Rigid Gas Permeable Contact Lenses
RGP Contact Lens Use
Rigid gas permeable (RGP) lenses are lenses made of durable plastic that transmits oxygen.
RGP contact lenses are rigid, but they shouldn’t be confused with old-fashioned hard contact lenses, which are now obsolete. Hard contact lenses were made of a material known as PMMA. Though PMMA hard contacts had excellent optical qualities, they were not oxygen-permeable, and the front surface of the eye needs plenty of oxygen to stay healthy. Also, old-fashioned hard lenses were not as comfortable as modern GP lenses. RGP lenses also provide better vision, durability, and deposit resistance than soft contact lenses. And because they last longer than soft lenses, they can be less expensive in the long term.. Below are some tips for the successful handling and wearing of RGP lenses.
Handling Your Contact Lenses
Always ensure you hands are washed before touching your contact lenses. Choose a fragrance-free and moisturizer-free soap and, if possible, ensure it is antibacterial. Dry your hands thoroughly with a towel after washing your hands. To prevent lint from fluffy towels sticking to your fingers and in turn your contact lenses, perhaps dry your hands using a paper towel or a clean tea towel instead. Washing your hands prevents dirt, oils or bacteria being transferred from your finger to the contact lens and subsequently into your eye.
Insertion of Lenses
Open your storage case and remove the lens by gently scooping the lens upwards with your index finger, so as not to scratch the lens against the hard case. Place the lens of the index finger of your right hand if you are right handed (alternately place the lens on the index finger of your left hand if you are left handed). Inspect the lens on your finger to inspect the lens intergrity and that no foreign matter (like tissue lint) is on the lens.
There are many methods of inserting a contact lens and every wearer will find a method that feels comfortable to them. The recommended method involves you looking at your eye directly in the mirror. With your non-dominant hand (ie if you are right-handed, the non-dominant hand is the left hand), hold your top lid up by the eyelashes against your brow bone. Hold down your bottom lid with the middle finger of your dominant hand. This will align the contact lens on your index finger of your dominant hand with the eye’s surface. Keeping your gaze steady looking into the mirror, place the contact lens directly on the coloured part of the eye’s surface (the cornea).
Once the lens has made contact with the ocular surface, take the index finger away. The lens should stay on the eye’s surface. To ensure the lens doesn’t easily blink out, maintain hold of the top lid against the brow bone. Then centre the contact lens on the cornea by nudging the lens upwards using the lower lid. Once the lens appears centred, slowly release the top lid and allow it to blink over the contact lens. Keep blinking for a couple of seconds to enable the lens to settle.
Removing Your Lenses
Wash and dry your hands as previously mentioned. Looking at your eye in the mirror, ensure your lens is properly centred on your eye before removing. If you cannot see the lens on the coloured part of the eye, cover over the alternate eye and see if the vision is clear. If it is, your lens is on eye and centred. Again, hold your top lid by the eyelashes against your brow bone with your non-dominant hand. With your dominant hand, use your middle finger to pull down the lower lid. Then, by grasping a small RGP lens remover (or ‘suction cap’) between the index finger and thumb of your dominant hand, gently place the remover upon the contact lens surface. As you pull the ‘suction cap’ away from the eye, the contact lens should adhere to the remover and leave the ocular surface. Then gently slide the contact lens from the remover. Repeat for the other lens.
Alternatively, you can remove an RGP lens from the eye using the ‘blink’ technique. By placing the third finger of your dominant hand between the outer corner of the top and bottom lids, pull the eyelids out and upwards. By keeping the lids taught at that particular angle, blink hard. The force of the blink and the tight eyelids should flick the RGP from the ocular surface. Place your non-dominant hand beneath your chin so that you can catch the lens easily when it flicks out. This technique is quite simple but does require practice, especially if the RGP lens is of a larger diameter.
RGP Lens Care
Rigid gas permeable (RGP) lenses require a specialized care and maintenance regime due to the different material type. When an RGP lens is removed from the eye, it must be cleaned to remove the proteins, mucins and lipids that the lens builds up through a day’s wear. Place the RGP lens in the palm of the hand and add a few drops of Boston Advance Cleaner (Brown lid on bottle – red tip under lid). Rub the lens with the ball of the finger in the cleaner for approximately 15 seconds. Rinse the cleaner from the lens using Saline. IMPORTANT NOTE: DO NOT GET CLEANER IN YOUR EYE. If cleaner is mistakenly left on a lens and inserted into the eye, remove the contact lens immediately and flush out the eye with saline or water for several minutes. Do not reinsert a lens until the eye has fully settled, which may be up to 24 hours later. Once the lenses are cleaned and rinsed, place them in the storage case. Add Boston Conditioning Solution (Blue lid on bottle) until you can see the lens is covered entirely. Replace the lids on the storage cases and leave to soak for at least four hours (to ensure the lenses are disinfected). Afterwards, remove the lenses from the case, rinse with a little extra Boston Conditioning Solution or add a drop of Boston Rewetting Solution to the back of the lens and insert.
For a wearer who is prone to lots of protein deposits of their RGP lenses, Boston Enzymatic Cleaner can also be added to the care system. With the lenses soaking in the Boston Conditioning Solution in the storage case, add a drop of Boston Enzymatic Cleaner to each side of the case and leave for at least four hours. Afterwards, rinse the lenses with Boston Conditioning Solution or add a drop of Boston Rewetting Solution to the back of the lens and insert.
Once both lenses have been inserted, empty the storage case of all solution. Wipe the inside of the storage case dry with a clean tissue. Leave the case with the lids off upside down on a bench to air-dry through the daytime. Once a week, put the empty case in a clean coffee mug and pour boiling water over it to help sterilise the case. Afterwards, dry the case again with a tissue and store on a tissue upside down with the lids off.
Do's and Dont's
Signs and Problems
All contact lenses are designed to be compatible with your eyes, and you should have trouble free wear, however there is a small risk of infection with all contact lens wear. This can include serious complications like corneal ulcers, which can leave permanent scarring and blurred vision. Current research indicates the risk of a serious eye infection with daily disposables is approx 1 in 5000. If any signs of problems or symptoms occur, take the lenses out immediately, examine the lens for any splits or defects, and seek our professional advice as soon as is practical.
Never continue to wear a lens that is sore or uncomfortable for any length of time. Remember: IF IN DOUBT, TAKE IT OUT!
Follow Up Visits
Always wear your lenses to your contact lens follow up visits UNLESS you have been suffering with significant sore eyes. Try to insert your lenses at least two hours before the appointment so we can evaluate the lens fitting accurately and also assess for any adverse eye reactions. If you were unable to wear the lenses on the day of your appointment because you were too busy, it is better to rebook for another day so comprehensive evaluation can be performed.