I. What are keratoplasty lenses?
Orthokeratologycontact lenses (Ortho-K CL) is the full name of rigid gas permeable contact lenses for orthokeratology. It is a rigid gas permeable contact lens (RGP) that corrects myopia by changing the shape of the cornea. Unlike the design of ordinary RGP lenses, Ortho-KCL has a simple outer surface and a relatively complex inner surface. By creating some gaps between the inner surface and the corneal surface, the thin hydraulic effect of the tear film is used to redistribute the corneal tissue, and the anterior surface of the cornea becomes flat. After the cornea is flattened, the focal length of the eye is lengthened, so that the focal point of the incoming light in myopic eyes is shifted from the front of the fundus to the retina just in front of the eye, thus achieving the effect of corneal shaping and controlling the development of myopia.
The effect of keratomileusis is temporary. Once you stop wearing them, the cornea of most patients will return to its original form within 7-10 days, and all patients will return to its original form 30 days after stopping wearing them. Therefore, corneal shaping lenses should be worn for a long time to maintain the shaping effect.
Second, which groups of people are suitable for the use of keratoplasty lenses?
1, 8 to 12 years old and above, progressive myopia, the wearer is more capable of self-care or parents can assist in wearing. 8 years old and below, the wearer needs to be closely followed up by an ophthalmologist before using with caution.
2, myopic spherical lens degree -0.75D~-5.50D, the higher the spherical lens degree, the less predictable the shaping effect.
3, Corneal refraction (K value) 40.00D~46.00D, the difference between the corneal flat K value and the expected corrected myopia is more than 36D.
4, <1.5 D cis-regular corneal astigmatism, <0.75 D retro-regular corneal astigmatism; astigmatism less than 1/3 spherical lens degree.
5, larger corneal e value, flatter peripheral part of corneal morphology.
5, central corneal thickness >0.4 mm.
6, pupil diameter is normal.
7.IOP is normal.
8.No other eye diseases or history of eye trauma or eye surgery.
9, good personal hygiene and sanitary habits, able to comply with medical advice.
10, have some financial ability to bear all the costs during the treatment.
11, the correction effect has reasonable expectations.
Third, which people are not suitable for wearing keratomileusis?
1, myopic spherical lens >-5.50 D, paragon astigmatism >1.50 D, retrocontrast astigmatism >0.75 D, corneal shape irregularity, with obvious lens astigmatism.
2, corneal too flat ≤ 39.00 D, or too steep ≥ 46.00 D.
3, corneal e value ≤ 0.1, corneal spherical, corneal e value and refractive error degree mismatch.
4.The pupil diameter is too large.
5, various eye diseases, such as dry eye, inflammation, glaucoma, proptosis, nystagmus, etc.
6, systemic diseases, such as diabetes, immune system diseases, psychiatric patients, etc.
7, unreasonable expectations of the correction effect.
8.Poor trial wear effect.
9, poor personal hygiene habits, can not adhere to the medical prescription wearers.
10, the elderly, poor corneal compliance, eyelid laxity, poor correction effect.