position, it is not acceptable in any circumstance. It is important to always have the pa- tient back for a follow up visit, especially if it is a new contact lens brand. Any change in lens material or lens brand requires a follow up visit. At the follow up, it is im- portant to check the contact lens fit, spe- cifically the lens movement. It is known that soft contact lens materials dry out over a period of lens wear and as there is less moisture, the lens fit tightens. Consid- er removing the lens and inserting NaFl to check for dryness or areas where the contact may be fitting poorly. Often times staining is present even when the patient is asymptomatic. Depending on the severity and location of the staining, a lens change may be indicated. Soft Contact Lens Designs As alluded to previously, there are spheri- cal, toric, and multifocal soft contact lens designs available on the market. One of the challenges of toric soft contact lenses is how to stabilize the For all modalities, finding out the patient's goals, visual demands, and expected wear time can help you determine the most appropriate contact lens. Setting realistic expectations from the start can improve overall success for you and your patients. allergens on the lens surface is a huge draw for these patients. They are also a great option for patients who only want to wear contacts part-time such as on the weekends or for sports. The convenience of daily disposable contacts comes at a slightly higher price; however, no solu- tions are required for this modality. Encourage patients to not swim in their contact lenses, but sometimes it is unavoidable. Swimming with contact lenses and the protocol for what a patient should do after they swim in their contact lenses is still murky and no contact lens fit- ter will have the same opinion. If a patient is a swimmer and is likely to swim in their contact lenses, then this is a great example of a patient that should go into daily dis- posables. Daily disposable contact lenses should be used particularly for those wa- ter activities, but remind them to dispose lenses. There are at minimum three things that a practitioner needs to check after the lens has equilibrated on the patient's eye: coverage, position, and movement. Full lens coverage is necessary at all times – this means that the contact lens must be covering the entire cornea and that the limbus must never be exposed, even on a lid blink. This is typically as- sessed in primary gaze; however, even if a patient is moving their eye around, the contact lens should not be uncovering any part of the cornea. Ideally, there is a minimum of 0.50mm of lens coverage past the limbus onto the sclera 360˚. Lens position dictates where the contact lens has settled on the eye. Eval- uate it based on vertical and lateral de- viations in primary gaze – has it settled superiorly? Temporally? Nasally? Infe- rior-temporally? Ideally, the lens is com-

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