Semi-rigid contact lenses: when the astigmatism is very high or there are irregularities in the cornea

Also known as RGP, they are smaller, harder and, therefore, less flexible than soft lenses.

Lentes de contacto semirrígidas

Semi-rigid or rigid gas permeable (RGP) lenses are indicated for patients with very high astigmatism which cannot be compensated with a soft lens, or those with irregularities in the cornea. These irregularities can occur after certain surgical procedures or due to corneal degeneration, such as keratoconus, “which, in fairly advanced stages, causes loss of visual sharpness as a result of aberrations that cannot be corrected with glasses,” explains Mireia Campos, an optometrist at IMO. In these cases, and often as a complement to other treatments, such as intracorneal rings or crosslinking, we fit a semi-rigid contact lens, which, as it is a smooth and optically perfect surface, replaces the irregularity of the damaged cornea and allows visual quality to be gained.

What precautions should be taken with the eyes when using such lenses?

If you wear RGP contact lenses, your corneas also need a respite. For this, it is important to follow these recommendations:

  • Do not insert your contact lenses as soon as you wake up: wait for at least 20 minutes. The same applies when removing them: do not do so just before going to sleep, take them out at least 20 minutes before.
  • Never sleep with your contact lenses in, as the cornea needs to breathe. If you do so by mistake, moisten the lenses with artificial tears before removing them. Never directly remove the lenses, because you run the risk of causing damage to the cornea.
  • Try to moisten the cornea throughout the day, especially if you are indoors with the heating or air conditioning on. For this, use artificial tears, preferably in a single-dose (without preservatives).

How should RGP lenses be inserted?

  1. Wash your hands thoroughly with water and neutral soap and dry them with a paper towel or towel that does not shed fluff.
  2. Rub the lens on both sides with soap solution and rinse with saline solution.
  3. Place the lens on the tip of your index finger and add a drop of artificial tears before inserting it into your eye.
  4. With the middle finger of the same hand, hold the lower eyelid and, with the index finger of the other hand, hold the upper eyelid and place the lens on the cornea with the help of a mirror.
  5. Any feeling of discomfort or itching at the beginning is normal. To prevent this, look down with your eyes half-closed and avoid blinking too much.

How should they be removed?

  1. Wash your hands thoroughly with neutral soap and water and dry them with a paper towel or a towel that does not shed fluff.
  2. To remove the lens, there are 2 methods: - Tilt your head down. With your index fingers, one on the upper eyelid and the other on the lower eyelid on the lash line, gently press both eyelids towards the lens, and it will pop out. - Tilt your head down. Place one hand with the palm open in front of the eye and, with the other hand, stretch the upper and lower eyelids outwards towards the ear. The lens should fall out into your hand.
  3. If the lens sticks to your eye, apply one or two drops of artificial tears, blink a couple of times and try again. Place the lens in its case and follow the instructions shown in the section “How should rigid lenses be stored?”.

How should rigid lenses be stored?

  1. Wash your hands thoroughly for 10 seconds with neutral soap and dry them with a paper towel or a towel that does not shed fluff.
  2. Pick up the lens and put a drop of cleaner on each side. Gently rub the lens with the soap for 20 seconds.
  3. Remove any soap from the lens by rinsing with saline solution.
  4. Place in the corresponding lens holder (left/right) of the case and cover completely with the conditioning solution. For proper disinfection, each lens should remain in the case for at least 6 hours.
  5. Before reinserting the lenses, rub them with soap, rinse with saline solution and discard the conditioning liquid from the case, leaving it empty and well sealed to prevent contamination. It is advisable to change the lens holder case every 3 months.
  6. Never use expired products to clean or store the lenses.
  7. Make sure that the lenses do not come into contact with water or saliva, as both elements can cover them with germs and cause eye infections.

Tips for using semi-rigid contact lenses

Here are some precautions that you should keep in mind if you are a user of this type of lens:

  • Do not use tap water to rinse your lenses.
  • Insert the contact lenses before applying make-up and try to avoid using too much on the eyelids and lashes.
  • If you play a contact sport or one in which you could suffer a knock, it is preferable not to use semi-rigid contact lenses.
  • Never insert a broken or cracked lens.
  • If your contact lenses cause you any discomfort, you may have to perform a thorough cleaning. Please contact us!

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